May 2000 arXiv papers

M. J. Graf, A. V. Balatsky

We have analyzed heat capacity and thermal conductivity measurements of Sr2RuO4 in the normal and superconducting state and come to the conclusion that an order parameter with nodal lines on the Fermi surface is required to account for the observed low-temperature behavior. A gapped order parameter is inconsistent with the reported thermodynamic and transpor

Vinod B. Johri

The role of the quintessence field as a probable candidate for the repulsive dark energy, the conditions for tracking and the requisites for tracker fields are examined. The concept of `integrated tracking' is introduced and a new criterion for the existence of tracker potentials is derived assuming monotonic increase in the scalar energy density paramet

A. P. Balachandran, E. Batista, I. P. Costa e Silva, P. Teotonio-Sobrinho

It has been known for some time that topological geons in quantum gravity may lead to a complete violation of the canonical spin-statistics relation : there may exist no connection between spin and statistics for a pair of geons. We present an algebraic description of quantum gravity in (2 + 1)d based on the first order formalism of general relativity and sh

J. T. Lenaghan

The SU(3)_{r} \times SU(3)_{\ell} linear sigma model is used to study the chiral symmetry restoring phase transition of QCD at nonzero temperature. The line of second order phase transitions separating the first order and smooth crossover regions is located in the plane of the strange and nonstrange quark masses. It is found that if the U(1)_{A} symmetry is

H. Arodz, R. Pelka

Interfaces in a model with a single, real nonconserved order parameter and purely dissipative evolution equation are considered. We show that a systematic perturbative approach, called the expansion in width and developed for curved domain walls, can be generalized to the interfaces. Procedure for calculating curvature corrections is described. We also deriv

E. Akkermans, D. M. Gangardt, K. Mallick

We present an analysis of the magnetic response of a mesoscopic superconductor, i.e. a system of sizes comparable to the coherence length and to the London penetration depth. Our approach is based on special properties of the two dimensional Ginzburg-Landau equations, satisfied at the dual point $(κ= \frac{1}{\sqrt{2}}).$ Closed expressions for the free ener

Daisuke Ida

A common property of known black hole solutions in (2+1)-dimensional gravity is that they require a negative cosmological constant. In this letter, it is shown that a (2+1)-dimensional gravity theory which satisfies the dominant energy condition forbids the existence of a black hole to explain the above situation.

Luis Masperi, Milva Orsaria

Observed events of ultra-high energy cosmic rays may indicate a hard component for the energy spectrum of their flux, which might have origin in the decay of long-lived vortons presumably condensed in the galactic halo. To be consistent with the needed present density, vortons may have been formed during the breaking of an abelian symmetry contained in a lar

M. Picco, F. Ricci-Tersenghi, F. Ritort

We investigate chaotic, memory and cooling rate effects in the three dimensional Edwards-Anderson model by doing thermoremanent (TRM) and AC susceptibility numerical experiments and making a detailed comparison with laboratory experiments on spin glasses. In contrast to the experiments, the Edwards-Anderson model does not show any trace of re-initialization

L. Giusti, A. Vladikas

We perform a comparative study of the ratio of lattice (Wilson fermion) renormalization constants Z_P/Z_S, obtained non-perturbatively from the RI/MOM renormalization conditions and from Ward Identities of on- and off-shell Green's functions. The off-shell Ward Identity used in this work relies on correlation functions with non-degenerate quark masses. W

N. Mankoc Borstnik, H. B. Nielsen

We are answering the question why 4-dimensional space has the metric 1+3 by making a general argument from a certain type of equations of motion linear in momentum for any spin (except spin zero) in any even dimension d. All known free equations for non-zero spin for massless fields belong to this type of equations. Requiring Hermiticity(This is a generaliza

S. J. van Enk, J. McKeever, H. J. Kimble, J. Ye

We present detailed discussions of cooling and trapping mechanisms for an atom in an optical trap inside an optical cavity, as relevant to recent experiments. The interference pattern of cavity QED and trapping fields in space makes the trapping wells distinguishable from one another. This adds considerable flexibility to creating effective trapping and cool

M. C. Banuls, J. Bernabeu

In this work we analyze the observable asymmetries one can build from entangled B-meson states, in order to extract information on the parameters epsilon and delta which govern indirect violation of discrete symmetries. The traditionally proposed observables, based on flavour tags, are not helpful for the study of the Bd-system, where the tiny value of the w

T. Mizoguchi, M. Biyajima

The recent data for Bose-Einstein Correlations (BEC) of three-charged particles obtained by NA44 Collaboration have been analysed using theoretical formula with Coulomb wave functions. It has been recently proposed by Alt et al. It turns out that there are discrepancies between these data and the respective theoretical values. To resolve this problem we seek

Yun-Young Choi, Jongmann Yang, Insu Yi

We investigate a large number of cosmological evolution models for QSOs and Active Galactic Nuclei (AGN). We introduce a spectrum-luminosity correlation as a new input parameter and adopt the estimated mass function (MF) of massive black holes in centers of nearby galactic nuclei as a constraint to distinguish among different QSO/AGN models. We explore three

Amir Aghamohammadi, Mohammad Khorrami

The exact solution for a system with two-particle annihilation and decoagulation has been studied. The spectrum of the Hamiltonian of the system is found. It is shown that the steady state is two-fold degenerate. The average number density in each cite <n_i(t)> and the equal time two-point functions <n_i(t), n_j(t)> are calculated. Any equal time correlation

A. A. Shatskiy, A. Yu. Andreev

The radial motion of matter in a centrally symmetric gravitational field in a comoving reference frame is investigated for a realistic equation of state of matter. The dynamics of the formation of an event horizon are investigated.

B. Chen, H. Itoyama, T. Matsuo, K. Murakami

We study worldsheet and spacetime properties of the p-p&#39; (p < p&#39;) open string system with constant B_{ij} field viewed from the Dp&#39; brane. The description of this system in terms of the CFT with spin and twist fields leads us to consider the renormal ordering procedure from the SL(2,R) invariant vacuum to the oscillator vacuum. We compute the att

W. Beenakker, A. Werthenbach

To match the expected experimental precision at future linear colliders, improved theoretical predictions beyond next-to-leading order are required. At the anticipated energy scale of sqrt(s)=1 TeV the electroweak virtual corrections are strongly enhanced by collinear-soft Sudakov logarithms of the form log^2(s/M^2), with M being the generic mass scale of th

Yu. B. Ivanov, J. Knoll, H. van Hees, D. N. Voskresensky

Effects of the propagation of particles, which have a finite life-time and an according width in their mass spectrum, are discussed in the context of transport description. First, the importance of coherence effects (Landau-Pomeranchuk-Migdal effect) on production and absorption of field quanta in non-equilibrium dense matter is considered. It is shown that

Cong-Feng Qiao, Changzheng Yuan

The production of Charmonium states $\etacp$ and $\hc$ at fixed-target experiment of $pN$ collisions at HERA-$B$ is considered. It is found that the HERA-$B$ at DESY is one of the best machines in further confirming and detecting these two kinds of Charmonia in the near future.

Edward Malec

Electromagnetic waves propagate in the Schwarzschild spacetime like in a nonuniform medium with a varying refraction index. A fraction of the radiation scatters off the curvature of the geometry. The energy of the backscattered part of an initially outgoing pulse of electromagnetic radiation can be estimated, in the case of dipole radiation, by a compact for

L. J. Garay, J. R. Anglin, J. I. Cirac, P. Zoller

The sonic analog of a gravitational black hole in dilute-gas Bose-Einstein condensates is investigated. It is shown that there exist both dynamically stable and unstable configurations which, in the hydrodynamic limit, exhibit a behavior completely analogous to that of gravitational black holes. The dynamical instabilities involve creation of quasiparticle p

Silvano Simula

Existing data on the (unpolarised) transverse structure function of the proton are analyzed for large values of the Bjorken variable x. The leading-twist and a phenomenological higher-twist contributions are simultaneously determined from a power correction analysis of the Nachtmann moments for values of the squared four-momentum transfer between ~ 1 and 20

T. Asaga, T. Fujita, M. Hiramoto

We present generalized Schiff&#39;s transformation on electric dipole moments (EDM) in quantum field theory. By the unitary transformation, the time and parity violating interaction $i{ge\over 2} \bar ψσ_{μν} γ_5 ψF^{μν}$ is transformed into a new form, but its nonrelativistic reduction has a unique form, which is free from Schiff&#39;s theorem. The relativi

Taekoon Lee

We discuss an interesting possibility of nontrivial, quark-mass induced chiral vacuum alignment in color-flavor locking phase of cold, dense QCD. With the simplifying assumption that the gaps for quarks are identical to those of antiquarks and the light quark masses are given by $m_u = m_d$ and $ m_s/m_d=15$, we find the true chiral vacuum can align only to

J. Mark Ettinger

Time-frequency transforms represent a signal as a mixture of its time domain representation and its frequency domain representation. We present efficient algorithms for the quantum Zak transform and quantum Weyl-Heisenberg transform.

V. Hnizdo

A frequently given version of the argument of Einstein, Podolsky and Rosen against the completeness of the quantum mechanical description is criticized as a misrepresentation that lacks the cogency of the original EPR argument.

H. K. Avetissian, A. L. Khachatryan, G. F. Mkrtchian

Within the scope of the relativistic quantum theory for electron-laser interaction in a medium and using the resonant approximation for the two degenerated states of an electron in a monochromatic radiation field [1] a nonperturbative solution of the Dirac equation (nonlinear over field solution of the Hill type equation) are obtained. The multiphoton cross

Kazuyuki Fujii

We in this paper consider a further generalization of the (optical) holonomic quantum computation proposed by Zanardi and Rasetti (quant-ph/9904011), and reinforced by Fujii (quant-ph/9910069) and Pachos and Chountasis (quant-ph/9912093). We construct a quantum computational bundle on some parameter space, and calculate non-abelian Berry connections and curv

F. Yamaguchi, C. P. Master, Y. Yamamoto

A quantum computer is a multi-particle interferometer that comprises beam splitters at both ends and arms, where the n two-level particles undergo the interactions among them. The arms are designed so that relevant functions required to produce a computational result is stored in the phase shifts of the 2^n arms. They can be detected by interferometry that a

P. Warszawski, H. M. Wiseman

Feedback in compound quantum systems is effected by using the output from one sub-system (``the system&#39;&#39;) to control the evolution of a second sub-system (``the ancilla&#39;&#39;) which is reversibly coupled to the system. In the limit where the ancilla responds to fluctuations on a much shorter time scale than does the system, we show that it can be

Detlef Kip, Marin Soljacic, Mordechai Segev, Evgenia Eugenieva

We present the first experimental observation of modulation instability of partially spatially incoherent light beams in non-instantaneous nonlinear media. We show that even in such a nonlinear partially coherent system (of weakly-correlated particles) patterns can form spontaneously. Incoherent MI occurs above a specific threshold that depends on the beams&

J. L. Friar

Most nuclear physics ranges from insensitive to relatively insensitive to many-nucleon forces. The dominant ingredient in calculations of nuclear properties is the nucleon-nucleon potential. Three-nucleon forces nevertheless play an important role in nuclear physics because of the great precision of modern calculational methods for systems of relatively few

Eurico Covas, Reza Tavakol

It has recently been shown that nonlinear skew product dynamical systems with invariant subspaces which are capable of displaying on-off intermittency can show supersensitivity to small input signals. Here we show that this supersensitivity is absent for more general dynamical systems with non-skew product structure, capable of displaying a generalized form

Anna Maria Morgante, Magnus Johansson, Georgios Kopidakis, Serge Aubry

In one-dimensional anharmonic lattices, we construct nonlinear standing waves (SWs) reducing to harmonic SWs at small amplitude. For SWs with spatial periodicity incommensurate with the lattice period, a transition by breaking of analyticity versus wave amplitude is observed. As a consequence of the discreteness, oscillatory linear instabilities, persisting

L. Ts. Adzhemyan, N. V. Antonov, M. Hnatič, S. V. Novikov

Field theoretic renormalization group and the operator product expansion are applied to a model of a passive scalar field, advected by the Gaussian strongly anisotropic velocity field. Inertial-range anomalous scaling behavior is established, and explicit asymptotic expressions for the n-th order structure functions of scalar field are obtained; they are rep

Steven Duplij, Wladyslaw Marcinek

We propose to extend ``invertibility&#39;&#39; to ``regularity&#39;&#39; for categories in general abstract algebraic manner. Higher regularity conditions and ``semicommutative&#39;&#39; diagrams are introduced. Distinction between commutative and ``semicommutative&#39;&#39; cases is measured by non-zero obstruction proportional to the difference of some sel

Brian C. Hall

These notes give an elementary introduction to Lie groups, Lie algebras, and their representations. Designed to be accessible to graduate students in mathematics or physics, they have a minimum of prerequisites. Topics include definitions and examples of Lie groups and Lie algebras, the relationship between Lie groups and Lie algebras via the exponential map

Roberto De Leo

We show that ``ergodic regime&#39;&#39; appears for generic dispersion relations in the semiclassical motion of electrons in a metal and we prove that, in the fixed energy picture, the measure of the set of such directions is zero.

Dan Abramovich, Kalle Karu, Kenji Matsuki, Jarosław Włodarczyk

Building on the work of the fourth author in math.AG/9904074, we prove the weak factorization conjecture for birational maps in characteristic zero: a birational map between complete nonsingular varieties over an algebraically closed field K of characteristic zero is a composite of blowings up and blowings down with smooth centers. Such a factorization exist

J. M. Landsberg, J. Piontkowski

Withdrawn by the authors, the main theorem is incorrect

Paul Seidel

In the usual setup, the grading on Floer homology is relative: it is unique only up to adding a constant. &#34;Graded Lagrangian submanifolds&#34; are Lagrangian submanifolds with a bit of extra structure, which fixes the ambiguity in the grading. The idea is originally due to Kontsevich. This paper contains an exposition of the theory. Several applications

Dan Haran, Moshe Jarden, Jochen Koenigsmann

The free profinite product of finitely many absolute Galois group is an absolute Galois group.

Alexander Schmidt

We extend the notion of a tame covering of a pair (X,D) where X is a regular scheme and D is a normal crossing divisor (cf. SGA1), to pairs (X,Y) where X is an arbitrary scheme and Y is a closed subset in X. We show that the abelianized tame fundamental group of a regular scheme which is flat and of finite type over Spec(Z) is finite and does not depend on t

J. Brian Conrey

In 1972 H. L. Montgomery announced a remarkable connection between the distribution of the zeros of the Riemann zeta-function and the distribution of eigenvalues of large random Hermitian matrices. Since then a number of startling developments have occurred making this connection more profound. In particular, random matrix theory has been found to be an extr

Bang-He Li

For Seifert manifold $M=X({p_1}/_{\f{q_1}},{p_2}/_{\f{q_2}}, ...,{p_n}/_ {\f{q_n}}), τ^{&#39;}_r(M)$ is calculated for all $r$ odd $\geq 3$. If $r$ is coprime to at least $n-2$ of $p_k$ (e.g. when $M$ is the Poincare homology sphere), it is proved that $(\sqrt {\dfrac{4}{r}}\sin \dfracπ{r})^ντ^{&#39;}_r(M)$ is an algebraic integer in the r-th cyclotomic fiel

Ya-Qing Li

In the framework of nonstandard analysis, Bang-He Li and the author defined the product of any two distributions on $R^n$ via their harmonic representations. The product of $δ(x_{1},..., x_{n})$ and $δ(x_{1})$ was calculated by Kuribayashi and the author in [LK]. In this paper, the result of [LK] is improved to $$δ(x_{1},..., x_{n})\circ δ(x_{1}) =\dfrac{1}{

Bang-He Li, Tian-Jun Li

Two lens spaces are given to show that Ohtsuki&#39;s $τ$ for rational homology spheres does not determine Kirby-Melvin&#39;s $\{τ_r^{&#39;}, r odd\geq3\}$

Gregory F. Lawler, Oded Schramm, Wendelin Werner

We show that the intersection exponents for planar Brownian motions are analytic. More precisely, let $B$ and $B&#39;$ be independent planar Brownian motions started from distinct points, and define the exponent $ξ(1, λ)$ by $$ E[P[B[0,t] \cap B&#39;[0,t] = \emptyset | B[0,t]]^λ] \approx t^{-ξ(1, λ)/2}, t \to \infty. $$ Then the mapping $λ\mapsto ξ(1, λ)$ is

Gregory F. Lawler, Oded Schramm, Wendelin Werner

This paper determines values of intersection exponents between packs of planar Brownian motions in the half-plane and in the plane that were not derived in our first two papers. For instance, it is proven that the exponent $ξ(3,3)$ describing the asymptotic decay of the probability of non-intersection between two packs of three independent planar Brownian mo

A. Higuchi, B. S. Kay, C. M. Wood

The stability of the 3-dimensional Hopf vector field, as a harmonic section of the unit tangent bundle, is viewed from a number of different angles. The spectrum of the vertical Jacobi operator is computed, and compared with that of the Jacobi operator of the identity map on the 3-sphere. The variational behaviour of the 3-dimensional Hopf vector field is co

William M. Goldman, Gregory A. Margulis

This paper gives a new proof of a result of Geoff Mess that the linear holonomy group of a complete flat Lorentz 3-manifold cannot be cocompact in SO(2,1). The proof uses a signed marked Lorentzian length-spectrum invariant developed by G.Margulis, reinterpreted in terms of deformations of hyperbolic surfaces.

Vladimir Turaev

A 3-dimensional homotopy quantum field theory (HQFT) can be described as a TQFT for surfaces and 3-cobordisms endowed with homotopy classes of maps into a given space. For a group $π$, we introduce a notion of a modular crossed $π$-category and show that such a category gives rise to a 3-dimensional HQFT with target space $K(π,1)$. This includes numerical in

Hitoshi Murakami

I calculate optimistically asymptotic behaviors of the WRT SU(2) invariants for the three-manifolds obtained from the figure-eight knot by p-surgeries with p=0,1,2,...,10, from which one can extract volumes and the Chern-Simons invariants of these closed manifolds. I conjecture that this also holds for general closed three-manifolds.

Martin Schlichenmaier

By the quantization condition compact quantizable Kaehler manifolds can be embedded into projective space. In this way they become projective varieties. The quantum Hilbert space of the Berezin-Toeplitz quantization (and of the geometric quantization) is the projective coordinate ring of the embedded manifold. This allows for generalization to the case of si

N. Tsilevich, A. Vershik, M. Yor

We study fundamental properties of the gamma process and their relation to various topics such as Poisson-Dirichlet measures and stable processes. We prove the quasi-invariance of the gamma process with respect to a large group of linear transformations. We also show that it is a renormalized limit of the stable processes and has an equivalent sigma-finite m

Yucai Su, Xiaoping Xu

One of the four well-known series of simple Lie algebras of Cartan type is the series of Lie algebras of Special type, which are divergence-free Lie algebras associated with polynomial algebras and the operators of taking partial derivatives, connected with volume-preserving diffeomorphisms. In this paper, we determine the structure space of the divergence-f

Andrew Kricker

This work develops some technology for accessing the loop expansion of the Kontsevich integral of a knot. The setting is an application of the LMO invariant to certain surgery presentations of knots by framed links in the solid torus. A consequence of this technology is a certain recent conjecture of Rozansky&#39;s. Rozansky conjectured that the Kontsevich i

Gary T. Horowitz, Veronika E. Hubeny

It is commonly believed that small black holes in AdS_5 x S^5 can be described by the ten dimensional Schwarzschild solution. This requires that the self-dual five-form (which is nonzero in the background) does not fall through the horizon and cause the black hole to grow. We verify that this is indeed the case: There are static solutions to the five-form fi

A. I. Davydychev, M. Yu. Kalmykov

Some problems related to construction of the epsilon-expansion of dimensionally regulated Feynman integrals are discussed. For certain classes of diagrams, an arbitrary term of the epsilon-expansion can be expressed in terms of log-sine integrals related to the polylogarithms. It is shown how the analytic continuation of these functions can be constructed in

E. V. Gorbar

Chiral symmetry breaking in the Nambu-Jona-Lasinio model in a constant magnetic field is studied in spacetimes of dimension D > 4. It is shown that a constant magnetic field can be characterized by [(D-1)/2] parameters. For the maximal number of nonzero field parameters, we show that there is an effective reduction of the spacetime dimension for fermions in

Morten Nielsen, N. K. Nielsen

Wigner&#39;s method of induced representations is applied to the N=1 super-Poincare group, and by using a state corresponding to the basic vector of the little group as a Clifford vacuum we show that the spin operator of a supersymmetric point particle obeys Wigner&#39;s constraints. As dynamical variables for the particle we use canonical coordinates on the

A. V. Kopylov

The comparison of magnetic moments of neutron and proton reveals three possible states of a nucleon with the same correction of 0.033 for the central quarks. This may be interpreted as the contribution of a universal coupling as the common value where all the running couplings unite.

C. Anastasiou, J. B. Tausk, M. E. Tejeda-Yeomans

Using a Mellin-Barnes representation, we compute the on-shell massless planar double box Feynman diagram with an irreducible scalar product of loop momenta in the numerator. This diagram is needed in calculations of two loop corrections to scattering processes of massless particles, together with the double box without numerator calculated previously by Smir

Alessandro Ballestrero

The relevance of fermion loop corrections to four fermion processes at e+ e- colliders is reviewed with regard to the recent extension to the case of massive external particles and its application to single-W processes.

G. Heinrich, T. Binoth

In order to calculate cross sections with a large number of particles/jets in the final state at next-to-leading order, one has to reduce the occurring scalar and tensor one-loop integrals to a small set of known integrals. In massless theories, this reduction procedure is complicated by the presence of infrared divergences. Working in n=4-2*epsilon dimensio

John Ellis

The nucleon wave function may contain a significant component of ssbar pairs, according to several measurements including the pi-nucleon sigma term, charm production and polarization effects in deep-inelastic scattering. In addition, there are excesses of phi production in LEAR and other experiments, above predictions based the naive Okubo-Zweig-Iizuka rule,

L. Lavoura

I suggest a model based on a softly broken symmetry L_e - L_mu - L_tau and on Babu&#39;s mechanism for two-loops radiative generation of the neutrino masses. The model predicts that one of the physical neutrinos (nu_3) is massless and that its component along the nu_e direction (U_e3) is zero. Moreover, if the soft-breaking term is assumed to be very small,

O. Martin, A. Schafer

We compare theoretical results for jet and prompt photon production in polarized pp-collisions at RHIC obained with three different methods: a) the unpolarized event generator PYTHIA combined with hadronic asymmetry weights calculated from leading order formulae, b) the polarized event generator SPHINX which treats the partonic helicity in the hard scatterin

Miroslav Pardy

After the historical background concerning the pressure of light, we derive the quantum field theory force of the laser radiation acting on electron. Numerically, we determine the velocity of an electron accelerated by laser beam, after acceleration time $Δt = 1 {\rm s}$.

H. W. Huang, P. Kroll

Assuming the proton&#39;s light-cone wave function to be dominated by small parton virtualities and small intrinsic transverse momenta, we show that the electroproduction amplitudes at large momentum transfer factorize into parton-level subprocess amplitudes and form factors representing 1/x-moments of skewed parton distributions. On the basis of a wave func

Eri Asakawa, S. Y. Choi, Kaoru Hagiwara, Jae Sik Lee

We present a model-independent study of the effects of a neutral Higgs boson without definite CP-parity in the process $γγ\to t\bar{t}$ around the mass pole of the Higgs boson. Near the resonance pole, the interference between the Higgs-exchange and the continuum amplitudes can be sizable if the photon beams are polarized and helicities of the top and anti-t

D. Kharzeev, E. Levin

We evaluate the non-perturbative contribution to the double-diffractive production of the Higgs boson, which arises due to the QCD scale anomaly if the mass of the Higgs M_H is smaller than the mass of the top quark M_T, M_H < M_T. The cross section appears to be larger than expected from perturbative calculations; we find σ_H = 0.019 - 0.14 pbarn at the Tev

Bogdan A. Dobrescu, Greg Landsberg, Konstantin T. Matchev

In extended Higgs models, the Higgs boson may decay into a pair of light CP-odd scalars, with distinctive collider signatures. We study the ensuing Higgs signals at the upgraded Tevatron, considering the subsequent decays of the scalars into pairs of gluons or photons. For CP-odd scalars lighter than a few GeV, the Higgs boson manifests itself as a diphoton

Michael E. Peskin

This is the proceedings article for the concluding lecture of the 1999 High Energy Physics Conference of the European Physical Society. In this article, I review a number of topics that were highlighted at the meeting and have more general importance in high energy physics. The major topics discussed include: (1) precision electroweak physics, (2) CP violati

E. L. Koschmieder

The size of the stable elementary particles is investigated with the standing wave model. The particle size follows from the magnitude of the radiation pressure. It is shown that the outward directed radiation pressure is balanced by the inward directed elastic force per unit area in the cubic nuclear lattice, provided that the sidelength of the lattice is 1

Chang Kee Jung

The feasibility of a next generation underground water Cherenkov detector is examined and a conceptual design (UNO) is presented. The design has a linear detector configuration with a total volume of 650 kton which is 13 times the total volume of the Super-Kamiokande detector. It corresponds to a 20 times increase in fiducial volume for physics analyses. The

Walter Landry, Saul A. Teukolsky

The merger of two neutron stars has been proposed as a source of gamma-ray bursts, r-process elements, and detectable gravitational waves. Extracting information from observations of these phenomena requires fully relativistic simulations. Unfortunately, the only demonstrated method for stably evolving neutron stars requires solving elliptic equations at eac

Warner A. Miller, Arkady Kheyfets

We revisit the issue of time in quantum geometrodynamics and suggest a quantization procedure on the space of true dynamic variables. This procedure separates the issue of quantization from enforcing the constraints caused by the general covariance symmetries. The resulting theory, unlike the standard approach, takes into account the states that are off shel

Ion I. Cotaescu

We propose a generalization of the isometry transformations to the geometric context of the field theories with spin where the local frames are explicitly involved. We define the external symmetry transformations as isometries combined with suitable tetrad gauge transformations and we show that these form a group which is locally isomorphic with the isometry

William A. Hiscock, Shane L. Larson, Joshua R. Routzahn, Ben Kulick

The possibility that Galactic halo MACHOs are white dwarfs has recently attracted much attention. Using the known properties of white dwarf binaries in the Galactic disk as a model, we estimate the possible contribution of halo white dwarf binaries to the low-frequency (10^{-5} Hz} < f < 10^{-1}Hz) gravitational wave background. Assuming the fraction of whit

Nicholas. G. Phillips, B. L. Hu

We present calculations of the variance of fluctuations and of the mean of the energy momentum tensor of a massless scalar field for the Minkowski and Casimir vacua as a function of an intrinsic scale defined by a smeared field or by point separation. We point out that contrary to prior claims, the ratio of variance to mean-squared being of the order unity i

Ninan Sajeeth Philip, K. Babu Joseph

The difference-boosting algorithm is used on letters dataset from the UCI repository to classify distorted raster images of English alphabets. In contrast to rather complex networks, the difference-boosting is found to produce comparable or better classification efficiency on this complex problem.

Ninan Sajeeth Philip, K. Babu Joseph

A Bayesian classifier that up-weights the differences in the attribute values is discussed. Using four popular datasets from the UCI repository, some interesting features of the network are illustrated. The network is suitable for classification problems.

Emanuele Panizzi, Bernardo Pastorelli

The goal of this paper is the description and analysis of multimethod implementation in a new object-oriented, class-based programming language called OOLANG. The implementation of the multimethod typecheck and selection, deeply analyzed in the paper, is performed in two phases in order to allow static typechecking and separate compilation of modules. The fi

Gabriel Istrate

Phase transitions in combinatorial problems have recently been shown to be useful in locating &#34;hard&#34; instances of combinatorial problems. The connection between computational complexity and the existence of phase transitions has been addressed in Statistical Mechanics and Artificial Intelligence, but not studied rigorously. We take a step in this dir

Sviatoslav S. Sokolov, Nelson Studart

Density-density response functions are evaluated for nondegenerate multisubband electron systems in the random-phase approximation for arbitrary wave number and subband index. We consider both quasi-two-dimensional and quasi-one- dimensional systems for electrons confined to the surface of liquid helium. The dispersion relations of longitudinal intrasubband

Wei Chen, Kazuo Hida, B. C. Sanctuary

The plateau-non-plateau transition in the antiferromagnetic-(ferromagnetic)$_{n}$ polymerized $S=1/2$ XXZ chains under the magnetic field is investigated. The universality class of this transition belongs to the Brezinskii-Kosterlitz-Thouless (BKT) type. The critical points are determined by level spectroscopy analysis of the numerical diagonalization data f

Olexei Motrunich, Kedar Damle, David A. Huse

We present results on the low-frequency dynamical and transport properties of random quantum systems whose low temperature ($T$), low-energy behavior is controlled by strong disorder fixed points. We obtain the momentum and frequency dependent dynamic structure factor in the Random Singlet (RS) phases of both spin-1/2 and spin-1 random antiferromagnetic chai

N. Manyala, Y Siids, J. F. DiTusa, G. Aeppli

The desire to maximize the sensitivity of read/write heads and thus the information density of magnetic storage devices has produced an intense interest in the magnetoresistance (MR) of magnetic materials. Recent discoveries include &#34;colossal&#34; MR of the manganites1-4 and the enhanced MR of low carrier density ferromagnets4-6. In the low carrier densi

Paul L. Kaprivsky, Clément Sire

Ballistic annihilation with continuous initial velocity distributions is investigated in the framework of Boltzmann equation. The particle density and the rms velocity decay as $c=t^{-α}$ and $<v>=t^{-β}$, with the exponents depending on the initial velocity distribution and the spatial dimension. For instance, in one dimension for the uniform initial veloci

Sumiyoshi Abe

The Shannon-Khinchin axioms for the ordinary information entropy are generalized in a natural way to the nonextensive systems based on the concept of nonextensive conditional entropy, and a complete proof of the uniqueness theorem for the Tsallis entropy is presented.

Klaus Ziegler

The Hubbard model is used to study an electronic system at half filling. Starting from a functional integral representation the spin-up Grassmann field is integrated out. It is shown that the resulting spinless fermion theory has an instantaneous cluster interaction, and that the spinless fermions are coupled to thermally fluctuating Ising spins. The couplin

C. Presura, D. van der Marel, M. Dischner, C. Geibel

The dielectric function of alpha&#39;-Na(1-x)Ca(x)V2O5 (0 < x < 20%) was measured for the a and b axes in the photon energy range 0.8-4.5 eV at room temperature. By varying the Ca-concentration we control the relative abundancy of V4+ and V5+. We observe that the intensity of the main optical absorption peak at 1 eV is proportional to the number of V5+ ions.

Z. Zhai, P. V. Parimi, J. B. Sokoloff, A. Erb

We report the observation of two dielectric transitions at 110K and 60K in the microwave response of non-superconducting YBa_{2}Cu_{3}O_{6.0} crystals. The transitions are characterized by a change in polarizability and presence of loss peaks, associated with overdamped dielectric modes. An explanation is presented in terms of changes in polarizability of th

J. L. Gavilano, S. Mushkolaj, H. R. Ott, P. Millet

We report the results of $^{7}$Li nuclear magnetic resonance (NMR) studies of LiVGe$_{2}$O$_{6}$, a quasi one--dimensional spin $S = 1$ model system, at low temperatures. Our data, including NMR spectra and the temperature dependence of the spin-lattice relaxation rate $T_{1}^{-1}$, indicate a first order phase transition to occur at $T_{c}\simeq 23$ K. The

Olivier Ronsin, Karine Labastie Coeyrehourcq

We present an experimental investigation of the non stationary frictional properties of multicontact interfaces between rough elastomers and rough hard glass at low velocities (<= 200 mu m s^{-1}). These systems, for which the deformation contribution to friction is negligible, are shown to exhibit a phenomenology which is similar to what is observed for non

Gwang-Hee Kim, E. M. Chudnovsky

We have studied numerically the quantum-classical crossover in the escape-rate for an uniaxial spin system with an arbitrarily directed field. Using the simple quantum transition-state theory, we have obtained the boundary separating the first- and the second-order crossover and the escape-rate in the presence of the transverse and longitudinal field. The re

Miodrag L. Kulic, Igor M. Kulic

It is shown that in magnetic superconductors with spiral magnetic order the Josephson current has an additional contribution which depends: (i) on the relative orientation (magnetic phase) $θ=θ_{L}-θ_{R}$ of magnetizations on the left ($L$) and right ($R$) banks of the contact, (ii) on the junction helicity $χ=χ_{L}χ_{R}$, (with spiral helicity $χ_{L(R)}=\pm