February 2001 arXiv papers — page 2

William F. Grainger, Rhiju Das, Keith Grainge, Michael E. Jones

We describe a maximum-likelihood technique for the removal of contaminating radio sources from interferometric observations of the Sunyaev-Zel'dovich (SZ) effect. This technique, based on a simultaneous fit for the radio sources and extended SZ emission, is also compared to techniques previously applied to Ryle Telescope observations and is found to be r

R. F. Coker, S. Markoff

At the center of the Milky Way lurks a unique compact nonthermal radio source, Sgr A*. It is thought to be powered by a 2.6 million solar mass black hole that is accreting the stellar winds from the numerous early-type stars that exist in the central parsec. However, until recent high resolution Chandra observations, Sgr A* had never been unequivocably detec

D. Guetta, M. Spada, E. Waxman

Observations imply that gamma-ray bursts (GRBs) are produced by the dissipation of the kinetic energy of a highly relativistic fireball. Photo-meson interactions of protons with gamma-rays within the fireball dissipation region are expected to convert a significant fraction of fireball energy to >10^14 eV neutrinos. We present an analysis of the internal sho

M. Sereno, G. Covone, E. Piedipalumbo, R. de Ritis

We investigate the properties of cosmological distances in locally inhomogeneous universes with pressureless matter and dark energy (quintessence), with constant equation of state. We give exact solutions for angular diameter distances in theempty beam approximation. In this hypothesis, the distance-redshift equation is derived fron the multiple lens-plane t

Alexei V. Filippenko

I present an overview of optical observations (mostly spectra) of Type II, Ib, and Ic supernovae (SNe). SNe II are defined by the presence of hydrogen, and exhibit a very wide variety of properties. SNe II-L tend to show evidence of late-time interaction with circumstellar material. SNe IIn are distinguished by relatively narrow emission lines with little or

Eiji Hayashi, Takuya Matsuda

The derivation of the viscosity formula of accretion disks appearing in a number of textbooks is based on a mean free path theory of gas particles. However, this procedure, when followed precisely, leads to the incorrect conclusion that the angular momentum of an accretion disk flows from the outer part to the inner part.

Igor V. Igumenshchev, Marek A. Abramowicz

Recent numerical simulations of radiatively inefficient accretion flows onto compact objects have shown that convection is a general feature in such flows. Dissipation of rotational and gravitational energies in the accretion flows results in inward increase of entropy and development of efficient convective motions. Convection-dominated accretion flows (CDA

F. Bernardeau, P. Valageas

We present a general method for the reconstruction of the one-point Probability Distribution Function of the local aperture mass in weak lensing maps. Exact results, that neglect the lens-lens coupling and departure form the Born approximation, are derived for both the quasilinear regime at leading order and the strongly nonlinear regime assuming the tree hi

C. M. Hofman, W. K. Ma

We study deformations of topological closed strings. A well-known example is the perturbation of a topological closed string by itself, where the associative OPE product is deformed, and which is governed by the WDVV equations. Our main interest will be closed strings that arise as the boundary theory for topological open membranes, where the boundary string

P. G. Tinyakov, I. I. Tkachev

We calculate angular correlation function between ultra-high energy cosmic rays (UHECR) observed by Yakutsk and AGASA experiments, and most powerful BL Lacertae objects. We find significant correlations which correspond to the probability of statistical fluctuation less than $10^{-4}$, including penatly for selecting the subset of brightest BL Lacs. We concl

D. Bacon, J. Kempe, D. P. DiVincenzo, D. A. Lidar

We revisit the question of universality in quantum computing and propose a new paradigm. Instead of forcing a physical system to enact a predetermined set of universal gates (e.g., single-qubit operations and CNOT), we focus on the intrinsic ability of a system to act as a universal quantum computer using only its naturally available interactions. A key elem

Vatche Sahakian

Gravitational tidal forces may induce polarization of D0 branes, in analogy to the same effects arising in the context of constant background gauge fields. Such phenomena can teach us about the correspondence between smooth curved spacetime and its underlying non-commutative structure. However, unlike polarization by gauge fields, the gravitational counterpa

J. E. Hirsch, F. Marsiglio

The BCS electron-phonon mechanism and the unconventional 'hole mechanism' have been proposed as explanations for the high temperature superconductivity observed in $MgB_2$. It is proposed that a critical test of which theory is correct is the dependence of $T_c$ on hole doping: the hole mechanism predicts that $T_c$ will drop rapidly to zero as holes

Archil B. Kobakhidze

We discuss the proton decay problem in theories with low gravity and/or GUT scales. We pointed out that the gravity induced proton decay can be indeed suppressed up to a desired level, while the GUT origin of the proton instability is rather problematic. To solve this problem we suggest the GUT model where the proton is stable in all orders of perturbation t

Kristen Menou, Rosalba Perna, Lars Hernquist

We show that thin accretion disks made of Carbon or Oxygen are subject to the same thermal ionization instability as Hydrogen and Helium disks. We argue that the instability applies to disks of any metal content. The relevance of the instability to supernova fallback disks probably means that their power-law evolution breaks down when they first become neutr

Paul S. Aspinwall

We explore some aspects of monodromies of D-branes in the Kahler moduli space of Calabi-Yau compactifications. Here a D-brane is viewed as an object of the derived category of coherent sheaves. We compute all the interesting monodromies in some nontrivial examples and link our work to recent results and conjectures concerning helices and mutations. We note s

D. Boyanovsky, F. J. Cao, H. J. de Vega

We investigate inflation driven by the evolution of highly excited quantum states within the framework of out of equilibrium field dynamics. These states are characterized by a non-perturbatively large number of quanta in a band of momenta but with vanishing expectation value of the scalar field.They represent the situation in which initially a non-perturbat

K. Itakura, S. Maedan

We discuss a description of chiral symmetry breaking in the light-front (LF) formalism. Based on careful analyses of several models, we give clear answers to the following three fundamental questions: (i) What is the difference between the LF chiral transformation and the ordinary chiral transformation? (ii) How does a gap equation for the chiral condensate

Eric Sharpe

In this paper we describe explicitly how the twisted ``bundles'' on a D-brane worldvolume in the presence of a nontrivial B field, can be understood in terms of sheaves on stacks. We also take this opportunity to provide the physics community with a readable introduction to stacks and generalized spaces.

S. Parker, M. B. Plenio

We demonstrate that, in the case of Shor's algorithm for factoring, highly mixed states will allow efficient quantum computation, indeed factorization can be achieved efficiently with just one initial pure qubit and a supply of initally maximally mixed qubits (S. Parker and M. B. Plenio, Phys. Rev. Lett. 85, 3049 (2000)) . This leads us to ask how this a

D. Gunlycke, S. Bose, V. M. Kendon, V. Vedral

We investigate the entanglement arising naturally in a 1D Ising chain in a magnetic field in an arbitrary direction. We find that for different temperatures, different orientations of the magnetic field give maximum entanglement. In the high temperature limit, this optimal orientation corresponds to the magnetic field being perpendicular to the Ising orienta

Peter Watson, Reinhard Alkofer

Expanding the Landau gauge gluon and ghost two-point functions in a power series we investigate their infrared behavior. The corresponding powers are constrained through the ghost Dyson-Schwinger equation by exploiting multiplicative renormalizability. Without recourse to any specific truncation we demonstrate that the infrared powers of the gluon and ghost

Y. Kong, O. V. Dolgov, O. Jepsen, O. K. Andersen

For the 40K-superconductor MgB2 we have calculated the electronic and phononic structures and the electron-phonon interaction throughout the Brillouin zone ab initio. In contrast to the isoelectronic graphite, MgB2 has holes in the bonding sigma-bands, which contribute 42 per cent to the density of states: N(0) =0.355 states/(MgB2 eV spin). The total interac

J. Matyjasek, O. B. Zaslavskii

We consider the effect of backreaction of quantized massive fields on the metric of extreme black holes (EBH). We find the analytical approximate expression for the stress-energy tensor for a scalar (with an arbitrary coupling), spinor and vector fields near an event horizon. We show that, independent of a concrete type of EBH, the energy measured by a freel

Gun Yong Sung, Sang Hyeob Kim, JunHo Kim, Dong Chul Yoo

The microstructure of the MgB2 superconductor sintered at high temperature under a high pressure of about 3 GPa was investigated by using a high-resolution transmission electron microscope (HRTEM). The TEM images did not show any pores in the specimen. All grains were compactly connected, and no discernable empty spaces or impurities at the boundaries existe

Donam Youm

We argue that the four-dimensional universe on the TeV brane of the Randall-Sundrum scenario takes the bimetric structure of Clayton and Moffat, with gravitons traveling faster than photons instead, while the radion varies with time. We show that such brane world bimetric model can thereby solve the flatness and the cosmological constant problems, provided t

Takao Suyama

We investigate spectrum of open strings on D-branes after tachyon condensation in bosonic string theory. We calculate 1-loop partition function of the string and show that its limiting forms coincide with partition functions of open strings with different boundary conditions.

Rabin Banerjee, Biswajit Chakraborty

We propose a technique called dimensional descent to show that Wigner's little group for massless particles, which acts as a generator of gauge transformation for usual Maxwell theory, has an identical role even for topologically massive gauge theories. The examples of $B\wedge F$ theory and Maxwell-Chern-Simons theory are analyzed in details.

Dongsu Bak, Kimyeong Lee, Jeong-Hyuck Park

We investigate U(N) Chern-Simons theories on noncommutative plane. We show that for the theories to be consistent quantum mechanically, the coefficient of the Chern-Simons term should be quantized $κ= n/2π$ with an integer $n$. This is a surprise for the U(1) gauge theory. When uniform background charge density $ρ_e$ is present, the quantization rule changes

Mirt Gramann, Gert H"utsi

We investigate a spatially-flat cold dark matter model (with the matter density parameter $Ω_m=0.3$) with a primordial feature in the initial power spectrum. We assume that there is a bump in the power spectrum of density fluctuations at wavelengths $λ\sim 30-60h^{-1}$Mpc, which correspond to the scale of superclusters of galaxies. There are indications for

C. Renner, J. Peinke, R. Friedrich

We present a stochastic analysis of a data set consisiting of 10^6 quotes of the US Doller - German Mark exchange rate. Evidence is given that the price changes x(tau) upon different delay times tau can be described as a Markov process evolving in tau. Thus, the tau-dependence of the probability density function (pdf) p(x) on the delay time tau can be descri

C. Timm, K. H. Bennemann

A unified response theory for the time-resolved nonlinear light generation and two-photon photoemission (2PPE) from metal surfaces is presented. The theory allows to describe the dependence of the nonlinear optical response and the photoelectron yield, respectively, on the time dependence of the exciting light field. Quantum-mechanical interference effects a

H. S. Köhler, K. Morawetz

The Kadanoff-Baym (KB) equations are solved numerically for infinite nuclear matter. In particular we calculate correlation energies and correlation times. Approximating the Green's functions in the KB collision kernel by the free Green's functions the Levinson equation is obtained. This approximation is valid for weak interactions and/or low densiti

Peter Coles

The first direct experimental test of Einstein's theory of general relativity involved a pair of expeditions to measure the bending of light at a total solar eclipse that took place one hundred years ago, on 29 May 1919. So famous is this experiment, and so dramatic was the impact on Einstein himself, that history tends not to recognise the controversy t

M. Z. Hasan, E. D. Isaacs, Z-X. Shen, L. L. Miller

We report particle-hole pair excitations in a cuprate insulator in the intermediate regimes of momentum-transfers using high energy inelastic x-ray scattering. The excitation spectra show dispersive features near the Mott edge which shed light on the momentum structure of the upper Hubbard band in cuprates. We briefly discuss the potential use of such a tech

Pijush K. Ghosh

We show that the width of the wave-packet of a class of generalized nonlinear Schrodinger equations (NLSE) trapped in an arbitrary time-dependent harmonic well in any dimensions is universally determined by the same Hill's equation. This class of generalized NLSE is characterized by a dynamical O(2,1) symmetry in absence of the trap. As an application, w

M. Z. Hasan, E. D. Isaacs, Z-X. Shen, L. L. Miller

The electronic structure of Mott insulators continues to be a major unsolved problem in physics despite more than half-century of intense research efforts. Well-developed momentum-resolved spectroscopies such as photoemission or neutron scattering cannot probe the full Mott gap. We report observation of dispersive charge excitations across the Mott gap in a

G. -q. Zheng, K. Tanabe, T. Mito, S. Kawasaki

We report measurements of the ^{115}In nuclear spin-lattice relaxation rate (1/T_1) between T=0.09 K and 100 K in the new heavy fermion (HF) compound CeIrIn_5. At 0.4 K < T < 100 K, 1/T_1 is strongly T-dependent, which indicates that CeIrIn_5 is much more itinerant than known Ce-based HFs. We find that 1/T_1T, subtracting that for LaIrIn_5, follows a 1/(T+θ)

Jun Yokogawa, Ken&#39;ichi Torii, Takayoshi Kohmura, Katsuji Koyama

This paper has been withdrawn because the class file must not be uploaded.

L. Vaidman

According to recent reports, the last loopholes in testing Bell&#39;s inequality are closed. It is argued that the really important task in this field has not been tackled yet and that the leading experiments claiming to close locality and detection efficiency loopholes, although making a very significant progress, have conceptual drawbacks.

C. R. Hagen

The Casimir force between two conducting planes is considered in both the electromagnetic and scalar field cases. This is done by the usual summation over energy eigenmodes of the system as well as by a calculation of the stress tensor in the region between the planes. The latter case requires that careful attention be given to singular operator products, an

Burkhard Kuemmerer, Hans Maassen

For a quantum-mechanical counting process we show ergodicity, under the condition that the underlying open quantum system approaches equilibrium in the time mean. This implies equality of time average and ensemble average for correlation functions of the detection current to all orders and with probability 1.

Ping-Xing Chen, Lin-Mei Liang, Cheng-Zu Li, Ming-Qiu Huang

The necessary and sufficient condition of separability of a mixed state of any systems is presented, which is practical in judging the separability of a mixed state. This paper also presents a method of finding the disentangled decomposition of a separable mixed state.

D. Petz, Cs. Sudar

Chentsov studied Riemannian metrics on the set of probability measures from the point of view of decision theory. He proved that up to a constant factor the Fisher information is the only metric which is monotone under stochastic transformations. The present paper deals with monotone metrics on the space of finite density matrices on the basis motivated by q

Partha Ghose

Marchildon&#39;s arguments against my earlier work are refuted.

B. Desplanques, L. Theußl

Form factors are calculated in the point form of relativistic quantum mechanics for the lowest energy states of a system made of two scalar particles interacting via the exchange of a massless boson. They are compared to the exact results obtained by using solutions of the Bethe-Salpeter equation which are well known in this case (Wick-Cutkosky model). Defic

V. Kotecha

We consider kink-antikink collisions in the topological discrete sine-Gordon system. We find that the TDSG kink supports extra internal modes of vibration and this results in resonance effects of the kind seen for the continuum phi^4 theory.

B. Durand, E. Formenti, Z. Roka

We compare several definitions for number-conserving cellular automata that we prove to be equivalent. A necessary and sufficient condition for \cas to be number-conserving is proved. Using this condition, we give a linear-time algorithm to decide number-conservation. The dynamical behavior of number-conserving \cas is studied and a classification that focus

Pierre Duclos, Pavel Exner, David Krejcirik

We consider a nonrelativistic quantum particle constrained to a curved layer of constant width built over a non-compact surface embedded in $R^3$. We suppose that the latter is endowed with the geodesic polar coordinates and that the layer has the hard-wall boundary. Under the assumption that the surface curvatures vanish at infinity we find sufficient condi

Paul Federbush

We present some conjectured approximations for spin expectations in a Quantum Heisenberg system. The conjectures are based on numerical experimentation, some theoretical insights and underpinning, and aesthetic value. We hope theoretical developments will follow from these ideas, even leading to a proof of the phase transition (in three dimensions).

Paul B. Slater

This paper has been superseded by math-ph/0102032, &#34;Bures geometry of the three-level quantum systems. II&#34;.

M. Garbey, H. G. Kaper, N. Romanyukha

In this paper we present a fast algorithm for the numerical solution of systems of reaction-diffusion equations, $\partial_t u + a \cdot \nabla u = Δu + F (x, t, u)$, $x \in Ω\subset \mathbf{R}^3$, $t > 0$. Here, $u$ is a vector-valued function, $u \equiv u(x, t) \in \mathbf{R}^m$, $m$ is large, and the corresponding system of ODEs, $\partial_t u = F(x, t, u

S. Neshveyev, E. Stormer

An extension of the Shannon-McMillan-Breiman theorem to a class of non-commutative dynamical systems is given.

Arturo Magidin

In a 1985 paper, Berthold J. Maier gave necessary and sufficient conditions for the weak embeddability of amalgams of two nilpotent groups of class two over a common subgroup. Then he derived simpler conditions for some special cases. One of his subsequent results is incorrect, and we provide a counterexample. Finally, we provide a fix for the result.

Shu-Chiuan Chang

This paper describes an improvement in the upper bound for the magnitude of a coefficient of a term in the chromatic polynomial of a general graph. If $a_r$ is the coefficient of the $q^r$ term in the chromatic polynomial $P(G,q)$, where $q$ is the number of colors, then we find $a_r \le {e \choose v-r} - {e-g+2 \choose v-r-g+2} + {e-k_g-g+2 \choose v-r-g+2}

Peter G. Casazza, Niels J. Nielsen

We prove that the symmetric convexified Tsirelson space is of weak cotype 2 but not of cotype 2

Asma Harcharras, Stefan Neuwirth, Krzysztof Oleszkiewicz

We study unconditional subsequences of the canonical basis e_rc of elementary matrices in the Schatten class S^p. They form the matrix counterpart to Rudin&#39;s Lambda(p) sets of integers in Fourier analysis. In the case of p an even integer, we find a sufficient condition in terms of trails on a bipartite graph. We also establish an optimal density conditi

Stefan Neuwirth

Reiman produced a quadratic inequality for the size of bipartite graphs of girth six. We get its counterpart for girth eight, a cubic inequality. It is optimal in as far as it admits the algebraic structure of generalized quadrangles as case of equality. This enables us to obtain the optimal estimate e ~ v^(4/3) for balanced bipartite graphs. We also get an

Daniele Guido, Tommaso Isola

To any spectral triple (A,D,H) a dimension d is associated, in analogy with the Hausdorff dimension for metric spaces. Indeed d is the unique number, if any, such that |D|^-d has non trivial logarithmic Dixmier trace. Moreover, when d is finite non-zero, there always exists a singular trace which is finite nonzero on |D|^-d, giving rise to a noncommutative i

Mohamed Ait Nouh, Akira Yasuhara

We give a necessary condition for a torus knot to be untied by a single twisting. By using this result, we give infinitely many torus knots that cannot be untied by a single twisting.

A. J. Roberts, M. E. Simpson

The levelling of short-wave irregularities on a thin film of fluid is primarily due to the action of surface tension. Surface tension gradients are often created by a number of different factor including evaporation, thermal gradients or deposition of surfactants. Lubrication theory, which ignores inertia terms in favour of viscous terms, produces a system o

Doug Hensley, Francis Edward Su

Using the discrepancy metric, we analyze the rate of convergence of a random walk on the circle generated by d rotations, and establish sharp rates that show that badly approximable d-tuples in R^d give rise to walks with the fastest convergence. We use the discrepancy metric because the walk does not converge in total variation. For badly approximable d-tup

Francis Edward Su

We analyze the drunkard&#39;s walk on the unit sphere with step size theta and show that the walk converges in order constant/sin^2(theta) steps in the discrepancy metric. This is an application of techniques we develop for bounding the discrepancy of random walks on Gelfand pairs generated by bi-invariant measures. In such cases, Fourier analysis on the act

Alicia Dickenstein, Bernd Sturmfels

New formulas are given for Chow forms, discriminants and resultants arising from (not necessarily normal) toric varieties of codimension 2. Exact descriptions are also given for the secondary polygon and for the Newton polygon of the discriminant.

L. Vaksman

This work produces a q-analogue of the Cauchi-Szegö integral representation that retrieves a holomorphic function in the matrix ball from its values on the Shilov boundary. Besides that, the Shilov boundary of the quantum matrix ball is described and the U_q su(m,n)-covariance of the U_q s(u(m)x u(n))-invariant integral on this boundary is established. The l

Franc Forstneric, Josip Globevnik

In this paper we investigate the global behavior of proper holomorphic maps f from the unit disc U={|z|<1} to C^2. The fact that U is transcendental imposes certain restrictions on the image f(U). For instance, f(U) cannot be contained in any proper complex cone in C^2 since this would force it to be algebraic. On the other hand, we show that a real cone in

Scott Sheffield

Let $G=(V,E)$ be a bipartite graph embedded in a plane (or $n$-holed torus). Two subgraphs of $G$ differ by a {\it $Z$-transformation} if their symmetric difference consists of the boundary edges of a single face---and if each subgraph contains an alternating set of the edges of that face. For a given $ϕ: V \mapsto \mathbb Z^+$, $S_ϕ$ is the set of subgraphs

Esteban A. Calzetta, Bei Lok Hu, Francisco D. Mazzitelli

In this report we introduce the basic techniques (of the Closed Time Path - Coarse Grained Effective Action CTP-CGEA) and ideas (scaling, coarse-graining and backreaction) behind the treatment of quantum processes in dynamical background spacetimes and fields. We show how they are useful for the construction of renormalization group (RG) theories for studyin

Nurcan Ozturk

The algebraic structure of the neutrino mass Hamiltonian is presented for two neutrino flavors considering both Dirac and Majorana mass terms. It is shown that the algebra is Sp(8) and also discussed how the algebraic structure generalizes for the case of more than two neutrino flavors.

D. M. Medeiros, R. R. Landim, C. A. S. Almeida

In this work we use the method of consistent deformations of the master equation by Barnich and Henneaux in order to prove that an abelian topological coupling between a zero and a two form fields in D=3 has no nonabelian generalization. We conclude that a topologically massive model involving the Kalb-Ramond two-form field does not admit a nonabelian genera

M. Bordag, I. G. Pirozhenko

We calculate the \hkks for the \elm field in the background of a dielectric cylinder with non equal speeds of light inside and outside. The coefficient $a_{2}$ whose vanishing makes the vacuum energy of a massless field unique, turns out to be zero in dilute order, i.e., in order $(\ep-1)^{2}$, and nonzero beyond. As a consequence, the vanishing of the vacuu

L. K. Hoevenaars, R. Martini

A proof that the prepotential for pure N=2 Super-Yang-Mills theory associated with Lie algebras B_r and C_r satisfies the generalized WDVV (Witten-Dijkgraaf-Verlinde-Verlinde) system was given by Marshakov, Mironov and Morozov. Among other things, they use an associative algebra of holomorphic differentials. Later Ito and Yang used a different approach to tr

Richard S. Wittman

Abelian and nonabelian gauge invariant states are directly compared to revisit how the unconfined abelian theory is expressed. It is argued that the Yang-Mills equations have no obvious physical content apart from their relation to underlying physical states. The main observation is that the physical states of electrostatics can be regarded as point charges

Dan N. Vollick

Anisotropic cosmological spacetimes are constructed from spherically symmetric solutions to Einstein&#39;s equations coupled to nonlinear electrodynamics and a positive cosmological constant. This is accomplished by finding solutions in which the roles of $r$ and $t$ are interchanged for all $r>0$ (i.e. $r$ becomes timelike and $t$ becomes spacelike). Consta

Z. Bern

We discuss string theory relations between gravity and gauge theory tree amplitudes. Together with $D$-dimensional unitarity, these relations can be used to perturbatively quantize gravity theories, i.e. they contain the necessary information for calculating complete gravity $S$-matrices to any loop orders. This leads to a practical method for computing non-

M. Cvetic, G. W. Gibbons, H. Lu, C. N. Pope

We obtain a simple explicit expression for the hyper-Kahler Calabi metric on the co-tangent bundle of CP^{n+1}, for all n, in which it is constructed as a metric of cohomogeneity one with SU(n+2)/U(n) principal orbits. These results enable us to obtain explicit expressions for an L^2-normalisable harmonic 4-form in D=8, and an L^2-normalisable harmonic 6-for

Y. S. Myung

We discuss the brane cosmology in the 5D anti de Sitter Schwarzschild (AdSS$_5$) spacetime. A brane with the tension $σ$ is defined as the edge of an AdSS$_5$ space. We point out that the location of the horizon is an apparently, singular point at where we may not define an embedding of the AdSS$_5$ spacetime into the moving domain wall (MDW). We resolve thi

F. Hautmann

We study infrared QCD effects in radiative quarkonia decays. We examine the endpoint region z -> 1 of the photon spectrum. We point out a cancellation mechanism for the corrections in $α_s^n \ln^{m} (1-z)$, $m \leq 2 n$, in the short-distance coefficient for the color-singlet Fock state in the quarkonium. The cancellation is due to the coherence of the color

B. Pasquini, M. Gorchtein, D. Drechsel, A. Metz

We present in detail a dispersion relation formalism for virtual Compton scattering (VCS) off the proton from threshold into the $Δ(1232)$-resonance region. Such a formalism can be used as a tool to extract the generalized polarizabilities of the proton from both unpolarized and polarized VCS observables over a larger energy range. We present calculations fo

D. H. Beck, R. D. McKeown

The measurement of parity violation in the helicity dependence of electron-nucleon scattering provides unique information about the basic quark structure of the nucleons. In this review, the general formalism of parity-violating electron scattering is presented, with emphasis on elastic electron-nucleon scattering. The physics issues addressed by such experi

R. Lednicky, V. Lyuboshitz

The difference in the properties of the spin correlation tensor for factorizable and nonfactorizable two-particle states is analyzed. The inequalities for linear combinations of the components of this tensor are obtained for the case of incoherent mixtures of factorizable two-particle spin states. They include the well known Bell inequalities and can be viol

J. Ellis, D. V. Nanopoulos, K. A. Olive

We combine the constraint suggested by the recent BNL E821 measurement of the anomalous magnetic moment of the muon on the parameter space of the constrained MSSM (CMSSM) with those provided previously by LEP, the measured rate of b to s gamma decay and the cosmological relic density Omega-hsquared. Our treatment of Omega-hsquared includes carefully the dire

Alex Kovner

We point out that the effective action of hot Yang--Mills theories has semi-classical solutions, which are naturally identified with monopole world lines, ``frozen&#39;&#39; into the short imaginary time dimension. The solutions look like wall junctions: lines along which N electric Z(N) domain walls come together. They are instrumental in reconciling explic

N. Ya. Ivanov

We analyze in the framework of pQCD the properties of the single spin asymmetry in heavy flavor production by linearly polarized photons. At leading order, the parallel- perpendicular asymmetry in azimuthal distributions of both charm and bottom quark is predicted to be about 20% in a wide region of initial energy. Using the soft gluon resummation formalism,

Leszek Roszkowski

There exist several well-motivated candidates for non-baryonic cold dark matter, including neutralinos, axions, axinos, gravitinos, Wimpzillas. I review the dark matter properties of the neutralino and the current status of its detection. I also discuss the axino as a new interesting alternative.

Leszek Roszkowski

As experimental sensitivity increases, one is approaching the range of WIMP-nucleon interaction strengths characteristic of neutralinos. But this continuing progress also unearths new experimental challenges and uncertainties.

Leszek Roszkowski

Supersymmetric extensions of the Standard Model when combined with the Peccei-Quinn solution to the strong CP problem necessarily contain also the axino, the fermionic partner of the axion. In contrast to the neutralino and the gravitino, the axino mass is generically not of the order of the supersymmetry breaking scale and can be much smaller. The axino is

Tarek Ibrahim, Utpal Chattopadhyay, Pran Nath

We use the recently derived CP phase dependent analytic results for the supersymmetric electro-weak correction to $g_μ-2$ to constrain the explicit CP phases in softly broken supersymmetry using the new physics effect seen in the g-2 Brookhaven measurement. It is shown that the BNL data strongly constrains the CP violating phase $θ_μ$ (the phase of the Higgs

S. M. Troshin, N. E. Tyurin

Deep-inelastic scattering at low x and elastic vector meson production are considered on the basis of the off-shell extension of the s-channel unitarity. We discuss behavior of the structure function F_2(x,Q^2) at low x and the total cross-section of virtual photon-proton scattering and obtain, in particular, the dependence sigma^{tot}_{gamma^* p}\sim (W^2)^

M. Lublinsky, E. Gotsman, E. Levin, U. Maor

We suggest a new procedure for extrapolating the parton distributions from HERA energies to higher energies at THERA and LHC. The procedure suggested consists of two steps: first, we solve the non-linear evolution equation which includes the higher twists contributions, however this equation is deficient due to the low ($log(1/x)$) accuracy of our calculatio

S. M. Bilenky, C. Giunti

In this short review we discuss the notion of lepton numbers. The strong evidence in favor of neutrino oscillations obtained recently in the Super-Kamiokande atmospheric neutrino experiment and in solar neutrino experiments imply that the law of conservation of family lepton numbers L_e, L_mu and L_tau is strongly violated. We consider the states of flavor n

A. Mikovic

We study the transition amplitudes in state-sum models of quantum gravity in D=2,3,4 spacetime dimensions by using the field theory over a Lie group formulation. By promoting the group theory Fourier modes into creation and annihilation operators we construct a Fock space for the quantum field theory whose Feynman diagrams give the transition amplitudes. By

Ioannis Raptis

The notion of finitary spacetime sheaves is introduced based on locally finite approximations of the continuous topology of a bounded region of a spacetime manifold. Finitary spacetime sheaves are seen to be sound mathematical models of approximations of continuous spacetime observables.

Diego M. Forni, Mirta S. Iriondo, Carlos N. Kozameh, M. F. Parisi

In this work we establish a relationship between Cartan&#39;s geometric approach to third order ODEs and the 3-dim Null Surface Formulation (NSF). We then generalize both constructions to allow for caustics and singularities that necessarily arise in these formalisms.

Patricia M. Hill, Roberto Bagnara, Enea Zaffanella

It is important that practical data-flow analyzers are backed by reliably proven theoretical results. Abstract interpretation provides a sound mathematical framework and necessary generic properties for an abstract domain to be well-defined and sound with respect to the concrete semantics. In logic programming, the abstract domain Sharing is a standard choic

Boris A. Rodriguez, Augusto Gonzalez

A BCS-like variational wave-function, which is exact in the infinite field limit, is used to study the interplay among Zeeman energies, lateral confinement and particle correlations induced by the Coulomb interactions in strongly pumped neutral quantum dots. Band mixing effects are partially incorporated by means of field-dependent masses and g-factors. The

Wei Bao, G. Aeppli, J. W. Lynn, P. G. Pagliuso

CeRhIn5 is a heavy fermion antiferromagnet that orders at 3.8 K. The observation of pressure-induced superconductivity in CeRhIn5 at a very high Tc of 2.1 K for heavy fermion materials has led to speculations regarding to its magnetic fluctuation spectrum. Using magnetic neutron scattering, we report anisotropic three-dimensional antiferromagnetic fluctuatio

D. D. Sarma

Ordered double perovskite oxides of the general formula, A2BB&#39;O6, have been known for several decades to have interesting electronic and magnetic properties. However, a recent report of a spectacular negative magnetoresistance effect in a specific member of this family, namely Sr2FeMoO6, has brought this class of compounds under intense scrutiny. It is n

F. Reynaud, D. Mertz, F. Celestini, J. -M. Debierre

We report on the ESR, magnetization and magnetic susceptibility measurements performed over a large temperature range, from 1.5 to 750 K, on high-quality stoichiometric LiNiO2. We find that this compound displays two distinct temperature regions where its magnetic behavior is anomalous. With the help of a statistical model based on the Kugel&#39;-Khomskii Ha

H. P. Ying, L. Wang, J. B Zhang, M. Jiang

Critical scaling and universality in short-time dynamics for spin models on a two-dimensional triangular lattice are investigated by using Monte Carlo simulation. Emphasis is placed on the dynamic evolution from fully ordered initialstates to show that universal scaling exists already in the short-time regime in form of power-law behavior of the magnetizatio