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alg-geom/9402007
Boundedness and $K^2$ for log surfaces
Let $\epsilon, C$ be two positive real numbers, and $\mathcal C \subset \mathbb R$ be a DCC (descending chain condition) set. Let $(X, B = \sum b_j B_j)$ denote a projective surface with an $\mathbb R$-divisor. Then (1) The class $\{X\}$ of surfaces for which there exists a divisor $B$ such that $(X,B)$ is $\epsilon$...
1994-02-09
2017-02-20
[ "alg-geom", "math.AG" ]
Valery Alexeev
alg-geom/9402008
Variation of Geometric Invariant Theory Quotients
Geometric Invariant Theory gives a method for constructing quotients for group actions on algebraic varieties which in many cases appear as moduli spaces parametrizing isomorphism classes of geometric objects (vector bundles, polarized varieties, etc.). The quotient depends on a choice of an ample linearized line bundl...
1994-02-09
2008-02-03
[ "alg-geom", "math.AG" ]
Igor V. Dolgachev and Yi Hu
alg-geom/9402006
On surfaces in P^4 and 3-folds in P^5
This is a survey on the classification of smooth surfaces in P^4 and smooth 3-folds in P^5. We recall the corresponding results arising from adjunction theory and explain how to construct examples via syzygies. We discuss some examples in detail and list all families of smooth non-general type surfaces in P^4 and 3-fol...
1994-02-08
2008-02-03
[ "alg-geom", "math.AG" ]
Wolfram Decker and Sorin Popescu
alg-geom/9402005
The Tangent Space at a Special Symplectic Instanton Bundle on $P_{2n+1}$
Mathematical instanton bundles on $ P_3$ have their analogues in rank--$2n$ instanton bundles on odd dimensional projective spaces $ P_{2n+1}$. The families of special instanton bundles on these spaces generalize the special 'tHooft bundles on $ P_3$. We prove that for a special symplectic instanton bundle $ E$ on $ P_...
1994-02-07
2016-08-14
[ "alg-geom", "math.AG" ]
Giorgio Ottaviani and G\"unther Trautmann
alg-geom/9402004
Boundedness theorem for Fano log-threefolds
The main purpose of this article is to prove that the family of all Fano threefolds with log-terminal singularities with bounded index is bounded.
1994-02-06
2008-02-03
[ "alg-geom", "math.AG" ]
A. Borisov
alg-geom/9402003
The combinatorics of the Verlinde formulas
A residue formula is given for the Verlinde formula, which allows one to calculate its coefficients as a polynomial in the level and connects it to the Riemann-Roch formula on the moduli space of vector bundles on a curve.
1994-02-04
2008-02-03
[ "alg-geom", "hep-th", "math.AG" ]
Andras Szenes
alg-geom/9402002
Dual Cones and Mirror Symmetry for Generalized Calabi-Yau Manifolds
We introduce a special class of convex rational polyhedral cones which allows to construct generalized Calabi-Yau varieties of dimension $(d + 2(r-1))$, where $r$ is a positive integer and d is the dimension of critical string vacua with central chatge $c = 3d$. It is conjectured that the natural combinatorial duality ...
1994-02-03
2008-02-03
[ "alg-geom", "math.AG" ]
Victor V. Batyrev and Lev A. Borisov
alg-geom/9402001
The theta divisior of the bidegree (2,2) threefold in ${\bf P}^{2} \times {\bf P}^{2}$
Let T be a general bidegree (2,2) divisor in the product of two projective planes. Recently A.Verra proved that the existence of two conic bundle structures (c.b.s.) on T implies a new counterexample to the Torelli theorem for Prym varieties. Let J(T) be the jacobian of T. In this paper we prove that any of the two c.b...
1994-02-03
2008-02-03
[ "alg-geom", "math.AG" ]
Atanas Iliev
alg-geom/9401010
Diagram Method for 3-Folds and its Application to Kahler Cone and Picard Number of Calabi-Yau 3-Folds, I. with Appendix by Vyacheslav V. Shokurov: "Anticanonical boundedness for curves"
We prove the general diagram method theorem valid for the quite large class of 3-folds with Q-factorial singularities (see Basic Theorem 1.3.2 and also Theorem 2.2.6). This gives the generalization of our results about Fano 3-folds with Q-factorial terminal singularities (Preprint alg-geom/9311007). As an application...
1994-01-31
2008-02-03
[ "alg-geom", "math.AG" ]
Viacheslav V. Nikulin
alg-geom/9401009
The Connectedness of Space Curve Invariants
It is a result of Gruson and Peskine that the invariants of a set points in $\ptwo$ in general position are connected. Associated to a space curve there are sequences of invariants which generalize the invariants of points in $\ptwo$. The main result of this paper is to show that the invariants of reduced, irreducible,...
1994-01-28
2008-02-03
[ "alg-geom", "math.AG" ]
Michele Cook
alg-geom/9401006
A common generalization of the Fr\"olicher-Nijenhuis bracket and the Schouten bracket for symmetry multi vector fields
There is a canonical mapping from the space of sections of the bundle $\wedge T^\ast M\otimes ST\ M$ to $\Omega(T^\ast M ; T(T^\ast M))$. It is shown that this is a homomorphism on $\Omega(M;TM) for the Fr\"olicher-Nijenhuis brackets, and also on $\Gamma(ST\ M)$ for the Schouten bracket of symmetric multi vector fields...
1994-01-25
2008-02-03
[ "alg-geom", "hep-th", "math.AG" ]
M. Dubois-Violette, P.W. Michor
alg-geom/9401007
A blow-up construction and graph coloring
Given a graph G (or more generally a matroid embedded in a projective space), we construct a sequence of varieties whose geometry encodes combinatorial information about G. For example, the chromatic polynomial of G (giving at each m>0 the number of colorings of G with m colors, such that no adjacent vertices are assig...
1994-01-25
2012-04-10
[ "alg-geom", "math.AG" ]
Paolo Aluffi
alg-geom/9401008
Stable triples, equivariant bundles and dimensional reduction
This is a resubmission of preprint 9401008 , which has some TeXnical errors introduced by the "reform" procedure (designed to avoid precisely these problems!). The original can be formatted by editing out the messages "%% following line cannot be broken..." at line 1674. This problem has been corrected in the current v...
1994-01-25
2008-02-03
[ "alg-geom", "math.AG" ]
Steven B. Bradlow and Oscar Garcia-Prada
alg-geom/9401005
Stable cohomology of the mapping class group with symplectic coefficients and of the universal Abel-Jacobi map
This replacement corrects statement and proof of the main result. Also, a section on the universal Abel-Jacobi map has been added.
1994-01-24
2008-02-03
[ "alg-geom", "math.AG" ]
Eduard Looijenga
alg-geom/9401004
Matrix identities connected with the jacobian conjecture
We give necessary and sufficient conditions, in the form of matrix identities, for a polynomial f in C[X,Y] to be a component of a polynomial automorphism of C^2 and to be a component of a Keller polynomial mapping of C^2, respectively ((f,g) is a Keller polynomial mapping iff Jac(f,g) = 1).
1994-01-21
2008-02-03
[ "alg-geom", "math.AG" ]
Tadeusz Krasin\'nski
alg-geom/9401003
The Fundamental Group of Some Siegel Modular Threefolds
Let A be the moduli space of (1,p)-polarised abelian surfaces with a level structure, for p an odd prime. Let X be a desingularisation of any algebraic compactification of A. Then X is simply-connected.
1994-01-18
2008-02-03
[ "alg-geom", "math.AG" ]
K. Hulek and G.K. Sankaran
alg-geom/9401002
Holomorphic functions on an algebraic group invariant under a Zariski-dense subgroup
Let G be complex linear-algebraic group, H a subgroup, which is dense in G in the Zariski-topology. Assume that G/[G,G] is reductive and furthermore that (1) G is solvable, or (2) the semisimple elements in G'=[G,G] are dense. Then every H-invariant holomorphic function on G is constant. If G=G', furthermore every H-in...
1994-01-16
2008-02-03
[ "alg-geom", "math.AG" ]
Joerg Winkelmann
alg-geom/9401001
Binomial Ideals
We investigate the structure of ideals generated by binomials (polynomials with at most two terms) and the schemes and varieties associated to them. The class of binomial ideals contains many classical examples from algebraic geometry, and it has numerous applications within and beyond pure mathematics. The ideals defi...
1994-01-11
2008-02-03
[ "alg-geom", "math.AC", "math.AG" ]
David Eisenbud and Bernd Sturmfels
astro-ph/9412097
Large-angle Polarization of the Cosmic Microwave Background Radiation and Reionization
We discuss the effect of matter reionization on the large-angular-scale anisotropy and polarization of the cosmic microwave background radiation (CMBR) in the standard CDM model. We separate three cases in which the anisotropy is induced by pure scalar, pure tensor, and mixed metric perturbations respectively. It is fo...
1994-12-31
2009-10-22
[ "astro-ph" ]
Ka Lok Ng & Kin-Wang Ng, 19 pages, latex, 10 figures, available upon request
astro-ph/9412098
Gamma-Ray Bursts and Binary Neutron Star Mergers
Neutron star binaries, such as the one observed in the famous binary pulsar PSR 1916+13, end their life in a catastrophic merge event (denoted here NS$^2$M). The merger releases $\approx 5 \cdot 10^{53}$ergs, mostly as neutrinos and gravitational radiation. A small fraction of this energy suffices to power $\gamma$-ray...
1994-12-31
2009-09-25
[ "astro-ph" ]
Tsvi Piran
astro-ph/9412096
Cosmic confusion
We propose to minimise the cosmic confusion between Gaussian and non Gaussian theories by investigating the structure in the m's for each multipole of the cosmic radiation temperature anisotropies. We prove that Gaussian theories are (nearly) the only theories which treat all the m's equally. Hence we introduce a set o...
1994-12-30
2009-10-22
[ "astro-ph" ]
J.C.R.Magueijo
astro-ph/9412095
Galaxy Dynamics Predictions in the Nonsymmetric Gravitational Theory
In the weak field approximation, the nonsymmetric gravitational theory has, in addition to the Newtonian gravitational potential, a Yukawa potential produced by the exchange of a spin $1^+$ boson between fermions. If the range $r_0$ is of order $30$ kpc, then the potential due to the interaction of known neutrinos in t...
1994-12-28
2015-06-24
[ "astro-ph" ]
J. W. Moffat
astro-ph/9412094
Big-Bang Nucleosynthesis as a Probe of the Geometry of Superspace
We study the effect from a general ultralocal supermetric on primordial nucleosynthesis for Friedmann-Robertson-Walker Cosmology. The parameter $\lambda$ of the supermetric changes the effective number of degrees of freedom, $g_*$, which modifies the Friedmann equation. This modification produces variations in the prod...
1994-12-28
2010-11-01
[ "astro-ph", "gr-qc" ]
A. Llorente and J. Perez-Mercader
astro-ph/9412092
Similarities Between the Inner Solar System and the Planetary System of PSR B1257+12
We call attention to the surprising similarity between the newly discovered planetary system around PSR B1257+12 and the inner solar system. The similarity is in the ratios of the orbital radii and the masses of the three planets.
1994-12-27
2009-10-22
[ "astro-ph" ]
Tsevi Mazeh and Itzhak Goldman
astro-ph/9412093
The z=0.8596 Damped Lyman Alpha Absorbing Galaxy Toward PKS 0454+039
We present {\it Hubble Space Telescope} and ground--based data on the $z_{abs}=0.8596$ metal line absorption system along the line of sight to PKS 0454+0356. The system is a moderate redshift damped Lyman alpha system, with ${\rm N(HI)}=(5.7\pm0.3)\times10^{20}$~cm$^{-2}$ as measured from the {\it Faint Object Spectrog...
1994-12-27
2009-10-22
[ "astro-ph" ]
C. Steidel, D. Bowen, J. C. Blades, and M. Dickinson
astro-ph/9412091
Very High Energy Gamma Rays from PSR1706-44
We have obtained evidence of gamma-ray emission above 1 TeV from PSR1706-44, using a ground-based telescope of the atmospheric \v{C}erenkov imaging type located near Woomera, South Australia. This object, a $\gamma$-ray source discovered by the COS B satellite (2CG342-02), was identified with the radio pulsar through t...
1994-12-27
2011-04-04
[ "astro-ph" ]
T. Kifune, et al, CANGAROO Collaboration
astro-ph/9412090
Limits on the global Hubble constant and the age of the universe
While the recent discovery of the Cepheid variables in the Virgo cluster galaxies puts additional support for the Hubble constant $H_0 \sim 80$km/sec/Mpc, a relatively lower value $H_0 \sim 50$km/sec/Mpc is suggested by other distance indicators based on the Sunyaev-Zel'dovich effect and the gravitational lens which pr...
1994-12-26
2017-02-01
[ "astro-ph" ]
Y. Suto, T. Suginohara, and Y. Inagaki
astro-ph/9412088
An analytic model for the gravitational clustering of dark matter haloes
We develop a simple analytic model for the gravitational clustering of dark haloes. The statistical properties of dark haloes are determined from the initial density field (assumed to be Gaussian) through an extension of the Press-Schechter formalism. Gravitational clustering is treated by a spherical model which descr...
1994-12-22
2007-05-23
[ "astro-ph" ]
H. J. Mo and S. D. M. White
astro-ph/9412087
Predicting Big Bang Deuterium
We present new upper and lower bounds to the primordial abundances of deuterium and helium-3 based on observational data from the solar system and the interstellar medium. Independent of any model for the primordial production of the elements we find (at the 95\% C.L.): $1.5 \times 10^{-5} \le (D/H)_P \le 10.0 \times 1...
1994-12-22
2009-10-22
[ "astro-ph", "hep-ph" ]
N. Hata, R.J. Scherrer, G. Steigman, D. Thomas and T.P. Walker
astro-ph/9412086
Interaction of the Loop I Supershell with the Local Hot Bubble
A soft X-ray shadow has been discovered on the periphery of the Loop I supershell in the ROSAT All Sky Survey. The distance, size, geometry and spectral data indicate that it is cast by an annular volume of dense neutral matter which has formed in the collision of the Loop I superbubble and the Local Hot Bubble. This i...
1994-12-22
2007-05-23
[ "astro-ph" ]
Roland J. Egger & Bernd Aschenbach, MPE Garching, GERMANY
astro-ph/9412082
On the measurement of the Hubble constant in a local low-density universe
Astrophysical observations indicate that the ``Local Universe" has a relatively lower matter density ($\Omega_0$) than the predictions of the standard inflation cosmology and the large-scale motions of galaxies which provide a mean mass density to be very close to unity. In such a local underdense region the Hubble exp...
1994-12-21
2016-08-30
[ "astro-ph" ]
Xiang-Ping Wu, Zugan Deng, Zhenlong Zou, Li-Zhi Fang and Bo Qin
astro-ph/9412084
R-Band Imaging of Fields Around 1<z<2 Radiogalaxies
We have taken deep $R$-band images of fields around five radiogalaxies: 0956+47, 1217+36, 3C256, 3C324 and 3C294 with $1<z<2$ . 0956+47 is found to show a double nucleus. Our data on 1217+36 suggest the revision of its classification as a radiogalaxy. We found a statistically significant excess of bright ($19.5<R<22$) ...
1994-12-21
2009-10-22
[ "astro-ph" ]
N.Benitez, E.Martinez-Gonzalez, J.I. Gonzalez-Serrano & L. Cayon
astro-ph/9412085
Thermal Comptonization in Mildly Relativistic Pair Plasmas
We use a Monte Carlo simulation to calculate the spectra of mildly relativistic thermal plasmas in pair balance. We use the exact integral expression for the electron-positron thermal annihilation spectrum, and provide accurate expressions for the Gaunt factors of electron-ion, electron-electron, and electron-positron ...
1994-12-21
2009-10-22
[ "astro-ph" ]
J. G. Skibo, C. D. Dermer, R. Ramaty and J. M. McKinley
astro-ph/9412083
The Eddington Limit and Soft Gamma Repeaters
Observed intensities and inferred distances of soft gamma repeaters imply luminosities in excess of the nominal (electron-scattering opacity) Eddington limit by four to six orders of magnitude. I review the physical basis of this limit. Accretional luminosities may exceed it if energy is hydrodynamically coupled from a...
1994-12-21
2007-05-23
[ "astro-ph" ]
J. I. Katz
astro-ph/9412071
BETA PICTORIS : Evidence of light variations
We have analyzed Beta Pictoris photometric measurements obtained from La Silla by the Geneva Observatory from 1975 to 1992. These data show evidence of variations in the brightness of the star, with no color dependency. Here, we demonstrate that the light variations are present on long as well as on short time scales. ...
1994-12-20
2011-05-23
[ "astro-ph" ]
A. Lecavelier des Etangs, M. Deleuil, A. Vidal-Madjar et al
astro-ph/9412076
Small Deviations from the R^1/4 Law, the Fundamental Plane, and Phase Densities of Elliptical Galaxies
The light profiles of elliptical (E) galaxies are known to display small systematic deviations (0.1-0.2 mag.) from the R^1/4 law. In this paper we show that the senses and amplitudes of these departures can be naturally accounted for by a simple distribution function constructed on the basis of statistical mechanics of...
1994-12-20
2009-07-22
[ "astro-ph" ]
Jens Hjorth and Jes Madsen
astro-ph/9412081
On The Validity of the Streaming Model for the Redshift-Space Correlation Function in the Linear Regime
The relation between the galaxy correlation function in real and redshift-space is derived in the linear regime by an appropriate averaging of the joint probability distribution of density and velocity. The derivation recovers the familiar linear theory result on large scales but has the advantage of clearly revealing ...
1994-12-20
2009-10-22
[ "astro-ph" ]
Karl B. Fisher (Institute for Advanced Study)
astro-ph/9412079
Cosmological Perturbations from Cosmic Strings
Some aspects of the theory of cosmological perturbations from cosmic strings and other topological defects are outlined, with particular reference to a simple example: a spatially flat CDM-dominated universe. The conserved energy-momentum pseudo-tensor is introduced, and the equation for the density perturbation derive...
1994-12-20
2010-11-01
[ "astro-ph" ]
Mark Hindmarsh
astro-ph/9412080
The Sloan Digital Sky Survey
We summarize the plans for and the current status of the Sloan Digital Sky Survey, a digital imaging and spectroscopic survey of $\pi$ steradians in the northern Galactic cap. The CCD photometric survey will produce images in five bands to limiting magnitudes of order 23. The spectroscopic survey will obtain redshifts ...
1994-12-20
2007-05-23
[ "astro-ph" ]
James E. Gunn and David H. Weinberg
astro-ph/9412072
Substructures and Density Profiles of Clusters in Models of Galaxy Formation
In this paper we investigate, using high resolution N-body simulations, the density profiles and the morphologies of galaxy clusters in seven models of structure formation. We show that these properties of clusters are closely related to the occurrence of a significant merging event in the recent past. The seven models...
1994-12-20
2015-06-24
[ "astro-ph" ]
Y.P. Jing, H.J. Mo, G. Boerner, L.Z. Fang
astro-ph/9412075
Optimized Lagrangian Approximations for Modelling Large--Scale Structure at Non--Linear Stages
Approximations to the exact solutions for gravitational instability in the expanding Universe are extremely useful for understanding the evolution of large--scale structure. We report on a series of tests of Newtonian Lagrangian perturbation schemes using N--body simulations for various power--spectra with scale--indep...
1994-12-20
2007-05-23
[ "astro-ph" ]
T. Buchert, A.L. Melott, A.G. Weiss
astro-ph/9412070
Generation of Density Perturbations by Primordial Magnetic Fields
We study the generation and evolution of density perturbations and peculiar velocities due to primordial magnetic fields. We assume that a random magnetic field was present before recombination and follow the field's effect on the baryon fluid starting at recombination. We find that magnetic fields generate growing den...
1994-12-20
2009-10-22
[ "astro-ph" ]
Eun-jin Kim, Angela Olinto, and Robert Rosner
astro-ph/9412077
K Band Microlensing of the Inner Galaxy
Microlensing searches toward the inner galaxy $(|l|,|b|\leq 22.\hskip-2pt'5)$ have several major advantages. First, the event rate is strongly dominated by bulge-bulge lensing events where both the source and lens lie in the bulge. Second, these bulge-bulge events have very short time scales $t_e\sim 2\,$days and are t...
1994-12-20
2009-10-22
[ "astro-ph" ]
Andrew Gould
astro-ph/9412078
Dynamics and Interactions of Binaries and Neutron Stars in Globular Clusters
We model the dynamics of test binaries in isotropic, multi-mass models of galactic globular clusters. The evolution of binary orbits through the cluster potentials is modeled, including second order diffusion terms, and probabilities for close encounters with field stars are calculated. We carry out Monte Carlo simulat...
1994-12-20
2008-11-26
[ "astro-ph" ]
Steinn Sigurdsson and E.S. Phinney
astro-ph/9412074
High-Resolution Imaging of the Gravitational Lens Candidate 1208+1011 with the Nordic Optical Telescope
The large-redshift (z=3.8) quasar 1208+1011 has recently been discovered to be a gravitational lens candidate with a separation of 0.47" between the two imaged components (A and B). NOT (Nordic Optical Telescope) and HST (Hubble Space Telescope) studies from 1992 probing primarily the continuum light show that the ampl...
1994-12-20
2011-05-23
[ "astro-ph" ]
Jens Hjorth, Frank Grundahl, Kari Nilsson and Leif Festin
astro-ph/9412073
The Connection between X-ray- and Radio-Selected BL Lacertae Objects
We explain the properties of X-ray selected BL Lacertae objects, under the assumption that they constitute the small minority of the BL Lac population with energy cutoff located in the UV/X-ray band, as suggested by their multifrequency spectra. In particular, we derive their X-ray luminosity function, log N-log S, and...
1994-12-20
2009-10-22
[ "astro-ph" ]
Paolo Padovani and Paolo Giommi
astro-ph/9412069
Chemical Evolution of the Galactic Disk and Bulge
Invited Review at IAU Symp 164 on Stellar Populations. The Milky Way Galaxy offers a unique opportunity for testing theories of galaxy formation and evolution. The study of the spatial distribution, kinematics and chemical abundances of stars in the Milky Way Galaxy allows one to address specific questions pertinent to...
1994-12-19
2009-10-22
[ "astro-ph" ]
Rosemary F.G. Wyse (JHU and Ucb)
astro-ph/9412066
Cosmogony of Generic Structures
The problem of formation of generic structures in the Universe is addressed, whereby first the kinematics of inertial continua for coherent initial data is considered. The generalization to self--gravitating continua is outlined focused on the classification problem of singularities and metamorphoses arising in the den...
1994-12-19
2007-05-23
[ "astro-ph" ]
T. Buchert
astro-ph/9412067
Axisymmetric galaxy models wth central BHs, with an application to M32
The contour integral method of Hunter & Qian is applied to axisymmetric galaxy models in which the distribution function (DF) is of the form f=f(E,L_z), where E and L_z are the classical integrals of motion in an axisymmetric potential. A practical way to construct the unique even part of the DF for such systems is pre...
1994-12-19
2015-06-24
[ "astro-ph" ]
E.E. Qian, P.T. de Zeeuw, R.P. van der Marel, C. Hunter
astro-ph/9412065
On the preferred length scale in the anisotropy field of extragalactic IRAS sources
We investigate the existence and meaning of a preferred length in the large-scale distribution of 60-micron IRAS sources applying three tests to the 2-dimensional distribution on the celestial sphere, involving respectively the rms fluctuation and the correlation function of the source number density, and the peak numb...
1994-12-19
2011-05-23
[ "astro-ph" ]
R. Fabbri, V. Natale
astro-ph/9412068
Massive Neutrinos and Galaxy Formation
We report the most recent results from high-resolution numerical simulations of structure formation in two flat cold+hot dark matter models with neutrino mass densities $\onu=0.2$ and 0.3. We find that structure forms too late in all CDM+HDM models with $\onu>0.2$ to account for the amount of dense neutral gas in high-...
1994-12-19
2009-10-22
[ "astro-ph" ]
Chung-Pei Ma
astro-ph/9412064
A method for extracting maximum resolution power spectra from microwave sky maps
A method for extracting maximal resolution power spectra from microwave sky maps is presented and applied to the 2 year COBE data, yielding a power spectrum that is consistent with a standard n=1, Q=20 micro-Kelvin model. By using weight functions that fall off smoothly near the galactic cut, it is found that the spect...
1994-12-18
2015-06-24
[ "astro-ph" ]
Max Tegmark
astro-ph/9412062
Constraints onOmega from the IRAS Redshift Surveys
We measure the anisotropy of the redshift-space power spectrum in the 1.2-Jy and QDOT redshift surveys of IRAS-selected galaxies. On large scales, this anisotropy is caused by coherent peculiar motions, and gravitational instability theory predicts a distortion of the power spectrum that depends only on the ratio $\bet...
1994-12-17
2015-06-24
[ "astro-ph" ]
Shaun Cole, Karl B. Fisher and David H. Weinberg
astro-ph/9412063
Probes of the Early Universe
One of the main challenges in cosmology is to quantify how small density fluctuations at the recombination epoch z around 1000 evolved into the galaxies and the large-scale structure we observe in the universe today. This thesis discusses ways of probing the intermediate epoch, focusing on the thermal history. The main...
1994-12-17
2008-02-03
[ "astro-ph" ]
Max Tegmark
astro-ph/9412061
Robust Morphological Measures for Large-Scale Structure
A complete family of statistical descriptors for the morphology of large--scale structure based on Minkowski--Functionals is presented. These robust and significant measures can be used to characterize the local and global morphology of spatial patterns formed by a coverage of point sets which represent galaxy samples....
1994-12-17
2007-05-23
[ "astro-ph" ]
T. Buchert
astro-ph/9412055
Electromagnetic Cascade in the Early Universe and its Application to the Big-Bang Nucleosynthesis
We investigate the electromagnetic cascade initiated by injection of very high energy photons in the early Universe and calculate the cascade spectrum by solving a set of Boltzmann equations numerically. In the calculation we take account of Compton scattering off the background electrons and pair creation off the back...
1994-12-16
2009-10-22
[ "astro-ph", "hep-ph" ]
M.Kawasaki and T. Moroi
astro-ph/9412057
Nuclear bars and blue nuclei within barred spiral galaxies
Multicolour near IR photometry for a sample of 32 large barred spiral galaxies is presented. By applying ellipse fitting techniques, we identify significant isophote twists with respect to the primary bar axis in the nuclear regions of $\sim$70 \%\ of the sample. These twists are identified in galaxies as late as SBbc ...
1994-12-16
2015-06-24
[ "astro-ph" ]
M. Shaw, D. Axon, R. Probst, I. Gatley
astro-ph/9412060
DUMAND-II (Deep Underwater Muon and Neutrino Detector) PROGRESS Report
The DUMAND-II detector will search for astronomical sources of high energy neutrinos. Successful deployment of the basic infrastructure, including the shore cable, the underwater junction box, and an environmental module was accomplished in December, 1993. One optical module string was also deployed and operated, loggi...
1994-12-16
2009-10-22
[ "astro-ph", "hep-ex" ]
Kenneth K. Young (Dept. of Physics, Univ. of Washington, Seattle, WA 98195 USA, for The DUMAND Collaboration)
astro-ph/9412058
On the Origin of Low-Surface-Brightness Galaxies
We reconsider the problem of the origin of Low-Surface-Brightness (LSB) galaxies within the standard Cold Dark Matter (CDM) cosmological model ($\Omega =1, h=0.5$). Taking into account the effect of substructure on the collapse times of low overdensity peaks, we show that the abundance of these peaks is larger than pre...
1994-12-16
2007-05-23
[ "astro-ph" ]
V. Antonuccio-Delogu
astro-ph/9412059
The Production of Strings and Monopoles at Phase Transitions
We shall show that the density of defects produced at a second-order phase transition is determined by the correlation length of the fields. This is true both for defects appearing in the Ginzburg regime and for defects produced at a quench, when the Ginzburg regime is irrelevant. (Invited lectures given by R.J.R. to...
1994-12-16
2007-05-23
[ "astro-ph" ]
R.J. Rivers and T.S.Evans
astro-ph/9412056
Radiation constraints from cosmic strings
We show that it is possible to evolve a network of global strings numerically including the effects of radiative backreaction, using the renormalised equations for the Kalb-Ramond action. We calculate radiative corrections to the equations of motion and deduce the effect on a network of global strings. We also discuss ...
1994-12-16
2009-10-22
[ "astro-ph", "hep-ph" ]
R.A.Battye, E.P.S.Shellard
astro-ph/9412052
Are There Top Quarks In Superdense Hybrid Stars?
It is examined whether primordial top quarks from the Big Bang could survive under natural conditions till present days. Hybrid quark-neutron stars, with dense enough core to maintain the existence of top quarks, is discussed. In this paper only final states are investigated. Zero temperature quark-lepton matter is mod...
1994-12-15
2009-09-25
[ "astro-ph" ]
M. Prisznyak, B. Lukacs and P. Levai (CRIP, RMKI, Bp. Hungary)
astro-ph/9412053
Monopole Annihilation and Highest Energy Cosmic Rays
Cosmic rays with energies exceeding $10^{20}\eV$ have been detected. The origin of these highest energy cosmic rays remains unknown. Established astrophysical acceleration mechanisms encounter severe difficulties in accelerating particles to these energies. Alternative scenarios where these particles are created by the...
1994-12-15
2009-10-22
[ "astro-ph" ]
P.Bhattacharjee and G.Sigl
astro-ph/9412050
Statistics of Cosmological Inhomogeneities
This contribution to the Proceedings is based on the talk given at the Conference on Birth of the Universe and Fundamental Physics, Rome, May 18-21, 1994. Some selected topics of the subject are reviewed: Models of Primordial Fluctuations; Reconstruction of the Cosmological Density Probability Distribution Function (PD...
1994-12-15
2009-10-22
[ "astro-ph" ]
Lev Kofman (IfA, U of Hawaii)
astro-ph/9412054
Cosmic Fluctuations and Dark Matter from Scalar Field Oscillations
Scale-invariant fluctuations and cold dark matter could originate from two different modes of a single scalar field, fluctuations from massless Goldstone oscillations and matter from massive Higgs modes. Matching the fluctuations and dark matter density observed requires a heavy scale ($\phi_0\approx 10^{16}$GeV) for t...
1994-12-15
2009-10-22
[ "astro-ph", "gr-qc" ]
Craig J. Hogan (University of Washington)
astro-ph/9412051
Cluster mass estimates from weak lensing
The reliability of cluster lens reconstruction techniques based on weak lensing is studied in terms of the accuracy of their reproduction of the total cluster mass as a function of distance from the cluster center. To do so, a variety of reconstruction algorithms is applied to synthetic lensing data created using a sam...
1994-12-15
2011-05-23
[ "astro-ph" ]
Matthias Bartelmann
astro-ph/9412047
On Stationary, Self-Similar Distributions of a Collisionless, Self-Gravitating, Gas
We study systematically stationary solutions to the coupled Vlasov and Poisson equations which have `self-similar' or scaling symmetry in phase space. In particular, we find analytically {\it all} spherically symmetric distribution functions where the mass density and gravitational potential are strict power laws in $r...
1994-12-14
2015-06-24
[ "astro-ph" ]
R. N. Henriksen, Lawrence M. Widrow (Queen's University)
astro-ph/9412048
Fast Radiative Shocks in Dense Media. III. Properties of the Emission
Evolution of fast, radiative shocks in high density medium is presented. Ionizing spectra and approximate broad band light curves of the shocked gas are calculated. Emergent shock spectra, as seen by a distant observer, are obtained from photoionization models. The emergent spectra have a power-law shape $F_{\nu}\propt...
1994-12-14
2015-06-24
[ "astro-ph" ]
Tomasz Plewa (Warsaw University Observatory)
astro-ph/9412045
Note on a Comment by Edward L. Wright
Recently Wright (1994, preprint) has criticized a paper of ours on the quasi-steady state cosmology (Hoyle et al. 1994, {\em M.N.R.A.S.,} {\bf 267,} 1007) arguing that the results from a radio source survey by Allington-Smith (1982 {\em M.N.R.A.S.,} {\bf 199,} 611) show that our model published in the paper referenced ...
1994-12-14
2007-05-23
[ "astro-ph" ]
F. Hoyle, G. Burbidge and J.V. Narlikar
astro-ph/9412049
Dark Matter -- Personal View
Traditional evidence for large amount of dark matter is based on dynamical consideration for systems with $ t_{dyn} \gg t_{obs} $. Recent observational and theoretical developments in gravitational lensing offer a much more robust determination of the mass distribution in some galaxies and their clusters, with the prec...
1994-12-14
2009-10-22
[ "astro-ph" ]
Bohdan Paczy\'nski
astro-ph/9412046
Quantum Aspects of Gravity
Contributions from the G1 Working Group at the APS Summer Study on Particle and Nuclear Astrophysics and Cosmology in the Next Millennium, Snowmass, Colorado, June 29 - July 14, 1994. V. Frolov and L. Thorlacius: Quantum Aspects of Gravity. S.B. Giddings and L. Thorlacius: Introduction to the Information Problem. ...
1994-12-14
2007-05-23
[ "astro-ph", "gr-qc", "hep-ph", "hep-th" ]
P.C. Argyres, A.O. Barvinski, V. Frolov, S.B. Giddings, D.A. Lowe, A. Strominger, and L. Thorlacius
astro-ph/9412044
Gravitational Lensing of Variability-slected QSO by Galaxy Clusters
Distribution and properties of QSOs behind galaxy clusters in the UKJ287 field were studied. QSOs were selected using variability criteria and are confined to $z \ge 0.4$ and $m_B \le 19.5$. No reddening or obscuration of background QSOs due to dust in clusters is detected. A statistically significant positive angular ...
1994-12-13
2009-10-22
[ "astro-ph" ]
L.L. Rodrigues-Williams and M.R.S. Hawkins
astro-ph/9412043
An Adaptive Multigrid Solver for High-Resolution Cosmological Simulations
We have developed an adaptive multigrid code for solving the Poisson equation in gravitational simulations. Finer rectangular subgrids are adaptively created in locations where the density exceeds a local level-dependent threshold. We describe the code, test it in cosmological simulations, and apply it to the study of ...
1994-12-13
2015-06-24
[ "astro-ph" ]
I. Suisalu, E. Saar
astro-ph/9412042
Exponential Tails in the Centroid Velocity Distributions of Star-Forming Regions
Probability density functions (pdfs) of $^{13}CO$ emission line centroid (line-of-sight, intensity-weighted average) velocities are presented for several densely sampled molecular clouds as quantitative descriptors of their underlying dynamics. Although some are approximately Gaussian in form, most of the pdfs exhibit ...
1994-12-13
2009-10-22
[ "astro-ph", "chao-dyn", "nlin.CD" ]
Mark S. Miesch (JILA) and John M. Scalo (U of Texas)
astro-ph/9412041
Dynamics of the nuclear gas & dust disc in the E4 radio galaxy NGC 7052
We present high spatial resolution ground-based broad-band imaging, H-alpha +[NII] narrow-band imaging and long-slit spectroscopy for the E4 radio galaxy NGC 7052, which has a nuclear dust disc. We detect ionized gas with a LINER spectrum, residing also in a nuclear disc. The gas rotates rapidly and the emission line w...
1994-12-12
2015-06-24
[ "astro-ph" ]
Frank C. van den Bosch & Roeland P. van der Marel
astro-ph/9412040
ROSAT Observations of Compact Groups of Galaxies
A search for X-ray emission from compact groups revealed detection from 8 out of the 12 HCG images extracted from the ROSAT public archive. For two of them the X-ray emission originates from galaxies in the group. On the contrary, three groups show an extended emission clearly caused by hot intracluster gas. A Raymond-...
1994-12-11
2008-02-03
[ "astro-ph" ]
P. Saracco and P. Ciliegi
astro-ph/9412039
Monte-Carlo Analysis of Big Bang Production of Beryllium and Boron
There is continued interest in the possibility that big bang nucleosynthesis may produce significant quantities of Be and B. In this paper we reevaluate the primordial abundances taking into account uncertainties in reactions rates. We discuss the implications for primordial nucleosynthesis, and for galactic cosmic ray...
1994-12-11
2009-09-25
[ "astro-ph" ]
David Thomas (Ohio State University)
astro-ph/9412036
HI 2334+26: An Extended HI Cloud near Abell 2634
We report the serendipitous discovery of a large HI cloud with an associated HI mass of $6(\pm1.5)\times 10^9 h^{-2}$ M$_\odot$ and a heliocentric velocity 8800 \kms, located near the periphery of the cluster of galaxies Abell 2634. Its velocity field appears to be very quiescent, as no gradients in the peak velocity a...
1994-12-09
2009-10-22
[ "astro-ph" ]
Riccardo Giovanelli, Marco Scodeggio, Jose` M. Solanes, Martha P. Haynes, Hector Arce, and Shoko Sakai
astro-ph/9412035
Primordial Deuterium Abundance and Cosmic Baryon Density
The comparison of cosmic abundances of the light elements with the density of baryonic stars and gas in the universe today provides a critical test of big bang theory and a powerful probe of the nature of dark matter. A new technique allows determination of cosmic deuterium abundances in quasar absorption clouds at lar...
1994-12-09
2009-09-25
[ "astro-ph" ]
Craig J. Hogan (University of Washington)
astro-ph/9412031
No Very Large Scale Structure in an Open Universe
We study the effects of negative spatial curvature on the statistics of inhomogeneities in open cosmological models. In particular we examine the suppression of large-separation correlations in density and gravitational potential fluctuations and the resulting suppression of large-angle correlations in the anisotropy o...
1994-12-09
2009-10-22
[ "astro-ph" ]
Albert Stebbins and R.R. Caldwell
astro-ph/9412038
Ultra-Low Frequency Gravitational Radiation from Massive Black Hole Binaries
For massive black hole binaries produced in galactic mergers, we examine the possibility of inspiral induced by interaction with field stars. We model the evolution of such binaries for a range of galaxy core and binary parameters, using numerical results from the literature to compute the binary's energy and angular m...
1994-12-09
2010-11-01
[ "astro-ph" ]
Mohan Rajagopal and Roger W. Romani
astro-ph/9412037
Hydrodynamic Simulations of Galaxy Formation
We have developed an accurate, one-dimensional, spherically symmetric, Lagrangian hydrodynamics/gravity code, designed to study the effects of radiative cooling and photo-ionization on the formation of protogalaxies. We examine the ability of collapsing perturbations to cool within the age of the universe. In contrast ...
1994-12-09
2009-10-22
[ "astro-ph" ]
A.A. Thoul
astro-ph/9412034
Gas at Large Distances from Galaxies and QSO Absorption Lines
We present the calculations of steady, spherical gas outflows from galaxies in an effort to understand the effects of the galaxy mass on the flow properties such as the size of the outflow regions, the efficiency of radiative cooling, and the fate of the cooled gas. We show that there exist no transonic flows but eithe...
1994-12-09
2007-05-23
[ "astro-ph" ]
Boqi Wang (The Johns Hopkins University)
astro-ph/9412032
Induced gravity inflation in the SU(5) GUT
We investigate the cosmological consequences of a theory of induced gravity in which the scalar field is identified with the Higgs field of the first symmetry breaking of a mi\-ni\-mal SU(5) GUT. The mass of the X-boson determines a great value for the coupling constant of gravity-particle physics. Because of this fact...
1994-12-09
2009-10-22
[ "astro-ph", "gr-qc" ]
J.L.Cervantes-Cota and H. Dehnen
astro-ph/9412033
Cooling Gas Outflows from Galaxies
We study steady, radial gas outflows from galaxies in an effort to understand the way tenuous and hot gas is transported to large distances away from galaxies. In particular, we obtain solutions for outflow problems, and study the outflow topology, effects of the galaxy mass, the size of outflow regions, the efficiency...
1994-12-09
2009-10-22
[ "astro-ph" ]
Boqi Wang (The Johns Hopkins University)
astro-ph/9412028
Optical Properties of the South Pole Ice at Depths Between 0.8 and 1 km
The optical properties of the ice at the geographical South Pole have been investigated at depths between 0.8 and 1 kilometers. The absorption and scattering lengths of visible light ($\sim$515 nm) have been measured {\it in situ } using the laser calibration setup of the AMANDA neutrino detector. The ice is intrinsica...
1994-12-08
2012-08-27
[ "astro-ph" ]
The AMANDA collaboration
astro-ph/9412027
Galaxies, Human Eyes and Artificial Neural Networks
Quantitative morphological classification of galaxies is important for understanding the origin of type frequency and correlations with environment. But galaxy morphological classification is still mainly done visually by dedicated individuals, in the spirit of Hubble's original scheme, and its modifications. The rapid...
1994-12-08
2009-10-22
[ "astro-ph" ]
O. Lahav, A. Naim, R. J. Buta, H. G. Corwin, G. de Vaucouleurs, A. Dressler, J. P. Huchra, S. van den Bergh, S. Raychaudhury, L. Sodre Jr. & M. C. Storrie-Lombardi
astro-ph/9412029
On the Relationship between Optical and X-Ray Luminosity of Quasars
The issue of the X-ray to optical luminosity relationship ($L_o-L_x$) is addressed for both optically and X-ray selected quasar samples. We have applied a generalized regression algorithm for the case of samples involving censored data, with errors on both the dependent and the independent variable. Contrary to some pr...
1994-12-08
2011-05-23
[ "astro-ph" ]
F. la Franca, A. Franceschini, S. Cristiani, R. Vio
astro-ph/9412030
Spin-Up/Spin-Down of Magnetized Stars with Accretion Disks and Outflows
An investigation is made of disk accretion of matter onto a rotating star with an aligned dipole magnetic field. A new aspect of this work is that when the angular velocity of the star and disk differ substantially we argue that the $\bf B$ field linking the star and disk rapidly inflates to give regions of open field ...
1994-12-08
2015-06-24
[ "astro-ph" ]
R.V.E. Lovelace, M.M. Romanova, G.S. Bisnovatyi-Kogan
astro-ph/9412026
Modelling the millimetre-infrared flaring behaviour of the quasar 1253-055 (3C 279)
The infrared through millimetre light curve of 3C 279 is investigated for the period of 1986 until mid-1994, during which time several flares were observed. A quiescent spectrum (identified with emission from an underlying jet) is presented. Both the near-IR and 375-150 GHz regimes are shown to be well described by pow...
1994-12-08
2015-06-24
[ "astro-ph" ]
S. J. Litchfield, J. A. Stevens, E. I. Robson, W. K. Gear
astro-ph/9412019
DUMAND and AMANDA: High Energy Neutrino Astrophysics
The field of high energy neutrino astrophysics is entering an exciting new phase as two new large-scale observatories prepare to come on line. Both DUMAND (Deep Underwater Muon and Neutrino Detector) and AMANDA (Antarctic Muon and Neutrino Detector) had major deployment efforts in 12/93--1/94. Results were mixed, with ...
1994-12-07
2010-11-01
[ "astro-ph", "hep-ex" ]
R. Jeffrey Wilkes (Department of Physics, University of Washington, Seattle, WA 98195)
astro-ph/9412022
Gamma-Ray Pulsars: Beaming Evolution, Stats and Unident. EGRET Sources
We compute the variation of the beaming fraction with the efficiency of high energy gamma-ray production in the outer gap pulsar model of Romani and Yadigaroglu. This allows us to correct the fluxes observed for pulsars in the EGRET band and to derive a simple estimate of the variation of efficiency with age. Integrati...
1994-12-07
2009-10-22
[ "astro-ph" ]
I.-A. Yadigaroglu and Roger W. Romani
astro-ph/9412021
Degree Scale Anisotropy: Current Status
The Cosmic Background Radiation gives us one of the few probes into the density perturbations in the early universe that should later lead to the formation of structure we now observe. Recent advances in degree scale anisotropy measurements have allowed us to begin critically testing cosmological models. Combined with ...
1994-12-07
2007-05-23
[ "astro-ph" ]
P.M. Lubin
astro-ph/9412020
Degree Scale Anisotropy: SP94 Results
We present results from 2 observations of the CMB performed from the South Pole during the 93-94 austral summer. Each observation employed a 3$^{\circ}$ peak to peak sinusoidal, single difference chop and consisted of a $20^{\circ}\times 1^{\circ}$ strip on the sky near our SP91 observations. The first observation used...
1994-12-07
2007-05-23
[ "astro-ph" ]
J. Gundersen, M. Lim, J. Staren, C. Wuensche, N. Figueiredo, T. Gaier T. Koch, P. Meinhold, M. Seiffert, G. Cook, A. Segale, P. Lubin
astro-ph/9412024
Constraints on the Power Spectrum of Mass Fluctuations from from Galaxy Cluster Peculiar Velocities
We investigate the feasibility of carrying out likelihood analysis on the velocities of galaxy clusters to determine power spectrum parameters. Using N-body simulations of cosmological density fields we show that the velocity field traced by clusters is highly non-linear on small scales (r < 10 h^-1 Mpc), mostly due to...
1994-12-07
2007-05-23
[ "astro-ph" ]
Rupert Croft and George Efstathiou (Physics Dept., Univ. of Oxford)
astro-ph/9412023
The Effects of High-Velocity Supernova Kicks on the Orbital Properties and Sky Distributions of Neutron Star Binaries
We systematically investigate the effects of high supernova kick velocities on the orbital parameters of post-supernova neutron-star binaries. Using Monte- Carlo simulations, we determine the post-supernova distributions of orbital parameters for progeneitors of HMXBs and LMXBs. With the recent distribution of pulsar b...
1994-12-07
2007-05-23
[ "astro-ph" ]
W.N. Brandt, Ph. Podsiadlowski
astro-ph/9412025
Cosmic Background Anisotropies in CDM Cosmology
Cosmic microwave background (CMB) anisotropies and density fluctuations are calculated for flat cold dark matter (CDM) models with a wide range of parameters, i.e., $\Omega_0, h$ and $\Omega_B$ for both standard recombination and various epochs of reionization. Tables of the power spectrum of CMB anisotropies in the fo...
1994-12-07
2009-10-22
[ "astro-ph" ]
Naoshi Sugiyama
astro-ph/9412017
Determining the Motion of the Local Group Using SN Ia Light Curve Shapes
We have measured our Galaxy's motion relative to distant galaxies in which type Ia supernovae (SN Ia) have been observed. The effective recession velocity of this sample is 7000 km s$^{-1}$, which approaches the depth of the survey of brightest cluster galaxies by Lauer and Postman (1994). We use the Light Curve Shape ...
1994-12-06
2009-10-22
[ "astro-ph" ]
Adam G. Riess, William H. Press, and Robert P. Kirshner (Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138)
astro-ph/9412015
Absolute Ages of Globular Clusters and the Age of the Universe
The main sequence turnoff luminosity is the best stellar `clock' which can be used to determine the absolute ages of globular clusters. This is due to the fact that it is generally assumed that the luminosity and lifetimes of main sequence globular cluster stars are independent of the properties of stellar convection a...
1994-12-06
2009-10-22
[ "astro-ph" ]
Brian Chaboyer
astro-ph/9412018
Summary of Nuclear and Particle Astrophysics Sessions
Astrophysics is gaining increased attention from the particle and nuclear physics communities, as budget cuts, delays, and cancellations limit opportunities for breakthrough research at accelerator laboratories. Observations of cosmic rays (protons and nuclei), gamma rays and neutrinos present a variety of puzzles whos...
1994-12-06
2009-10-22
[ "astro-ph", "hep-ph" ]
R. Jeffrey Wilkes (Dept. of Physics, University of Washington, Seattle, WA 98195 USA)