August 1999 arXiv papers — page 8

Tin-Lun Ho, Lan Yin

Motivated by the recent discoveries of spin-1 and spin-1/2 Bose gas, we have studied the general structure of the Bose gases with arbitrary spin. A general method is developed to uncover the elementary building blocks of the angular momentum eigenstates, as well as the relations (or interactions) between them. Applications of this method to Bose gases with i

M. Thies, B. Schmittmann

With the help of Monte Carlo simulations and a mean-field theory, we investigate the ordered steady-state structures resulting from the motion of a single vacancy on a periodic lattice which is filled with two species of oppositely ``charged'' particles. An external field biases particle-vacancy exchanges according to the particle's charge, subje

A. Chattopadhyay, A. J. Millis, S. Das Sarma

We present a thorough and quantitative comparison of double-exchange models to experimental data on the colossal magnetoresistance manganese perovskites. Our results settle a controversy by showing that physics beyond double-exchange is important even in La$_{0.7}$Sr$_{0.3}$MnO$_3$, which has been regarded as a conventional double-exchange system. We show th

Arkadiusz Wojs, John J. Quinn

The pseudopotentials describing the interactions of quasiparticles in fractional quantum Hall (FQH) states are studied. Rules for the identification of incompressible quantum fluid ground states are found, based upon the form of the pseudopotentials. States belonging to the Jain sequence nu=n/(1+2pn), where n and p are integers, appear to be the only incompr

S. Anantha Ramakrishna, E. Krishna Das, G. V. Vijayagovindan, N. Kumar

The probability distribution of the reflection coefficient for light reflected from a one-dimensional random amplifying medium with {\it cross-correlated} spatial disorder in the real and the imaginary parts of the refractive index is derived using the method of invariant imbedding. The statistics of fluctuations have been obtained for both the correlated te

N. A. Miller, F. N. Owen, J. O. Burns, M. J. Ledlow

Investigations of the cluster environment of radio sources have not shown a correlation between radio power and degree of clustering. However, it has been demonstrated that extended X-ray luminosity and galaxy clustering do exhibit a positive correlation. This study investigates a complete sample of 25 nearby (z less than 0.06) radio galaxies which are not c

Gerhard Hensler, Andreas Rieschick, Joachim K"oppen

Because of their low gravitational energies dwarf galaxies are greatly exposed to energetical influences by the interstellar medium, like e.g. stellar radiation, winds or explosions, or by their environment. While the metallicity depletion in dwarf galaxies can be explained in general by supernova-driven galactic winds, the reason for their low N/O ratios at

N. V. Voshchinnikov, V. B. Il'in, Th. Henning, B. Michel

We use the separation of variables and T-matrix methods to calculate the optical properties of homogeneous spheroids with refractive indices from m = 1.3+0.0i up to 3+4i. It is found that the extinction cross-sections for highly absorbing spheroids are normally 1.5 -- 2 times larger than those for spheres of the same volume. The albedo of the non-spherical p

Nikolai V. Voshchinnikov, John S. Mathis

Interstellar grains may be composite collections of particles of distinct materials, including voids, agglomerated together. We determine the various optical cross sections of such composite grains, given the optical properties of each constituent, using an approximate model of the composite grain. We assume it consists of many concentric spherical layers of

D0 collaboration, B. Abbott

We present a measurement of the W boson mass using data collected by the D0 experiment at the Fermilab Tevatron during 1994--1995. We identify W bosons by their decays to e-nu final states where the electron is detected in a forward calorimeter. We extract the W boson mass, Mw, by fitting the transverse mass and transverse electron and neutrino momentum spec

P. G. Blunden, M. Burkardt, G. A. Miller

The principles behind the detailed results of a light-front mean field theory of finite nuclei are elucidated by deriving the nucleon mode equation using a simple general argument, based on the idea that a static source in equal time coordinates corresponds to a moving source in light front coordinates. This idea also allows us to solve several simple toy mo

Toshiya Ueta, Margaret Meixner, Matthew Bobrowsky

We report the results from an optical imaging survey of proto-planetary nebula candidates using the HST. We exploited the high resolving power and wide dynamic range of HST and detected nebulosities in 21 of 27 sources. All detected reflection nebulosities show elongation, and the nebula morphology bifurcates depending on the degree of the central star obscu

Ulrike Feichtinger

We study the non-perturbative, instanton-corrected effective action of the N=2 SU(2) x SU(2) supersymmetric Yang-Mills theory with a massless hypermultiplet in the bifundamental representation. Starting from the appropriate hyperelliptic curve, we determine the periods and the exact holomorphic prepotential in a certain weak coupling expansion. We discuss th

Nathan Seiberg, Edward Witten

We extend earlier ideas about the appearance of noncommutative geometry in string theory with a nonzero B-field. We identify a limit in which the entire string dynamics is described by a minimally coupled (supersymmetric) gauge theory on a noncommutative space, and discuss the corrections away from this limit. Our analysis leads us to an equivalence between

H. Aoki, N. Ishibashi, S. Iso, H. Kawai

We show that twisted reduced models can be interpreted as noncommutative Yang-Mills theory. Based upon this correspondence, we obtain noncommutative Yang-Mills theory with D-brane backgrounds in IIB matrix model. We propose that IIB matrix model with D-brane backgrounds serve as a concrete definition of noncommutative Yang-Mills. We investigate D-instanton s

V. A. Bednyakov, H. V. Klapdor-Kleingrothaus

We perform an investigation of the MSSM parameter space at the Fermi scale taking into account available accelerator, non-accelerator and cosmological constraints. Extra assumptions about upper bounds for some of the SUSY particles are also imposed. We show that a non-observation of the SUSY dark matter candidates with a high-accuracy dark matter detector, s

A. Campbell-Smith, N. E. Mavromatos

We propose a new mechanism for the formation of conical singularities on D-branes by means of recoil resulting from scattering of closed string states propagating in the (large) transverse dimensions. By viewing the (spatial part of the) four-dimensional world as a 3-brane with large transverse dimensions the above mechanism can lead to supersymmetry obstruc

M. D. Betterton, Michael P. Brenner

Under special conditions bacteria excrete an attractant and aggregate. The high density regions initially collapse into cylindrical structures, which subsequently destabilize and break up into spherical aggregates. This paper presents a theoretical description of the process, from the structure of the collapsing cylinder to the spacing of the final aggregate

Mauri Miettinen, Antti J. Niemi

The Arnold conjecture yields a lower bound to the number of periodic classical trajectories in a Hamiltonian system. Here we count these trajectories with the help of a path integral, which we inspect using properties of the spectral flow of a Dirac operator in the background of a $\Sp(2N)$ valued gauge field. We compute the spectral flow from the Atiyah-Pat

Koji Uryu, Yoshiharu Eriguchi

We propose a new numerical method to compute quasi-equilibrium sequences of general relativistic irrotational binary neutron star systems. It is a good approximation to assume that (1) the binary star system is irrotational, i.e. the vorticity of the flow field inside component stars vanishes everywhere (irrotational flow), and (2) the binary star system is

M. Letz, R. Schilling

Molecular fluids show rich and complicated dynamics close to the glass transition. Some of these observations are related to the fact that translational and orientational degrees of freedom couple in nontrivial ways. A model system which can serve as a paradigm to understand these couplings is a system of hard ellipsoids of revolution. To test this we compar

A. Harindranath, Asmita Mukherjee, Raghunath Ratabole

We address the long standing problem of the construction of relativistic spin operators for a composite system in QCD. Exploiting the kinematical boost symmetry in light front theory, we show that transverse spin operators for massless particles can be introduced in an arbitrary reference frame, in analogy with those for massive particles. In light front QCD

Shamit Kachru, John McGreevy

We describe physical phenomena associated with a class of transitions that occur in the study of supersymmetric three-cycles in Calabi-Yau threefolds. The transitions in question occur at real codimension one in the complex structure moduli space of the Calabi-Yau manifold. In type IIB string theory, these transitions can be used to describe the evolution of

X. M. Liu, G. J. Milburn

We describe the classical and quantum two dimensional nonlinear dynamics of large blue-detuned eveanescent-wave guiding cold atoms in hollow fiber. We show that chaotic dynamics exists for classic dynamics, when the intensity of the beam is periodically modulated. The two dimensional distributions of atoms in (x,y) plane are simulated. We show that the atoms

H. Furutsu, T. Kojima, Y. -H. Quano

Presented is a free boson representation of the type II vertex operators for the $A_{n-1}^{(1)}$ face model. Using the bosonization, we derive some properties of the type II vertex operators, such as commutation, inversion and duality relations.

Adrian Kent

This paper has been withdrawn. See quant-ph/9806031 for a discussion.

Adrian Kent

This paper is withdrawn. See quant-ph/9806031 for a discussion.

Edgar Paternina

The purpose of this paper is to present a new proposal to both dualistic and holistic paradigm, by introducing a complex basic unit system mathematical concept in which the quantitative and the qualitative aspects of reality commingle in a unit, and by presenting a new principle, the principle of synergy, we have then a new framework in which the opposites c

Yu. Malyuta

The spectrum of D-brane charges in the Type IIB string theory compactified on $AdS_{p+2}\times S^{8-p}$ is computed using the K-theory approach. The result differs from the corresponding result presented in the digest of Olsen and Szabo.

W. M. Kloet, Frank Tabakin

Extraction of spin observables from vector meson photoproduction on a nucleon target is described. Starting from density matrix elements in the vector meson's rest frame, we transform to spin observables in the photon-nucleon c.m. frame. Several constraints on the transformed density matrix and on the spin observables follow from requiring that the angul

R. Machleidt, M. K. Banerjee

The recent determination of the charged $πNN$ coupling constant, $g_{π^\pm}$, by the Uppsala Neutron Research Group implies that there may be considerable charge-splitting of the pion coupling constant. We investigate the consequences of this for the charge-independence breaking (CIB) of the $^1S_0$ scattering length, $Δa_{CIB}$. We find that $Δa_{CIB}$ depe

D. O. Riska

The relation between the Skyrme model and the constituent quark model, which appears in the large $N_c$ limit is described. Examples of similarity in the predicted phenomenology for baryons are shown. Finally the application to nuclei is discussed.

Masatomi Yasuhira, Toshitaka Tatsumi

Equation of state with kaon condensate is derived for isentropic and neutrino-trapped matter. Both are important ingredients to study the delayed collapse of protoneutron stars. Solving the TOV equation, we discuss the static properties of protoneutron stars and implications for their delayed collapse.

D. E. Kahana, S. H. Kahana

Recent analysis of both new (1998) and old (1995,1996) data obtained by the NA50 Collaboration on J/Psi suppression in Pb+Pb are examined in light of our already existing calculations with the relativistic heavy ion simulation LUCIFER. In particular we comment on the unexplained change of transverse energy scale by NA50 and the apparent disappearance from th

F. Marti, R. C. York, H. Blosser, M. M. Gordon

The creation of intense radioactive beams requires intense and energetic primary beams. A task force analysis of this subject recommended an acceleration system capable of 400 MeV/u uranium at 1 particle uA as an appropriate driver for such a facility. The driver system should be capable of accelerating lighter ions at higher intensity such that a constant f

Elliott H. Lieb, Peter Schupp

We find that ground states of the quantum Heisenberg antiferromagnet on the geometrically frustrated pyrochlore checkerboard lattice are singlets and can be expressed in terms of positive matrices. The magnetization at zero external field vanishes for each frustrated tetrahedral unit separately and there is an upper bound of 1/8 in natural units on the susce

S. P. Hrabak

We describe the multisymplectic analysis of the constraints of first-order embedded submanifolds inherited from diffeomorphisms of the ambient manifold. The ambient diffeomorphism deformations of first-order embedded submanifolds are examined. We find that the covariant Noether currents, corresponding to the inherited ambient diffeomorphism symmetry, satisfy

Pavel Etingof, Olivier Schiffmann

In early eighties, Belavin and Drinfeld showed that nonskewsymmetric classical r-matrices for simple Lie algebras are classified by combinatorial objects which are now called Belavin-Drinfeld triples. Later the second author of the present paper generalized this result to the case of dynamical r-matrices, and showed that they correspond to generalized Belavi

Nigel Hitchin, Justin Sawon

We express characteristic numbers of compact hyperkähler manifolds in graph-theoretical form, considering them as a special case of the curvature invariants introduced by Rozansky and Witten. The appropriate graphs are generated by ``wheels'' and we use the recently proved Wheeling Theorem to give a formula for the L2 norm of the curvature of an irre

D. Gayet

We prove that a compact, immersed, submanifold of C^n, lagrangian for a Kahler form, is rationally convex, generalizing a theorem of Duval and Sibony for embedded submanifolds.

Jose Bonet, Andreas Defant

Extending the classical Levy-Steinitz rearrangement theorem, which in turn extended Riemann's theorem, Banaszczyk proved in 1990/93 that a metrizable, locally convex space is nuclear if and only if the domain of sums of every convergent series (i.e. the set of all elements in the space which are sums of a convergent rearrangement of the series) is a tran

Andreas Defant

The Maurey-Rosenthal theorem states that each bounded and linear operator T from a quasi normed space E into some L_p(ν) which satisfies a certain vector-valued inequality even allows a weighted norm inequality. Continuing the work of Garcia Cuerva and Rubio de Francia we give several scalar and vector-valued variants of this fundamental result within the fr

Marco Castrillon Lopez, Tudor S. Ratiu, Steve Shkoller

Let $π:P\to M^n$ be a principal G-bundle, and let ${\mathcal{L}}: J^1P \toΛ^n(M)$ be a G-invariant Lagrangian density. We obtain the Euler-Poincare equations for the reduced Lagrangian l defined on ${\mathcal C}(P)$, the bundle of connections on P.

Atsushi Yoshida

It is shown from a simple scaling invariance that the ultra-relativistic Hamiltonian (mu=0) does not have bound states when the potential is Coulombic. This supplements the application of the relativistic virial theorem derived by Lucha and Schoeberl which shows that bound states do not exist for potentials more singular than the Coulomb potential.

I. Antoniadis, J. -P. Derendinger, C. Kounnas

We obtain the non-perturbative effective potential for the dual five-dimensional N=4 strings in the context of finite-temperature regarded as a breaking of supersymmetry into four space-time dimensions. Using the properties of gauged N=4 supergravity we derive the universal thermal effective potential describing all possible high-temperature instabilities of

Hitoshi Nishino, S. J. Gates,

We present component and superspace formulations for the recently-proposed Type IIA* (or so-called `star') supergravity theory, which is timelike dual to the conventional Type IIB theory. First, within the component approach, all terms in the action are fixed up to the quartic fermionic ones. As desired, the kinetic terms for Ramond-Ramond fields have si

Dumitru Baleanu, Yurdahan Guler

In this paper the $Guler's$ formalism for the systems with finite degrees of freedom is applied to the field theories with constraints. The integrability conditions are investigated and the path integral quantization is performed using the action given by Hamilton-Jacobi formulation. The Proca's model is investigated in details.

K. Terasaki

Two pion decays of K mesons, K_L-K_S mass difference, two photon and the Dalitz decays of K_L are studied systematically by assuming that their amplitude is given by a sum of factorizable and non-factorizable ones. The former is estimated by using a naive factorization while the latter is assumed to be dominated by dynamical contributions of various hadron s

L. M. Sehgal, J. van Leusen

The origin of the large CP-odd and T-odd asymmetry observed in the decay K_L -> pi^+ pi^- e^+ e^- is traced to the polarization properties of the photon in the decay K_L -> pi^+ pi^- gamma. The Stokes vector of the photon S = (S_1, S_2, S_3) is studied as a function of the photon energy and found to possess CP-violating components S_1 and S_2 which are sizea

M. Wakamatsu, T. Watabe

After taking account of the scale dependence by means of the standard DGLAP evolution equation, the theoretical predictions of the chiral quark soliton model for the unpolarized and longitudinally polarized structure functions of the nucleon are compared with the recent high energy data. The theory is shown to explain all the qualitative features of the expe

L. Ya. Glozman

I begin with a key problem of light and strange baryon spectroscopy which suggests a clue for our understanding of underlying dynamics. Then I discuss spontaneous breaking of chiral symmetry in QCD, which implies that at low momenta there must be quasiparticles - constituent quarks with dynamical mass, which should be coupled to other quasiparticles - Goldst

Y. Kurihara, J. Fujimoto, T. Ishikawa, Y. Shimizu

A new event generator is proposed for two processes e+e- -> nu nu-bar gamma and e+e- -> nu nu-bar gamma gamma where nu includes all the neutrino species. The exact matrix elements of single- and double-photon emission, generated by the GRACE system, are convoluted with the QED parton shower(QEDPS) to deal with the initial state radiations(ISR). It is pointed

N. N. Nikolaev

In a consistent QCD approach to diffractive DIS gluons in the pomeron have soft $z_{g}$ distribution and very broad intrinsic $k_{\perp}$ distribution. The latter has not yet been incorporated into diffractive Monte-Carlo generators (RAPGAP,....). I argue that the so-introduced bias in the diffractive jet analysis may be the reason why H1 Collaboration finds

Bernd A. Berg, Harald Markum, Rainer Pullirsch, Tilo Wettig

We investigate the spectrum of the staggered Dirac operator in 4d quenched U(1) lattice gauge theory and its relationship to random matrix theory. In the confined as well as in the Coulomb phase the nearest-neighbor spacing distribution of the unfolded eigenvalues is well described by the chiral unitary ensemble. The same is true for the distribution of the

S. Capitani, M. Goeckeler, R. Horsley, P. E. L. Rakow

The improvement of fermionic operators for Ginsparg-Wilson fermions is investigated. We present explicit formulae for improved Green's functions, which apply both on-shell and off-shell.

M. Gockeler, R. Horsley, B. Klaus, W. Kurzinger

A completely non-perturbative estimate is given for the u/d and strange quark masses in quenched QCD using O(a) improved fermions and, for comparison, Wilson fermions. For improved fermions we find m_{u/d}^MSbar(μ=2 GeV) = 4.4(2) MeV, m_s^MSbar(μ=2 GeV) = 105(4) MeV when using r_0 to set the physical scale.

H. Reinhardt, M. Engelhardt, K. Langfeld, M. Quandt

The topological properties of magnetic monopoles and center vortices arising, respectively, in Abelian and center gauges are studied in continuum Yang-Mills Theory. For this purpose the continuum analog of the maximum center gauge is constructed.

The NuTeV Collaboration, D. A. Harris, J. Yu

NuTeV is a neutrino-nucleon deep-inelastic scattering experiment at Fermilab. The detector consists of an iron-scintillator sampling calorimeter interspersed with drift chambers, followed by a muon toroidal spectrometer. We present determinations of response and resolution functions of the NuTeV calorimeter for electrons, hadrons, and muons over an energy ra

I. T. Drummond

We show how to reformulate Variable Speed of Light Theories (VSLT) in a covariant fashion as Variable Light-Cone Theories (VLCT) by introducing two vierbein bundles each associated with a distinct metric. The basic gravitational action relates to one bundle while matter propagates relative to the other in a conventional way. The variability of the speed of l

Keshav N. Shrivastava, S. S. C. Ammal, H. Tsuruya, S. Takami

Density-functional-theory calculations for the adsorption of molecular nitrogen on ruthenium surface are reported. It is found that nitrogen molecule is adsorbed while standing perpendicular to the triangular surface of ruthenium. The doping by K atoms favours the adsorption of molecular nitrogen. The calculation of the adsorption energy has also been perfor

Fabio Cecconi, Jayanth R. Banavar, Amos Maritan

We present the results of analytical and numerical studies of a one-dimensional nonlocal and nonlinear diffusion equation describing non-equilibrium processes ranging from aggregation phenomena to cooperation of individuals. We study a dynamical phase transition that is obtained on tuning the initial conditions and demonstrate universality and characterize t

M. Turlakov

The Johnson-Nyquist noise in narrow semiconducting wires having a transverse size smaller than the screening length is shown to be white up to frequency $D/L^2$ and to decay at higher frequencies as $ω^{-{1/2}}$. This result is contrasted with the noise spectra in neutral and charged liquids.

M. Eremin, S. Varlamov, I. Eremin

Self-consistent calculation of spin (charge) density wave order (SDW/CDW) parameters have been performed for bilayered cuprates on the basis of a singlet correlated band model. Evolution of the Fermi surface in the strongly underdoped regime is described by using a two-band approach. The smooth development of the pseudogap formation temperature is explained

J. O. Fjaerestad, A. Sudbo, A. Luther

We calculate zero-temperature correlation functions for a model of 2D interacting electrons with short-range interactions and a square Fermi surface. The model was arrived at by mapping electronic states near a square Fermi surface with Hubbard-like interactions onto one-dimensional quantum chains, retaining terms which can be written in terms of bosonic den

C. Meyer, M. Potthoff, W. Nolting, G. Borstel

An improved formulation of the one-step model of photoemission from crystal surfaces is proposed which overcomes different limitations of the original theory. Considering the results of an electronic-structure calculation, the electronic (one-particle) potential and the (many-body) self-energy, as given quantities, we derive explicit expressions for the dipo

S. Mair, H. -A. Krug von Nidda, M. Lohmann, A. Loidl

Below a characteristic temperature, due to hybridisation effects Kondo insulators exhibit a gap in the electronic density of states and behave like semiconductors. By using Gd3+ electron spin resonance (ESR), the compound CeNiSn was investigated as a representative of this class. In addition, the metal-to-insulator transition was studied as a function of dop

Giovanni Filatrella, Boris A. Malomed

By means of numerical simulations, we demonstrate that ac field can support stably moving collective nonlinear excitations in the form of dislocations (topological solitons, or kinks) in the Frenkel-Kontorova (FK) lattice with weak friction, which was qualitatively predicted by Bonilla and Malomed [Phys. Rev. B{\bf 43}, 11539 (1991)]. Direct generation of th

M. Pleimling, W. Selke

Using Monte Carlo techniques, Ising cubes with ferromagnetic nearest-neighbor interactions and enhanced couplings between surface spins are studied. In particular, at the surface transition, the corner magnetization shows non-universal, coupling-dependent critical behavior in the thermodynamic limit. Results on the critical exponent of the corner magnetizati

Takashi Yamamoto, Mitsuhiro Arikawa

The thermodynamic limit of the dynamical density and spin-density two-point correlation functions for the spin Calogero-Sutherland model are derived from Uglov's finite-size results. The resultant formula for the density two-point correlation function is consistent with the previous conjecture on the basis of the minimal number of elementary excitations.

Akihisa Koga, Norio Kawakami

We present a novel mixed-spin cluster expansion method for a quasi-one-dimensional Haldane system with bond alternation. By mapping the s=1 antiferromagnetic spin model on square and cubic lattices to the equivalent mixed-spin model, we study the competition among the Haldane, the dimer and the magnetically ordered phases. The mixed-spin cluster expansion pr

C. Bauer, S. Dietrich

Using an interface displacement model we calculate the shapes of thin liquidlike films adsorbed on flat substrates containing a chemical stripe. We determine the entire phase diagram of morphological phase transitions in these films as function of temperature, undersaturation, and stripe width

Suman Kumar Banik, Jyotipratim Ray Chaudhuri, Deb Shankar Ray

We consider the motion of an overdamped particle in a force field in presence of an external, adiabatic noise, without the restriction that the noise process is Gaussian or the stochastic process is Markovian. We examine the condition for attainment of steady state for this nonequilibrium open system and calculate the adiabatic noise-induced rate of escape o

Robert W. O'Connell

I review recent progress in exploring the formation times of spheroidal stellar populations (elliptical galaxies and large spiral bulges) using spectrophotometric techniques. A quickly growing body of evidence shows that although massive spheroids can form at early times, there are strong environmental dependencies, and major transitions in star formation hi

Adam G. Riess

Type Ia supernovae have only recently been employed to measure the peculiar motions of galaxies. The great distances to which SNe Ia can be seen makes them particularly well-suited to constraining large-scale velocity flows. The high precision of SN Ia distance measurements limits the contamination of such measurements by Malmquist or sample selection biases

G. Brunetti

The problem of the anisotropic Inverse Compton scattering between a monochromatic photon beam and relativistic electrons is revisited and formally solved without approximations. Solutions are given for the single scattering with an electron beam and with a population of electrons isotropically distributed, under the assumption that the energy distribution of

N. V. Voshchinnikov, D. A. Semenov, Th. Henning

A model of spheroidal particles is used to calculate the steady-state temperature of dust grains immersed in the interstellar radiation field. It is found that the temperature of non-spherical grains with the aspect ratios a/b <= 2 deviates from that of spheres less than 10%. More elongated or flattened particles are usually cooler than spheres of the same m

V. M. Lipunov, S. B. Popov

Estimates of the magnetic field of neutron stars in X-ray pulsars are obtained using the hypothesis of the equilibrium period for disk and wind accretion and also from the BATSE data on timing of X-ray pulsars using the observed maximum spin-down rate. Cyclotron lines at energies $\ge 100$ keV in several Be-transient are predicted for future observations.

R. J. Wilman, C. S. Crawford, R. G. Abraham

(Abridged) We analyse the morphology, kinematics and ionization structure of the extended emission-line regions in four ULIRGs at 0.118<z<0.181, using ARGUS integral-field spectroscopy. The gas kinematics in the hyperluminous system IRAS F20460+1925 lack coherent structure, with FWHM>1000 km/s within 1&#34; of the nucleus; an isolated blob ~8kpc from the nuc

B. McBreen, L. Hanlon

The effect of a nearby $γ$-ray burst (GRB) on the preplanetary solar nebula is considered. The intense irradiation by x-rays and $γ$-rays would have caused dust balls to become molten in a matter of seconds, cooling more slowly to form chondrules. The role of iron is crucial in this process because it was the major absorber of x-rays between 7 keV and 30 keV

Gerard Gilmore, Xavier Hernandez, David Valls-Gabaud

Objective determination of a star formation history from a colour-magnitude diagram, independently of assumed parametric descriptions, is necessary to determine the evolutionary history of a galaxy. We introduce a new method for solving maximum likelihood problems through variational calculus, and apply it to the case of recovering an unknown star formation

N. E. Jessop, D. Ward-Thompson

We present a catalogue of molecular cloud cores drawn from high latitude, medium opacity clouds, using the all-sky IRAS Sky Survey Atlas (ISSA) images at 60 and 100~$μ$m. The typical column densities of the cores are $ N(H_2)\sim 3.8 \times 10^{21} $cm$^{-2}$ and the typical volume densities are $ n(H_2) \sim 2 \times 10^3$cm$^{-3}$. They are therefore signi

H. Murakami, K. Koyama, M. Sakano, M. Tsujimoto

We present the ASCA results of imaging spectroscopy of the giant molecular cloud Sgr B2. The X-ray spectrum is found to be very peculiar; it exhibits a strong emission line at 6.4 keV, a low energy cutoff below about 4 keV and a pronounced edge-structure at 7.1 keV. The X-ray image is extended and its peak position is shifted from the core of the molecular c

K. S. Cheng, Jian-Min Wang

The production rate of compact objects, i.e. neutron stars (NS) and black holes (BH), in active galactic nuclei (AGN) and quasars (QSO), where the frequent supernova explosion is used to explain the high metallicity, is very high due to the interaction between the accretion disk and main sequence stars in the nucleus of the quasar. The compact object-red gia

Jian-Min Wang

In this paper we pursue the suggestion by Shu, Lubow & Anderson (1979) and Wang (1995) that contact discontinuity (DSC) may exist in the secondary in the expansion TRO (thermal relaxation oscillation) state. It is demonstrated that there is a mass exchange instability in some range of mass ratio for the two components. We show that the assumption of {\it con

P. Höflich, K. Nomoto, H. Umeda, J. C. Wheeler

The influence of the metallicity at the main sequence on the chemical structure of the exploding white dwarf, the nucleosynthesis during the explosion and the light curves of an individual Type Ia supernovae have been studied. Detailed calculations of the stellar evolution, the explosion, and light curves of delayed detonation models are presented. Detailed

Ryoichi Nishi, Hajime Susa

We investigate the evolution of cosmological low mass (low virial temperature) objects and the formation of the first luminous objects. First, the `cooling diagram&#39; for low mass objects is shown. We assess the cooling rate taking into account the contribution of H_2, which is not in chemical equilibrium generally, with a simple argument of time scales. T

Andrew P. Billyard, Alan A. Coley

We investigate spatially flat isotropic cosmological models which contain a scalar field with an exponential potential and a perfect fluid with a linear equation of state. We include an interaction term, through which the energy of the scalar field is transferred to the matter fields, consistent with a term that arises from scalar--tensor theory under a conf

Scott C. Chapman, Simon L. Morris, Almudena Alonso-Herrero, Heino Falcke

We present near-IR adaptive optics, VLA radio and HST optical imaging of the nearby Seyfert galaxy NGC2992. Spiral structure and an extension to the West are traced down to the core region at the limiting resolution of our near-IR images. A faint, diffuse loop of near-IR and radio emission is also observed to the north, embedded within the prominent 2 arcsec

T. P. Orlando, J. E. Mooji, Lin Tian, Caspar H. van der Wal

We present the design of a superconducting qubit that has circulating currents of opposite sign as its two states. The circuit consists of three nano-scale aluminum Josephson junctions connected in a superconducting loop and controlled by magnetic fields. The advantages of this qubit are that it can be made insensitive to background charges in the substrate,

Juan M. Maldacena, Jorge G. Russo

Using the correspondence between gauge theories and string theory in curved backgrounds, we investigate aspects of the large $N$ limit of non-commutative gauge theories by considering gravity solutions with $B$ fields. We argue that the total number of physical degrees of freedom at any given scale coincides with the commutative case. We then compute a two-p

Michal Horodecki, Pawel Horodecki, Ryszard Horodecki

We show that {\it any} entanglement measure $E$ suitable for the regime of high number of entangled pairs satisfies $E_D\leq E\leq E_F$ where $E_D$ and $E_F$ are entanglement of distillation and formation respectively. We also exhibit a general theorem on bounds for distillable entanglement. The results are obtained by use of a very transparent reasoning bas

David B. Massey

A working mathematician's summary of many results on the derived category, perverse sheaves, and vanishing cycles. This is the August 2025 version, with a completely revised section on vanishing cycles.

J. Ruostekoski

We theoretically study the optical properties of a Fermi-Dirac gas in the presence of a superfluid state. We calculate the leading quantum-statistical corrections to the standard column density result of the electric susceptibility. We also consider the Bragg diffraction of atoms by means of light-stimulated transitions of photons between two intersecting la

Nathan Salwen, Dean Lee

We use the massless Thirring model to demonstrate a new approach to non-perturbative fermion calculations based on the spherical field formalism. The methods we present are free from the problems of fermion doubling and difficulties associated with integrating out massless fermions. Using a non-perturbative regularization, we compute the two-point correlator

Stefanie Komossa, Jochen Greiner

We report the discovery of large-amplitude X-ray variability from the direction of the previously unknown, optically inactive galaxy pair RXJ1242.6-1119. The X-ray source shows variability by a factor > 20 between the ROSAT all-sky survey and a later pointed observation separated by ~1.5 yr. Its spectrum is extremely soft with photon index Gamma_x ~ -5, amon

Raghavan Rangarajan, Hiranmaya Mishra

The mass term for Majorana neutrinos explicitly violates lepton number. Several authors have used this fact to create a lepton asymmetry in the universe by considering CP violating effects in the one loop self-energy correction for the decaying heavy Majorana neutrino. We compare and comment on the different approaches used to calculate the lepton asymmetry

Ralph Blumenhagen, Lars Goerlich, Boris Kors

We study a new class of N=1 supersymmetric orientifolds in six space-time dimensions. The world-sheet parity transformation is combined with a permutation of the internal complex coordinates. In contrast to ordinary orientifolds the twisted sectors contribute to the Klein bottle amplitude leading to new tadpoles to be cancelled by twisted open string sectors

G. Colangelo, G. Isidori, J. Portoles

We analyze the supersymmetric contributions to direct-CP-violating observables in $K \to ππγ$ decays induced by gluino-mediated magnetic-penguin operators. We find that $\epsp_{+-γ}$ and the differential width asymmetry of $K^\pm \to π^\pm π^0 γ$ decays could be substantially enhanced with respect to their Standard Model values, especially in the scenario wh

R. J. McLure, J. S. Dunlop

We present the results of a comprehensive re-analysis of the images of a virtually complete sample of 28 powerful 3CR radio galaxies with redshifts 0.6<z<1.8 from the HST archive. Using a two-dimensional modelling technique we have derived scalelengths and absolute magnitudes for a total of 16 3CR galaxies with a median redshift of z=0.8. Our results confirm

Richard F. Lebed

A class of meson decay modes sensitive to only one quark topology at leading G_F order (annihilation of valence quarks through a W) is described. No experimental observations, nor even upper limits, have been reported for these decays. This work presents a simpleminded (order-of-magnitude) calculation of their branching fractions, and compares to results of