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1209.2420 | i | in the past decade it has become clear that the majority of galaxies have likely had one or more brief active periods , shifting our view of astrophysical black holes ( bhs ) from the role of exotic phenomena to fundamental ingredients of cosmic structures . the question of when and under which physical conditions the ... | we present the first direct measurement of the mean halo occupation distribution ( hod ) of x - ray selected agn in the cosmos field at , based on the association of 41 xmm and 17 c - cosmos agn with member galaxies of 189 x - ray detected galaxy groups from xmm and _ chandra _ data . we perform a measurement of the pr... | we present the first direct measurement of the mean halo occupation distribution ( hod ) of x - ray selected agn in the cosmos field at , based on the association of 41 xmm and 17 c - cosmos agn with member galaxies of 189 x - ray detected galaxy groups from xmm and _ chandra _ data . we model the mean agn occupation i... |
1209.2420 | c | we have performed the first direct measurement of the mean halo occupation distribution of x - ray agn as function of halo mass , by directly counting the number of agn within x - ray galaxy groups with masses @xmath1 = 13- 14.5 $ ] , in the cosmos field at @xmath0 . our findings are summarized as follows . 1 . we i... | we model the mean agn occupation in the halo mass range = 13- 14.5 $ ] with a rolling - off power - law with the best fit index and normalization parameter . we find the mean hod of agn among central galaxies to be modelled by a softened step function at loglog while for the satellite agn hod we find a preference for a... | we present the first direct measurement of the mean halo occupation distribution ( hod ) of x - ray selected agn in the cosmos field at , based on the association of 41 xmm and 17 c - cosmos agn with member galaxies of 189 x - ray detected galaxy groups from xmm and _ chandra _ data . we model the mean agn occupation i... |
1105.1792 | i | little is known about the properties of the dense gas component on gmc scales in external galaxies yet it is dense gas ( @xmath5 @xmath6 ) that most directly correlates with global star formation rates ( e.g. , * ? ? ? * ; * ? ? ? * ) . to understand the evolution and regulation of current star formation in galaxies , ... | we present the first images of the j=54 and j=1615 lines of the dense gas tracer , cyanoacetylene , hcn , in an external galaxy . the central 200 pc of the nearby star - forming spiral galaxy , ic 342 , was mapped using the vla and the plateau de bure interferometer . the j=1615 and 109 lines are also faint near the l... | we present the first images of the j=54 and j=1615 lines of the dense gas tracer , cyanoacetylene , hcn , in an external galaxy . the central 200 pc of the nearby star - forming spiral galaxy , ic 342 , was mapped using the vla and the plateau de bure interferometer . hcn(54 ) line emission is found across the nuclear... |
1105.1792 | r | continuum subtracted integrated intensity line maps of hc@xmath0n(54 ) , hc@xmath0n(109 ) and hc@xmath0n(1615 ) in ic 342 are shown in figure [ inti ] . figure [ inticont ] shows the 54 transition overlaid on the 7 mm continuum image generated from offline channels . locations of giant molecular cloud ( gmc ) cores @... | hcn(54 ) line emission is found across the nuclear mini - spiral , but is very weak towards the starburst site , the location of the strongest mid - ir and radio emission . the brightest hcn emission is located in the northern arm of the nuclear minispiral , 100 pc away from the radio / ir source to the southwest of th... | we present the first images of the j=54 and j=1615 lines of the dense gas tracer , cyanoacetylene , hcn , in an external galaxy . the central 200 pc of the nearby star - forming spiral galaxy , ic 342 , was mapped using the vla and the plateau de bure interferometer . hcn(54 ) line emission is found across the nuclear... |
1105.1792 | c | we have imaged the hc@xmath9n j=54 line in the nucleus of ic 342 with the vla and the hc@xmath0n(1615 ) line with the pdbi at @xmath141 resolution . these are the first maps of these transitions in an external galaxy . we have detected emission extended along the nuclear mini - spiral " in ( 54 ) and more concentrate... | excitation temperatures are consistent with those determined from co ; the gas is dense , and cool , t k. so as to not violate limits on the total h mass determined from co , at least two dense components are required to model ic 342 s giant molecular clouds . this explains the high star formation efficiency seen in th... | we present the first images of the j=54 and j=1615 lines of the dense gas tracer , cyanoacetylene , hcn , in an external galaxy . the central 200 pc of the nearby star - forming spiral galaxy , ic 342 , was mapped using the vla and the plateau de bure interferometer . hcn(54 ) line emission is found across the nuclear... |
1503.05340 | i | it is well known that the virtual pair production and destruction occur always when the external field acts to the vacuum . further these virtual pair produced particles gain the energy from the external field and then these particles appear as real particles . in quantum electrodynamics ( qed ) or similar , in particu... | when summing up with respect to the time the contribution of pair production of each time - slice we obtain the ricci scalar and then it is related to the trace part of the energy - momentum tensor to produce weyl anomaly . oiqp-15 - 03 * a state description of pair production from dirac sea + in gravitational fi... | we present the method that the pair production of particles is described as a fock space state vector , where the pair production stems from receiving energy from , as an example , gravitational background field . at the same time we show a sort of new mechanism that in the diffeomorphism - invariant dirac sea the weyl... |
1503.05340 | c | in the present article we presented that when the dirac sea in the background space - time with the metric @xmath144 is expanded in terms of the fock space basis of the space - time with the metric @xmath41 there appears the state of the sum of the dirac sea and a state called @xmath78}$ ] . in particular , in the case... | we present the method that the pair production of particles is described as a fock space state vector , where the pair production stems from receiving energy from , as an example , gravitational background field . at the same time we show a sort of new mechanism that in the diffeomorphism - invariant dirac sea the weyl... | we present the method that the pair production of particles is described as a fock space state vector , where the pair production stems from receiving energy from , as an example , gravitational background field . at the same time we show a sort of new mechanism that in the diffeomorphism - invariant dirac sea the weyl... |
1609.06611 | i | we have presented 21-cm line observations for a sample of four galactic cepheids . our goal was to search for circumstellar gas associated with previous or ongoing mass loss . if present , such matter would help to reconcile the persistent discrepancies of @xmath210 - 20% between the masses of cepheids derived from st... | the observations were aimed at detecting gas associated with previous or ongoing mass loss . near the long - period cepheid t mon , we report the detection of a partial shell - like structure whose properties appear consistent with originating from an earlier epoch of cepheid mass loss . at the distance of t we deriv... | we present the results of a search for 21-cm line emission from the circumstellar environments of four galactic cepheids ( rs pup , x cyg , gem , and t mon ) based on observations with the karl g. jansky very large array . the observations were aimed at detecting gas associated with previous or ongoing mass loss .... |
astro-ph0311106 | c | we have studied the cluster systems of dwarf irregular galaxies using hst / wfpc2 observations of 28 galaxies in the virgo and fornax clusters , 11 of which are confirmed members . in these 11 confirmed members we have found 237 cluster candidates and determined their magnitudes , core radii , and v - i colors . based ... | we present the results of a search for clusters in dwarf irregular galaxies in the virgo and fornax cluster using hst wfpc2 snapshot data . the galaxy sample includes 28 galaxies , 11 of which are confirmed members of the virgo and fornax clusters . in the 11 confirmed members , we detect 237 cluster candidates and det... | we present the results of a search for clusters in dwarf irregular galaxies in the virgo and fornax cluster using hst wfpc2 snapshot data . the galaxy sample includes 28 galaxies , 11 of which are confirmed members of the virgo and fornax clusters . in the 11 confirmed members , we detect 237 cluster candidates and det... |
0707.2249 | i | clusters of galaxies represent the most massive bound systems in the cosmos . although they result from non - linear structure evolution , the departure from linear growth is modest compared to that for less massive objects . as a result , simple analytic models can provide an accurate indication of their expected numb... | we present the results of an ongoing weak lensing survey conducted with the subaru telescope whose initial goal is to locate and study the distribution of shear - selected structures or _ halos_. using a suprime - cam imaging survey spanning 21.82 deg , we present a catalog of 100 candidate halos located from lensing c... | we present the results of an ongoing weak lensing survey conducted with the subaru telescope whose initial goal is to locate and study the distribution of shear - selected structures or _ halos_. using a suprime - cam imaging survey spanning 21.82 deg , we present a catalog of 100 candidate halos located from lensing c... |
1603.00947 | i | we examined the x - ray properties of 16 young radio sources with _ chandra _ and observed variety of interesting characteristics , which we summarize below . * we found that our cso sample covers a wide range in x - ray luminosity , @xmath2@xmath3ergs@xmath4 and that the majority of sources contains a modest amount of... | we observed six of them for the first time in x - rays using _ chandra _ , re - observed four with the previous _ xmm - newton _ or _ beppo - sax _ data , and included six other with the archival data . the sample covers a range in x - ray luminosity ,ergs , and intrinsic absorbing column density of . in particular , w... | we present the results of the first x - ray study of a sample of 16 young radio sources classified as compact symmetric objects ( csos ) . we observed six of them for the first time in x - rays using _ chandra _ , re - observed four with the previous _ xmm - newton _ or _ beppo - sax _ data , and included six other wit... |
astro-ph0601634 | i | structure formation and evolution in the universe and the formation and growth of supermassive black holes ( smbhs ) are two fundamental problems in astronomy which are still not fully understood . while recent progresses in the cosmic microwave background , the high redshift type ia supernovae survey , and the large o... | we present the spatial correlation function analysis of non - stellar x - ray point sources in the _ chandra _ large area synoptic x - ray survey of lockman hole northwest ( clasxs ) . we find a very mild evolution in the clustering amplitude , which show the same evolution trend found in optically selected quasars in ... | we present the spatial correlation function analysis of non - stellar x - ray point sources in the _ chandra _ large area synoptic x - ray survey of lockman hole northwest ( clasxs ) . our 9 acis - i fields cover a contiguous solid angle of 0.4 deg and reach a depth of in the 28 kev band . we supplement our analysis w... |
astro-ph0601634 | r | we calculate the redshift - space correlation function in the clasxs sample for non - stellar sources with @xmath82 and 28 kev fluxes @xmath83 , assuming constant clustering in comoving coordinates . the total number of sources in the sample is 233 . the median redshift of the sample is 1.2 . by comparing the number o... | we calculate both redshift - space and projected correlation functions in comoving coordinates , averaged over the redshift range of , for both clasxs and cdfn fields for a standard cosmology with , and ( km s mpc ) . we compare the correlation functions for hard and soft spectra sources in the clasxs field and find... | we present the spatial correlation function analysis of non - stellar x - ray point sources in the _ chandra _ large area synoptic x - ray survey of lockman hole northwest ( clasxs ) . our 9 acis - i fields cover a contiguous solid angle of 0.4 deg and reach a depth of in the 28 kev band . we supplement our analysis w... |
astro-ph0601634 | c | the bias evolution of optical quasar is extensively discussed in c05 . they found that the bias increases rapidly with redshift(@xmath166 ) . we will follow these arguments to estimate the bias evolution of the x - ray samples . on scales of 20 mpc , the clustering of dark matter and agns are both in the linear reg... | our 9 acis - i fields cover a contiguous solid angle of 0.4 deg and reach a depth of in the 28 kev band . the correlation function for the clasxs field over scales of 3 mpc 200 mpc can be modeled as a power - law of the form , with and mpc . we have also found that the correlation between x - ray luminosity and cl... | we present the spatial correlation function analysis of non - stellar x - ray point sources in the _ chandra _ large area synoptic x - ray survey of lockman hole northwest ( clasxs ) . our 9 acis - i fields cover a contiguous solid angle of 0.4 deg and reach a depth of in the 28 kev band . we supplement our analysis w... |
astro-ph0601634 | c | in this paper we study the clustering of the x - ray selected agns in the 0.4 deg@xmath0 _ chandra _ contiguous survey of the lockman hole northwest region . based on our previous study , the size of the clasxs field is large enough that the cosmic variance should not be important . we supplement our study with the pu... | we supplement our analysis with data from the chandra deep field north ( cdfn ) . the addition of this field allows better probe of the correlation function at small scales . a total of 233 and 252 sources with spectroscopic information are used in the study of the clasxs and cdfn fields respectively . the redshift ... | we present the spatial correlation function analysis of non - stellar x - ray point sources in the _ chandra _ large area synoptic x - ray survey of lockman hole northwest ( clasxs ) . our 9 acis - i fields cover a contiguous solid angle of 0.4 deg and reach a depth of in the 28 kev band . we supplement our analysis w... |
0709.4512 | i | rs ophiuchi ( rs oph ) is a member of a rare subclass of cataclysmic variable known as recurrent novae ( rn ) . as the name suggests , rn are systems which are observed to go into outburst more than once . nova outbursts are believed to be the result of thermonuclear runaway ( tnr ) on the surface of a white dwarf accr... | we present the x - ray grating spectra of the recurrent nova rs ophiuchi during its 2006 outburst , obtained with the xmm - newton and chandra observatories . the absorption lines did not appear to be significantly blue - shifted as previously observed in another classical nova . therefore , rs oph may be an important ... | we present the x - ray grating spectra of the recurrent nova rs ophiuchi during its 2006 outburst , obtained with the xmm - newton and chandra observatories . two weeks after optical maximum , the x - ray spectrum was hard and dominated by emission lines of h - like and he - like ions . the x - ray luminosity was 2.4 1... |
astro-ph0108424 | c | we have discovered two wide separation l - dwarf common proper motion companions to nearby stars and identified a third candidate from 2mass . spectral types assigned from optical spectroscopy were l0 v , l2.5 v , and l8 v. nir low resolution spectra of the companions were provided as well as a grid of known objects sp... | we present two confirmed wide separation l - dwarf common proper motion companions to nearby stars and one candidate identified from the two micron all sky survey . spectral types from optical spectroscopy are l0 v , l2.5 v , and l8 v. near - infrared low resolution spectra of the companions are provided as well as a g... | we present two confirmed wide separation l - dwarf common proper motion companions to nearby stars and one candidate identified from the two micron all sky survey . spectral types from optical spectroscopy are l0 v , l2.5 v , and l8 v. near - infrared low resolution spectra of the companions are provided as well as a g... |
1408.3778 | i | it is well - known that many special functions , e.g. the airy , bessel , or legendre functions , originate as series solutions of _ linear _ ordinary differential equations ( odes ) . such functions play a crucial role in describing a wide range of important physical and mathematical phenomena . an essential point he... | we present two examples of reductions from the evolution equations describing discrete schlesinger transformations of fuchsian systems to difference painlev equations : difference painlev equation d- with the symmetry group and difference painlev equation d- with the symmetry group . in both cases we describe in detail... | we present two examples of reductions from the evolution equations describing discrete schlesinger transformations of fuchsian systems to difference painlev equations : difference painlev equation d- with the symmetry group and difference painlev equation d- with the symmetry group . in both cases we describe in detail... |
astro-ph0403103 | i | interactions between the interstellar medium ( ism ) of a galaxy and the gas in the intracluster medium ( icm ) are believed to be one of the main processes which drive galaxy evolution in clusters ( gunn & gott 1972 ; poggianti 1999 ; van gorkom 2003 ; koopmann & kenney 2004 ) . gas stripping is likely responsible for... | we present vla hi observations at.5 kpc resolution of the highly inclined , hi - deficient virgo cluster spiral galaxy ngc 4522 , which is one of the clearest and nearest cases of ongoing icm - ism stripping . . forty percent of the total hi , corresponding to 1.5 m , is extraplanar and has likely been removed from th... | we present vla hi observations at.5 kpc resolution of the highly inclined , hi - deficient virgo cluster spiral galaxy ngc 4522 , which is one of the clearest and nearest cases of ongoing icm - ism stripping . hi is abundant and spatially coincident with the stellar disk in the center , but beyond r = 3 kpc the hi dis... |
astro-ph0403103 | c | ngc 4522 is a clear case of ism gas selectively removed from an undisturbed stellar disk . the ism removal from the outer disk , and the existence of hi only on one side of the disk , argue strongly that the ism has been pushed out of the disk by icm - ism pressure , as the galaxy moves through the gas of the virgo in... | the sw side of the galaxy has less hi in the disk but more hi in the halo , suggesting more effective gas removal on the side of the galaxy which is rotating into the icm wind . in recent simulations of icm - ism interactions , large surface densities of extraplanar gas like that in ngc 4522 are seen at relatively ear... | we present vla hi observations at.5 kpc resolution of the highly inclined , hi - deficient virgo cluster spiral galaxy ngc 4522 , which is one of the clearest and nearest cases of ongoing icm - ism stripping . hi is abundant and spatially coincident with the stellar disk in the center , but beyond r = 3 kpc the hi dis... |
astro-ph0403103 | c | \1 . the virgo cluster sc galaxy ngc 4522 is a clear case of ism gas selectively removed from an undisturbed stellar disk by an icm - ism interaction . the existence of a one - sided distribution of extraplanar gas and an undisturbed stellar disk clearly indicates a non - gravitational external process which has selec... | the kinematics and the morphology of the hi appear more consistent with ongoing stripping , and less consistent with gas fall - back which may occur long after peak pressure . some of the extraplanar gas has linewidths ( fwzi ) of 150 km s , including a blueshifted tail of weaker emission , and much of the extraplanar ... | we present vla hi observations at.5 kpc resolution of the highly inclined , hi - deficient virgo cluster spiral galaxy ngc 4522 , which is one of the clearest and nearest cases of ongoing icm - ism stripping . hi is abundant and spatially coincident with the stellar disk in the center , but beyond r = 3 kpc the hi dis... |
0704.0827 | c | because ngc 5466 resides at high galactic latitude , it suffers little if any reddening . though @xcite found a reddening of @xmath39 from the maps of dust ir emission , we adopted @xmath40 @xcite . for our interests in this paper , the small difference is of small importance . most of the comparisons below between obs... | we present wide - field photometry for about 11,500 stars in the low - metallicity cluster ngc 5466 . we have detected the red giant branch bump for the first time , although it is at least 0.2 mag fainter than expected relative to the turnoff . the number of red giants ( relative to main sequence turnoff stars ) is in... | we present wide - field photometry for about 11,500 stars in the low - metallicity cluster ngc 5466 . we have detected the red giant branch bump for the first time , although it is at least 0.2 mag fainter than expected relative to the turnoff . the number of red giants ( relative to main sequence turnoff stars ) is in... |
0704.0827 | c | examinations of the luminosity functions of globular clusters continue to produce interesting tests of astrophysics . in this study , we found that ngc 5466 has a luminosity function that is in better overall agreement with theoretical models than the anomalous cluster m30 , which has a similar low metallicity . in add... | we discuss theoretical predictions from different research groups and find that the inclusion or exclusion of helium diffusion and strong limit coulomb interactions may be partly responsible . ngc 5466 has a very shallow mass function , consistent with large mass loss and recently - discovered tidal tails . the blue st... | we present wide - field photometry for about 11,500 stars in the low - metallicity cluster ngc 5466 . we have detected the red giant branch bump for the first time , although it is at least 0.2 mag fainter than expected relative to the turnoff . the number of red giants ( relative to main sequence turnoff stars ) is in... |
1206.5563 | i | in the last decades , the angular momentum of light has received much attention from very diverse areas of physics . from experimental astrophysics proposals for the detection of exotic cosmic objects @xcite to the use of light beams to rotate atoms @xcite , through the exploitation of the infinite number of possible a... | the fundamental problem of spin and orbital angular momentum separability is avoided , predictions are made based on the symmetries of the systems , and the practical application of the concepts is straightforward . finally , the framework is used to show that the concept of spin to orbit transfer applied to focusing a... | we propose a new theoretical and practical framework for the study of light - matter interactions and the angular momentum of light . our proposal is based on helicity , total angular momentum , and the use of symmetries . we compare the new framework to the current treatment , which is based on separately considering ... |
1403.6405 | i | the investigation of single - photon properties has experienced an increasing interest over the last years @xcite . one of the reasons has to be sought in the escalating request , in many quantum information and cryptography protocols @xcite , for highly accurate manipulations of spatial and polarization single - photo... | we propose a procedure for defining all single - photon observables in terms of positive - operator valued measures ( povms ) , in particular spin and position . we identify the suppression of-helicity photon states as a projection from an extended hilbert space onto the physical single - photon hilbert space . we show... | we propose a procedure for defining all single - photon observables in terms of positive - operator valued measures ( povms ) , in particular spin and position . we identify the suppression of-helicity photon states as a projection from an extended hilbert space onto the physical single - photon hilbert space . we show... |
0812.1785 | i | the last enzyme of the respiratory chain of animal cells and bacteria , cytochrome @xmath0 oxidase ( cco ) , operates as an efficient nanoscale machine converting electron energy into a transmembrane proton electrochemical gradient @xcite . the atp ( adenosine triphosphate ) synthase enzyme uses this energy to synthesi... | we propose a simple model of cytochrome c oxidase , including four redox centers and four protonable sites , to study the time evolution of electrostatically coupled electron and proton transfers initiated by the injection of a single electron into the enzyme . we derive a system of master equations for electron and pr... | we propose a simple model of cytochrome c oxidase , including four redox centers and four protonable sites , to study the time evolution of electrostatically coupled electron and proton transfers initiated by the injection of a single electron into the enzyme . we derive a system of master equations for electron and pr... |
cond-mat0703049 | i | during the last decade , ultrafast light - induced magnetization dynamics has been a subject of many experimental studies , which have yielded results of interest from both the insight into the basic physical processes occurring in ferromagnets at short time - scales , and from the possible practical implications for u... | a prominent example of a class of materials falling into this category are ferromagnetic ( iii , mn)v semiconductors , in which ultrafast demagnetization has been recently observed . in the proposed model light excitation this triggers the process of energy and angular momentum exchange between the two spin systems , w... | we propose and analyze a theoretical model of ultrafast light - induced magnetization dynamics in systems of localized spins that are coupled to carriers spins by sp - d exchange interaction . a prominent example of a class of materials falling into this category are ferromagnetic ( iii , mn)v semiconductors , in which... |
cond-mat0605198 | i | ultracold atoms stored in optical lattices can be controlled and manipulated with a very high degree of precision and flexibility . this places them among the most promising candidates for implementing quantum computations @xcite and quantum simulations of certain classes of quantum many body systems @xcite . quantum ... | we propose and analyze several schemes for cooling bosonic and fermionic atoms in an optical lattice potential close to the ground state of the no tunnelling regime . we also design algorithms that create an ensemble of defect - free quantum registers . we study the efficiency of our protocols for realistic temperatur... | we propose and analyze several schemes for cooling bosonic and fermionic atoms in an optical lattice potential close to the ground state of the no tunnelling regime . some of the protocols rely on the concept of algorithmic cooling , which combines occupation number filtering with ideas from ensemble quantum computati... |
1204.3806 | r | here we present results for prof model considered on the networks of cambridge and oxford universities in year 2006 , taken from @xcite . the properties of pagerank distribution @xmath50 for these networks have been analyzed in @xcite . the total number of nodes @xmath2 and links @xmath51 are : @xmath52 , @xmath53 ( ca... | we find that the society elite , corresponding to the top pagerank nodes , can impose its opinion to a significant fraction of the society . however , for a homogeneous distribution of two opinions there exists a bistability range of opinions which depends on a conformist parameter characterizing the opinion formation ... | we propose the pagerank model of opinion formation and investigate its rich properties on real directed networks of universities of cambridge and oxford , livejournal and twitter . in this model the opinion formation of linked electors is weighted with their pagerank probability . we find that the society elite , corre... |
1204.3806 | c | in this work we proposed the pagerank model of opinion formation of social networks and analyzed its properties on example of four different networks . for two university networks we find rather similar properties of opinion formation . it is characterized by the important feature according to which the society elite w... | we propose the pagerank model of opinion formation and investigate its rich properties on real directed networks of universities of cambridge and oxford , livejournal and twitter . in this model we also analyze the sznajd model generalized for scale - free networks with the weighted pagerank vote of electors . | we propose the pagerank model of opinion formation and investigate its rich properties on real directed networks of universities of cambridge and oxford , livejournal and twitter . in this model the opinion formation of linked electors is weighted with their pagerank probability . we find that the society elite , corre... |
1504.00547 | i | we denote by @xmath0 the space of symmetric tensors on @xmath4 ; such tensors can be identified with homogeneous polynomials of degree @xmath5 in @xmath6 variables , which are also referred to as _ forms_. in this symmetric setting , the most natural tensor rank decomposition is the classical waring decomposition , whi... | we prove that the general symmetric tensor in of rank is identifiable , provided that is smaller than the generic rank . that is , its waring decomposition as a sum of powers of linear forms is unique . only three exceptional cases arise , all of which were known in the literature . | we prove that the general symmetric tensor in of rank is identifiable , provided that is smaller than the generic rank . that is , its waring decomposition as a sum of powers of linear forms is unique . only three exceptional cases arise , all of which were known in the literature . our original contribution regards th... |
0708.0616 | i | potts models on hierarchical lattices have been introduced in 1979 by berker and ostlund @xcite as an interpretation of migdal - kadanoff models , defined in 1975 @xcite in order to approximate classical spin models on @xmath0 . later , in 1981 , griffiths and kaufman @xcite provided a rigorous definition of hierarchic... | we prove that the generator of the renormalization group of potts models on hierarchical lattices can be represented by a rational map acting on a finite - dimensional product of complex projective spaces . in this framework we can also consider models with an applied external magnetic field and multiple - spin interac... | we prove that the generator of the renormalization group of potts models on hierarchical lattices can be represented by a rational map acting on a finite - dimensional product of complex projective spaces . in this framework we can also consider models with an applied external magnetic field and multiple - spin interac... |
1412.8399 | i | a matroid captures the notion of a discrete collection of points in space . sometimes these points can be assigned coordinates in a consistent way , and sometimes they can not . the problem of characterising when a matroid is _ representable _ has been the prime motivating force in matroid research since whitney s foun... | we prove there is no sentence in the monadic second - order language that characterises when a matroid is representable over at least one field , and no sentence that characterises when a matroid is-representable , for any infinite field . by way of contrast , because rota s conjecture is true , there is a sentence th... | we prove there is no sentence in the monadic second - order language that characterises when a matroid is representable over at least one field , and no sentence that characterises when a matroid is-representable , for any infinite field . by way of contrast , because rota s conjecture is true , there is a sentence th... |
0802.1137 | i | with the recent success of model building in the framework of the heterotic @xmath0 string theory @xcite it becomes important to reconsider the questions of moduli stabilization and supersymmetry breakdown . early attempts considered fluxes and gaugino condensates @xcite , race track superpotentials @xcite and/or khler... | it requires a gaugino condensate and an up - lifting sector similar to the one postulated in type iib string theory . its signature is a hybrid mediation of supersymmetry breakdown with a variant of a mirage pattern for the soft breaking terms . the set - up is suited for the discussion of heterotic mssm candidates . | we provide a simple example of dilaton stabilization in the framework of heterotic string theory . it requires a gaugino condensate and an up - lifting sector similar to the one postulated in type iib string theory . its signature is a hybrid mediation of supersymmetry breakdown with a variant of a mirage pattern for t... |
astro-ph0211267 | c | it has been known for some time that agns comprise a fraction of the submm source population . indeed , the first identified source in a blank - field survey was found to be an agn ( smm j023990136 ; ivison 1998 ) , and at least three of the 15 submm - detected sources in the -lens survey are agns ( smail 2002 ) . in ... | we provide x - ray constraints and perform the first x - ray spectral analyses for bright sources ( 5 mjy ; s / n ) in an area of the 2 ms deep field - north survey containing the hubble deep field - north . x - ray emission is detected from seven of the ten bright submm sources in this region down to 0.58.0 kev ... | we provide x - ray constraints and perform the first x - ray spectral analyses for bright sources ( 5 mjy ; s / n ) in an area of the 2 ms deep field - north survey containing the hubble deep field - north . x - ray emission is detected from seven of the ten bright submm sources in this region down to 0.58.0 kev ... |
astro-ph0211267 | c | we have used the 2 ms exposure of the cdf - n to constrain the x - ray properties of bright sources ( @xmath0 5 mjy ; s / n@xmath1 ) . in this study we have focused on the x - ray spectral properties of the x - ray detected submm sources to determine whether the agn - classified sources are compton thick or compto... | five of the x - ray detected sources have flat effective x - ray spectral slopes ( ) , suggesting obscured agn activity . the rest - frame unabsorbed x - ray luminosities of these agns are more consistent with those of seyfert galaxies than qsos ( i.e. , erg s ) . thus , the low x - ray detection rate of bright subm... | we provide x - ray constraints and perform the first x - ray spectral analyses for bright sources ( 5 mjy ; s / n ) in an area of the 2 ms deep field - north survey containing the hubble deep field - north . x - ray emission is detected from seven of the ten bright submm sources in this region down to 0.58.0 kev ... |
1103.1932 | i | quasar absorption lines ( qals ) provide us a unique tool to study abundances , physical conditions and kinematics of gas in a wide variety of astrophysical environments . many of the early detected qals are associated systems with redshifts close to the quasar emission redshifts ( e.g. , burbidge et al . 1966 ; schmid... | we report detections of 39 2175- dust extinction bump candidates associated with strong mg ii absorption lines at z 11.8 on quasar spectra in sloan digital sky survey ( sdss ) dr3 . ( 2006 ) . most of the candidate bumps in this work are similar to the relatively weak 2175- bumps observed in the large magellanic cloud... | we report detections of 39 2175- dust extinction bump candidates associated with strong mg ii absorption lines at z 11.8 on quasar spectra in sloan digital sky survey ( sdss ) dr3 . these strong mg ii absorption line systems are detected among 2,951 strong mg ii absorbers with the rest equivalent width 1.0 at , whic... |
1103.1932 | c | the sdss dr7 database contains 105,783 quasar spectra ( schneider et al . 2010 ) . we expect to find more than 50 significant 2175- bumps associated with mg ii absorption line systems by implementing the same searching strategy in this paper . another possible approach of searching for the 2175- extinction bump on qua... | a total of 12 absorbers are detected with 2175- bumps at a 5 level of statistical significance , 10 are detected at a 4 level and 17 are detected at a 3 level . follow - up observations may rule out some of possible false detections and reveal the physical and chemical natures of 2175- quasar absorbers . | we report detections of 39 2175- dust extinction bump candidates associated with strong mg ii absorption lines at z 11.8 on quasar spectra in sloan digital sky survey ( sdss ) dr3 . these strong mg ii absorption line systems are detected among 2,951 strong mg ii absorbers with the rest equivalent width 1.0 at , whic... |
astro-ph0701710 | r | the 25 orionis group stands out as a concentration of tts stars in the ori ob1a sub - association ( figure [ fig1 ] ) , roughly surrounding the b1vpe star 25 ori ( @xmath52 ) . this star has been classified as a classical be object @xcite ; more recently @xcite determined a spectral type b2 . in @xcite we already point... | we report here on the photometric and kinematic properties of a well defined group of nearly 200 low - mass pre - main sequence stars , concentrated within of the early - b star 25 ori , in the orion ob1a sub - association . the group also harbors the herbig ae / be star v346 ori and a dozen other early type stars with... | we report here on the photometric and kinematic properties of a well defined group of nearly 200 low - mass pre - main sequence stars , concentrated within of the early - b star 25 ori , in the orion ob1a sub - association . we refer to this stellar aggregate as the 25 orionis group . the group also harbors the herbig ... |
astro-ph0701710 | i | we have used the hectochelle spectrograph on the 6.5 m mmt to obtain high resolution spectra of 149 low - mass pms stars distributed in two fields located in the orion ob1 association , one field placed on the 25 ori group originally identified by @xcite , the other near the belt star @xmath35 ori , in the ori ob1b sub... | the low - mass members follow a well defined band in the color - magnitude diagram , consistent with an isochronal age of myr , depending on the assumed evolutionary model . the drop in the overall li i equivalent widths and accretion fraction between the younger ori ob1b and the 25 ori group , is consistent with the ... | we report here on the photometric and kinematic properties of a well defined group of nearly 200 low - mass pre - main sequence stars , concentrated within of the early - b star 25 ori , in the orion ob1a sub - association . we refer to this stellar aggregate as the 25 orionis group . the group also harbors the herbig ... |
0704.1450 | i | it is a continuous topic of study how a galaxy evolves with time @xcite . integrated photometry of star clusters and star associations in a galaxy can provide fundamental insight on the star - formation history @xcite . @xmath5 colors of galaxies depend mainly on their history of star formation @xcite . the fact that m... | the images show many different structures indicating that star formation is going on in the most part of the disk . ngc 3367 is known to have a very high concentration of molecular gas distribution in the central regions of the galaxy and bipolar synchrotron emission from the nucleus with two lobes ( at 6 kpc ) forming... | we report new detailed surface and photometry of 81 stellar structures in the disk of the barred galaxy ngc 3367 . the images show many different structures indicating that star formation is going on in the most part of the disk . ngc 3367 is known to have a very high concentration of molecular gas distribution in the ... |
0704.1450 | c | to conclude , we have obtained several images in the broadband filters @xmath0 and @xmath1 in order to estimate the optical magnitudes and colors of 81 different stellar structures throughout the disk of ngc 3367 . the structures were chosen from the images in the @xmath1 and @xmath61 filters by eye at different locat... | we report new detailed surface and photometry of 81 stellar structures in the disk of the barred galaxy ngc 3367 . we have determined the and magnitudes and and colors for the central region ( nucleus ) , a region which includes supernovae 2003 aa , and 79 star associations throughout ngc 3367 . however , if the colors... | we report new detailed surface and photometry of 81 stellar structures in the disk of the barred galaxy ngc 3367 . the images show many different structures indicating that star formation is going on in the most part of the disk . ngc 3367 is known to have a very high concentration of molecular gas distribution in the ... |
astro-ph0502376 | c | the detection limit estimates also permit us to calculate an upper limit of the projected separation between a star and a potential planet , as follows . we consider a typical @xmath3m@xmath4 planet , we calculate the theoretical value ( retrieved by the models ) of the star / planet contrast , we then place this value... | for example , for the pictoris group , ( myr ) , we did not detect anym planet at distances larger than au . a previous study carried out with m class telescopes put an upper limit form planets at au . for our closest target ( v oph - d = pc ) our results are discussed with respect to mechanisms explaining planet forma... | we report on a survey devoted for the search of exo - planets around young and nearby stars carried out with naco at the vlt . the detection limit for among the best available targets vs. the angular separation from the star is presented . the non - detection of any planetary mass companion in our survey is used to der... |
1606.01138 | i | ( genzel et al . 2010 ) , the supermassive black hole ( bh ) at the galactic center ( gc ) , generates a deep gravitational potential that is expected to bind tens of thousands of stellar remnants , such as neutron stars ( ns ) or bh that have settled dynamically into the central parsec of the milky way ( morris 1993 ;... | we report on the identification of the new galactic center ( gc ) transient as a likely low mass x - ray binary ( lmxb ) located at only 16 arcsec from . we observed the field with on february for 35 ks , detecting the source in the soft state , characterised by a low level of variability and a soft x - ray thermal ... | we report on the identification of the new galactic center ( gc ) transient as a likely low mass x - ray binary ( lmxb ) located at only 16 arcsec from . this transient was detected on 2016 february during the gc monitoring , and it showed long - term spectral variations compatible with a hard to soft state transiti... |
1201.5056 | i | using our deep _ chandra _ observation , we detect metal - rich ejecta features in snr n49 . these ejecta features include a `` bullet '' that is most likely a stellar fragment travelling beyond the southwestern boundary of the snr . we also find an ejecta feature in the eastern part of the snr , nearly in the opposite... | the x - ray spectrum of the bullet is distinguished from that of the main snr shell , showing significantly enhanced si and s abundances . if n49 was produced by a core - collapse explosion of a massive star , the detected si - rich ejecta may represent explosive o - burning or incomplete si - burning products from dee... | we report on the results from our deep _ chandra _ observation ( 120 ks ) of the supernova remnant ( snr ) n49 and soft-ray repeater ( sgr ) 052666 in the large magellanic cloud . we firmly establish the detection of an ejecta `` bullet '' beyond the southwestern boundary of n49 . the x - ray spectrum of the bullet is ... |
astro-ph0509135 | i | investigations of multiply imaged high - redshift quasars are important for our basic understanding of the formation and growth of supermassive black holes in galactic centers ( turner 1991 ; haiman & loeb 2001 ) and the ionization state of the universe as a function of time ( madau , haardt , & rees 1999 ; wyithe & l... | we report on-band snapshot observations of 157 sloan digital sky survey ( sdss ) quasars at using the advanced camera for surveys on the _ hubble space telescope ( hst ) _ to search for evidence of gravitational lensing of these sources . none of the quasars appear to be strongly lensed and multiply imaged at the angul... | we report on-band snapshot observations of 157 sloan digital sky survey ( sdss ) quasars at using the advanced camera for surveys on the _ hubble space telescope ( hst ) _ to search for evidence of gravitational lensing of these sources . none of the quasars appear to be strongly lensed and multiply imaged at the angul... |
astro-ph0412110 | c | ps2000 drew attention to the relatively long periods and low orbital eccentricities of many of the binary stars they discovered . in combination with the high binary frequency and small fraction of double - lined systems , they argued that their results supported the identification of many of these binary systems as bl... | this suggests that the lithium gap " for hot metal - poor main sequence stars may not exist or lies at higher temperatures than found in the hyades . our results and those of preston & sneden ( 2000 ) show higher values of for the binary stars than those of comparable temperature constant velocity stars . the orbital... | we report radial velocity studies of five candidate metal - poor field blue stragglers , all known to be deficient in lithium . four of the five stars are single - lined spectroscopic binaries , with periods ranging from 302 to 840 days , and low orbital eccentricities , in agreement with similar behavior found for oth... |
1609.03453 | i | in dwarf novae , mass is transferred from a late - type star ( the secondary ) to a companion white dwarf ( wd ) via an accretion disc . they show recurrent outbursts on timescales of days - months , in which the disc brightens by factors 20 - 100 for @xmath2 days . outbursts are explained in terms of either a thermal ... | we report the analysis of 22 b - band light curves of the dwarf nova v4140 sgr obtained with soi / soar during two nights along the decline of a superoutburst in 2006 sep 12 - 24 and in quiescence over 50 days following the superoutburst . accretion , accretion discs binaries : eclipsing novae , cataclysmic variable... | we report the analysis of 22 b - band light curves of the dwarf nova v4140 sgr obtained with soi / soar during two nights along the decline of a superoutburst in 2006 sep 12 - 24 and in quiescence over 50 days following the superoutburst . three - dimensional eclipse mapping of the outburst light curves indicates that... |
1609.03453 | c | we applied 3d eclipse mapping techniques to follow the evolution of the surface brightness of the accretion disc of v4140 sgr in a superoutburst . we find that the disc is elliptical in outburst and decline , with an eccentricity @xmath0 . in both outburst stages , the disc orientation is such that superhump maximum o... | three - dimensional eclipse mapping of the outburst light curves indicates that the accretion disc is elliptical ( eccentricity ) and that superhump maximum occurs when the mass donor star is aligned with the bulge of the elliptical disc . the accretion disc is geometrically thin both in outburst and in quiescence ; it... | we report the analysis of 22 b - band light curves of the dwarf nova v4140 sgr obtained with soi / soar during two nights along the decline of a superoutburst in 2006 sep 12 - 24 and in quiescence over 50 days following the superoutburst . three - dimensional eclipse mapping of the outburst light curves indicates that... |
1611.00364 | c | [ sec : discussion ] empirical sequences of substellar isochrones in color - magnitude diagrams are important tools to chart the physical and spectral properties of brown dwarfs and giant planets at a given age , map their entire cooling history at a given mass , and jointly test low - temperature atmospheric and ev... | follow - up keck / osiris-band spectroscopy of the companion reveals strong co absorption similar to other faint red l dwarfs and lacks signs of methane absorption despite having an effective temperature of k. with a () color of 2.69 0.12 mag , the near - infrared slope of 2m2236 + 4751b is redder than all of the h... | we report the discovery of an extremely red planetary - mass companion to 2mass j22362452 + 4751425 , a.6 late - k dwarf likely belonging to the myr ab doradus moving group . 2m2236 + 4751b was identified in multi - epoch nirc2 adaptive optics imaging at keck observatory at a separation of 3.7 , or 230 20 au in pro... |
1611.00364 | i | [ sec : conclusions ] we have presented the discovery of a faint red l dwarf companion to the late k dwarf 2mass j22362452 + 4751425 . the radial velocity and proper motion of the host star are consistent with the 120 myr ab dor young moving group . 2m2236 + 4751a is relatively inactive , showing partly - filled h... | we report the discovery of an extremely red planetary - mass companion to 2mass j22362452 + 4751425 , a.6 late - k dwarf likely belonging to the myr ab doradus moving group . 2m2236 + 4751b was identified in multi - epoch nirc2 adaptive optics imaging at keck observatory at a separation of 3.7 , or 230 20 au in pro... | we report the discovery of an extremely red planetary - mass companion to 2mass j22362452 + 4751425 , a.6 late - k dwarf likely belonging to the myr ab doradus moving group . 2m2236 + 4751b was identified in multi - epoch nirc2 adaptive optics imaging at keck observatory at a separation of 3.7 , or 230 20 au in pro... |
0811.1562 | c | observations at various wavelengths suggest that irasf001837111 derives a substantial fraction of its bolometric power from accretion onto a central black hole . especially important in this respect is the detection by @xcite of a 6.7kev fek@xmath11 line ( fe xxv ) with a large equivalent width , indicating the presenc... | we report the first mid - infrared detection of highly disturbed ionized gas in the ultraluminous infrared galaxy ( ulirg ) irasf001837111 . for irasf001837111 , the neon / pah ratio is 8 times higher than the average ratio . similar mid - infrared kinematic and excitation characteristics are found for only two other u... | we report the first mid - infrared detection of highly disturbed ionized gas in the ultraluminous infrared galaxy ( ulirg ) irasf001837111 . the gas , traced by the 12.81 m [ ne ii ] and 15.56 m [ ne iii ] lines , spans a velocity range of 3500 to + 3000 km s with respect to systemic velocity . optical and near - infra... |
0811.1562 | c | we have discovered high - velocity ionized gas with velocities ranging from -3500 to + 3000 km s@xmath1 as part of a nuclear outflow from the ulirg irasf001837111 . the gas is traced by the mid - infrared 12.81@xmath0 m [ ne ii ] and 15.51@xmath0 m [ ne iii ] lines , which are dominated by blue shifted components . opt... | optical and near - infrared spectroscopic studies show no evidence for similarly high velocity gas components in forbidden lines at shorter wavelengths . we interpret this as the result of strong extinction ( a=1050 ) on the high - velocity gas , which identifies the base of the outflow traced in 5007 [ o iii ] as a p... | we report the first mid - infrared detection of highly disturbed ionized gas in the ultraluminous infrared galaxy ( ulirg ) irasf001837111 . the gas , traced by the 12.81 m [ ne ii ] and 15.56 m [ ne iii ] lines , spans a velocity range of 3500 to + 3000 km s with respect to systemic velocity . optical and near - infra... |
1701.03536 | i | quantum entanglement - a direct consequence of linearity of quantum mechanics and the superposition principle - is one of the most intriguing phenomena distinguishing quantum and classical description of physical systems . quantum correlated ( e.g. , entangled ) states of composite systems possess features unknown in t... | we review a geometric approach to classification and examination of quantum correlations in composite systems . since quantum information tasks are usually achieved by manipulating spin and alike systems or , in general , systems with a finite number of energy levels , classification problems are usually treated in fra... | we review a geometric approach to classification and examination of quantum correlations in composite systems . since quantum information tasks are usually achieved by manipulating spin and alike systems or , in general , systems with a finite number of energy levels , classification problems are usually treated in fra... |
cond-mat0205321 | i | it is often noted that nonequilibrium statistical mechanics lacks the comprehensive formalism of ensembles that has proved so useful in equilibrium . the reason is that equilibrium statistical mechanics treats stationary states for a special subclass of systems , that possess detailed balance . this allows one to bypas... | we show how to implement a diagrammatic perturbation theory for processes that do not admit an exact solution . analysis of a set of coupled malthus - verhulst processes on a lattice leads , in the continuum limit , to a field theory for directed percolation and allied models . 1em email : dickman@fisica.ufmg.br | we review and extend the formalism introduced by peliti , that maps a markov process to a path - integral representation . after developing the mapping , we apply it to some illustrative examples : the simple decay process , the birth - and - death process , and the malthus - verhulst process . in the first two cases w... |
1507.06054 | i | spintronics invokes the spin degree of freedom of the electron to improve the efficiency of and add functionalities to electronic devices @xcite . here the generation , propagation , processing , and detection of spin currents form central themes @xcite . the spin - orbit coupling ( soc ) provides a mechanism to couple... | the associated angular momentum transfer to the ferromagnetic layer and thereby the electrical resistance is modulated by the angle between the applied current and the magnetization direction . the smr provides a convenient tool to non - invasively measure the magnetization direction and spin - transfer torque to an in... | we review the so - called spin hall magnetoresistance ( smr ) in bilayers of a magnetic insulator and a metal , in which spin currents are generated in the normal metal by the spin hall effect . the associated angular momentum transfer to the ferromagnetic layer and thereby the electrical resistance is modulated by the... |
1103.0276 | i | supermassive black holes ( smbhs ) are now known to be ubiquitous in the centers of all massive galaxies @xcite . smbhs grow in an `` active '' phase of accretion , during which they are observed as active galactic nuclei ( agn ) . agn growth is intimately tied to galaxy evolution , as evident in the well - studied cor... | we avoid the systematic errors plaguing previous studies of agn accretion rate by using accurate accretion luminosities ( ) from well - sampled multiwavelength seds from the cosmic evolution survey ( cosmos ) , and accurate black hole masses derived from virial scaling relations ( for broad - line agns ) or host - agn ... | we show how accretion rate governs the physical properties of a sample of unobscured broad - line , narrow - line , and lineless active galactic nuclei ( agns ) . we avoid the systematic errors plaguing previous studies of agn accretion rate by using accurate accretion luminosities ( ) from well - sampled multiwaveleng... |
0804.1505 | i | there has been a renewed interest in higher dimensional solutions to einstein field equations . several interesting vacuum static / stationary solutions @xcite , the methods of their generations @xcite and study @xcite , as well as some general results on uniqueness of higher dimensional static vacuum black holes @xcit... | . the construction uses einstein - scalar field seed solutions in 4 dimensions and is performed both for the case when all the killing directions are spacelike , as well as when one of the killing vectors is timelike . some examples representing generalizations of known higher dimensional stationary solutions are discu... | we show how one can systematically construct vacuum solutions to einstein field equations with commuting killing vectors in dimensions . the construction uses einstein - scalar field seed solutions in 4 dimensions and is performed both for the case when all the killing directions are spacelike , as well as when one of ... |
1011.4864 | i | a branching random walk is a collection of points which , starting from a single point , diffuse and branch independently of the time , of their positions or of the other points , as in figure [ fig : brw ] . branching random walks appear in many contexts ranging from mathematics @xcite to biology @xcite . they... | we show that the distribution of all the distances between the rightmost points has a long time limit which can be understood as the delay of the fisher - kpp traveling waves when the initial condition is modified . the limiting measure exhibits the surprising property of superposability : the statistical properties of... | we show that all the time - dependent statistical properties of the rightmost points of a branching brownian motion can be extracted from the traveling wave solutions of the fisher - kpp equation . we show that the distribution of all the distances between the rightmost points has a long time limit which can be underst... |
1406.2722 | i | the aim of this article is to relate two generalizations of the burau representation of the braid groups to certain types of tangles . consider the standard presentation of the braid group in @xmath1 strands @xmath2 the _ unreduced _ burau representation @xmath3 is defined on the free @xmath4$]-module of rank @xmath... | we show that the exterior powers of the matrix valued random walk invariant of string links , introduced by lin , tian , and wang , are isomorphic to the graded components of the tangle functor associated to the alexander polynomial by ohtsuki divided by the zero graded invariant of the functor . several resulting prop... | we show that the exterior powers of the matrix valued random walk invariant of string links , introduced by lin , tian , and wang , are isomorphic to the graded components of the tangle functor associated to the alexander polynomial by ohtsuki divided by the zero graded invariant of the functor . several resulting prop... |
1111.3509 | i | the general aim in quantum tomography is to identify quantum states from measurement outcome statistics . a collection of observables with this property is called _ informationally complete _ @xcite . even a single observable can be informationally complete , but then it must be a noncommutative positive operator value... | if we require minimal noise in the joint measurement , then the joint observable is unique . if the dimension is odd , then this observable is informationally complete . but if is even , then the joint observable is not informationally complete and one has to allow more noise in order to obtain informational completene... | we show that there are informationally complete joint measurements of two conjugated observables on a finite quantum system , meaning that they enable to identify all quantum states from their measurement outcome statistics . we further demonstrate that it is possible to implement a joint observable as a sequential mea... |
astro-ph0701856 | c | we have performed a comprehensive calculation of the neutrino and @xmath0-ray flux distributions which are expected to be originated by the interaction of cr nuclei with the interstellar gas . our computation improves and updates previous analyses under several aspects . + modelling the spatial distribution of cr in th... | we simulate the neutrino and-ray emissions of the galaxy which are originated from the hadronic scattering of cosmic rays ( cr ) with the interstellar medium ( ism ) . rather than assuming a uniform cr density , we estimate the spatial distribution of cr nuclei by means of numerical simulations . we confirm that the ex... | we simulate the neutrino and-ray emissions of the galaxy which are originated from the hadronic scattering of cosmic rays ( cr ) with the interstellar medium ( ism ) . rather than assuming a uniform cr density , we estimate the spatial distribution of cr nuclei by means of numerical simulations . we consider several mo... |
1309.3709 | i | since half a century ago , the hubbard model has been widely studied as a simple model accounting for several nontrivial phenomena in electronic systems , such as the mott insulator , ( anti)ferromagnetism , and novel superconductivity@xcite . its bosonic version , the bose - hubbard ( bh ) model , has been appreciably... | we study a bose - hubbard model having on - site repulsion , nearest - neighbor tunneling , and ferromagneticlike coupling between occupation parities of nearest - neighbor sites . for a uniform system in any dimension at zero tunneling we also identify an exotic pair superfluid at relatively large tunneling strength .... | we study a bose - hubbard model having on - site repulsion , nearest - neighbor tunneling , and ferromagneticlike coupling between occupation parities of nearest - neighbor sites . for a uniform system in any dimension at zero tunneling , we obtain an exact phase diagram characterized by mott - insulator ( mi ) and pai... |
1309.3709 | c | in this paper , we studied an extended bose - hubbard model incorporating a ferromagneticlike coupling between the nearest - neighbor site - occupation parities . this parity coupling generates domain - wall energies that compete with the single - particle tunneling and favors pair doping rather than the single - parti... | , we obtain an exact phase diagram characterized by mott - insulator ( mi ) and pair liquid phases and regions of phase separation of two mis . for a general trapped system in one and two dimensions with finite tunneling , we perform quantum monte carlo and gutzwiller mean - field calculations , both of which show the ... | we study a bose - hubbard model having on - site repulsion , nearest - neighbor tunneling , and ferromagneticlike coupling between occupation parities of nearest - neighbor sites . for a uniform system in any dimension at zero tunneling , we obtain an exact phase diagram characterized by mott - insulator ( mi ) and pai... |
1412.2914 | i | observations of the cosmic microwave background ( cmb ) most recently @xcite have clearly established that scalar perturbations in the early universe were nearly scale - invariant . it is thus necessary for any realistic cosmological model to generate , in some fashion , scale - invariant perturbations . to achieve ... | we study a contracting universe composed of cold dark matter and radiation , and with a positive cosmological constant . as is well known from standard cosmological perturbation theory , under the assumption of initial quantum vacuum fluctuations the fourier modes of the comoving curvature perturbation that exit the ( ... | we study a contracting universe composed of cold dark matter and radiation , and with a positive cosmological constant . as is well known from standard cosmological perturbation theory , under the assumption of initial quantum vacuum fluctuations the fourier modes of the comoving curvature perturbation that exit the ( ... |
1412.2914 | c | in this paper we have seen how in a contracting universe cosmological perturbations , assumed to be initially in their quantum vacuum state , become scale - invariant if their sound wavelength becomes larger than the hubble radius when the dynamics of the universe is dominated by cold dark matter . a small red tilt is ... | we assume that loop quantum cosmology captures the correct high - curvature dynamics of the space - time , and this ensures that the big - bang singularity is resolved and is replaced by a bounce . we also show that the amplitude of the scalar perturbations in this cosmology depends on a combination of the sound speed ... | we study a contracting universe composed of cold dark matter and radiation , and with a positive cosmological constant . as is well known from standard cosmological perturbation theory , under the assumption of initial quantum vacuum fluctuations the fourier modes of the comoving curvature perturbation that exit the ( ... |
1203.2971 | r | , and kinetic and magnetic energies , @xmath128 and @xmath129 , respectively . two dotted vertical lines bound the period of gradually increasing turbulence . the resistivity in this model is set to @xmath130 and the shared component of magnetic field @xmath131 . in this model we inject turbulence in the magnetic field... | the model has been already successfully tested in confirming the dependencies of the reconnection speed on the turbulence injection power and the injection scale expressed by a constraint and no observed dependency on ohmic resistivity . in , in order to drive turbulence , we injected velocity fluctuations in fourier s... | we study a model of fast magnetic reconnection in the presence of weak turbulence proposed by using three - dimensional direct numerical simulations . the model has been already successfully tested in confirming the dependencies of the reconnection speed on the turbulence injection power and the injection scale express... |
1203.2971 | c | the lv99 model was introduced for both collisional and collisionless media and it claimed that the microphysics of collisionless reconnection events does not change the resulting reconnection rates . this point was subjected to further scrutiny in @xcite who provided a thorough investigation of the problem and conclude... | we study a model of fast magnetic reconnection in the presence of weak turbulence proposed by using three - dimensional direct numerical simulations . we extend our previous studies by comparing fast magnetic reconnection under different mechanisms of turbulence injection by introducing a new way of turbulence driving ... | we study a model of fast magnetic reconnection in the presence of weak turbulence proposed by using three - dimensional direct numerical simulations . the model has been already successfully tested in confirming the dependencies of the reconnection speed on the turbulence injection power and the injection scale express... |
1107.0813 | i | inflationary cosmology has become the prevalent paradigm to understand the early stage of our universe , with its advantages of resolving the flatness , homogeneity and monopole problems @xcite , and predicting a approximately scale - invariant primordial power spectrum consistent with current cosmological observations... | , these fields can be treated as a combination of decoupled fields , which are similar to normal modes in coupled oscillation . by virtue of such fields , the curvature perturbation at the horizon - crossing can be calculated up to the leading order of slow variation parameters via formalism . explicitly , we consider ... | we study a multi - field inflationary theory with separable lagrangian , which has different speed of sound for each field . we find that the fields always coupled at perturbative level through gravitational interaction . we show that if the coupling terms among the perturbation fields are weak enough , these fields ca... |
1608.03339 | i | in the era of big data , the rapid expansion of computing capacities in automatic data generation and acquisition brings data of unprecedented size and complexity , and raises a series of scientific challenges such as storage bottleneck and algorithmic scalability @xcite . to overcome the difficulty , some approaches f... | we study distributed learning with the least squares regularization scheme in a reproducing kernel hilbert space ( rkhs ) . by a divide - and - conquer approach , the algorithm partitions a data set into disjoint data subsets , applies the least squares regularization scheme to each data subset to produce an output fun... | we study distributed learning with the least squares regularization scheme in a reproducing kernel hilbert space ( rkhs ) . by a divide - and - conquer approach , the algorithm partitions a data set into disjoint data subsets , applies the least squares regularization scheme to each data subset to produce an output fun... |
0809.5141 | i | one of the most exciting recent events in physics has been the increasing overlap between two previously disjoint fields , quantum optics and condensed matter physics . this has become possible due to the enormous progress in cooling dilute bosonic and also fermionic gases down to temperatures where respectively bose -... | , we provide the evolution of typical experimentally available observables . _ , nature * 448 * , 1029 ( 2007 ) ; s. trotzky _ et al . _ , we provide theoretical background for the next step , the observation of coherent many - particle dynamics after coupling the double wells . contrary to the case of isolated double ... | we study how well magnetic models can be implemented with ultracold bosonic atoms of two different hyperfine states in an optical superlattice . the system is captured by a two - species bose - hubbard model , but realizes in a certain parameter regime actually the physics of a spin-1/2 heisenberg magnet , describing t... |
1101.2982 | i | in this paper we study a system of polynomials , orthogonal with respect to two different weight functions of meixner - pollaczek type . our work is motivated by the analysis of the six - vertex model in statistical mechanics introduced in @xcite and studied in many papers since then , see e.g. @xcite . colomo and pr... | we also provide a rodrigues formula and closed expressions for the recurrence coefficients . the proof of the main result follows from a connection with the eigenvalues of block toeplitz matrices , for which we provide some general results of independent interest . the motivation for this paper is the study of a model ... | we study multiple orthogonal polynomials of meixner - pollaczek type with respect to a symmetric system of two orthogonality measures . our main result is that the limiting distribution of the zeros of these polynomials is one component of the solution to a constrained vector equilibrium problem . we also provide a rod... |
1101.2982 | r | let @xmath6 and @xmath7 denote two distinct weight functions of meixner - pollaczek type ; @xmath8 with @xmath9 where @xmath10 , @xmath11 and @xmath12 are fixed parameters and @xmath13 denotes euler s gamma function @xcite . note that in the gamma function is evaluated in a complex argument and that @xmath14 furthermor... | our main result is that the limiting distribution of the zeros of these polynomials is one component of the solution to a constrained vector equilibrium problem . we show how the multiple meixner - pollaczek polynomials arise in an inhomogeneous version of this model . * keywords * : multiple orthogonal polynomial ,... | we study multiple orthogonal polynomials of meixner - pollaczek type with respect to a symmetric system of two orthogonality measures . our main result is that the limiting distribution of the zeros of these polynomials is one component of the solution to a constrained vector equilibrium problem . we also provide a rod... |
astro-ph0311377 | i | rotation is observed ubiquitously in star - forming cores . on the scale of @xmath00.1 pc , the detected rotation rate is small , with a typical value corresponding to a ratio of rotational to gravitational energy of @xmath1 ( goodman et al . 1993 ) . the rotation rate is much lower than expected if the core is conden... | we study numerically the collapse of rotating , magnetized molecular cloud cores , focusing on rotation and magnetic braking during the main accretion phase of isolated star formation . motivated by previous numerical work and analytic considerations , we idealize the pre - collapse core as a magnetized singular isothe... | we study numerically the collapse of rotating , magnetized molecular cloud cores , focusing on rotation and magnetic braking during the main accretion phase of isolated star formation . motivated by previous numerical work and analytic considerations , we idealize the pre - collapse core as a magnetized singular isothe... |
1211.5133 | c | we have analyzed the normal state of a degenerate fermi gas in the presence of artificial spin - orbit coupling and crossed zeeman fields . the specific form of the spin - orbit field chosen corresponds to a mixture of equal rashba and dresselhaus ( erd ) terms @xmath417 , which has been experimentally realized . the a... | we study quantum degenerate ultra - cold fermi gases in the presence of artificial spin - orbit coupling and crossed zeeman fields . we emphasize the case where parity is violated in the excitation spectrum and compare it with the simpler situation where parity is preserved . similarly , we show that thermodynamic prop... | we study quantum degenerate ultra - cold fermi gases in the presence of artificial spin - orbit coupling and crossed zeeman fields . we emphasize the case where parity is violated in the excitation spectrum and compare it with the simpler situation where parity is preserved . we investigate in detail spectroscopic prop... |
0710.4600 | i | in four dimensions , stationary black hole spactimes have been studied by many authors and these studies are known as _ uniqueness theorems of black holes _ @xcite . israel showed that the only static , asymptotically flat vacuum solution with a regular event horizon is the schwarzschild solution specified only by its... | we study the boundary value problem for asymptotically flat stationary black ring solutions to the five - dimensional vacuum einstein equations . assuming the existence of two additional commuting axial killing vector fields and the horizon topology of , we show that the only asymptotically flat black ring solution wit... | we study the boundary value problem for asymptotically flat stationary black ring solutions to the five - dimensional vacuum einstein equations . assuming the existence of two additional commuting axial killing vector fields and the horizon topology of , we show that the only asymptotically flat black ring solution wit... |
1205.2068 | i | equilibration can be defined as the evolution of a system out of equilibrium towards a stationary state in the long - time limit . for quantum systems , the question arises how equilibration is possible in spite of the linear and unitary time evolution , how the stationary state depends on the initial conditions , and ... | we study the dissipative quantum harmonic oscillator with general non - thermal preparations of the harmonic oscillator bath . we find a hierarchy of conditions for thermalization , together with the relation of the asymptotic temperature to the energy distribution in the initial bath state . we discuss the presence an... | we study the dissipative quantum harmonic oscillator with general non - thermal preparations of the harmonic oscillator bath . the focus is on equilibration of the oscillator in the long - time limit and the additional requirements for thermalization . our study is based on the exact solution of the microscopic model o... |
1009.4364 | i | the notion of subgroup distortion was first formulated by gromov in @xcite . for a group @xmath7 with finite generating set @xmath8 and a subgroup @xmath9 of @xmath7 finitely generated by @xmath10 , the distortion function of @xmath9 in @xmath7 is @xmath11 where @xmath12 represents the word length with respect to the g... | we study the effects of subgroup distortion in the wreath products , where is finitely generated abelian . moreover , for infinite , and for any polynomial , there is a-generated subgroup of having distortion function equivalent to the given polynomial . also a formula for the length of elements in arbitrary wreath pro... | we study the effects of subgroup distortion in the wreath products , where is finitely generated abelian . we show that every finitely generated subgroup of has distortion function equivalent to some polynomial . moreover , for infinite , and for any polynomial , there is a-generated subgroup of having distortion funct... |
math0301270 | i | a periodic two - dimensional lorentz gas ( sinai billiard ) is a billiard system on the two - dimensional torus with one or more circular regions ( scatterers ) removed . this model in classical mechanics was introduced by lorentz @xcite in 1905 to describe the dynamics of electrons in metals . the associated dynamical... | we study the free path length and the geometric free path length in the model of the periodic two - dimensional lorentz gas ( sinai billiard ) . we give a complete and rigorous proof for the existence of their distributions in the small - scatterer limit and gets a complete proof for the existence of the constant term ... | we study the free path length and the geometric free path length in the model of the periodic two - dimensional lorentz gas ( sinai billiard ) . we give a complete and rigorous proof for the existence of their distributions in the small - scatterer limit and explicitly compute them . as a corollary one gets a complete ... |
1206.5861 | i | the general analysis of the evolution of material systems interacting with their own gravitational field is undoubtedly a very important and very difficult problem in general relativity . as usual in any physical theory , one can gain insight into the more difficult issues by considering idealized simplified models tha... | we obtain a proof of the stability of static solutions under this type of perturbations . the explicit expression for the mode expansion are then used to obtain numerical values for some of the quasi normal mode complex frequencies . some examples involving the numerical evaluation of the integral mode expansions are d... | we study the perturbative evolution of the static configurations , quasinormal modes and quasi normal ringing in the apostolatos - thorne cylindrical shell model . we consider first an expansion in harmonic modes and show that it provides a complete solution for the characteristic value problem for the finite perturbat... |
hep-ph9806541 | i | the nonperturbative calculation of the anomalous moment of the electron @xmath0 , besides being of intrinsic interest itself , exposes many important issues for nonperturbative calculations within gauge theories which occur in the context of a truncated fock space . these include nonperturbative mass and coupling renor... | we present results for computed in a light - cone gauge fock space truncated to include one bare electron and at most two photons ; i.e. , up to two photons in flight . the calculational scheme uses an invariant mass cutoff , discretized light - cone quantization ( dlcq ) , a tamm dancoff truncation of the fock space ... | we study the physical electron in quantum electrodynamics expanded on the light - cone fock space in order to address two problems : ( 1 ) the physics of the electron s anomalous magnetic moment in nonperturbative qed , and ( 2 ) the practical problems of ultraviolet regularization and renormalization in truncated nonp... |
1103.4868 | i | designs for multi - user communications networks and systems have been extensively used during the past decade to implement low - cost , scalable , and limited - message - passing networks . in doing so , transmitter and receiver pairs with local information determine their transmission strategies in an autonomous mann... | the existence and uniqueness conditions of rne are derived using finite - dimensions variational inequalities . to describe the effect of uncertainty on the performance of the system , we use two criteria measured at the rne and at the equilibrium of the game without uncertainty . the first is the difference between th... | we study the robust nash equilibrium ( rne ) for a class of games in communications systems and networks where the impact of users on each other is an additive function of their strategies . each user measures this impact , which may be corrupted by uncertainty in feedback delays , estimation errors , movements of user... |
1103.4868 | c | we studied the rne for a wide range of problems in communication systems and networks when users impact on each other can be modeled as an additive function of system parameters and users strategies . in this game , since the user s observations of these impacts are uncertain , each user optimizes its utility using wor... | we study the robust nash equilibrium ( rne ) for a class of games in communications systems and networks where the impact of users on each other is an additive function of their strategies . simulations of the power control game in interference channels , and jackson networks validate our analysis . | we study the robust nash equilibrium ( rne ) for a class of games in communications systems and networks where the impact of users on each other is an additive function of their strategies . each user measures this impact , which may be corrupted by uncertainty in feedback delays , estimation errors , movements of user... |
cond-mat0606740 | r | the main goal of our experiment is the verification of the numerical simulation results of shifting and broadening of spectral lines caused by inhomogeneities and the possibility of resonator spectrum `` rarefaction '' . the another goal is as follows . in the paper [ 3 ] we detected strong spectrum stochastization cau... | the solitary spectral lines which have the distance to the nearest lines quite large is slightly changed due to small inhomogeneities . owing to such selective influence of inhomogeneities on the spectral lines the effective spectrum rarefaction appears . both the shift and broadening of spectral lines as well as spect... | we suggest the statistical spectral theory of oscillations in quasi - optical cavity resonator filled with random inhomogeneities . it is shown that inhomogeneities in the resonator result in intermode scattering leading to the shift and broadening of spectral lines . the shift and broadening of each line essentially d... |
cond-mat0606740 | c | the statistical spectral theory of quasi - optical cavity resonator filled with random dielectric inhomogeneities was developed in the present paper . we showed that the presence of inhomogeneities leads to the broadening and shifting of spectral lines . it is found out that the nature of broadening and shifting of spe... | we suggest the statistical spectral theory of oscillations in quasi - optical cavity resonator filled with random inhomogeneities . the inhomogeneous quasi - optical cavity millimeter wave resonator ( passive and active ) can serve as a model of semiconductor quantum billiard . based on our results we suggest using suc... | we suggest the statistical spectral theory of oscillations in quasi - optical cavity resonator filled with random inhomogeneities . it is shown that inhomogeneities in the resonator result in intermode scattering leading to the shift and broadening of spectral lines . the shift and broadening of each line essentially d... |
1006.0590 | i | the decision problem of whether a graph has a hamilton cycle is np - complete and so a satisfactory characterization of hamiltonian graphs seems unlikely . thus it makes sense to ask for degree conditions which ensure that a graph has a hamilton cycle . one such result is dirac s theorem @xcite , which states that eve... | we also combine some of these to prove the following approximate result towards kelly s conjecture on hamilton decompositions of regular tournaments : the edges of every regular tournament can be covered by a set of hamilton cycles which are ` almost ' edge - disjoint . new and old open problems are discussed . # 1 ... | we survey some recent results on long - standing conjectures regarding hamilton cycles in directed graphs , oriented graphs and tournaments . we also combine some of these to prove the following approximate result towards kelly s conjecture on hamilton decompositions of regular tournaments : the edges of every regular ... |
1007.3510 | i | we have used rc stars to trace the long tidal tail of the sgr dsph galaxy in the portion of the northern sky sampled by the sdss - dr6 . structures along the line - of - sight are identified as peaks in the ( otherwise smoothly increasing ) @xmath36- and @xmath37-band scps of color - selected samples of candidate rc st... | we trace the tidal stream of the sagittarius dwarf spheroidal galaxy ( sgr dsph ) using red clump stars from the catalog of the sloan digital sky survey - data release 6 , in the range , corresponding to the range of orbital azimuth . substructures along the line of sight are identified as significant peaks in the diff... | we trace the tidal stream of the sagittarius dwarf spheroidal galaxy ( sgr dsph ) using red clump stars from the catalog of the sloan digital sky survey - data release 6 , in the range , corresponding to the range of orbital azimuth . substructures along the line of sight are identified as significant peaks in the diff... |
0807.4934 | i | according to the current paradigm of structure formation , galaxies form and reside inside extended cold dark haloes . while the formation and evolution of dark matter haloes in the cosmic density field is mainly determined by gravitational processes , the formation and evolution of galaxies involves much more complica... | we use galaxy groups selected from the sloan digital sky survey ( sdss ) together with mass models for individual groups to study the galaxy - galaxy lensing signals expected from galaxies of different luminosities and morphological types . we compare our model predictions with the observational results obtained from t... | we use galaxy groups selected from the sloan digital sky survey ( sdss ) together with mass models for individual groups to study the galaxy - galaxy lensing signals expected from galaxies of different luminosities and morphological types . we compare our model predictions with the observational results obtained from t... |
1701.03213 | i | branching objects are found very widely @xcite , ranging from natural patterns like river networks , plants , and dendritic crystals , to conceptual expressions like binary search trees in computer science @xcite and phylogenetic trees in taxonomy @xcite . the topological structure of a branching pattern is modeled ... | * abstract * + the horton - strahler ordering method , originating in hydrology , formulates the hierarchical structure of branching patterns using a quantity called the bifurcation ratio . the main result of this paper is the central limit theorem for bifurcation ratio of general branch order . some useful relations... | * abstract * + the horton - strahler ordering method , originating in hydrology , formulates the hierarchical structure of branching patterns using a quantity called the bifurcation ratio . the main result of this paper is the central limit theorem for bifurcation ratio of general branch order . this is a generalized... |
astro-ph0602490 | i | the _ swift _ gamma - ray burst explorer @xcite has been returning unprecedented data about gamma ray bursts ( grbs ) for the past 18 months . of particular interest in the bursts followed by _ swift _ have been the early time lightcurves of the afterglows which have shown much greater structure and different temporal ... | _ swift _ discovered grb 050713a and slewed promptly to begin observing with its narrow field instruments 72.6 seconds after the burst onset , while the prompt gamma - ray emission was still detectable in the bat . this burst marks just the second time that the bat and xrt have simultaneously detected emission from a ... | _ swift _ discovered grb 050713a and slewed promptly to begin observing with its narrow field instruments 72.6 seconds after the burst onset , while the prompt gamma - ray emission was still detectable in the bat . simultaneous emission from two flares is detected in the bat and xrt . this burst marks just the second ... |
astro-ph0602490 | c | the k - w light curve in the 181160 kev energy range is similar to the _ swift_-bat light curve ( fig 1 ) . the small precursor peak detected by bat at t@xmath070 to t@xmath050 s is seen by k - w at statistically significant levels in all three broad , pre - trigger bands : g1 ( 1870 kev ) , g2 ( 70300 ) , and g3 ( ... | together , these four observatories provide unusually broad spectral coverage of the prompt emission and detailed x - ray follow - up of the afterglow for two weeks after the burst trigger . these spectral results together with the rapid temporal rise and decay of the flares suggest that flares are produced in internal... | _ swift _ discovered grb 050713a and slewed promptly to begin observing with its narrow field instruments 72.6 seconds after the burst onset , while the prompt gamma - ray emission was still detectable in the bat . simultaneous emission from two flares is detected in the bat and xrt . this burst marks just the second ... |
1512.02381 | i | for @xmath9 , a _ @xmath0-box _ is the cartesian product @xmath10 of @xmath0 intervals of @xmath1 . @xmath0-box representation _ of a graph @xmath11 is a collection @xmath12 of @xmath0-boxes in @xmath3 such that any two boxes @xmath13 and @xmath14 intersect if and only if the corresponding vertices @xmath15 and @xmath1... | -box representation _ of a graph is a representation of as the intersection graph of a set of-boxes in . it was proved by thomassen in 1986 that every planar graph has a 3-box representation . in this paper we prove that every graph embedded in a fixed orientable surface , without short non - contractible cycles , has ... | a _-box _ is the cartesian product of intervals of and a _ -box representation _ of a graph is a representation of as the intersection graph of a set of-boxes in . it was proved by thomassen in 1986 that every planar graph has a 3-box representation . in this paper we prove that every graph embedded in a fixed orientab... |
physics0605225 | i | it is now twenty years since ceperley and pollock ( cp ) carried out the first path integral monte carlo ( pimc ) simulation of the superfluid transition of liquid 4.@xcite albeit restricted to a system of 64 4 atoms with periodic boundary conditions , that study demonstrated the feasibility of _ ab initio _ numerical ... | a detailed description is provided of a new worm algorithm , enabling the accurate computation of thermodynamic properties of quantum many - body systems in continuous space , at finite temperature . the algorithm is formulated within the general path integral monte carlo ( pimc ) scheme , but also allows one to perfor... | a detailed description is provided of a new worm algorithm , enabling the accurate computation of thermodynamic properties of quantum many - body systems in continuous space , at finite temperature . the algorithm is formulated within the general path integral monte carlo ( pimc ) scheme , but also allows one to perfor... |
physics0605225 | r | in this section , we present wa simulation results for bulk liquid @xmath0he in two and three dimensions , with the aim of demonstrating that superfluid properties and off - diagonal correlations can be calculated with the wa for very large system sizes , orders of magnitude larger than accessible to the conventional p... | the computational scheme allows for efficient calculations of the superfluid fraction and off - diagonal correlations in space - time , for system sizes which are orders of magnitude larger than those accessible to conventional pimc . we present illustrative results for the superfluid transition in bulk liquid 4 in two... | a detailed description is provided of a new worm algorithm , enabling the accurate computation of thermodynamic properties of quantum many - body systems in continuous space , at finite temperature . the algorithm is formulated within the general path integral monte carlo ( pimc ) scheme , but also allows one to perfor... |
1606.00390 | i | photonic crystals , which consist of a periodically arranged lattice of dielectric scatterers , have attracted substantial research interest over the past decade @xcite . most commonly these structures are used to trap , guide , and otherwise manipulate pulses of light , and have led to a variety of important applicati... | a finite element - based modal formulation of diffraction of a plane wave by an absorbing photonic crystal slab of arbitrary geometry is developed for photovoltaic applications . the semi - analytic approach allows efficient and accurate calculation of the absorption of an array with a complex unit cell . this approach... | a finite element - based modal formulation of diffraction of a plane wave by an absorbing photonic crystal slab of arbitrary geometry is developed for photovoltaic applications . the semi - analytic approach allows efficient and accurate calculation of the absorption of an array with a complex unit cell . this approach... |
0708.3059 | i | characterization of statistical properties of coherent waves propagating through an elastically scattering disordered medium is relevant for a variety of physical situations , ranging from propagation of electromagnetic waves through interstellar space or the atmosphere , seismology , and medical imaging by ultrasound ... | a general method for calculating statistical properties of speckle patterns of coherent waves propagating in disordered media is developed . it allows one to calculate speckle pattern correlations in space , as well as their sensitivity to external parameters . this method , which is similar to the boltzmann - langevin... | a general method for calculating statistical properties of speckle patterns of coherent waves propagating in disordered media is developed . it allows one to calculate speckle pattern correlations in space , as well as their sensitivity to external parameters . this method , which is similar to the boltzmann - langevin... |
1402.2968 | i | disentangling the effects of electron - electron interactions in the ground and excited states of low - dimensional systems has become an exciting challenge in contemporary condensed matter physics . @xcite in particular , the discovery of high - tc superconductivity in the cuprates @xcite has acted as a driving force ... | a multi - reference configuration mixing scheme is used to describe the ground state , characterized by well defined spin and space group symmetry quantum numbers as well as doping fractions , of one dimensional hubbard lattices with nearest - neighbor hopping and periodic boundary conditions . within this scheme , eac... | a multi - reference configuration mixing scheme is used to describe the ground state , characterized by well defined spin and space group symmetry quantum numbers as well as doping fractions , of one dimensional hubbard lattices with nearest - neighbor hopping and periodic boundary conditions . within this scheme , eac... |
1402.2968 | c | in this section , we discuss the results of our fed calculations . first , we pay attention to lattices with @xmath13=30 sites and @xmath3=14 , 18 , 22 , 26 , 30 electrons . results are presented for on - site repulsions @xmath2=2@xmath5 , 4@xmath5 , and 8@xmath5 , respectively . in sec . [ gsandcoenergies ] , we compa... | the structure of the intrinsic symmetry - broken determinants resulting from the variational procedure is interpreted in terms of solitons whose translational and breathing motions can be regarded as basic units of quantum fluctuations . it is also shown that in the case of doped 1d lattices , a part of such fluctuatio... | a multi - reference configuration mixing scheme is used to describe the ground state , characterized by well defined spin and space group symmetry quantum numbers as well as doping fractions , of one dimensional hubbard lattices with nearest - neighbor hopping and periodic boundary conditions . within this scheme , eac... |
1211.5884 | i | relays are often used to aid communications , not only to improve the quality of service ( qos ) of the user pairs , which have weak direct links due to poor channel conditions , but also to increase the multiplexing gain of the network @xcite . among various relay transmit schemes , the most effective ones are amplify... | a multiple - antenna amplify - and - forward two - hop interference network with multiple links and multiple relays is considered . we optimize transmit precoders , receive decoders and relay af matrices to maximize the achievable sum rate . under per user and total relay sum power constraints , we propose an efficient... | a multiple - antenna amplify - and - forward two - hop interference network with multiple links and multiple relays is considered . we optimize transmit precoders , receive decoders and relay af matrices to maximize the achievable sum rate . under per user and total relay sum power constraints , we propose an efficient... |
1211.5884 | c | this paper considered the general @xmath1 mimo relay network . with per user and total relay power constraints , an algorithm for the tstinr model was proposed . for the individual user and individual relay fixed power constraints , the tstinr algorithm was extended , and the algorithms for the tlin and wmmse model in ... | computational complexity analysis shows that our proposed algorithm for tstinr has lower complexity than the existing weighted minimum mean square error ( wmmse ) algorithm . simulation results show that for single stream models , our tstinr algorithm outperforms the tlin algorithm generally and outperforms wmmse in me... | a multiple - antenna amplify - and - forward two - hop interference network with multiple links and multiple relays is considered . we optimize transmit precoders , receive decoders and relay af matrices to maximize the achievable sum rate . under per user and total relay sum power constraints , we propose an efficient... |
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