December 1997 arXiv papers — page 2

Hsiang-nan Li

I review the recent progress in small $x$ physics, concentrating on the topics relevant to the BFKL evolution.

Amand Faessler, Sergey Kovalenko, Fedor Simkovic

We discuss some phenomenological issues of the effective quark-lepton operators emerging from the bilinear lepton-Higgs couplings in the superpotential and in the soft supersymmetry (SUSY) breaking sector of the supersymmetric models without R-parity. The contribution of these operators to the neutrinoless double beta decay is derived. The corresponding nucl

A. A. Pivovarov

Local duality estimates for the $ρ$-meson leptonic width and the spectrum of radial excitations are updated. New perturbative corrections are included in the analysis that gives good agreement with experimental data on low energy resonances.

Kara Hoffman

We present the results of searches for Standard Model Higgs, charged stable massive particles, dijet mass resonances, and heavy neutral gauge bosons in Tevatron ppbar collisions at sqrt s = 1.8 TeV using the CDF and D0 detectors.

Pedro F. Gonzalez-Diaz

We review an attempt to set a suitable foundational principle for consistent quantization of gravity based on the canonical formulation. It requires extending the spacetime description of the relativistic postulates to also encompass an alternative formulation in momentum-energy continuum where the inertial physical laws can be equivalently described. The ex

H. -J. Schmidt

The conformal equivalence of fourth-order gravity following from a non-linear Lagrangian L(R) to theories of other types is widely known, here we report on a new conformal equivalence of these theories to theories of the same type but with different Lagrangian. For a quantization of fourth-order theories one needs a Hamiltonian formulation of them. One of th

D. Sornette, K. -T. Leung, J. V. Andersen

We argue that the existence of abrupt failure in the democratic fiber bundle model is more general than concluded by da Silveira in his comment (cond-mat/9709327). We refute his claim that the nature of the rupture process in the DFBM depends on the ``disorder distribution only via its large failure strength behavior''.

Alberto Garcia, David Vanderbilt

Using an effective Hamiltonian parametrized from first principles, Monte Carlo simulations are performed in order to study the piezoelectric response of BaTiO3 in the ferroelectric tetragonal phase as a function of temperature. The effect of an electric field on the phase behavior is also illustrated by a simulation of the transformation of a rhombohedral do

P. Dai, H. A. Mook, F. Dogan

Unpolarized inelastic neutron scattering is used to study the temperature and wave vector dependence of the dynamical magnetic susceptibility, $χ''(q,ω)$, of a well characterized single crystal $YBa_2Cu_3O_{6.6}$ ($T_c=62.7$ K). We find that a pseudogap opens in the spin fluctuation spectrum at temperatures well above $T_c$. We speculate that the app

S. Daul, R. M. Noack

We study the phase diagram of the one-dimensional Hubbard model with next-nearest-neighbor hopping using exact diagonalization, the density-matrix renormalization group, the Edwards variational ansatz, and an adaptation of weak-coupling calculations on the two-chain Hubbard model. We find that a substantial region of the strong-coupling phase diagram is ferr

Ajanta Bhowal

The onsets of toppling and dissipation in the BTW model are studied by computer simulation. The distributions of these two onset times and their dependences on the system size are also studied. Simple power law dependences of these two times on the system size are observed and the exponents are estimated. The fluctuation of the average (spatial) height in th

H. C. Lee, S. -R. Eric Yang

The charge and spin correlation functions of partially spin-polarized edge electrons of a quantum Hall bar are studied using effective Hamiltonian and bosonization techniques. In the presence of the Coulomb interaction between the edges with opposite chirality we find a different crossover behavior in spin and charge correlation functions. The crossover of t

Anirban Sain, Manu, Rahul Pandit

We present an extensive pseudospectral study of the randomly forced Navier-Stokes equation (RFNSE) stirred by a stochastic force with zero mean and a variance $\sim k^{4-d-y}$, where $k$ is the wavevector and the dimension $d = 3$. We present the first evidence for multiscaling of velocity structure functions in this model for $y \geq 4$. We extract the mult

K. Jahoda, M. J. Stark, T. E. Strohmayer, W. Zhang

GRO J1744-28, discovered by BATSE in December 95, is the second neutron star system known to produce frequent accretion powered bursts. The system has been regularly monitored with the RXTE PCA since the peak of the first outburst in January 96 at which time the observed persistent and bursting count rates were ~25,000 ct/sec and ~150,000 ct/sec, with corres

Eric H. Neilsen,, Zlatan I. Tsvetanov, Holland C. Ford

Using the surface brightness fluctuations in HST WFPC-2 images, we determine that M87, NGC 4486B, and NGC 4478 are all at a distance of ~16 Mpc, while NGC 4476 lies in the background at ~21 Mpc. We also examine the globular clusters of M87 using archived HST fields. We detect the bimodal color distribution, and find that the amplitude of the red peak relativ

Eve C. Ostriker

This paper reviews current theoretical work on the various stages of accretion in protostars, and the relationship of these ideal stages to the spectral classes of observed protostellar systems. I discuss scaling relationships that have been obtained for models of pre-stellar cores as they evolve by ambipolar diffusion toward a central singularity, and expec

J. W. Sulentic, P. Marziani, T. Zwitter, M. Calvani

We examine the properties of the Fe emission lines that arise near 6.4 keV in the ASCA spectra of AGN. Our emphasis is on the Seyfert 1 galaxies where broad and apparently complex Fe K alpha emission is observed. We consider various origins for the line but focus on the pros and cons for line emitting accretion disk models. We develop a simple model of an il

B. Guiderdoni

Recent optical observations have led to a significant progress in our understanding of galaxy formation and evolution. However, our view on the deep universe is currently limited to the starlight which directly escapes from high-redshift galaxies, since we so far ignore the fraction of luminosity absorbed by dust and released in the IR/submm wavelength range

E. Trussoni, F. Vagnetti, S. Massaglia, L. Feretti

We present the first results of BeppoSAX observations of a small sample of low brightness FRI radio galaxies. The flux of all the targets is consistent with a thermal spectrum, as due to the presence of hot intracluster gas or galactic corona. Moreover in three sources a non thermal absorbed spectrum can be present in the MECS spectrum at energies larger tha

T. Napier, M. Ramachandran

A new approach to Nori's weak Lefschetz theorem is described. The new approach, which involves the dbar-method, avoids moving arguments and gives much stronger results. In particular, it is proved that if X and Y are connected smooth projective varieties of positive dimension and f is a holomorphic immersion of Y into X with ample normal bundle, then the

M. Bando, J. Sato, K. Yoshioka

We analyze fermion mass-matrix structure in an asymptotically non-free model with 4 + 1bar generations. The texture at the GUT scale is uniquely determined by supposing that the masses of heavy up-type quarks (charm as well as top) are realized as their infrared fixed point values. By assuming SO(10) GUT-like relations for Yukawa couplings in this model, thi

G. Moore, N. Nekrasov, S. Shatashvili

We develop some useful techinques for integrating over Higgs branches in supersymmetric theories with 4 and 8 supercharges. In particular, we define a regularized volume for hyperkahler quotients. We evaluate this volume for certain ALE and ALF spaces in terms of the hyperkahler periods. We also reduce these volumes for a large class of hyperkahler quotients

Masahide Hirouchi, Minoru Tanaka

Lepton flavor violation at linear collider experiments is discussed. We show that detectable lepton flavor violation could occur through scalar lepton pair production and decay in the supersymmetric SU(5) grand unified theory in spite of the stringent present experimental constraints by rare process searches. Possible cross sections about 40fb for an e+e- co

Christophe Le Mouel, Gilbert Moultaka

We demonstrate, through the study of the one-loop effective potential in the MSSM, the existence of fully model-independent lower and upper theoretical bounds on $\tan β$. We give their general analytic form and illustrate some of their implications.

Peter Heinzner

Let G be a complex Lie group, G_R a real form of G and X a G_R-stable domain of holomorphy in a complex G-manifold. If there is a G_R-invariant strictly plurisubharmonic function on X which has certain exhaustion properties, then we show that the extended domain G.X is also a domain of holomorphy. As an application we give a proof of the extended future tube

Sergio Conti, Giovanni Vignale, A. H. MacDonald

We show that band-structure effects are likely to prevent superfluidity in semiconductor electron-hole double-layer systems. We suggest the possibility that superfluidity could be realized by the application of uniaxial pressure perpendicular to the electron and hole layers.

Alexander Esser, Siegfried Grossmann

We suggest a new, renormalization group (RG) based, nonperturbative method for treating the intermittency problem of fully developed turbulence which also includes the effects of a finite boundary of the turbulent flow. The key idea is not to try to construct an elimination procedure based on some assumed statistical distribution, but to make an ansatz for p

F. Darabi, M. A. Jafarizadeh, A. Rezaei-Aghdam

We study a model of free massless scalar fields on a two dimensional cylinder with metric that admits a change of signature between Lorentzian and Euclidean type (ET), across the two timelike hypersurfaces (with respect to Lorentzian region). Considering a long strip-shaped region of the cylinder, denoted by an angle θ, as the signature changed region it is

S. Ferrara, C. Fronsdal

We examine the boundary conditions associated with extended supersymmetric Maxwell theory in 5-dimensional anti-De Sitter space. Excitations on the boundary are identical to those of ordinary 4-dimensional conformal invariant super electrodynammics. Extrapolations of these excitations give rise to a 5-dimensional topological gauge theory of the singleton typ

A. V. Kitaev, A. H. Vartanian

Using the matrix Riemann-Hilbert factorization approach for nonlinear evolution systems which take the form of Lax-pair isospectral deformations and whose corresponding Lax operators contain both discrete and continuous spectra, the leading-order asymptotics as $t \to \pm \infty$ of the solution to the Cauchy problem for the modified nonlinear Schrödinger eq

Vladimir Kanovei

Theorem: Let $n\ge 2.$ There is a CCC in $L$ forcing notion $P=P_n\in L$ such that $P$-generic extensions of $L$ are of the form $L[a],$ where $a\subseteqω$ and 1) $a$ is $Δ^1_{n+1}$ in $L[a]$; and 2) if $b\in L[a],$ $b\subseteqω$ is $Σ^1_n$ in $L[a]$ then $b\in L$ and $b$ is $Σ^1_n$ in $L$. In addition, if a model $M$ extends $L$ and contains two different

Sergei Kerov

We study the Young graph with edge multiplicities arising in a Pieri-type formula for Jack symmetric polynomials $P_μ(x;a)$ with a parameter $a$. Starting with the empty diagram, we define recurrently the `dimensions' $\dim_a$ in the same way as for the Young lattice or Pascal triangle. New proofs are given for two known results. The first is the $a$-hoo

Katrin Becker, Melanie Becker

We compute graviton scattering amplitudes in M-theory using Feynman rules for a scalar particle coupled to gravity in eleven dimensions. The processes that we consider describe the single graviton exchange and the double graviton exchange, that in M(atrix) theory correspond to the $v^4/r^7$- and $v^6/r^{14}$-term respectively. We further show that the $ v^6/

Elena N. Selivanova

There is a well-known example of integrable conservative system on $S^2$, the case of Kovalevskaya in the dynamics of a rigid body, possessing an integral of fourth degree in momenta. Goryachev proposed a one-parameter family of examples of conservative systems on $S^2$ possessing an integral of fourth degree in momenta which includes the case of Kovalevskay

M. Furlan

We report on recent experimental results from transport measurements with large Hall bars made of high mobility GaAs/AlGaAs heterostructures. Thermally activated conductivities and hopping transport were investigated in the integer quantum Hall regime. The predominant transport processes in two dimensions are discussed. The implications of transport regime o

Takao Nakagawa, Yukari Yamashita Yui, Yasuo Doi, Haruyuki Okuda

We present results of our survey observations of the [C II] 158 micron line emission from the Galactic plane using the Balloon-borne Infrared Carbon Explorer (BICE). Our survey covers a wide area (350 deg < l < 25 deg, |b| < 3 deg) with a spatial resolution of 15&#39;. We employed a new observing method called the ``fast spectral scanning&#39;&#39; to make l

V. A. Gani, A. E. Kudryavtsev, T. I. Belova, B. L. Druzhinin

We discuss the space-time structure for the process of decay of a bubble of hypothetic phase -- disoriented chiral condensate (DCC). The evolution of the initial classical field configuration corresponding to the bubble of DCC is studied both numerically and analytically. The process of decay of this initial configuration depends crucially on selfinteraction

Roberto A. Monetti

A monomer-dimer reaction lattice model with lateral repulsion among the same species is studied using a mean-field analysis and Monte Carlo simulations. For weak repulsions, the model exhibits a first-order irreversible phase transition between two absorbing states saturated by each different species. Increasing the repulsion, a reactive stationary state app

Yupeng Wang

We show that the one-dimensional (1D) electron systems can also be described by Landau&#39;s phenomenological Fermi-liquid theory. Most of the known results derived from the Luttinger-liquid theory can be retrieved from the 1D Fermi-liquid theory. Exact correspondence between the Landau parameters and Haldane parameters is established. The exponents of the d

Kazuo Hida

The ground state of the square lattice bilayer quantum antiferromagnet with nearest ($J_1$) and next-nearest ($J_2$) neighbour intralayer interaction is studied by means of the dimer expansion method up to the 6-th order in the interlayer exchange coupling $J_3$. The phase boundary between the spin-gap phase and the magnetically ordered phase is determined f

Takashi Tonegawa, Toshiya Hikihara, Makoto Kaburagi, Tomotoshi Nishino

We investigate both analytically and numerically the ground-state and thermodynamic properties of the quantum mixed spin-1/2-1/2-1-1 chain described by the Hamiltonian $H=\sum_{\ell=1}^{N/4} (J_1\vecs_{4\ell-3}\cdot \vecs_{4\ell-2}+J_2\vecs_{4\ell-2}\cdot\vecS_{4\ell-1}+J_3\vecS_{4\ell-1}\cdot \vecS_{4\ell}+J_2\vecS_{4\ell}\cdot\vecs_{4\ell+1})$, where two $

E. -M. Ilgenfritz, B. V. Martemyanov, S. V. Molodtsov, M. Müller--Preussker

Field strength correlators are semi-classically evaluated in the dilute gas model of non-Abelian sources (instantons) and compared with lattice data for QCD at zero temperature. We show that one of the Euclidean invariant, tensorial structures vanishes for configurations being purely selfdual or anti-selfdual. We compute the invariant functions contributing

Julie D. Blum

We consider novel nonperturbative effects of type I theories compactified on singular ALE spaces obtained by adding NS branes. Such effects include a description of small $E_8$ instantons at singularities.

J. Goryo, K. Ishikawa

We show in this paper that Abelian Chern-Simons term is induced in 2+1 and 3+1 dimensional rotating superfluid $^{3}$He-A and plays important roles in its dynamics. Because U(1) symmetry is spontaneously broken in $^{3}$He-A, Goldstone mode appears and contributes to induced Chern-Simons term. We found that the coefficient of Chern-Simons term, which is equi

E. Mukhin, A. Varchenko

We consider the quantized Knizhnik-Zamolodchikov-Bernard difference equation (qKZB) with step $p$ and values in a tensor product of finite dimensional evaluation modules over the elliptic quantum group $E_{τ,η}(sl_2)$, the equation defined in terms of elliptic dynamical R-matrices. We solve the equation in terms of multidimensional q-hypergeometric integrals

Luis Gonzalez-Mestres

The Poincaré relativity principle has been tested at low energy with great accuracy, but its extrapolation to very high-energy phenomena is much less well established. Lorentz symmetry can be broken at Planck scale due to the renormalization of gravity or to some deeper structure of matter: we expect such a breaking to be a very high energy and very short di

H. Kleinert, A. Chervyakov

A general technique is developed for calculating functional determinants of second-order differential operators with Dirichlet, periodic, and antiperiodic boundary conditions. As an example, we give simple formulas for a harmonic oscillator with an arbitrary time-dependent frequency. Here our result is a generalization of Gel&#39;fand-Yaglom&#39;s famous for

Greg Hjorth

This paper obtains an algebraic characterization of the Polish groups that satisfy Vaught&#39;s conjecture on $\bfΣ^1_1$ sets.

T. Banks, W. Fischler, I. R. Klebanov

Recently, in collaboration with Susskind, we proposed a model of Schwarzschild black holes in Matrix theory. A large Schwarzschild black hole is described by a metastable bound state of a large number of D0-branes which are held together by a background, whose structure has so far been understood only in 8 and 11 dimensions. The Hawking radiation proceeds by

L. G. Mardoyan, A. N. Sissakian, V. M. Ter-Antonyan

In this report, in the framework of an analytical approach and with help of the generalized version of the Hurwitz transformation the five-dimensional SU(2)--monopole model is constructed from the eight-dimensional quantum oscillator. The SU(2)--monopole fields, the Clebsh-Gordan expansion stimulated by the space-gauge coupling, the hyperangle and the radial

T. Miyazaki, C. Ohzeki, M. Yamanobe

In the conventional $p$-brane theory, a gauge ($p+1$)-form field $ϕ^{(p+1)}$ mediates the interaction between $p$-branes, which is gauge invariant in the sense $ϕ^{(p+1)}\to ϕ^{(p+1)}+dΛ^{(p)}$ with $Λ^{(p)}$, an arbitrary $p$-form and $d$, a boundary operator. We, on the contrary, propose to introduce a new gauge field $ϕ^{(p+2)}$ mediating the interaction,

B. Tseng, Hsiang-nan Li

For the first time, a solution to the $a_2/a_1$ sign problem in heavy meson decay based on PQCD factorization theorems. The point is to include QCD evolution effort characteristic scales involved in decay processes.

B. Ananthanarayan

Chiral perturbation theory is the low energy effective theory of the strong interactions for the light pseudoscalar degrees of freedom. This program is based on effective Lagrangian techniques and is an expansion in the powers of the momenta and the powers of the quark masses, which correct the soft-pion theorems. After briefly reviewing these features and s

V. N. Baier, V. M. Katkov

The Landau, Pomeranchuk, Migdal (LPM) effect (suppression of the bremsstrahlung from high energy electron due to a multiple scattering of an emitting electron in dense media) is considered for the case when thickness of a target is of the order or less than the formation length of radiation. The effects of the polarization of a medium and transition radiatio

Motoo Sekiguchi, Hiroaki Wada, Shin Ishida

An interpretation that the HERA excess events are due to intermediate production and decay of composite leptoquarks in the left-right symmetric preon model is given. Because of the preon-line rule, expected to be valid well, the event-ratio of neutral to charged current interactions is predicted to be one.

Subhendra Mohanty, Sarira Sahu, Srubabati Goswami

We study the production of electron density waves by neutrinos propagating through a plasma. We treat this process in field theoretically as a Cerenkov emission of phonons (quanta of electron density waves) by neutrinos. We compute the energy transfered to the plasma by the neutrinos and apply it to the shock wave revival problem of supernovae.

Probir Roy

$R_p$ and motivation for explicit $R\!\!\!/}_p$, MSSM $\rightarrow$ $ R\!\!\!/}_p$ MSSM, Bounds on ${R\!\!\!/}_p$ couplings, Collider-specific phenomenology, Cosmological implications, Summary and outlook, References

Friedrich W. Hehl

We argue that from the point of view of gauge theory and of an appropriate interpretation of the interferometer experiments with matter waves in a gravitational field, the Einstein-Cartan theory is the best theory of gravity available. Alternative viable theories are general relativity and a certain teleparallelism model. Objections of Ohanian and Ruffini ag

Shingo Suzuki, Kei-ichi Maeda

We study stability of a circular orbit of a spinning test particle in a Kerr spacetime. We find that some of the circular orbits become unstable in the direction perpendicular to the equatorial plane, although the orbits are still stable in the radial direction. Then for the large spin case ($S < \sim O(1)), the innermost stable circular orbit (ISCO) appears

I. S. Tupitsyn

An effective Hamiltonian, describing quantum tunneling in ferrimagnetic nanoparticles which includes interactions between the electronic spins of nanoparticle and microscopic environmental spins (like nuclear spins or paramagnetic impurities), is obtained. Two limiting cases, describing tunneling in antiferromagnetic and ferromagnetic regimes are considered,

S. Tanda, K. Kagawa, T. Maeno, T. Nakayama

Experimental results of I-V characteristics near the superconductor-insulator transition observed for disorder-tuned YBaCuO thinfilms are presented. The I-V characteristics exibit new quasiperiodic structures as a function of the current. The current interval, the number of the dI/dV peaks, and the magnetic field dependence of the peaks are consistent with t

T. Tonegawa, T. Hikihara, T. Nishino, M. Kaburagi

Ground-state and thermodynamic properties of the one-dimensional Heisenberg antiferromagnet in which two S=1/2 and two S=1 spins are arranged alternatively are studied by a quantum Monte Carlo method and by analytical estimates. It is found that the ground state of the system undergoes a second-order phase transition which accompanies the vanishing of the en

Takashi Tonegawa, Takeshi Nishida, Makoto Kaburagi

Employing a method of exact diagonalization for finite-size systems, we investigate the magnetization curve in the ground state of an antiferromagnetic spin-1/2 ladder with additional exchange interactions on diagonal bonds, which is equivalent to an antiferromagnetic spin-1/2 chain with bond-alternating nearest-neighbor and uniform next-nearest-neighbor int

Yong-Jihn Kim

We reconsider the ordinary impurity effect on the transition temperature $T_{c}$ of superconductors using the Eliashberg formalism. It is shown that the correspondence principle, which relates strong-coupling and weak-coupling theories, works only when Anderson&#39;s pairing condition between the time-reversed scattered-states is used. For an Einstein phonon

Abdel Mouneim Ettouhami

This paper has been withdrawn.

T. E. Strohmayer, E. E. Fenimore, T. Murakami, Y. Yoshida

The proportional counter and scintillator on Ginga provided unprecented spectral coverage of GRBs, from 2 - 400 keV. Below 20 keV we find evidence for a positive spectral number index in approximately 40% of our burst sample, with some evidence for a strong rolloff at lower energies in a few events. There is a correlation (Pearson&#39;s r = -0.62) between th

E. E. Fenimore

We have averaged bright BATSE bursts to uncover the average overall temporal and spectral evolution of gamma-ray bursts (GRBs). We align the temporal structure of each burst by setting its duration to a standard duration, which we call T_<Dur>. The observed average ``aligned $T_<Dur>&#39;&#39; profile for 32 bright bursts with intermediate durations (16 to 4

C. A. Katz, J. N. Hewitt, C. B. Moore, B. E. Corey

The Survey for Transient Astronomical Radio Emission (STARE) is a wide-field monitor for transient radio emission at 611 MHz on timescales of fractions of a second to minutes. Consisting of multiple geographically separated total-power radiometers which measure the sky power every 0.125 sec, STARE has been in operation since March 1996. In its first seventee

Leonid M. Ozernoy

Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent improvements in observing techniques. A key element that makes a further use of this combination feasible is the periodicity

B. K. Agrawal, A. Ansari

In a realistic application of the SPA + RPA theory for calculation of the nuclear level densities we find that quantal fluctuation corrections (RPA) are important even up to temperature $T = 2.0 MeV$. This leads to a good agreement between calculated numbers and the available experimental data for $^{104}Pd$ and $^{114}Sn$, particularly the excitation energy

Hideo Suganuma, Kazuhisa Amemiya

We study the gluon propagator in the MA gauge with the lattice QCD Monte Carlo simulation. The simulation is performed using the heat-bath algorithm on the SU(2) lattice with $12^3 \times 24$ and $β= 2.3, 2.35$. The propagator of the off-diagonal charged gluon behaves as the massive gauge boson and provides the short-range interaction, while the diagonal glu

Boris Dubrovin, Youjin Zhang

We compute the genus one correction to the integrable hierarchy describing coupling to gravity of a 2D topological field theory. The bihamiltonian structure of the hierarchy is given by a classical W-algebra; we compute the central charge of this algebra. We also express the generating function of elliptic Gromov - Witten invariants via tau-function of the i

A. Tomita, K. Ohta, K. Nakanishi, T. T. Takeuchi

We present H-alpha velocity fields of thirteen giant H II regions in four nearby dwarf irregular galaxies, NGC 2366, Holmberg II, IC 2574, and WLM. We classify the velocity features as well as the morphologies of the H II regions. The H-alpha velocity features are divided into three categories; three H II regions show chaotic feature with a typical scale of

Katsuhisa Mimachi

We construct an integral representation of eigenfunctions for Macdonald&#39;s $q$-difference operator associated with the root system of type $C_n .$ It is given in terms of a restriction of a $q$-Jordan-Pochhammer integral. Choosing a suitable cycle of the integral, we obtain an integral representation of a special case of the Macdonald polynomial for the r

Anatol N. Kirillov

We study an action of the skew divided difference operators on the Schubert polynomials and give an explicit formula for structural constants for the Schubert polynomials in terms of certain weighted paths in the Bruhat order on the symmetric group. We also prove that, under certain assumptions, the skew divided difference operators transform Schubert polyno

J. F. van Diejen

A multidimensional generalization of Bailey&#39;s very-well-poised bilateral basic hypergeometric ${}_6ψ_6$ summation formula and its Dougall type ${}_5H_5$ hypergeometric degeneration for $q\to 1$ is studied. The multiple Bailey sum amounts to an extension corresponding to the case of a nonreduced root system of certain summation identities associated to th

Atsunori Tanaka, Hideo Suganuma

We study the dual Wilson loop and the inter-monopole potential(the static potential between the color magnetic monopoles) in the maximally abelian gauge to clarify the dual Higgs mechanism induced by monopole condensation. There is no (color-)electric current in the monopole part, which includes the essence of the nonperturbative QCD, and hence the system ca

M. Yu. Konstantinov

The conditions of the traversable wormhole joining with the exterior space-time are considered in details and the mixed boundary problem for the Einstein equations is formulated. It is shown that, in opposite to some declarations, the conditions of the wormhole joining with the exterior space-time have non-dynamical nature and can not be defined by the physi

Nandor Sieben

The notions of Busby-Smith and Green type twisted actions are extended to discrete unital inverse semigroups. The connection between the two types, and the connection with twisted partial actions, are investigated. Decomposition theorems for the twisted crossed products are given.

Hiroshi Imamura, Hideo Aoki, Peter A. Maksym

The total spin of correlated electrons in a quantum dot changes with magnetic field and this effect is generally linked to the change in the total angular momentum from one magic number to another, which can be understood in terms of an `electron molecule&#39; picture for strong fields. Here we propose to exploit this fact to realize a spin blockade, i.e., e

Hiroshi Imamura, Peter A. Maksym, Hideo Aoki

A molecular description for magic-number configurations of interacting electrons in a quantum dot in high magnetic fields developed by one of the authors has been elaborated for four, five and six electron dots. For four electrons, the magic spin-singlet states are found to alternate between two different resonating valence bond (RVB)-like states. For the fi

Kazuo Hida

The low temperature magnetization process of the ferromagnetic-antiferromagnetic Heisenberg chain is studied using the interacting boson approximation. In the low field regime and near the saturation field, the spin wave excitations are approximated by the $δ$ function boson gas for which the Bethe ansatz solution is available. The finite temperature propert

G. S. Bisnovatyi-Kogan, A. V. Dorodnitsyn

We have considered a stationary outflowing envelope from the star accelerated by the radiative force in arbitrary optical depth case. Introduced approximations provide satisfactory description of the behavior of the matter flux with partially separated radiation at arbitrary optical depths. The obtained system of differential equations provides a continuous

R. Misra, A. K. Kembhavi

We show that the Iron K emission line from MCG-6-30-15 could be broadened due to Comptonization by a surrounding highly ionized cloud with radius $\sim 10^{14}$ cms. We calculate the temperature of the cloud to be $\sim0.21\kev$, provided a reasonable estimate of the UV flux is made. The X-ray/$γ$-ray emission observed from the source is compatible with this

Alon E. Faraggi, Jogesh C. Pati

Recently a promising mechanism for supersymmetry breaking that utilizes both an anomalous U(1) gauge symmetry and an effective mass term m ~ 1TeV of certain relevant fields has been proposed. In this paper we examine whether such a mechanism can emerge in superstring derived free fermionic models. We observe that certain three generation string solutions, th

F. T. Brandt, J. Frenkel, A. Guerra

We derive the classical transport equation, in scalar field theory with a V(phi) interaction, from the equation of motion for the quantum field. We obtain a very simple, but iterative, expression for the effective action which generates all the n-point Green functions in the high-temperature limit. An explicit closed form is given in the static case.

Kenji Suzuki

We study the Euler numbers and the entropies of the non-extremal intersecting D-branes in ten-dimensions. We use the surface gravity to constrain the compactification radii. We correctly obtain the integer valued Euler numbers for these radii. Moreover, the entropies are found to be invariant under the T-duality transformation. In the extremal limit, we obta

S. Kachru, A. Lawrence, E. Silverstein

We point out that the matrix description of M-theory compactified on Calabi-Yau threefolds is in many respects simpler than the matrix description of a $T^6$ compactification. This is largely because of the differences between D6 branes wrapped on Calabi-Yau threefolds and D6 branes wrapped on six-tori. In particular, if we define the matrix theory following

J. F. Corney, G. J. Milburn

We investigate a non-destructive measurement technique to monitor Josephson-like oscillations between two spatially separated neutral atom Bose-Einstein condensates. One condensate is placed in an optical cavity, which is strongly driven by a coherent optical field. The cavity output field is monitored using a homodyne detection scheme. The cavity field is w

Uwe Mueller, Christian Schubert, Anton van de Ven

We derive an integral representation which encodes all coefficients of the Riemann normal coordinate expansion, and also a closed formula for those coefficients.

J. Hyam Rubinstein, Martin Scharlemann

It was shown by Bonahon-Otal and Hodgson-Rubinstein that any two genus-one Heegaard splittings of the same 3-manifold (typically a lens space) are isotopic. On the other hand, it was shown by Boileau, Collins and Zieschang that certain Seifert manifolds have distinct genus-two Heegaard splittings. In an earlier paper, we presented a technique for comparing H

Luis Gonzalez-Mestres

Special relativity has been tested at low energy with great accuracy, but these results cannot be extrapolated to very high-energy phenomena: this new domain of physics may actually provide the key to the, yet unsettled, question of the ether and the absolute rest frame. Introducing a critical distance scale, a, below 10E-25 cm (the wavelength scale of the h

Bogdan Morariu

I introduce a reality structure on the Heisenberg double of Fun_q(SL(N,C)) for q phase, which for N=2 can be interpreted as the quantum phase space of the particle on the q-deformed mass-hyperboloid. This construction is closely related to the q-deformation of the symmetric top. Finally, I conjecture that the above real form describes zero modes of certain n

P. Danielewicz, D. Kiderlen

Generalization of Gaussian trial wave functions in quantum molecular dynamics models is introduced, which allows for long-range correlations characteristic for composite nuclear fragments. We demonstrate a significant improvement in the description of light fragments with the correlations. Utilizing either type of Gaussian wave functions, with or without cor

Charles Radin, Lorenzo Sadun

We consider tilings of Euclidean spaces by polygons or polyhedra, in particular, tilings made by a substitution process, such as the Penrose tilings of the plane. We define an isomorphism invariant related to a subgroup of rotations and compute it for various examples. We also extend our analysis to more general dynamical systems.

Lorenzo Sadun

We introduce a new family of nonperiodic tilings, based on a substitution rule that generalizes the pinwheel tiling of Conway and Radin. In each tiling the tiles are similar to a single triangular prototile. In a countable number of cases, the tiles appear in a finite number of sizes and an infinite number of orientations. These tilings generally do not meet

Kurt Lechner

We review a recently developed covariant Lagrangian formulation for $p$--forms with (anti)self-dual field-strengths and present its extension to the supersymmetric case. As explicit examples we construct covariant Lagrangians for six-dimensional models with N=1 rigid and curved supersymmetry.

Duiliu-Emanuel Diaconescu, Michael R. Douglas, Jaume Gomis

We discuss the ``fractional D-branes'' which arise in orbifold resolution. We argue that they arise as subsectors of the Coulomb branch of the quiver gauge theory used to describe both string theory D-brane and Matrix theory on an orbifold, and thus must form part of the full physical Hilbert space. We make further observations confirming their interpretatio

M. Blagojević

Basic features of the conservation laws in the Hamiltonian approach to the Poincaré gauge theory are presented. It is shown that the Hamiltonian is given as a linear combination of ten first class constraints. The Poisson bracket algebra of these constraints is used to construct the gauge generators. By assuming that the asymptotic symmetry is the global Poi

Jonathan M. Evans, Jens Ole Madsen

We discuss certain integrable quantum field theories in (1+1)-dimensions consisting of coupled sine/sinh-Gordon theories with N=1 supersymmetry, positive kinetic energy, and bosonic potentials which are bounded from below. We show that theories of this type can be constructed as Toda models based on the exceptional affine Lie superalgebra $D(2,1;\A)^{(1)}$ (