Instruction: what is the prompt that generates the input?

Input: High dispersion near-infrared spectra have been taken of sevenhighly-evolved, variable, intermediate-mass (4-6 Msun) AGB stars in the LMC andSMC in order to look for C, N and O variations that are expected to arise fromthird dredge-up and hot-bottom burning. The pulsation of the objects has beenmodelled, yielding stellar masses, and spectral synthesis calculations havebeen performed in order to derive abundances from the observed spectra. For twostars, abundances of C, N, O, Na, Al, Ti, Sc and Fe were derived and comparedwith the abundances predicted by detailed AGB models. Both stars show verylarge N enhancements and C deficiencies. These results provide the firstobservational confirmation of the long-predicted production of primary nitrogenby the combination of third dredge-up and hot-bottom burning inintermediate-mass AGB stars. It was not possible to derive abundances for theremaining five stars: three were too cool to model, while another two hadstrong shocks in their atmospheres which caused strong emission to fill theline cores and made abundance determination impossible. The latter occurrenceallows us to predict the pulsation phase interval during which observationsshould be made if successful abundance analysis is to be possible.


Instruction: what is the prompt that generates the input?

Input: In the previous study (Hiremath 2006a), the solar cycle is modeled as aforced and damped harmonic oscillator and from all the 22 cycles (1755-1996),long-term amplitudes, frequencies, phases and decay factor are obtained. Usingthese physical parameters of the previous 22 solar cycles and by an {\emautoregressive model}, we predict the amplitude and period of the futurefifteen solar cycles. Predicted amplitude of the present solar cycle (23)matches very well with the observations. The period of the present cycle isfound to be 11.73 years. With these encouraging results, we also predict theprofiles of future 15 solar cycles. Important predictions are : (i) the periodand amplitude of the cycle 24 are 9.34 years and 110 ($\pm 11$), (ii) theperiod and amplitude of the cycle 25 are 12.49 years and 110 ($\pm$ 11), (iii)during the cycles 26 (2030-2042 AD), 27 (2042-2054 AD), 34 (2118-2127 AD), 37(2152-2163 AD) and 38 (2163-2176 AD), the sun might experience a very highsunspot activity, (iv) the sun might also experience a very low (around 60)sunspot activity during cycle 31 (2089-2100 AD) and, (v) length of the solarcycles vary from 8.65 yrs for the cycle 33 to maximum of 13.07 yrs for thecycle 35.


Instruction: what is the prompt that generates the input?

Input: This paper presents a geometric description of Lagrangian and Hamiltoniansystems on Lie affgebroids subject to affine nonholonomic constraints. Wedefine the notion of nonholonomically constrained system, and characterizeregularity conditions that guarantee that the dynamics of the system can beobtained as a suitable projection of the unconstrained dynamics. It is shownthat one can define an almost aff-Poisson bracket on the constraint AV-bundle,which plays a prominent role in the description of nonholonomic dynamics.Moreover, these developments give a general description of nonholonomic systemsand the unified treatment permits to study nonholonomic systems after or beforereduction in the same framework. Also, it is not necessary to distinguishbetween linear or affine constraints and the methods are valid for explicitlytime-dependent systems.


Instruction: what is the prompt that generates the input?

Input: We consider the accretion process in a disk with magnetic fields that aredragged in from the interstellar medium by gravitational collapse. Twodiffusive processes are at work in the system: (1) "viscous" torques exerted byturbulent and magnetic stresses, and (2) "resistive" redistribution of masswith respect to the magnetic flux arising from the imperfect conduction ofcurrent. In steady state, self-consistency between the two rates of driftrequires that a relationship exists between the coefficients of turbulentviscosity and turbulent resistivity. Ignoring any interactions with a stellarmagnetosphere, we solve the steady-state equations for a magnetized disk underthe gravitational attraction of a mass point and threaded by an amount ofmagnetic flux consistent with calculations of magnetized gravitational collapsein star formation. Our model mean-field equations have an exact analyticalsolution that corresponds to magnetically diluted Keplerian rotation about thecentral mass point. The solution yields the strength of the magnetic field andthe surface density as functions of radial position in the disk and theirconnection with the departure from pure Keplerian rotation in representativecases. We compare the predictions of the theory with the available observationsconcerning T Tauri stars, FU Orionis stars, and low- and high-mass protostars.Finally, we speculate on the physical causes for high and low states of theaccretion disks that surround young stellar objects. One of the more importantresults of this study is the physical derivation of analytic expressions forthe turbulent viscosity and turbulent resistivity.


Instruction: what is the prompt that generates the input?

Input: When the DNA double helix is subjected to external forces it can stretchelastically to elongations reaching 100% of its natural length. Thesedistortions, imposed at the mesoscopic or macroscopic scales, have a dramaticeffect on electronic properties at the atomic scale and on electrical transportalong DNA. Accordingly, a multiscale approach is necessary to capture theelectronic behavior of the stretched DNA helix. To construct such a model, webegin with accurate density-functional-theory calculations for electronicstates in DNA bases and base pairs in various relative configurationsencountered in the equilibrium and stretched forms. These results arecomplemented by semi-empirical quantum mechanical calculations for the statesof a small size [18 base pair poly(CG)-poly(CG)] dry, neutral DNA sequence,using previously published models for stretched DNA. The calculated electronicstates are then used to parametrize an effective tight-binding model that candescribe electron hopping in the presence of environmental effects, such as thepresence of stray water molecules on the backbone or structural features of thesubstrate. These effects introduce disorder in the model hamiltonian whichleads to electron localization. The localization length is smaller by severalorders of magnitude in stretched DNA relative to that in the unstretchedstructure.


Instruction: what is the prompt that generates the input?

Input: OH 231.8+4.2 is a well studied preplanetary nebula (pPN) around a binarystellar system that shows a remarkable bipolar outflow. To study the structureand kinematics of the inner 10-80 AU nebular regions we performedhigh-resolution observations of the H$_2$O 6$_{1,6}$--5$_{2,3}$ and $^{28}$SiO$v$=2, $J$=1--0 maser emissions with the Very Long Baseline Array. The absoluteposition of both emission distributions were recovered using the phasereferencing technique, and accurately registered in HST optical images. H$_2$Omaser clumps are found to be distributed in two areas of 20 mas in sizespatially displaced by $\sim$60 milli-arcseconds along an axis oriented nearlynorth-south. SiO masers are tentatively found to be placed between the twoH$_2$O maser emitting regions, probably indicating the position of the Miracomponent of the system. The SiO maser emission traces an inner equatorialcomponent with a diameter of 12 AU, probably a disk rotating around the M-typestar. Outwards, we detect in the H$_2$O data a pair of polar caps, separated by80 AU. We believe that the inner regions of the nebula probably have beenaltered by the presence of the companion, leading to an equator-to-pole densitycontrast that may explain the lack of H$_2$O masers and strong SiO maseremission in the denser, equatorial regions.


Instruction: what is the prompt that generates the input?

Input: Population structure induced by both spatial embedding and more generalnetworks of interaction, such as model social networks, have been shown to havea fundamental effect on the dynamics and outcome of evolutionary games. Theseeffects have, however, proved to be sensitive to the details of the underlyingtopology and dynamics. Here we introduce a minimal population structure that isdescribed by two distinct hierarchical levels of interaction. We believe thismodel is able to identify effects of spatial structure that do not depend onthe details of the topology. We derive the dynamics governing the evolution ofa system starting from fundamental individual level stochastic processesthrough two successive meanfield approximations. In our model of populationstructure the topology of interactions is described by only two parameters: theeffective population size at the local scale and the relative strength of localdynamics to global mixing. We demonstrate, for example, the existence of acontinuous transition leading to the dominance of cooperation in populationswith hierarchical levels of unstructured mixing as the benefit to cost ratiobecomes smaller then the local population size. Applying our model of spatialstructure to the repeated prisoner's dilemma we uncover a novel andcounterintuitive mechanism by which the constant influx of defectors sustainscooperation. Further exploring the phase space of the repeated prisoner'sdilemma and also of the "rock-paper-scissor" game we find indications of richstructure and are able to reproduce several effects observed in other modelswith explicit spatial embedding, such as the maintenance of biodiversity andthe emergence of global oscillations.


Instruction: what is the prompt that generates the input?

Input: Epitaxial self-assembled quantum dots (SAQDs) are of interest fornanostructured optoelectronic and electronic devices such as lasers,photodetectors and nanoscale logic. Spatial order and size order of SAQDs areimportant to the development of usable devices. It is likely that these twotypes of order are strongly linked; thus, a study of spatial order will alsohave strong implications for size order. Here a study of spatial order isundertaken using a linear analysis of a commonly used model of SAQD formationbased on surface diffusion. Analytic formulas for film-height correlationfunctions are found that characterize quantum dot spatial order andcorresponding correlation lengths that quantify order. Initial atomic-scalerandom fluctuations result in relatively small correlation lengths (about twodots) when the effect of a wetting potential is negligible; however, thecorrelation lengths diverge when SAQDs are allowed to form at a near-criticalfilm height. The present work reinforces previous findings about anisotropy andSAQD order and presents as explicit and transparent mechanism for ordering withcorresponding analytic equations. In addition, SAQD formation is by its naturea stochastic process, and various mathematical aspects regarding statisticalanalysis of SAQD formation and order are presented.


Instruction: what is the prompt that generates the input?

Input: Sub-100 nm nanomagnets not only are technologically important, but alsoexhibit complex magnetization reversal behaviors as their dimensions arecomparable to typical magnetic domain wall widths. Here we capture magnetic"fingerprints" of 1 billion Fe nanodots as they undergo a single domain tovortex state transition, using a first-order reversal curve (FORC) method. Asthe nanodot size increases from 52 nm to 67 nm, the FORC diagrams revealstriking differences, despite only subtle changes in their major hysteresisloops. The 52 nm nanodots exhibit single domain behavior and the coercivitydistribution extracted from the FORC distribution agrees well with acalculation based on the measured nanodot size distribution. The 58 and 67 nmnanodots exhibit vortex states, where the nucleation and annihilation of thevortices are manifested as butterfly-like features in the FORC distribution andconfirmed by micromagnetic simulations. Furthermore, the FORC method givesquantitative measures of the magnetic phase fractions, and vortex nucleationand annihilation fields.


Instruction: what is the prompt that generates the input?

Input: We investigate the accuracy of astrometric measurements with the VLT/FORS1camera and consider potential applications. The study is based on two-epoch(2000 and 2002/2003) frame series of observations of a selected Galactic Bulgesky region that were obtained with FORS1 during four consecutive nights each.Reductions were carried out with a novel technique that eliminates atmosphericimage motion and does not require a distinction between targets and referenceobjects. The positional astrometric precision was found to be limited only bythe accuracy of the determination of the star photocentre, which is typically200-300 microarcsec per single measurement for bright unsaturated starsB=18-19. Several statistical tests have shown that at time-scales of 1-4 nightsthe residual noise in measured positions is essentially a white noise with nosystematic instrumental signature and no significant deviation from a Gaussiandistribution. Some evidence of a good astrometric quality of the VLT for framesseparated by two years has also been found. Our data show that the VLT withFORS1/2 cameras can be effectively used for astrometric observations ofplanetary microlensing events and other applications where a high accuracy isrequired, that is expected to reach 30-40 microarcsec for a series of 50 frames(one hours with R filter).


Instruction: what is the prompt that generates the input?

Input: The purpose of the present work is to treat a new notion related to lineardynamics, which can be viewed as a "localization" of the notion ofhypercyclicity. In particular, let $T$ be a bounded linear operator acting on aBanach space $X$ and let $x$ be a non-zero vector in $X$ such that for everyopen neighborhood $U\subset X$ of $x$ and every non-empty open set $V\subset X$there exists a positive integer $n$ such that $T^{n}U\cap V\neq\emptyset$. Inthis case $T$ will be called a $J$-class operator. We investigate the class ofoperators satisfying the above property and provide various examples. It isworthwhile to mention that many results from the theory of hypercyclicoperators have their analogues in this setting. For example we establishresults related to the Bourdon-Feldman theorem and we characterize the$J$-class weighted shifts. We would also like to stress that even non-separableBanach spaces which do not support topologically transitive operators, as forexample $l^{\infty}(\mathbb{N})$, do admit $J$-class operators.


Instruction: what is the prompt that generates the input?

Input: WIMPs with electroweak scale masses (neutralinos, etc.) remain in kineticequilibrium with other particle species until temperatures approximately in therange of 10 MeV to 1 GeV, leading to the formation of dark matter substructurewith masses as small as $10^{-4} M_{\odot}$ to $10^{-12} M_{\odot}$. However,if dark matter consists of particles with MeV scale masses, as motivated by theobservation of 511 keV emission from the Galactic Bulge, such particles arenaturally expected to remain in kinetic equilibrium with the cosmic neutrinobackground until considerably later times. This would lead to a strongsuppression of small scale structure with masses below about $10^7 M_{\odot}$to $10^4 M_{\odot}$. This cutoff scale has important implications for presentand future searches for faint Local Group satellite galaxies and for themissing satellites problem.


Instruction: what is the prompt that generates the input?

Input: The origin of the ultrahigh-energy (UHE) cosmic rays (CRs) from the secondknee ($\sim6\times10^{17}$eV) above in the CR spectrum is still unknown.Recently, there has been growing evidence that a peculiar type of supernovae,called hypernovae, are associated with sub-energetic gamma-ray bursts (GRBs),such as SN1998bw/GRB980425 and SN2003lw/GRB031203. Such hypernovae appear tohave high (up to mildly relativistic) velocity ejecta, which may be linked tothe sub-energetic GRBs. Assuming a continuous distribution of the kineticenergy of the hypernova ejecta as a function of its velocity $E_k\propto(\Gamma\beta)^{-\alpha}$ with $\alpha\sim 2$, we find that 1) the externalshock wave produced by the high velocity ejecta of a hypernova can accelerateprotons up to energies as high as $10^{19} {\rm eV}$; 2) the cosmologicalhypernova rate is sufficient to account for the energy flux above the secondknee; and 3) the steeper spectrum of CRs at these energies can arise in thesesources. In addition, hypernovae would also give rise to a faint diffuse UHEneutrino flux, due to $p\gamma$ interactions of the UHE CRs with hypernovaoptical-UV photons.


Instruction: what is the prompt that generates the input?

Input: We consider gradient fields $(\phi_x:x\in \mathbb{Z}^d)$ whose law takes theGibbs--Boltzmann form $Z^{-1}\exp\{-\sum_{< x,y>}V(\phi_y-\phi_x)\}$, where thesum runs over nearest neighbors. We assume that the potential $V$ admits therepresentation \[V(\eta):=-\log\int\varrho({d}\kappa)\exp\biggl[-{1/2}\kappa\eta^2\biggr],\] where $\varrho$ is a positive measure with compact support in$(0,\infty)$. Hence, the potential $V$ is symmetric, but nonconvex in general.While for strictly convex $V$'s, the translation-invariant, ergodic gradientGibbs measures are completely characterized by their tilt, a nonconvexpotential as above may lead to several ergodic gradient Gibbs measures withzero tilt. Still, every ergodic, zero-tilt gradient Gibbs measure for thepotential $V$ above scales to a Gaussian free field.


Instruction: what is the prompt that generates the input?

Input: This paper focuses on the issue of energy efficiency in wireless datanetworks through a game theoretic approach. The case considered is that inwhich each user is allowed to vary its transmit power, spreading code, anduplink receiver in order to maximize its own utility, which is here defined asthe ratio of data throughput to transmit power. In particular, the case inwhich linear multiuser detectors are employed at the receiver is treated first,and, then, the more challenging case in which non-linear decision feedbackmultiuser receivers are adopted is addressed. It is shown that, for bothreceivers, the problem at hand of utility maximization can be regarded as anon-cooperative game, and it is proved that a unique Nash equilibrium pointexists. Simulation results show that significant performance gains can beobtained through both non-linear processing and spreading code optimization; inparticular, for systems with a number of users not larger than the processinggain, remarkable gains come from spreading code optimization, while, foroverloaded systems, the largest gainscome from the use of non-linearprocessing. In every case, however, the non-cooperative games proposed here areshown to outperform competing alternatives.


Instruction: what is the prompt that generates the input?

Input: Apart from its mass and width, the most important property of a new chargedgauge boson, $W'$, is the helicity of its couplings to the SM fermions. Suchparticles are expected to exist in many extensions of the Standard Model. Inthis paper we explore the capability of the LHC to determine the $W'$ couplinghelicity at low integrated luminosities in the $\ell +E_T^{miss}$ discoverychannel. We find that measurements of the transverse mass distribution,reconstructed from this final state in the $W-W'$ interference region, providesthe best determination of this quantity. To make such measurements requiresintegrated luminosities of $\sim 10(60) fb^{-1}$ assuming $M_{W'}=1.5(2.5)$ TeVand provided that the $W'$ couplings have Standard Model magnitude. Thishelicity determination can be further strengthened by the use of variousdiscovery channel leptonic asymmetries, also measured in the same interferenceregime, but with higher integrated luminosities.


Instruction: what is the prompt that generates the input?

Input: Let $(M,g,\si)$ be a compact spin manifold of dimension $n \geq 2$. Let$\lambda_1^+(\tilde{g})$ be the smallest positive eigenvalue of the Diracoperator in the metric $\tilde{g} \in [g]$ conformal to $g$. We then define$\lamin(M,[g],\si) = \inf_{\tilde{g} \in [g]} \lambda_1^+(\tilde{g})\Vol(M,\tilde{g})^{1/n} $. We show that $0< \lamin(M,[g],\si) \leq\lamin(\mS^n)$. %=\frac{n}{2} \om_n^{{1 \over n}}$ . We find sufficientconditions for which we obtain strict inequality $\lamin(M,[g],\si) <\lamin(\mS^n)$. This strict inequality has applications to conformal spingeometry.  -----  Soit $(M,g,\si)$ une vari\'et\'e spinorielle compacte de dimension $n \geq2$. %Si $\tilde{g} \in [g]$ est une m\'etrique conforme \`a $g$, On note$\lambda_1^+(\tilde{g})$ la plus petite valeur propre $>0$ de l'op\'erateur deDirac dans la m\'etrique $\tilde{g} \in [g]$ conforme \`a $g$. On d\'efinit$\lamin(M,[g],\si) = \inf_{\tilde{g} \in [g]} \lambda_1^+(\tilde{g})  \Vol(M,\tilde{g})^{1/n} $. On montre que $0< \lamin(M,[g],\si) \leq\lamin(\mS^n)$. %= \frac{n}{2} \om_n^{{1 \over n}}$ On trouve des conditionssuffisantes pour lesquelles on obtient l'in\'egalit\'e stricte$\lamin(M,[g],\si) < \lamin(\mS^n)$. Cette in\'egalit\'e stricte a desapplications en g\'eom\'etrie spinorielle conforme.


Instruction: what is the prompt that generates the input?

Input: A path-integral for the t-J model in two dimensions is constructed based onDirac quantization, with an action found originally by Wiegmann (Phys. Rev.Lett. {\bf 60}, 821 (1988); Nucl. Phys. B323, 311 (1989)). Concentrating on thelow doping limit, we assume short range antiferromagnetic order of the spindegrees of freedom. Going over to a local spin quantization axis of the dopantfermions, that follows the spin degree of freedom, staggered CP$^1$ fieldsresult and the constraint against double occupancy can be resolved. Thestaggered CP$^1$ fields are split into slow and fast modes, such that after agradient expansion, and after integrating out the fast modes and the dopantfermions, a CP$^1$ field-theory with a massive gauge field is obtained thatdescribes generically incommensurate coplanar magnetic structures, as discussedpreviously in the context of frustrated quantum antiferromagnets. Hence, thepossibility of deconfined spinons is opened by doping a colinearantiferromagnet.


Instruction: what is the prompt that generates the input?

Input: Using a large sample of spiral galaxies for which 21 cm single-dish and/orlong-slit optical spectra are available, we make a detailed comparison betweenvarious estimates of rotational widths. Different optical width estimators areconsidered and their limitations discussed, with emphasis on biases associatedwith rotation curve properties (shape and extent) and disk central surfacebrightness. The best match with HI rotational velocities is obtained withPolyex widths, which are measured at the optical radius (encompassing a fixedfraction of the total light of the galaxy) from a model fit to the rotationcurve. In contrast with Polyex widths, optical rotational velocities measuredat 2.15 disk scale lengths r_d deviate from HI widths by an amount thatcorrelates with the central surface brightness of the disk. This bias occursbecause the rotation curves of galaxies are in general still rising at 2.15r_d, and the fraction of total mass contained within this radius decreases withincreasing disk surface brightness. Statistical corrections, parameterized bythe radial extent of the observed rotation curve, are provided to reduce Polyexand HI width measurements into a homogeneous system. This yields a singlerobust estimate of rotational velocity to be used for applications of diskscaling relations.


Instruction: what is the prompt that generates the input?

Input: The notion of $\times$-homotopy from \cite{DocHom} is investigated in thecontext of the category of pointed graphs. The main result is a long exactsequence that relates the higher homotopy groups of the space $\Hom_*(G,H)$with the homotopy groups of $\Hom_*(G,H^I)$. Here $\Hom_*(G,H)$ is a spacewhich parametrizes pointed graph maps from $G$ to $H$ (a pointed version of theusual $\Hom$ complex), and $H^I$ is the graph of based paths in $H$. As acorollary it is shown that $\pi_i \big(\Hom_*(G,H) \big) \cong [G,\Omega^iH]_{\times}$, where $\Omega H$ is the graph of based closed paths in $H$ and$[G,K]_{\times}$ is the set of $\times$-homotopy classes of pointed graph mapsfrom $G$ to $K$. This is similar in spirit to the results of \cite{BBLL}, wherethe authors seek a space whose homotopy groups encode a similarly definedhomotopy theory for graphs. The categorical connections to those constructionsare discussed.


Instruction: what is the prompt that generates the input?

Input: The contact model for the spread of disease may be viewed as a directedpercolation model on $\ZZ \times \RR$ in which the continuum axis is orientedin the direction of increasing time. Techniques from percolation have enabled afairly complete analysis of the contact model at and near its critical point.The corresponding process when the time-axis is unoriented is an undirectedpercolation model to which now standard techniques may be applied. One mayconstruct in similar vein a random-cluster model on $\ZZ \times \RR$, withassociated continuum Ising and Potts models. These models are of independentinterest, in addition to providing a path-integral representation of thequantum Ising model with transverse field. This representation may be used toobtain a bound on the entanglement of a finite set of spins in the quantumIsing model on $\ZZ$, where this entanglement is measured via the entropy ofthe reduced density matrix. The mean-field version of the quantum Ising modelgives rise to a random-cluster model on $K_n \times \RR$, thereby extending theErdos-Renyi random graph on the complete graph $K_n$.


Instruction: what is the prompt that generates the input?

Input: This paper investigates the use of evolutionary optimisation techniques toregister a template with a scene image. An error function is created to measurethe correspondence of the template to the image. The problem presented here isto optimise the horizontal, vertical and scaling parameters that register thetemplate with the scene. The Genetic Algorithm, Simulated Annealing andParticle Swarm Optimisations are compared to a Nelder-Mead Simplex optimisationwith starting points chosen in a pre-processing stage. The paper investigatesthe precision and accuracy of each method and shows that all four methodsperform favourably for image registration. SA is the most precise, GA is themost accurate. PSO is a good mix of both and the Simplex method returns localminima the most. A pre-processing stage should be investigated for theevolutionary methods in order to improve performance. Discrete versions of theoptimisation methods should be investigated to further improve computationalperformance.


Instruction: what is the prompt that generates the input?

Input: We consider the Kalman - Yakubovich - Popov (KYP) inequality \[\begin{pmatrix} X-A^* XA-C^*C & -A^*X B- C^*D\cr -B^*X A-D^* C & I- B^*X B-D^*D\end{pmatrix} \ge 0 \] for contractive operator matrices $ \begin{pmatrix}A&B\cr C &D \end{pmatrix}:\begin{pmatrix}\mathfrak{H}\cr\mathfrak{M}\end{pmatrix}\to\begin{pmatrix}\mathfrak{H}\cr\mathfrak{N} \end{pmatrix}, $where $\mathfrak{H},$ $\mathfrak{M}$, and $\mathfrak{N}$ are separable Hilbertspaces. We restrict ourselves to the solutions $X$ from the operator interval$[0, I_\mathfrak{H}]$. Several equivalent forms of KYP are obtained. Using theparametrization of the blocks of contractive operator matrices, the Kre\u{\i}nshorted operator, and the M\"obius representation of the Schur classoperator-valued function we find several equivalent forms of the KYPinequality. Properties of solutions are established and it is proved that theminimal solution of the KYP inequality satisfies the corresponding algebraicRiccati equation and can be obtained by the iterative procedure with thespecial choice of the initial point. In terms of the Kre\u{\i}n shortedoperators a necessary condition and some sufficient conditions for uniquenessof the solution are established.


Instruction: what is the prompt that generates the input?

Input: We provide a model for how Kennicutt-Schmidt (KS) laws, which describe thecorrelation between star formation rate and gas surface or volume density,depend on the molecular line chosen to trace the gas. We show that, for linesthat can be excited at low temperatures, the KS law depends on how the linecritical density compares to the median density in a galaxy's star-formingmolecular clouds. High critical density lines trace regions with similarphysical properties across galaxy types, and this produces a linear correlationbetween line luminosity and star formation rate. Low critical density linesprobe regions whose properties vary across galaxies, leading to a starformation rate that varies superlinearly with line luminosity. We show that asimple model in which molecular clouds are treated as isothermal and homogenouscan quantitatively reproduce the observed correlations between galacticluminosities in far infrared and in the CO(1->0) and HCN(1->0) lines, andnaturally explains why these correlations have different slopes. We predictthat IR-line luminosity correlations should change slope for galaxies in whichthe median density is close to the line critical density. This prediction maybe tested by observations of lines such as HCO^+(1->0) with intermediatecritical densities, or by HCN(1->0) observations of intensely star-forming highredshift galaxies with very high densities. Recent observations by Gao et al.hint at just such a change in slope. We argue that deviations from linearity inthe HCN(1->0)-IR correlation at high luminosity are consistent with theassumption of a constant star formation efficiency.


Instruction: what is the prompt that generates the input?

Input: Temperature dependent impedance spectroscopy enables the many contributionsto the dielectric and resistive properties of condensed matter to bedeconvoluted and characterized separately. We have achieved this formultiferroic epitaxial thin films of BiFeO3 (BFO) and BiMnO3 (BMO), keyexamples of materials with strong magneto-electric coupling. We demonstratethat the true film capacitance of the epitaxial layers is similar to that ofthe electrode interface, making analysis of capacitance as a function of filmthickness necessary to achieve deconvolution. We modeled non-Debye impedanceresponse using Gaussian distributions of relaxation times and reveal thatconventional resistivity measurements on multiferroic layers may be dominatedby interface effects. Thermally activated charge transport models yieldedactivation energies of 0.60 eV +- 0.05 eV (BFO) and 0.25 eV +- 0.03 eV (BMO),which is consistent with conduction dominated by oxygen vacancies (BFO) andelectron hopping (BMO). The intrinsic film dielectric constants were determinedto be 320 +- 75 (BFO) and 450 +- 100 (BMO).


Instruction: what is the prompt that generates the input?

Input: We study the long term evolution of magnetic fields generated by acollisionless relativistic $e^+e^-$ shock which is initially unmagnetized. Our2D particle-in-cell numerical simulations show that downstream of such aWeibel-mediated shock, particle distributions are close to isotropic,relativistic Maxwellians, and the magnetic turbulence is highly intermittentspatially, with the non-propagating magnetic fields forming relatively isolatedregions with transverse dimension $\sim 10-20$ skin depths. These structuresdecay in amplitude, with little sign of downstream merging. The fields startwith magnetic energy density $\sim (0.1-0.2)$ of the upstream kinetic energywithin the shock transition, but rapid downstream decay drives the fields tomuch smaller values, below $10^{-3}$ of equipartition after $10^3$ skin depths.  In an attempt to construct a theory that follows field decay to these smallervalues, we explore the hypothesis that the observed damping is a variant ofLandau damping in an unmagnetized plasma. The model is based on the small valueof the downstream magnetic energy density, which suggests that particle orbitsare only weakly perturbed from straight line motion, if the turbulence ishomogeneous. Using linear kinetic theory applied to electromagnetic fields inan isotropic, relativistic Maxwellian plasma, we find a simple analytic formfor the damping rates, $\gamma_k$, in two and three dimensions for smallamplitude, subluminous electromagnetic fields. We find that magnetic energydoes damp due to phase mixing of current carrying particles as $(\omega_pt)^{-q}$ with $q \sim 1$. (abridged)


Instruction: what is the prompt that generates the input?

Input: We investigate cooperative wireless relay networks in which the nodes canhelp each other in data transmission. We study different coding strategies inthe single-source single-destination network with many relay nodes. Given themyriad of ways in which nodes can cooperate, there is a natural routingproblem, i.e., determining an ordered set of nodes to relay the data from thesource to the destination. We find that for a given route, thedecode-and-forward strategy, which is an information theoretic cooperativecoding strategy, achieves rates significantly higher than that achievable bythe usual multi-hop coding strategy, which is a point-to-point non-cooperativecoding strategy. We construct an algorithm to find an optimal route (in termsof rate maximizing) for the decode-and-forward strategy. Since the algorithmruns in factorial time in the worst case, we propose a heuristic algorithm thatruns in polynomial time. The heuristic algorithm outputs an optimal route whenthe nodes transmit independent codewords. We implement these coding strategiesusing practical low density parity check codes to compare the performance ofthe strategies on different routes.


Instruction: what is the prompt that generates the input?

Input: Capacity improvement from transmitter and receiver cooperation isinvestigated in a two-transmitter, two-receiver network with phase fading andfull channel state information available at all terminals. The transmitterscooperate by first exchanging messages over an orthogonal transmittercooperation channel, then encoding jointly with dirty paper coding. Thereceivers cooperate by using Wyner-Ziv compress-and-forward over an analogousorthogonal receiver cooperation channel. To account for the cost ofcooperation, the allocation of network power and bandwidth among the data andcooperation channels is studied. It is shown that transmitter cooperationoutperforms receiver cooperation and improves capacity over non-cooperativetransmission under most operating conditions when the cooperation channel isstrong. However, a weak cooperation channel limits the transmitter cooperationrate; in this case receiver cooperation is more advantageous.Transmitter-and-receiver cooperation offers sizable additional capacity gainover transmitter-only cooperation at low SNR, whereas at high SNR transmittercooperation alone captures most of the cooperative capacity improvement.


Instruction: what is the prompt that generates the input?

Input: In this paper, we report on the magnetic properties of Ba2CoS3, a spin-chaincompound recently found to be the first Co2+ containing one-dimensionalsulphide to show metallic-like conductivity and negative magnetoresistance. Wecarried out an in-depth experimental investigation of the local structure ofthe cobalt atoms, and ab-initio calculations of the resulting electronicconfiguration of Co2+. From theoretical considerations, the intra-chaincoupling was predicted to be antiferromagnetic. Experimentally, severalestimates of this magnetic coupling were derived by analysing the temperaturedependence of the magnetic susceptibility. Magnetic and heat capacitymeasurements also provided evidence of a three-dimensional antiferromagneticordering, a feature indicative of a noticeable inter-chain coupling in thisquasi-1D system.


Instruction: what is the prompt that generates the input?

Input: Although the giant radiogalaxy M 87 harbors many distinct regions ofbroad-band nonthermal emission, the recently reported fast variability of TeVgamma rays from M 87 on a timescale of days strongly constrains the range ofspeculations concerning the possible sites and scenarios of particleacceleration responsible for the observed TeV emission. A natural productionsite of this radiation is the immediate vicinity of the central supermassivemass black hole (BH). Because of the low bolometric luminosity, the nucleus ofM 87 is effectively transparent for gamma rays up to energy of 10 TeV, whichmakes this source an ideal laboratory for study of particle accelerationprocesses close to the BH event horizon. We critically analyse differentpossible radiation mechanisms in this region, and argue that the observed veryhigh-energy gamma ray emission can be explained by the inverse Compton emissionof ultrarelativistic electron-positron pairs produced through the developmentof an electromagnetic cascade in the BH magnetosphere. We demonstrate, throughdetailed numerical calculations of acceleration and radiation of electrons inthe magnetospheric vacuum gap, that this ``pulsar magnetosphere like'' scenariocan satisfactorily explain the main properties of TeV gamma-ray emission of M87.


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Input: Protein-DNA complexes with loops play a fundamental role in a wide variety ofcellular processes, ranging from the regulation of DNA transcription totelomere maintenance. As ubiquitous as they are, their precise in vivoproperties and their integration into the cellular function still remainlargely unexplored. Here, we present a multilevel approach that efficientlyconnects in both directions molecular properties with cell physiology and useit to characterize the molecular properties of the looped DNA-lac repressorcomplex while functioning in vivo. The properties we uncover include thepresence of two representative conformations of the complex, the stabilizationof one conformation by DNA architectural proteins, and precise values of theunderlying twisting elastic constants and bending free energies. Incorporationof all this molecular information into gene-regulation models reveals anunprecedented versatility of looped DNA-protein complexes at shaping theproperties of gene expression.


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Input: The stability of two-dimensional (2D) layers and membranes is subject of along standing theoretical debate. According to the so called Mermin-Wagnertheorem, long wavelength fluctuations destroy the long-range order for 2Dcrystals. Similarly, 2D membranes embedded in a 3D space have a tendency to becrumpled. These dangerous fluctuations can, however, be suppressed byanharmonic coupling between bending and stretching modes making that atwo-dimensional membrane can exist but should present strong heightfluctuations. The discovery of graphene, the first truly 2D crystal and therecent experimental observation of ripples in freely hanging graphene makesthese issues especially important. Beside the academic interest, understandingthe mechanisms of stability of graphene is crucial for understanding electronictransport in this material that is attracting so much interest for its unusualDirac spectrum and electronic properties. Here we address the nature of theseheight fluctuations by means of straightforward atomistic Monte Carlosimulations based on a very accurate many-body interatomic potential forcarbon. We find that ripples spontaneously appear due to thermal fluctuationswith a size distribution peaked around 70 \AA which is compatible withexperimental findings (50-100 \AA) but not with the current understanding ofstability of flexible membranes. This unexpected result seems to be due to themultiplicity of chemical bonding in carbon.


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Input: Theory of magnetic deflagration (avalanches) in crystals of molecular magnetshas been developed. The phenomenon resembles the burning of a chemicalsubstance, with the Zeeman energy playing the role of the chemical energy.Non-destructive reversible character of magnetic deflagration, as well as thepossibility to continuously tune the flammability of the crystal by changingthe magnetic field, makes molecular magnets an attractive toy system for adetailed study of the burning process. Besides simplicity, new features, ascompared to the chemical burning, include possibility of quantum decay ofmetastable spin states and strong temperature dependence of the heat capacityand thermal conductivity. We obtain analytical and numerical solutions forcriteria of the ignition of magnetic deflagration, and compute the ignitionrate and the speed of the developed deflagration front.


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Input: AIM: We have recently developed a microscopic Monte Carlo approach to studysurface chemistry on interstellar grains and the morphology of ice mantles. Themethod is designed to eliminate the problems inherent in the rate-equationformalism to surface chemistry. Here we report the first use of this method ina chemical model of cold interstellar cloud cores that includes both gas-phaseand surface chemistry. The surface chemical network consists of a small numberof diffusive reactions that can produce molecular oxygen, water, carbondioxide, formaldehyde, methanol and assorted radicals. METHOD: The simulationis started by running a gas-phase model including accretion onto grains but nosurface chemistry or evaporation. The starting surface consists of either flator rough olivine. We introduce the surface chemistry of the three species H, Oand CO in an iterative manner using our stochastic technique. Under theconditions of the simulation, only atomic hydrogen can evaporate to asignificant extent. Although it has little effect on other gas-phase species,the evaporation of atomic hydrogen changes its gas-phase abundance, which inturn changes the flux of atomic hydrogen onto grains. The effect on the surfacechemistry is treated until convergence occurs. We neglect all non-thermaldesorptive processes. RESULTS: We determine the mantle abundances of assortedmolecules as a function of time through 2x10^5 yr. Our method also allowsdetermination of the abundance of each molecule in specific monolayers. Themantle results can be compared with observations of water, carbon dioxide,carbon monoxide, and methanol ices in the sources W33A and Elias 16. Other thana slight underproduction of mantle CO, our results are in very good agreementwith observations.


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Input: We present the results of our investigation of the intermediate-age starcluster BS 90, located in the vicinity of the HII region N 66 in the SMC,observed with HST/ACS. The high-resolution data provide a unique opportunityfor a very detailed photometric study performed on one of the rareintermediate-age rich SMC clusters. The complete set of observations iscentered on the association NGC 346 and contains almost 100,000 stars down to V~28 mag. In this study we focus on the northern part of the region, whichcovers almost the whole stellar content of BS 90. We construct its stellarsurface density profile and derive structural parameters. Isochrone fits on theCMD of the cluster results in an age of about 4.5 Gyr. The luminosity functionis constructed and the present-day mass function of BS 90 has been obtainedusing the mass-luminosity relation, derived from the isochrone models. We founda slope between -1.30 and -0.95, comparable or somewhat shallower than atypical Salpeter IMF. Examination of the radial dependence of the mass functionshows a steeper slope at larger radial distances, indicating mass segregationin the cluster. The derived half-mass relaxation time of 0.95 Gyr suggests thatthe cluster is mass segregated due to its dynamical evolution. From theisochrone model fits we derive a metallicity for BS 90 of [Fe/H]=-0.72, whichadds an important point to the age-metallicity relation of the SMC. We discussour findings on this relation in comparison to other SMC clusters.


Instruction: what is the prompt that generates the input?

Input: Heavy-quark jets are important in many of today's collider studies andsearches, yet predictions for them are subject to much larger uncertaintiesthan for light jets. This is because of strong enhancements in higher ordersfrom large logarithms, ln(p_t/m_Q). We propose a new definition of heavy-quarkjets, which is free of final-state logarithms to all orders and such that allinitial-state collinear logarithms can be resummed into the heavy-quark partondistributions. Heavy-jet spectra can then be calculated in the masslessapproximation, which is simpler than a massive calculation and reduces thetheoretical uncertainties by a factor of three. This provides the first everaccurate predictions for inclusive b- and c-jets, and the latter havesignificant discriminatory power for the intrinsic charm content of the proton.The techniques introduced here could be used to obtain heavy-flavour jetresults from existing massless next-to-leading order calculations for a widerange of processes. We also discuss the experimental applicability of ourflavoured jet definition.


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Input: High resolution optical and ultraviolet spectra of two B-type post-AsymptoticGiant Branch (post-AGB) stars in globular clusters, Barnard 29 in M 13 and ROA5701 in omega Cen, have been analysed using model atmosphere techniques. Theoptical spectra have been obtained with FEROS on the ESO 2.2-m telescope andthe 2d-Coud\'e spectrograph on the 2.7-m McDonald telescope, while theultraviolet observations are from the GHRS on the HST. Abundances of lightelements (C, N, O, Mg, Al and S) plus Fe have been determined from the opticalspectra, while the ultraviolet data provide additional Fe abundance estimatesfrom Fe III absorption lines in the 1875-1900 {\AA} wavelength region. Ageneral metal underabundance relative to young B-type stars is found for bothBarnard 29 and ROA 5701. These results are consistent with the metallicities ofthe respective clusters, as well as with previous studies of the objects. Thederived abundance patterns suggest that the stars have not undergone a gas-dustseparation, contrary to previous suggestions, although they may have evolvedfrom the AGB before the onset of the third dredge-up. However, the Feabundances derived from the HST spectra are lower than those expected from themetallicities of the respective clusters, by 0.5 dex for Barnard 29 and 0.8 dexfor ROA 5701. A similar systematic underabundance is also found for otherB-type stars in environments of known metallicity, such as the MagellanicClouds. These results indicate that the Fe III ultraviolet lines may yieldabundance values which are systematically too low by typically 0.6 dex andhence such estimates should be treated with caution.


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Input: We construct a new random probability measure on the sphere and on the unitinterval which in both cases has a Gibbs structure with the relative entropyfunctional as Hamiltonian. It satisfies a quasi-invariance formula with respectto the action of smooth diffeomorphism of the sphere and the intervalrespectively. The associated integration by parts formula is used to constructtwo classes of diffusion processes on probability measures (on the sphere orthe unit interval) by Dirichlet form methods. The first one is closely relatedto Malliavin's Brownian motion on the homeomorphism group. The second one is aprobability valued stochastic perturbation of the heat flow, whose intrinsicmetric is the quadratic Wasserstein distance. It may be regarded as thecanonical diffusion process on the Wasserstein space.


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Input: Any stretching of Ringel's non-Pappus pseudoline arrangement when projectedinto the Euclidean plane, implicitly contains a particular arrangement of ninetriangles. This arrangement has a complex constraint involving the sines of itsangles. These constraints cannot be satisfied by any projection of the initialarrangement. This is sufficient to prove Pappus's theorem. The derivation ofthe constraint is via systems of inequalities arising from the polarcoordinates of the lines. These systems are linear in r for any given theta,and their solubility can be analysed in terms of the signs of determinants. Theevaluation of the determinants is via a normal form for sums of products ofsines, giving a powerful system of trigonometric identities. The particularresult is generalized to arrangements derived from three edge connected totallycyclic directed graphs, conjectured to be sufficient for a complete analysis ofangle constraining arrangements of lines, and thus a full response to Ringel'sslope conjecture. These methods are generally applicable to the realizabilityproblem for rank 3 oriented matroids.


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Input: We report a detection of the 9.7 micrometer silicate absorption feature in adamped Lyman-alpha (DLA) system at z_{abs} = 0.524 toward AO0235+164, using theInfrared Spectrograph (IRS) onboard the Spitzer Space Telescope. The featureshows a broad shallow profile over about 8-12 micrometers in the absorber restframe and appears to be > 15 sigma significant in equivalent width. The featureis fit reasonably well by the silicate absorption profiles for laboratoryamorphous olivine or diffuse Galactic interstellar clouds. To our knowledge,this is the first indication of 9.7 micrometer silicate absorption in a DLA. Wediscuss potential implications of this finding for the nature of the dust inquasar absorbers. Although the feature is relatively shallow (tau_{9.7} =0.08-0.09), it is about 2 times deeper than expected from extrapolation of thetau_{9.7} vs. E(B-V) relation known for diffuse Galactic interstellar clouds.Further studies of the 9.7 micrometer silicate feature in quasar absorbers willopen a new window on the dust in distant galaxies.


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Input: Tseytlin has recently proposed that an action functional exists whosegradient generates to all orders in perturbation theory the RenormalizationGroup (RG) flow of the target space metric in the worldsheet sigma model. Thegradient is defined with respect to a metric on the space of coupling constantswhich is explicitly known only to leading order in perturbation theory, but atthat order is positive semi-definite, as follows from Perelman's work on theRicci flow. This gives rise to a monotonicity formula for the flow which isexpected to fail only if the beta function perturbation series fails toconverge, which can happen if curvatures or their derivatives grow large. Wetest the validity of the monotonicity formula at next-to-leading order inperturbation theory by explicitly computing the second-order terms in themetric on the space of coupling constants. At this order, this metric is foundnot to be positive semi-definite. In situations where this might spoilmonotonicity, derivatives of curvature become large enough for higher orderperturbative corrections to be significant.


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Input: SQUID magnetometry and polarised neutron reflectivity measurements have beenemployed to characterise the magnetic properties of U/Fe, U/Co and U/Gdmultilayers. The field dependence of the magnetisation was measured at 10K inmagnetic fields from -70kOe to 70kOe. A temperature dependent study of themagnetisation evolution was undertaken for a selection of U/Gd samples. PNR wascarried out in a field of 4.4kOe for U/Fe and U/Co samples (at roomtemperature) and for U/Gd samples (at 10K). Magnetic 'dead' layers of about 15Angstrom were observed for U/Fe and U/Co samples, consistent with a picture ofinterdiffused interfaces. A large reduction in the magnetic moment, constantover a wide range of Gd layer thicknesses, was found for the U/Gd system (about4 Bohr magnetons compared with 7.63 for the bulk metal). This could beunderstood on the basis of a pinning of Gd moments arising from a column-likegrowth mechanism of the Gd layers. A study of the effective anisotropy suggeststhat perpendicular magnetic anisotropy could occur in multilayers consisting ofthick U and thin Gd layers. A reduction in the Curie temperature was observedas a function of Gd layer thickness, consistent with a finite-size scalingbehaviour.


Instruction: what is the prompt that generates the input?

Input: In this paper we study a novel spin chain with nearest-neighbors interactionsdepending on the sites coordinates, which in some sense is intermediate betweenthe Heisenberg chain and the spin chains of Haldane-Shastry type. We show thatwhen the number of spins is sufficiently large both the density of sites andthe strength of the interaction between consecutive spins follow the Gaussianlaw. We develop an extension of the standard freezing trick argument thatenables us to exactly compute a certain number of eigenvalues and theircorresponding eigenfunctions. The eigenvalues thus computed are all integers,and in fact our numerical studies evidence that these are the only integereigenvalues of the chain under consideration. This fact suggests that thischain can be regarded as a finite-dimensional analog of the class ofquasi-exactly solvable Schroedinger operators, which has been extensivelystudied in the last two decades. We have applied the method of moments to studysome statistical properties of the chain's spectrum, showing in particular thatthe density of eigenvalues follows a Wigner-like law. Finally, we emphasizethat, unlike the original freezing trick, the extension thereof developed inthis paper can be applied to spin chains whose associated dynamical spin modelis only quasi-exactly solvable.


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Input: The Stanley lattice, Tamari lattice and Kreweras lattice are three remarkableorders defined on the set of Catalan objects of a given size. These latticesare ordered by inclusion: the Stanley lattice is an extension of the Tamarilattice which is an extension of the Kreweras lattice. The Stanley order can bedefined on the set of Dyck paths of size $n$ as the relation of \emph{beingabove}. Hence, intervals in the Stanley lattice are pairs of non-crossing Dyckpaths. In a former article, the second author defined a bijection $\Phi$between pairs of non-crossing Dyck paths and the realizers of triangulations(or Schnyder woods). We give a simpler description of the bijection $\Phi$.Then, we study the restriction of $\Phi$ to Tamari's and Kreweras' intervals.We prove that $\Phi$ induces a bijection between Tamari intervals and minimalrealizers. This gives a bijection between Tamari intervals and triangulations.We also prove that $\Phi$ induces a bijection between Kreweras intervals andthe (unique) realizers of stack triangulations. Thus, $\Phi$ induces abijection between Kreweras intervals and stack triangulations which are knownto be in bijection with ternary trees.


Instruction: what is the prompt that generates the input?

Input: To understand the whole set of positive and null data on theTheta+(1530)-production, we suggest the hypothesis that multiquark hadrons aremainly generated from many-quark states, which emerge either as short-termhadron fluctuations, or as hadron remnants in hard processes. This approachallows us to describe both non-observation of the Theta+ in current nullexperiments and peculiar features of its production in positive experiments.Further, we are able to propose new experiments that might be decisive for theproblem of the Theta+ existence. Distributions of the Theta+ in suchexperiments can give important information both on higher Fock components ofconventional hadrons and about structure and hadronization properties of hadronremnants produced in hard processes. We also explain that description ofmultiquark hadrons may require a modified form of the constituent quark model,with quark masses and couplings being intermediate between their values for thefamiliar constituent quarks and the current ones.


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Input: We calculate the CP averaged branching ratios and CP-violating asymmetriesfor $B_s^0 \to \eta \eta, \eta \eta^\prime$ and $\eta^\prime \eta^\prime$decays in the perturbative QCD (pQCD) approach here. The pQCD predictions forthe CP-averaged branching ratios are $Br(B_s^0 \to \eta \eta) = \left(14.2^{+18.0}_{-7.5}) \times 10^{-6}$, $Br(B_s^0 \to \eta \eta^\prime)= \left(12.4 ^{+18.2}_{-7.0}) \times 10^{-6}$, and $Br(B_s^0 \to \eta^{\prime}\eta^{\prime}) = \left (9.2^{+15.3}_{-4.9}) \times 10^{-6}$, which agree wellwith those obtained by employing the QCD factorization approach and also beconsistent with available experimental upper limits. The gluonic contributionsare small in size: less than 7% for $B_s \to \eta \eta$ and $ \eta \eta^\prime$decays, and around 18% for $B_s \to \eta' \eta'$ decay. The CP-violatingasymmetries for three decays are very small: less than 3% in magnitude.


Instruction: what is the prompt that generates the input?

Input: We investigate dynamical systems characterized by a time series of distinctsemi-stable activity patterns, as they are observed in cortical neural activitypatterns. We propose and discuss a general mechanism allowing for an adiabaticcontinuation between attractor networks and a specific adjoined transient-statenetwork, which is strictly dissipative. Dynamical systems with transient statesretain functionality when their working point is autoregulated; avoidingprolonged periods of stasis or drifting into a regime of rapid fluctuations. Weshow, within a continuous-time neural network model, that a single localupdating rule for online learning allows simultaneously (i) for informationstorage via unsupervised Hebbian-type learning, (ii) for adaptive regulation ofthe working point and (iii) for the suppression of runaway synaptic growth.Simulation results are presented; the spontaneous breaking of time-reversalsymmetry and link symmetry are discussed.


Instruction: what is the prompt that generates the input?

Input: We describe azimuth structure commonly associated with elliptic and directedflow in the context of 2D angular autocorrelations for the purpose of preciseseparation of so-called nonflow (mainly minijets) from flow. We extend theFourier-transform description of azimuth structure to include power spectra andautocorrelations related by the Wiener-Khintchine theorem. We analyze severalexamples of conventional flow analysis in that context and question therelevance of reaction plane estimation to flow analysis. We introduce the 2Dangular autocorrelation with examples from data analysis and describe asimulation exercise which demonstrates precise separation of flow and nonflowusing the 2D autocorrelation method. We show that an alternative correlationmeasure based on Pearson's normalized covariance provides a more intuitivemeasure of azimuth structure.


Instruction: what is the prompt that generates the input?

Input: Recently [J. Haro and E. Elizalde, Phys. Rev. Lett. {\bf 97}, 130401 (2006)],a Hamiltonian formulation has been introduced in order to address somelongstanding severe problems associated with the physical description of thedynamical Casimir effect at all times while the mirrors are moving. Here wepresent the complete calculation providing precise details, in particular, ofthe regularization procedure, which is decisive for the correct derivation ofphysically meaningful quantities. A basic difference when comparing with theresults previously obtained by other authors is the fact that the motion forcederived in our approach contains a reactive term --proportional to the mirrors'acceleration. This is of the essence in order to obtain particles with apositive energy all the time during the oscillation of the mirrors --whilealways satisfying the energy conservation law. A careful analysis of theinterrelations among the different results previously obtained in theliterature is then carried out. For simplicity, the specific case of a neutralscalar field in one dimension, with one or two partially transmitting mirrors(a fundamental proviso for the regularization issue) is considered in moredetail, but our general method is shown to be generalizable, without essentialproblems (Sect. 2 of this paper), to fields of any kind in two and higherdimensions.


Instruction: what is the prompt that generates the input?

Input: In the present work we compare in detail some of the major theoreticallibraries with observations, aiming at detecting weaknesses and strengths fromthe stellar population modelling point of view. We compared model predictionsand observations for broad- band colours and for high resolution spectralfeatures. Concerning the broad-band colours, we measured the stellar colourgiven by three recent sets of model atmospheres and flux distributions(Castelli& Kurucz 2003; Gustafsson et al. 2003; Brott & Hauschildt 2005), and comparedthem with a recent UBVRIJHK calibration (Worthey & Lee 2007). We found that themodels can reproduce with reasonable accuracy the stellar colours for a fairinterval in effective temperatures and gravities. The exceptions are: 1) theU-B colour, where the models are typically redder than the observations, and;2) the very cool stars in general (V-K > ~3).Concerning the high resolutionfeatures, we measured 35 spectral indices defined in the literature on threehigh resolution synthetic libraries (Coelho et al. 2005; Martins et al. 2005;Munari et al. 2005), and compared them with the observed measurements given bythree empirical libraries (Valdes et al.2004; Sanchez-Blazquez et al. 2006;Prugniel & Soubiran 2001). We found that the direct comparison between modelsand observations is not a simple task, given the uncertainties in parameterdeterminations of empirical libraries. Taking that aside, we found that ingeneral the three libraries present similar behaviours and systematicdeviations. For stars with Teff < 7000K, the library by Coelho et al. (2005) isthe one with best average performance. We detect that lists of atomic andmolecular line opacities still need improvement, specially in the blue regionof thespectrum, and for the cool stars (Teff < ~4500K).


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Input: We analyze the scaling parameter, extracted from the fidelity for twodifferent ground states, for the one-dimensional quantum Ising model in atransverse field near the critical point. It is found that, in thethermodynamic limit, the scaling parameter is singular, and the derivative ofits logarithmic function with respect to the transverse field strength islogarithmically divergent at the critical point. The scaling behavior isconfirmed numerically by performing a finite size scaling analysis for systemsof different sizes, consistent with the conformal invariance at the criticalpoint. This allows us to extract the correlation length critical exponent,which turns out to be universal in the sense that the correlation lengthcritical exponent does not depend on either the anisotropic parameter or thetransverse field strength.


Instruction: what is the prompt that generates the input?

Input: Yield design formulation for porous media subjected to flow, usingapproximate pressure field. We attempt here to use the kinematic method ofyield design in the case of a porous medium subjected to flow (with or withoutfree surface), without looking for the exact solution of the pressure field.The method proposed here is based on the use of approximate pressure fields. Inthis paper, we show how, under different conditions concerning the yieldcriterion and the velocity field, the use of such approximate fields allows toobtain a necessary condition for stability without having to find the realpressure field. Nous cherchons ici \`a utiliser la m\'ethode cin\'ematique ducalcul \`a la rupture dans le cas d'un milieu poreux soumis \`a un \'ecoulementavec ou sans surface libre sans conna\^itre la solution exacte du champ depression. La m\'ethode propos\'ee ici repose sur l'utilisation de champs depression approch\'es par d\'efaut. Nous montrerons comment sous certainesconditions portant sur le crit\`ere de r\'esistance et sur le champ de vitesseutilis\'e, l'utilisation de tels champs de pression approch\'es permetd'obtenir une condition n\'ecessaire de stabilit\'e sans avoir \`a d\'eterminerexactement l'\'ecoulement.


Instruction: what is the prompt that generates the input?

Input: Dissipation-free current transport in high-temperature superconductors is oneof the most crucial properties of this class of materials which is directlyrelated to the effective inhibition of flux line movement by defect structures.In this respect epitaxially grown thin films of YBa2Cu3O7-d (YBCO) are provingto be the strongest candidates for many widescale applications that are closeto realization. We show that the relation between different defect structuresand flux line pinning in these films exhibits universal features which areclearly displayed in a detailed analysis of the temperature-dependent behaviourof local critical currents. This allows us to identify different pinningmechanisms at different temperatures to be responsible for the found criticalcurrents. Additionally, the presence of grain boundaries with very lowmisorientation angles affects the temperature stability of the criticalcurrents which has important consequences for future applications.


Instruction: what is the prompt that generates the input?

Input: INTEGRAL monitoring of the Galactic Plane is revealing a growing number ofrecurrent X-ray transients, characterised by short outbursts with very fastrise times (~ tens of minutes) and typical durations of a few hours. Asubstantial fraction of these sources are associated with OB supergiants andhence define a new class of massive X-ray binaries, which we call SupergiantFast X-ray Transients. Characterisation of the astrophysical parameters oftheir counterparts is underway. So far, we have found a number of late O andearly B supergiants of different luminosities at a large range of distances.Nothing in their optical properties sets them apart from classical SupergiantX-ray Binaries. On the other hand, there is now rather concluding evidence thatpersistent supergiant X-ray binaries also show fast outbursts. This suggests acontinuum of behaviours between typical persistent supergiant systems andpurely transient systems, but offers very little information about the physicalcauses of the outbursts.


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Input: We continue our study of chaotic mixing and transport of passive particles ina simple model of a meandering jet flow [Prants, et al, Chaos {\bf 16}, 033117(2006)]. In the present paper we study and explain phenomenologically aconnection between dynamical, topological, and statistical properties ofchaotic mixing and transport in the model flow in terms of dynamical traps,singular zones in the phase space where particles may spend arbitrary long butfinite time [Zaslavsky, Phys. D {\bf 168--169}, 292 (2002)]. The transport ofpassive particles is described in terms of lengths and durations of zonalflights which are events between two successive changes of sign of zonalvelocity. Some peculiarities of the respective probability density functionsfor short flights are proven to be caused by the so-called rotational-islandstraps connected with the boundaries of resonant islands (including those of thevortex cores) filled with the particles moving in the same frame. Whereas, thestatistics of long flights can be explained by the influence of the so-calledballistic-islands traps filled with the particles moving from a frame to frame.


Instruction: what is the prompt that generates the input?

Input: We report on the transport and magnetic properties of hybrid trilayers andbilayers that consist of low spin-polarized Ni80Fe20 exhibiting in-plane but nouniaxial anisotropy and low-Tc Nb. We reveal a magnetoresistance effect that ispronounced. In our trilayers the magnetoresistance exhibits an increase of twoorders of magnitude when the superconducting state is reached: from theconventional normal-state values 0.6 % it goes up to 1000 % for temperaturesbelow Tc. In contrast, in the bilayers the effect is only minor since from 3%in the normal state increases only to 70 % for temperatures below Tc.Magnetization data of both the longitudinal and transverse magnetic componentsare presented. Most importantly, we present data not only for the normal stateof Nb but also in its superconducting state. Strikingly, these data show thatbelow its Tc SC the Nb interlayer under the influence of the outer Ni80Fe20layers attains a magnetization component transverse to the external field. Bycomparing the transport and magnetization data we propose a candidate mechanismthat could motivate the pronounced magnetoresistance effect observed in thetrilayers. Adequate magnetostatic coupling of the outer Ni80Fe20 layers ismotivated by stray fields that emerge naturally in their whole surface due tothe multidomain magnetic structure that they attain near coercivity. Atomicforce microscopy is employed in order to examine the possibility that suchmagnetostatic coupling could be promoted by interface roughness. Referring tothe bilayers, although out-of-plane rotation of the magnetization of the singleNi80Fe20 layer is still observed, in these structures magnetostatic couplingdoes not occur due to the absence of a second Ni80Fe20 one so that the observedmagnetoresistance peaks are only modest.


Instruction: what is the prompt that generates the input?

Input: The dynamical discrete web (DDW), introduced in recent work of Howitt andWarren, is a system of coalescing simple symmetric one-dimensional random walkswhich evolve in an extra continuous dynamical parameter s. The evolution is byindependent updating of the underlying Bernoulli variables indexed by discretespace-time that define the discrete web at any fixed s. In this paper, we studythe existence of exceptional (random) values of s where the paths of the web donot behave like usual random walks and the Hausdorff dimension of the set ofsuch exceptional s. Our results are motivated by those about exceptional timesfor dynamical percolation in high dimension by H\"aggstrom, Peres and Steif,and in dimension two by Schramm and Steif. The exceptional behavior of thewalks in DDW is rather different from the situation for dynamical random walksof Benjamini, H\"aggstrom, Peres and Steif. In particular, we prove that thereare exceptional values of s for which the walk from the origin S^s(n) haslimsup S^s(n)/\sqrt n \leq K with a nontrivial dependence of the Hausdorffdimension on K. We also discuss how these and other results extend to thedynamical Brownian web, a natural scaling limit of DDW. The scaling limit isthe focus of a paper in preparation; it was studied by Howitt and Warren and isrelated to the Brownian net of Sun and Swart.


Instruction: what is the prompt that generates the input?

Input: For positive semidefinite matrices $A$ and $B$, Ando and Zhan proved theinequalities $||| f(A)+f(B) ||| \ge ||| f(A+B) |||$ and $||| g(A)+g(B) ||| \le||| g(A+B) |||$, for any unitarily invariant norm, and for any non-negativeoperator monotone $f$ on $[0,\infty)$ with inverse function $g$. Theseinequalities have very recently been generalised to non-negative concavefunctions $f$ and non-negative convex functions $g$, by Bourin and Uchiyama,and Kosem, respectively.  In this paper we consider the related question whether the inequalities $|||f(A)-f(B) ||| \le ||| f(|A-B|) |||$, and $||| g(A)-g(B) ||| \ge ||| g(|A-B|)|||$, obtained by Ando, for operator monotone $f$ with inverse $g$, also have asimilar generalisation to non-negative concave $f$ and convex $g$. We answerexactly this question, in the negative for general matrices, and affirmativelyin the special case when $A\ge ||B||$.  In the course of this work, we introduce the novel notion of $Y$-dominatedmajorisation between the spectra of two Hermitian matrices, where $Y$ is itselfa Hermitian matrix, and prove a certain property of this relation that allowsto strengthen the results of Bourin-Uchiyama and Kosem, mentioned above.


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Input: The Hamiltonian approach to the General Relativity and the Standard Model isstudied in the context of its consistency with the Newton law, the Higgseffect, the Hubble cosmological evolution and the Cosmic Microwave Backgroundradiation physics.  The version of the Higgs potential is proposed, where its constant parameteris replaced by the dynamic zeroth Fourier harmonic of the very Higgs field. Inthis model, the extremum of the Coleman--Weinberg effective potential obtainedfrom the unit vacuum--vacuum transition amplitude immediately predicts mass ofHiggs field and removes tremendous vacuum cosmological density.  We show that the relativity principles unambiguously treat the Planck epoch,in the General Relativity, as the present-day one. It was shown that there areinitial data of the Electro-Weak epoch compatible with supposition that allparticles in the Universe are final products of decays of primordial Higgsparticles and W-, Z-vector bosons created from vacuum at the instant treated asthe "Big-Bang".


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Input: We develop distributed algorithms to allocate resources in multi-hop wirelessnetworks with the aim of minimizing total cost. In order to observe thefundamental duplexing constraint that co-located transmitters and receiverscannot operate simultaneously on the same frequency band, we first devise aspectrum allocation scheme that divides the whole spectrum into multiplesub-bands and activates conflict-free links on each sub-band. We show that theminimum number of required sub-bands grows asymptotically at a logarithmic ratewith the chromatic number of network connectivity graph. A simple distributedand asynchronous algorithm is developed to feasibly activate links on theavailable sub-bands. Given a feasible spectrum allocation, we then designnode-based distributed algorithms for optimally controlling the transmissionpowers on active links for each sub-band, jointly with traffic routes and userinput rates in response to channel states and traffic demands. We show thatunder specified conditions, the algorithms asymptotically converge to theoptimal operating point.


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Input: We propose and study a model with glassy behavior. The state space of themodel is given by all triangulations of a sphere with $n$ nodes, half of whichare red and half are blue. Red nodes want to have 5 neighbors while blue oneswant 7. Energies of nodes with different numbers of neighbors are supposed tobe positive. The dynamics is that of flipping the diagonal of two adjacenttriangles, with a temperature dependent probability. We show that this systemhas an approach to a steady state which is exponentially slow, and show thatthe stationary state is unordered. We also study the local energy landscape andshow that it has the hierarchical structure known from spin glasses. Finally,we show that the evolution can be described as that of a rarefied gas withspontaneous generation of particles and annihilating collisions.


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Input: ``Top--down'' models explain the observation of ultra high energy cosmic rays(UHECR; $E \gsim 5 \cdot 10^{19}$ eV) through the decay of very massive,long--lived ``$X$ particles''. If superparticles with masses near a TeV exist,$X$ decays also lead to a significant flux of very energetic neutralinos,assumed to be the (stable or long--lived) lightest superparticles. There is arange of energies where neutrinos get absorbed in the Earth, but neutralinoscan still traverse it. These neutralinos could in principle be detected. Wecalculate the detection rate in planned experiments such as OWL and EUSO. Forbino--like neutralinos, which have been considered previously, we finddetection rates below 1 event per Teraton of target and year in all cases;often the rates are much smaller. In contrast, if the neutralino ishiggsino--like, more than ten events per year per Teraton might be observed, ifthe mass of the $X$ particle is near its lower bound of $\sim 10^{12}$ GeV.


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Input: While ferromagnetism at relatively high temperatures is seen in dilutedmagnetic semiconductors such as Ga_(1-x)Mn_(x)As, doped semiconductors withoutmagnetic ions have not shown evidence for ferromagnetism. Using a generalizeddisordered Hubbard model designed to characterize hydrogenic centers insemiconductors, we find that such systems may also exhibit a ferromagneticground state, at least on the nanoscale. This is found most clearly in a regimeinaccessible to bulk systems, but attainable in quantum dots as well asheterostructures. We present numerical results demonstrating the occurrence ofhigh spin ground states in both lattice and positionally disordered systems. Weexamine how the magnetic phases are affected by characteristics of real dopedsemiconductors, such as positional disorder and electron-hole asymmetry.


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Input: Halo samples that have no kinematic bias have been successfully isolated byphotometric observations. We show that the near-UV (NUV) magnitude of the GALEXAll-Sky Survey can be used, together with Johnson BV magnitudes in a (NUV-V)_0vs. (B-V)_0 plot, to distinguish blue horizontal branch (BHB) from other Astars of the same B-V color for 12<V<18. In addition, we use SDSS gr magnitudesin a (NUV - r)_0 vs. (g-r)_0 plot for 14<r<18. The faint limit will be extendedby ~3 magnitudes for the GALEX Medium-Deep Survey. Attempts to use NUV inconjunction with 2MASS magnitudes and ROTSE m_r magnitudes did not proveuseful. The (NUV - V)_0 vs. (B-V)_0 plot was used to examine BHB starcandidates of varying quality near the South Galactic Pole. We conclude thatthe addition of the GALEX NUV significantly adds to the reliabilty with whichthese stars can be identified.


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Input: We present a theoretical framework for plasma turbulence in astrophysicalplasmas (solar wind, interstellar medium, galaxy clusters, accretion disks).The key assumptions are that the turbulence is anisotropic with respect to themean magnetic field and frequencies are low compared to the ion cyclotronfrequency. The energy injected at the outer scale scale has to be convertedinto heat, which ultimately cannot be done without collisions. A KINETICCASCADE develops that brings the energy to collisional scales both in space andvelocity. Its nature depends on the physics of plasma fluctuations. In each ofthe physically distinct scale ranges, the kinetic problem is systematicallyreduced to a more tractable set of equations. In the "inertial range" above theion gyroscale, the kinetic cascade splits into a cascade of Alfvenicfluctuations, which are governed by the RMHD equations at both the collisionaland collisionless scales, and a passive cascade of compressive fluctuations,which obey a linear kinetic equation along the moving field lines associatedwith the Alfvenic component. In the "dissipation range" between the ion andelectron gyroscales, there are again two cascades: the kinetic-Alfven-wave(KAW) cascade governed by two fluid-like Electron RMHD equations and a passivephase-space cascade of ion entropy fluctuations. The latter cascade brings theenergy of the inertial-range fluctuations that was damped by collisionlesswave-particle interaction at the ion gyroscale to collisional scales in thephase space and leads to ion heating. The KAW energy is similarly damped at theelectron gyroscale and converted into electron heat. Kolmogorov-style scalingrelations are derived for these cascades. Astrophysical and space-physicalapplications are discussed in detail.


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Input: The dynamics of many socioeconomic systems is determined by the decisionmaking process of agents. The decision process depends on agent'scharacteristics, such as preferences, risk aversion, behavioral biases, etc..In addition, in some systems the size of agents can be highly heterogeneousleading to very different impacts of agents on the system dynamics. The largesize of some agents poses challenging problems to agents who want to controltheir impact, either by forcing the system in a given direction or by hidingtheir intentionality. Here we consider the financial market as a model system,and we study empirically how agents strategically adjust the properties oflarge orders in order to meet their preference and minimize their impact. Wequantify this strategic behavior by detecting scaling relations of allometricnature between the variables characterizing the trading activity of differentinstitutions. We observe power law distributions in the investment timehorizon, in the number of transactions needed to execute a large order and inthe traded value exchanged by large institutions and we show that heterogeneityof agents is a key ingredient for the emergence of some aggregate propertiescharacterizing this complex system.


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Input: We propose a new concept for a very low background multi-ton liquid xenonDark Matter experiment. The detector consists of two concentric spheres and acharge readout device in the centre. Xenon between the two spheres forms aself-shield and veto device. The inner surface of the central sphere is coatedwith CsI to form an internal photocathode with minimum of 2\pi coverage for anyevent in the active volume. Photoelectrons from the CsI photocathode drifttoward the charge readout micro-structure in the centre of the detector. Bothscintillation and ionisation are measured simultaneously for backgroundrejection and 3-D event mapping. In addition to external shielding, the lowbackground is achieved by eliminating PMTs and by using low radioactivity purematerials throughout the detector. We present detailed calculations of thecharge readout system and design details. The detector is expected to probe thefull SUSY parameter space.


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Input: Aims. This work presents a new hydrodynamical algorithm to studyastrophysical detonations. A prime motivation of this development is thedescription of a carbon detonation in conditions relevant to superbursts, whichare thought to result from the propagation of a detonation front around thesurface of a neutron star in the carbon layer underlying the atmosphere.Methods. The algorithm we have developed is a finite-volume method inspired bythe original MUSCL scheme of van Leer (1979). The algorithm is of second-orderin the smooth part of the flow and avoids dimensional splitting. It is appliedto some test cases, and the time-dependent results are compared to thecorresponding steady state solution. Results. Our algorithm proves to be robustto test cases, and is considered to be reliably applicable to astrophysicaldetonations. The preliminary one-dimensional calculations we have performeddemonstrate that the carbon detonation at the surface of a neutron star is amultiscale phenomenon. The length scale of liberation of energy is $10^6$ timessmaller than the total reaction length. We show that a multi-resolutionapproach can be used to solve all the reaction lengths. This result will bevery useful in future multi-dimensional simulations. We present alsothermodynamical and composition profiles after the passage of a detonation in apure carbon or mixed carbon-iron layer, in thermodynamical conditions relevantto superbursts in pure helium accretor systems.


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Input: The large quantity and high quality of modern radio and infrared lineobservations require efficient modeling techniques to infer physical andchemical parameters such as temperature, density, and molecular abundances. Wepresent a computer program to calculate the intensities of atomic and molecularlines produced in a uniform medium, based on statistical equilibriumcalculations involving collisional and radiative processes and includingradiation from background sources. Optical depth effects are treated with anescape probability method. The program is available on the World Wide Web athttp://www.sron.rug.nl/~vdtak/radex/index.shtml . The program makes use ofmolecular data files maintained in the Leiden Atomic and Molecular Database(LAMDA), which will continue to be improved and expanded. The performance ofthe program is compared with more approximate and with more sophisticatedmethods. An Appendix provides diagnostic plots to estimate physical parametersfrom line intensity ratios of commonly observed molecules. This program shouldform an important tool in analyzing observations from current and future radioand infrared telescopes.


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Input: We propose a model of a heterogeneous glass forming liquid and compute thelow-temperature behavior of a tagged molecule moving within it. This modelexhibits stretched-exponential decay of the wavenumber-dependent, selfintermediate scattering function in the limit of long times. At temperaturesclose to the glass transition, where the heterogeneities are much larger inextent than the molecular spacing, the time dependence of the scatteringfunction crosses over from stretched-exponential decay with an index $b=1/2$ atlarge wave numbers to normal, diffusive behavior with $b = 1$ at smallwavenumbers. There is a clear separation between early-stage, cage-breaking$\beta$ relaxation and late-stage $\alpha$ relaxation. The spatialrepresentation of the scattering function exhibits an anomalously broadexponential (non-Gaussian) tail for sufficiently large values of the moleculardisplacement at all finite times.


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Input: A detailed study of the geometries that emerge by a gravitating generalizedYang monopole in even dimensions is carried out. In particular, those whichpresent black hole and cosmological horizons. This two-horizon system isthermally unstable. The process of thermalization will drive both horizons tocoalesce. This limit is what is profusely studied in this paper. It is shownthat eventhough coordinate distance shrinks to zero, physical distance doesnot. So, there is some remaining space which geometry has been computed andidentified as a generalized Nariai solution. The thermal properties of this newspacetime are then calculated. Topics, as the elliptical relation between radiiof spheres in the geometry or a discussion about whether a mass-type termshould be present in the line element or not, are also included.


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Input: The geometric constructions are elaborated on (semi) Riemannian manifolds andvector bundles provided with nonintegrable distributions defining nonlinearconnection structures induced canonically by metric tensors. Such spaces arecalled nonholonomic manifolds and described by two equivalent linearconnections also induced in unique forms by a metric tensor (the Levi Civitaand the canonical distinguished connection, d-connection). The lifts ofgeometric objects on tangent bundles are performed for certain classes ofd-connections and frame transforms when the Riemann tensor is parametrized byconstant matrix coefficients. For such configurations, the flows ofnon-stretching curves and corresponding bi-Hamilton and solitonic hierarchiesencode information about Ricci flow evolution, Einstein spaces and exactsolutions in gravity and geometric mechanics. The applied methods wereelaborated formally in Finsler geometry and allows us to develop the formalismfor generalized Riemann-Finsler and Lagrange spaces. Nevertheless, allgeometric constructions can be equivalently re-defined for the Levi Civitaconnections and holonomic frames on (semi) Riemannian manifolds.


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Input: We extend Hendriks' classification theorem and Turaev's realisation andsplitting theorems for Poincare duality complexes in dimension three to therelative case of Poincare duality pairs. The results for Poincare dualitycomplexes are recovered by restricting the results to the case of Poincareduality pairs with empty boundary. Up to oriented homotopy equivalence,three-dimensional Poincare duality pairs are classified by their fundamentaltriple consisting of the fundamental group system, the orientation characterand the image of the fundamental class under the classifying map. Using thederived module category we provide necessary and sufficient conditions for agiven triple to be realised by a three-dimensional Poincare duality pair. Theresults on classification and realisation yield splitting or decompositiontheorems for three-dimensional Poincare duality pairs, that is, conditionsunder which a given three-dimensional Poincare duality pair decomposes asinterior or boundary connected sum of two three-dimensional Poincare dualitypairs.


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Input: We critically examine issues associated with determining the fundamentalproperties of the black hole and the surrounding accretion disk in an X-raybinary based on modeling the disk X-ray continuum of the source. We base ourwork mainly on two XMM-Newton observations of GX 339-4, because they providedhigh-quality data at low energies (below 1 keV) which are critical for reliablymodeling the spectrum of the accretion disk. A key issue examined is thedetermination of the so-called "color correction factor", which is oftenempirically introduced to account for the deviation of the local disk spectrumfrom a blackbody (due to electron scattering). This factor cannot bepre-determined theoretically because it may vary with, e.g., mass accretionrate, among a number of important factors. We follow up on an earliersuggestion to estimate the color correction observationally by modeling thedisk spectrum with saturated Compton scattering. We show that the spectra canbe fitted well and the approach yields reasonable values for the colorcorrection factor. For comparison, we have also attempted to fit the spectrawith other models. We show that even the high-soft-state continuum (which isdominated by the disk emission) cannot be satisfactorily fitted bystate-of-the-art disk models. We discuss the implication of the results.


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Input: Although there is mounting observational evidence that the cosmic expansionis undergoing a late-time acceleration, the physical mechanism behind such aphenomenon is yet unknown. In this paper, we investigate a holographic darkenergy (HDE) model with interaction between the components of the dark sectorin the light of current cosmological observations. We use both the new\emph{gold} sample of 182 type Ia supernovae (SNe Ia) and the 192 SNe IaESSENCE data, the baryon acoustic oscillation measurement from the SloanDigital Sky Survey and the shift parameter from the three-year WilkinsonMicrowave Anisotropy Probe data. In agreement with previous results, we showthat these observations suggest a very weak coupling or even a noninteractingHDE. The phantom crossing behavior in the context of these scenarios is alsobriefly discussed.


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Input: Mixing is one of the basic functions which automated lab-on-chips require forthe effective management of liquid samples. In this paper we report on theworking principle, design, fabrication and experimental characterization of asoft-lithographed micromixer for microfluidic applications. The deviceeffectively mixes two liquids by means of chaotic advection obtained as animplementation of a Linked Twisted Map (LTM). In this sense it is chaotic. Theliquids are electrokinetically displaced by generating rolls through ACelectroosmosis on co-planar electrodes. The device performance has been testedon dyed DI-water for several voltages, frequencies and flow-rates, displayinggood mixing properties in the range of $10 \div 100$kHz, at low peak-to-peakvoltages ($\sim15 \div 20$ volts). Low voltage supply, small dimensions andpossibility of fabrication via standard lithographic techniques make the devicehighly integrable in lab-on-a-chip platforms.


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Input: This paper is devoted to the analysis of a second order method for recoveringthe \emph{a priori} unknown shape of an inclusion $\omega$ inside a body$\Omega$ from boundary measurement. This inverse problem - known as electricalimpedance tomography - has many important practical applications and hence hasfocussed much attention during the last years. However, to our best knowledge,no work has yet considered a second order approach for this problem. This paperaims to fill that void: we investigate the existence of second order derivativeof the state $u$ with respect to perturbations of the shape of the interface$\partial\omega$, then we choose a cost function in order to recover thegeometry of $\partial \omega$ and derive the expression of the derivativesneeded to implement the corresponding Newton method. We then investigate thestability of the process and explain why this inverse problem is severelyill-posed by proving the compactness of the Hessian at the global minimizer.


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Input: The existence of a clumpy, large-scale filamentary structure is at the basisof the current paradigm of cosmic formation and evolution of clusters. Thestar-formation history of galaxies falling into a cluster is altered as aresult of the environmental stresses. We investigate the relation betweensubstructure and properties of the galaxy population in a 30'x30' regioncentered on the massive merging cluster A2744 at z~0.3. Multi-objectspectroscopy at low resolution and BVR photometry are used to detect thepresence of substructure through a Dressler-Schectman analysis and thephotometric redshift technique, respectively. Galaxies at the same photometricredshift of the cluster are divided into red and blue according to theirdistribution in the B-R vs. R colour-magnitude diagram. We identify twolarge-scale filaments associated with A2744. Along these filaments, theblue-to-red galaxy number ratio increases together with the cluster-centricdistance but peaks slightly beyond the cluster virial radius. The filamentshost a population of bright, large (i.e. more luminous than R* for the mainbody of the cluster and with angular sizes of 13-22 $h_{70}^{-1}$ kpc) bluegalaxies that is hardly found among galaxies lying in a neighbouringlow-density environment at the same redshift of the cluster. These results canbe interpreted as a manifestation of galaxy harassment.


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Input: The past two Decadal Surveys in Astronomy and Astrophysics recommended thecompletion of a space-based interferometry mission, known today as SIMPlanetQuest, for its unique ability to detect and characterize nearby rockyplanets (Bahcall 1991, McKee & Taylor 2001), as well as contributions to abroad range of problems in astrophysics. Numerous committees of the NationalResearch Council as well as NASA Roadmaps have similarly highlighted SIM as theone technology that offers detection and characterization of rocky planetsaround nearby stars and which is technically ready. To date, SIM remains theonly program with the capability of detecting and confirming rocky planets inthe habitable zones of nearby solar-type stars. Moreover, SIM measures massesand three-dimensional orbits of habitable planets around nearby stars (within25 pc); these are the only stars for which follow-up by other techniques isfeasible, such as space-based spectroscopy, ground-based interferometry, and ofcourse TPF.


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Input: We present a hierarchical simulation approach for the dependability analysisand evaluation of a highly available commercial cache-based RAID storagesystem. The archi-tecture is complex and includes several layers ofoverlap-ping error detection and recovery mechanisms. Three ab-straction levelshave been developed to model the cache architecture, cache operations, anderror detection and recovery mechanism. The impact of faults and errorsoc-curring in the cache and in the disks is analyzed at each level of thehierarchy. A simulation submodel is associated with each abstraction level. Themodels have been devel-oped using DEPEND, a simulation-based environment forsystem-level dependability analysis, which provides facili-ties to injectfaults into a functional behavior model, to simulate error detection andrecovery mechanisms, and to evaluate quantitative measures. Several faultmodels are defined for each submodel to simulate cache component failures, diskfailures, transmission errors, and data errors in the cache memory and in thedisks. Some of the parame-ters characterizing fault injection in a givensubmodel cor-respond to probabilities evaluated from the simulation of thelower-level submodel. Based on the proposed method-ology, we evaluate andanalyze 1) the system behavior un-der a real workload and high error rate(focusing on error bursts), 2) the coverage of the error detection mechanismsimplemented in the system and the error latency distribu-tions, and 3) theaccumulation of errors in the cache and in the disks.