February 2003 arXiv papers — page 16

Lubomir Alexandrov

We found a regularity of the behavior of primes that allows to represent both prime and natural numbers as infinite matrices with a common formation rule of their rows. This regularity determines a new class of infinite cyclic groups that permit the proposition a plane--spiral geometric concept of the arithmetic.

Hidekazu Furusho

The MZV algebra is the graded algebra over ${\bold Q}$ generated by all multiple zeta values. The stable derivation algebra is a graded Lie algebra version of the Grothendieck-Teichmüller group. We shall show that there is a canonical surjective $\bold Q $-linear map from the graded dual vector space of the stable derivation algebra over $\bold Q$ to the new

Alex Buchel

In hep-th/0004063 Pilch and Warner (PW) constructed N=2 supersymmetric RG flow corresponding to the mass deformation of the N=4 SU(N) Yang-Mills theory. In this paper we present exact deformations of PW flow when the gauge theory 3-space is compactified on S^3. We consider also the case with the gauge theory world-volume being dS_4 instead of R^{3,1}. The so

Sergei Yu. Alexandrov, Vladimir A. Kazakov, Ivan K. Kostov

We show that the $c=1$ bosonic string theory at finite temperature has two matrix-model realizations related by a kind of duality transformation. The first realization is the standard one given by the compactified matrix quantum mechanics in the inverted oscillator potential. The second realization, which we derive here, is given by the normal matrix model.

Andreas Aste

In a recent paper by Johan Hansson [hep-ph/0208137] it is claimed that the non-appearance of quarks and gluons as physical particles is an automatic result of the nonabelian nature of the color interaction in quantum chromodynamics. It is shown that the arguments given by Hansson are insufficient to support his claim by giving simple counter arguments.

Sultan Catto

Vertex symmetry for interacting fermions will be shown to lead to a Lagrangian exhibiting $SU(2N)_W$ invariance associated with the subgroup $SU(2N)_q \times SU(2N)_{\bar{q}}$ generated by $C$-odd and $C$-even spin operators. Approximate $SU(6)_W$ vertex symmetry as well as chiral invariance will then be shown to follow from a principle of maximum smoothness

Y. M. Cho, Haewon Lee, D. G. Pak

The effective action with homogeneous valence (off-diagonal) gluons as background fields in the extended SU(2) model of QCD is obtained in one-loop approximation. We keep the manifest gauge and Lorentz invariance during whole calculation by using a special gauge-fixing recipe and taking into account the quartic interaction terms in the original Lagrangian as

A. Kulesza, G. Sterman, W. Vogelsang

We study applications of QCD soft-gluon resummations to electroweak annihilation cross sections. We focus on a formalism that allows to resum logarithmic corrections arising near partonic threshold and at small transverse momentum simultaneously.

A. Gutiérrez-Rodríguez, M. A. Hernández-Ruíz, O. A. Sampayo

We study the Higgs pair-production in the Standard Model of the strong and electroweak interactions at future $e^{+}e^{-}$ collider energies, with the reaction $e^{+}e^{-}\to t \bar t HH$. We evaluated the total cross section of $t\bar tHH$ and calculate the number total of events considering the complete set of Feynman diagrams at tree-level. The numerical

J. R. Hiller, S. S. Pinsky, U. Trittmann

We consider N=1 supersymmetric Yang-Mills theory with fundamental matter in the large-N_c approximation in 1+1 dimensions. We add a Chern-Simons term to give the adjoint partons a mass and solve for the meson bound states. Here mesons are color-singlet states with two partons in the fundamental representation but are not necessarily bosons. We find that this

C. Wetterich

The time variation of fundamental mass scales can have profound cosmological implications. We investigate a particular model of crossover quintessence which is compatible with all present cosmological observations. This model can also reconcile the reported time variation of the fine structure constant from quasar absorption lines with the bounds from archeo

Urko Reinosa

We consider a scalar theory at finite temperature in the 2PI resummation scheme, including phi^3 and phi^4 interactions. Already at the one loop level in this scheme, we have to deal with a non local approximation. We carry out the renormalization and obtain finite equations for the propagator. Within this model we can explore the effect of non local contrib

M. T. Dova, P. Garcia-Abia, W. Lohmann

The energy dependence of the production cross section of a light Higgs boson is studied at threshold and compared to the expectations of several spin assumptions. Cross section measurements at three centre-of-mass energies with an integrated luminosity of 20 fb-1 allow the confirmation of the scalar nature of the Higgs Boson.

A. Ringwald

This review emphasizes the close analogy between hard QCD instanton-induced chirality violating processes in deep-inelastic scattering and electroweak instanton-induced baryon plus lepton number (B+L) violating processes in Quantum Flavor Dynamics (QFD). Recent information about QCD instantons, both from lattice simulations and from the H1 experiment at HERA

D. V. Kiptily, M. V. Polyakov

The genuine twist-3 quark-gluon contributions to the Generalized Parton Distributions (GPDs) are estimated in the model of the instanton vacuum. These twist-3 effects are found to be parametrically suppressed relative to the ``kinematical'' twist-3 ones due to the small packing fraction of the instanton vacuum. We derive exact sum rules for the twist

D. Cremades, L. E. Ibanez, F. Marchesano

We discuss the structure of Yukawa couplings in D-brane models in which the SM fermion spectrum appears at the intersections of D-branes wrapping a compact space. In simple toroidal realistic examples one can explicitly compute the Yukawa couplings as a function of the geometrical data summing over world-sheet instanton contributions. A particular simple mod

NuSea Collaboration, J. C. Webb, T. C. Awes, M. L. Brooks

The Fermilab E866/NuSea Collaboration has measured the Drell-Yan dimuon cross sections in 800 GeV/$c$ $pp$ and $pd$ collisions. This represents the first measurement of the Drell-Yan cross section in $pp$ collisions over a broad kinematic region and the most extensive study to date of the Drell-Yan cross section in $pd$ collisions. The results indicate that

D. Gonzalez, J. Morales, S. Cebrian, E. Garcia

The IGEX experiment has been operating enriched germanium detectors in the Canfranc Underground Laboratory (Spain) in a search for the neutrinoless double decay of 76Ge. The implementation of Pulse Shape Discrimination techniques to reduce the radioactive background is described in detail. This analysis has been applied to a fraction of the IGEX data, leadin

B. Armbruster, I. M. Blair, B. A. Bodmann, N. E. Booth

We investigated mu+ decays at rest produced at the ISIS beam stop target. Lepton flavor (LF) conservation has been tested by searching for \nueb via the detection reaction p(\nueb,e+)n. No \nueb signal from LF violating mu+ decays was identified. We extract upper limits of the branching ratio for the LF violating decay mu+ -> e+ \nueb νcompared to the Standa

G. Giacomelli, L. Patrizii

In this lecture notes will be discussed the status of the searches (i) for classical Dirac Magnetic Monopoles (MMs) at accelerators, (ii) for GUT superheavy MMs in the penetrating cosmic radiation and (iii) for Intermediate Mass MMs in the cosmic radiation underground, underwater and at high altitude. An outlook and a discussion on future searches follows.

R. Meinel, G. Neugebauer

A new class of exact solutions to the axisymmetric and stationary vacuum Einstein equations containing n arbitrary complex parameters and one arbitrary real solution of the axisymmetric three-dimensional Laplace equation is presented. The solutions are related to Jacobi's inversion problem for hyperelliptic Abelian integrals.

Kashif Alvi

In a previous paper, a binary black hole four-metric was presented in a post-Newtonian corotating coordinate system valid only up to the holes' apparent horizons. In this paper, I define an ingoing coordinate transformation that extends this corotating coordinate system through the holes' horizons and into their interiors. The motivation for using in

G. Neugebauer, R. Meinel

In a recent paper we presented analytic expressions for the axis potential, the disk metric, and the surface mass density of the global solution to Einstein's field equations describing a rigidly rotating disk of dust. Here we add the complete solution in terms of ultraelliptic functions and quadratures.

Kouji Nakamura, Ken-ichi Nakao, Takeshi Mishima

The initial data of gravity for a cylindrical matter distribution confined to a brane are studied in the framework of the single-brane Randall-Sundrum scenario. In this scenario, the 5-dimensional nature of gravity appears in the short-range gravitational interaction. We find that a sufficiently thin configuration of matter leads to the formation of a margin

Gary Simons, Steven Bird

The Open Language Archives Community (OLAC) is an international partnership of institutions and individuals who are creating a worldwide virtual library of language resources. The Dublin Core (DC) Element Set and the OAI Protocol have provided a solid foundation for the OLAC framework. However, we need more precision in community-specific aspects of resource

J. H. Miller, G. Cardenas, A. Garcia-Perez, W. More

A large body of experimental evidence suggests that the decay of the false vacuum, accompanied by quantum pair creation of soliton domain walls, can occur in a variety of condensed matter systems. Examples include nucleation of charge soliton pairs in density waves [eg. J. H. Miller, Jr. et al., Phys. Rev. Lett. 84, 1555 (2000)] and flux soliton pairs in lon

V. M. Loktev, Yu. G. Pogorelov, V. M. Turkowski

We discuss static fluctuations of the d-wave superconducting order parameter $Δ$ in CuO$_2$ planes, due to quasiparticle scattering by charged dopants. The analysis of two-particle anomalous Green functions at $T = 0$ permits to estimate the mean-square fluctuation $δ^2 = <Δ^2> - <Δ>^2$, averaged in random dopant configurations, to the lowest order in doping

L. E. Golub, E. L. Ivchenko

Spin splitting of conduction electron states has been analyzed for all possible point symmetries of SiGe quantum well structures. A particular attention is paid to removal of spin degeneracy caused by the rotoinversion asymmetry of a (001) heterointerface between two diamond-lattice materials. Consequences of the spin splitting on the electron spin relaxatio

Joachim Krug

There is a close relation between the problems of second layer nucleation in epitaxial crystal growth and chemical surface reactions, such as hydrogen recombination, on interstellar dust grains. In both cases standard rate equation analysis has been found to fail because the process takes place in a confined geometry. Using scaling arguments developed in the

M. Acquarone, L. Romano&#39;

We investigate the origin of the inter-band coupling in MgB2 by focusing on its unusual phononic features, namely, the strong anharmonicity of the phonons and the presence of both linear and quadratic electron-phonon interactions of the Su-Schrieffer-Heeger (SSH) type. The bare electronic Hamiltonian has two bands with intra- and inter-band hopping, which le

P. Gallo, M. Rovere

The Van Hove self correlation function of water confined in a silica pore is calculated from Molecular Dynamics trajectories upon supercooling. At long time in the $α$ relaxation region we found that the behaviour of the real space time dependent correlators can be decomposed in a very slow, almost frozen, dynamics due to the bound water close to the substra

M. K. Karkkainen

The propagation and refraction of a cylindrical wave created by a line current through a slab of backward wave medium, also called left-handed medium, is numerically studied with FDTD. The slab is assumed to be uniaxially anisotropic. Several sets of constitutive parameters are considered and comparisons with theoretical results are made. Electric field dist

Youichi Yanase, Masao Ogata

Triplet superconductivity in Sr_2RuO_4 is investigated with main interest on its internal degree of freedom. We perform a microscopic calculation to investigate how the chiral state d(k) = (k_x \pm ik_y)z is realized among the underlying six degenerate states. Starting from the three band Hubbard model with spin-orbit interaction, we use a perturbation theor

P. Gallo, R. Pellarin, M. Rovere

Dynamical properties of a Lennard-Jones binary mixture embedded in an off lattice matrix of soft spheres are studied in the direct space upon supercooling by molecular dynamics simulations. On lowering temperature the smaller particles tend to avoid the soft sphere interfaces and correspondingly their mobility decreases below the one of the larger particles.

František Máca, Alexander B. Shick, Josef Redinger, Raimund Podloucky

Ni/Cu(001) is known as a unique system showing the spin-reorientation transition from an in-plane to out-of-plane magnetization direction when the Ni-overlayer thickness is increased. We investigate different relaxed multilayer structures with a hydrogen adlayer using the full-potential linearized augmented plane-wave method. The relaxed geometries, determin

Petter Holme, Fredrik Liljeros, Christofer R. Edling, Beom Jun Kim

Systems with two types of agents with a preference for heterophilous interaction produces networks that are more or less close to bipartite. We propose two measures quantifying the notion of bipartivity. The two measures--one well-known and natural, but computationally intractable; one computationally less complex, but also less intuitive--are examined on mo

Malte Henkel, Michel Pleimling

Reply to the Comment by F. Corberi, E. Lipiello and M. Zannetti (cond-mat/0211609).

S. Di Matteo, G. Jackeli, N. B. Perkins

We formulate a superexchange theory of insulating double-perovskite compounds such as Sr$_2$FeWO$_6$. An effective spin-orbital Hamiltonian is derived in the strong coupling limit of Hubbard model for d-electrons on Fe and W ions. The relevant degrees of freedom are the spins S=2 and the three-fold orbital degeneracy of Fe$^{2+}$-ions. W-sites are integrated

S. Lebègue, M. Alouani, B. Arnaud, W. E. Pickett

A pressure-induced simultaneous metal-insulator transition (MIT) and structural-phase transformation in lithium hydride with about 1% volume collapse has been predicted by means of the local density approximation (LDA) in conjunction with an all-electron GW approximation method. The LDA wrongly predicts that the MIT occurs before the structural phase transit

Haijun Zhou

We study the vertex cover problem on finite connectivity random graphs by zero-temperature cavity method. The minimum vertex cover corresponds to the ground state(s) of a proposed Ising spin model. When the connectivity c>e=2.718282, there is no state for this system as the reweighting parameter y, which takes a similar role as the inverse temperature βin co

S. Dorbolo, M. Ausloos, N. Vandewalle

The electrical properties 2D of packed metallic pentagons have been studied. The characterization of such metallic pentagon heaps (like $i-V$ measurements) has been achieved and has allowed to point out two distinct conduction regimes. They are separated by a transition line along which the system exhibits a memory effect behavior due to the irreversible imp

Yu Zhu, Qing-feng Sun, Wei Li, Zhong-shui Ma

We investigate ac Josephson effect in the resonant tunneling through mesoscopic superconducting junctions. In the presence of microwave irradiation, we show that the trajectory of multiple Andreev reflections can be closed by emitting or absorbing photons. Consequently, photon-assisted Andreev states are formed and play the role of carrying supercurrent. On

Izumi Ojima

The essence of a general formulation to accommodate non-equilibrium local states in relativistic quantum field theory is explained from the viewpoint of comparison at a spacetime point between unknown generic states to be characterized as such states and the known family of probabilistic mixtures of equilibrium states. Taking advantage of the local nature of

R. D. Sedgewick, D. J. Scalapino, R. L. Sugar, L. Capriotti

We show how canonical ensemble expectation values can be extracted from quantum Monte Carlo simulations in the grand canonical ensemble. In order to obtain results for all particle sectors, a modest number of grand canonical simulations must be performed, each at a different chemical potential. From the canonical ensemble results, grand canonical expectation

Y. D. Jho, D. S. Kim, A. J. Fischer, J. J. Song

Femtosecond pump-probe (PP) differential reflectivity spectroscopy (DRS) and four-wave mixing (FWM) experiments were performed simultaneously to study the initial temporal dynamics of the exciton line-shapes in GaN epilayers. Beats between the A-B excitons were found \textit{only for positive time delay} in both PP and FWM experiments. The rise time at negat

M. Cristina Marchetti, A. Alan Middleton, Karl Saunders, J. M. Schwarz

Extended systems driven through strong disorder are modeled generically using coarse-grained degrees of freedom that interact elastically in the directions parallel to the driving force and that slip along at least one of the directions transverse to the motion. A realization of such a model is a collection of elastic channels with transverse viscous couplin

J. Ding, J. C. Charlton, N. A. Bond, S. G. Zonak

The z=0.9902 system along the quasar PG 1634+706 line of sight is a strong MgII absorber (W(2796)>0.3A) with only weak CIV absorption (it is ``CIV-deficient&#39;&#39;). To study this system, we used high-resolution spectra from both HST/STIS (R=30,000) and Keck/HIRES (R=45,000). These spectra cover key transitions, such as MgI, MgII, FeII, SiII, CII, SiIII,

I. Baraffe, G. Chabrier, T. Barman, F. Allard

We present evolutionary models for cool brown dwarfs and extra-solar giant planets. The models reproduce the main trends of observed methane dwarfs in near-IR color-magnitude diagrams. We also present evolutionary models for irradiated planets, coupling for the first time irradiated atmosphere profiles and inner structures. We focus on HD 209458-like systems

Kim-Vy Tran, Luc Simard, Garth Illingworth, Marijn Franx

[Abridged] We examine the physical properties of 173 cluster members in CL1358+62 (z=0.33) from HST WFPC2 imaging taken in the F606W & F814W filters (rest-frame B & V) over a 2.2x2.2 Mpc^2 field. Structural parameters are measured for each member by fitting a PSF-convolved, two component model to their 2D surface brightness distribution. We examine bulge+dis

D. E. Harris

We monitored the M87 jet with the ACIS-S detector on Chandra with 5 observations between 2002 Jan and 2002 Jul. Our goal was to determine the presence and degree of variability in morphology, intensity, and spectral parameters. We find strong variability of the core and HST-1, the knot lying 0.8" from the core. These observations were designed to constrain t

J. A. Stevens, M. J. Page, R. J. Ivison, Ian Smail

We report on the X-ray, optical, near-infrared, submillimetre and radio properties of five Extremely Red Objects (EROs) selected at X-ray wavelengths by XMM-Newton in the Lockman Hole field. They all have enough counts in the X-ray band to allow spectral fitting: four are most probably obscured, Compton-thin AGN with redshift dependent absorbing column densi

D. R. Ballantyne, S. Vaughan, A. C. Fabian

Ionized reflection has often been considered as the explanation for the unusual Fe K variability observed in MCG--6-30-15. In this paper, we test this model using a 325 ks observation of MCG--6-30-15 by XMM-Newton and BeppoSAX. The data are fit between 2.5 and 80 keV with the constant density models of Ross & Fabian. The best fit ionized reflection model req

Ralf Klessen, Eva Grebel, Daniel Harbeck

We test whether the structural properties of the nearby dwarf spheroidal (dSph) galaxy Draco, a well-studied Milky Way companion, can be reconciled with the suggestion that dSphs are unbound tidal remnants with a large depth extent along the line of sight. In order to apply the observational test of this hypothesis suggested by Klessen & Zhao, we use public

R. de Grijs, U. Fritze-v. Alvensleben, P. Anders, J. S. Gallagher

(ABBREVIATED:) The large majority of extragalactic star cluster studies done to date have essentially used two or three-passband aperture photometry, combined with theoretical stellar population synthesis models, to obtain age, mass and extinction estimates, and sometimes also metallicities. The accuracy to which this can be done depends on the choice of pas

R. Salvaterra, A. Ferrara

Population III stars are now believed to contribute to the observed Near Infrared Background (NIRB) and heavy element pollution of the intergalactic medium. Here we show that a Pop III contribution to the primordial He abundance consistent with NIRB constraints, might mask a lower value for the Big Bang Nucleosynthesis (BBN) He abundance.

Dean E. McLaughlin

The main aspects of the globular cluster luminosity function needing to be explained by a general theory of cluster formation are reviewed, and the importance of simultaneously understanding globular cluster systematics (the fundamental plane) within such a theory is pointed out.

Dean E. McLaughlin

The basic ingredients of models for the internal dynamics of globular clusters are reviewed, with an emphasis on the description of equilibrium configurations. The development of progressive complexity in the models is traced, concentrating on the inclusion of velocity anisotropy, rotation, and integrals of motion other than energy. Applications to observati

Dafne Guetta, Jonathan Granot

We present the main observational features expected for Gamma-Ray Bursts (GRBs) that occur inside pulsar wind bubbles (PWBs). This is the most natural outcome of the supranova model, where initially a supernova (SN) explosion takes place, leaving behind a supra-massive neutron star, which loses its rotational energy over a time t_sd and collapses to a black

P. D. Barthel, I. M. van Bemmel

The 2002 status of unification models for extragalactic radio sources is examined, with particular emphasis on the dust properties of these objects.

P. J. Outram, Fiona Hoyle, T. Shanks, S. M. Croom

We present a power spectrum analysis of the final 2dF QSO Redshift Survey catalogue containing 22652 QSOs. Utilising the huge volume probed by the QSOs, we can accurately measure power out to scales of ~500Mpc and derive new constraints, at z~1.4, on the matter and baryonic contents of the Universe. Importantly, these new cosmological constraints are derived

Michael Malquarti, Edmund J Copeland, Andrew R Liddle, Mark Trodden

K-essence models, relying on scalar fields with non-canonical kinetic terms, have been proposed as an alternative to quintessence in explaining the observed acceleration of the Universe. We consider the use of field redefinitions to cast k-essence in a more familiar form. While k-essence models cannot in general be rewritten in the form of quintessence model

C. Abia, I. Dominguez, R. Gallino, S. Masera

A chemical study of normal Galactic C(N) carbon stars is presented. Abundances of Li, CNO isotopes and s-elements are derived. The derived abundances of s-elements nicely agree with theoretical s-process nucleosynthesis predictions during the AGB phase. However, the figures obtained for Li and the 12C/13C ratios might imply the existence of a non-standard mi

C. Sbarra, E. Carretti, S. Cortiglioni, M. Zannoni

We describe a simple but effective iterative procedure specifically designed to destripe Q and U Stokes parameter data as those collected by the SPOrt experiment onboard the International Space Station (ISS). The method is general enough to be useful for other experiments, both in polarization and total intensity. The only requirement for the algorithm to wo

C. Zanni, G. Bodo, P. Rossi, S. Massaglia

X-ray observations of extragalactic radiosources show strong evidences of interaction between the radio emitting plasma and the X-ray emitting ambient gas. In this paper we perform a detailed study of this interaction by numerical simulations. We study the propagation of an axisymmetric supersonic jet in an isothermal King atmosphere and we analyze the evolu

M. Cappellari, R. C. E. van den Bosch, E. K. Verolme, R. Bacon

We describe our program for the dynamical modeling of early-type galaxies observed with the panoramic integral-field spectrograph SAURON. We are using Schwarzschild&#39;s numerical orbit superposition method to reproduce in detail all kinematical and photometric observables, and recover the intrinsic orbital structure of the galaxies. Since catastrophes are

Falk Herwig, Norbert Langer, Maria Lugaro

We model the nucleosynthesis during a radiative interpulse phase of a rotating 3Msun Asymptotic Giant Branch (AGB) star. We find an enhanced production of the neutron source species C13 compared to non-rotating models due to shear mixing of protons and C12 at the core-envelope interface. We estimate that the resulting total production of heavy elements by sl

Zumin Luo, Jonathan L. Rosner

The recent observation of the decay $\ob \to Λ_c^+ \bar p$ suggests that related decays may soon be visible at $e^+ e^-$ colliders. It is shown how these decays can shed light on strong final-state phases and amplitudes involving the spectator quark, both of which are normally expected to be small in B decays.

Jorge Iniguez, David Vanderbilt, L. Bellaiche

We report a first-principles study of a class of (BiScO3)_{1-x}-(PbTiO3)_x (BS-PT) alloys recently proposed by Eitel et al. as promising materials for piezoelectric actuator applications. We show that (i) BS-PT displays very large structural distortions and polarizations at the morphotropic phase boundary (MPB) (we obtain a c/a of ~1.05-1.08 and P_tet of ~1.

Eric Lauga, Michael P. Brenner

Recent experiments (Zhu & Granick (2001) Phys. Rev. Lett. 87 096105) have measured a large shear dependent fluid slip at partially wetting fluid-solid surfaces. We present a simple model for such slip, motivated by the recent observations of nanobubbles on hydrophobic surfaces. The model considers the dynamic response of bubbles to change in hydrodynamic pre

R. G. Beausoleil, W. J. Munro, T. P. Spiller

We develop a theoretical framework for the exploration of quantum mechanical coherent population transfer phenomena, with the ultimate goal of constructing faithful models of devices for classical and quantum information processing applications. We begin by outlining a general formalism for weak-field quantum optics in the Schrödinger picture, and we include

R. Akhoury, Y. -P. Yao

Modifications of Heisenberg&#39;s uncertainty relations have been proposed in the literature which imply a minimum position uncertainty. We study the low energy effects of the new physics responsible for this by examining the consequent change in the quantum mechanical commutation relations involving position and momenta. In particular, the modifications to

Yaroslav Tserkovnyak, Bertrand I. Halperin, Ophir M. Auslaender, Amir Yacoby

We present theoretical calculations and experimental measurements which reveal the Luttinger-liquid (LL) nature of elementary excitations in a system consisting of two quantum wires connected by a long narrow tunnel junction at the edge of a GaAs/AlGaAs bilayer heterostructure. The boundaries of the wires are important and lead to a characteristic interferen

Kaj H. Hoglund, Anders W. Sandvik

We use a quantum Monte Carlo method (stochastic series expansion) to study the effects of a magnetic or nonmagnetic impurity on the magnetic susceptibility of the two-dimensional Heisenberg antiferromagnet. At low temperatures, we find a log-divergent contribution to the transverse susceptibility. We also introduce an effective few-spin model that can quanti

R. C. Thomas, David Branch, E. Baron, Ken&#39;ichi Nomoto

High-velocity features in Type Ia supernova spectra provide a way to probe the outer layers of these explosions. The maximum-light spectra of the unique Type Ia supernova 2000cx exhibit interesting Ca II features with high-velocity components. The infrared triplet absorption is quadruply notched, while the H&K absorption is wide and flat. Stimulated by a thr

H. Reinhardt, T. Tok

The spectrum of the Dirac Hamiltonian in the background of crossing vortices is studied. To exploit the index theorem, and in analogy to the lattice the space-time manifold is chosen to be the four-torus $\T^4$. For sake of simplicity we consider two idealized cases: infinitely fat and thin transversally intersecting vortices. The time-dependent spectrum of

Yiing-Rei Chen, Vasili Perebeinos, Philip B. Allen

Under heating, $α$-AlF$_3$ undergoes a structural phase transition from rhombohedral to cubic at temperature $T$ around 730 K. The density functional method is used to examine the $T$=0 energy surface in the structural parameter space, and finds the minimum in good agreement with the observed rhombohedral structure. The energy surface and electronic wave-fun

J. M. Diego, J. Silk, W. Sliwa

We cross-correlate WMAP and ROSAT diffuse X-ray background maps and look for common features in both data sets. We use the power spectrum of the product maps and the cross-power spectrum to highlight a possible correlation. The power spectrum of the product maps does not detect any correlation and the cross-power spectrum does not show any significant deviat

Victor M. Yakovenko

This article is written for the online newspaper &#34;The Photon&#34; published by the Department of Physics, University of Maryland. The article describes econophysics research done in the group of Victor Yakovenko. It briefly surveys the subjects &#34;Statistical Mechanics of Money, Income, and Wealth&#34; and &#34;Probability Distribution of Stock-Market

Cosmas K Zachos, Thomas L Curtright

Phase Space is the framework best suited for quantizing superintegrable systems--systems with more conserved quantities than degrees of freedom. In this quantization method, the symmetry algebras of the hamiltonian invariants are preserved most naturally, as illustrated on nonlinear $σ$-models, specifically for Chiral Models and de Sitter $N$-spheres. Classi

Michael E. Peskin

In upper-division undergraduate physics courses, it is desirable to give numerical problem-solving exercises integrated naturally into weekly problem sets. I explain a method for doing this that makes use of the built-in class structure of the Java programming language. I also supply a Java class library that can assist instructors in writing programs of thi

A. Caldararu, S. Katz, E. Sharpe

In this paper we extend previous work on calculating massless boundary Ramond sector spectra of open strings to include cases with nonzero flat B fields. In such cases, D-branes are no longer well-modelled precisely by sheaves, but rather they are replaced by `twisted&#39; sheaves, reflecting the fact that gauge transformations of the B field act as affine t

Paola Mosconi

We study free massive fermionic ghosts, in the presence of an extended line of impurities, relying on the Lagrangian formalism. We propose two distinct defect interactions, respectively, of relevant and marginal nature. The corresponding scattering theories reveal the occurrence of resonances and instabilities in the former case and the presence of poles wit

Nicola Manini, Erio Tosatti

A recent Letter reports photoemission data for the free C60 molecule, showing an interesting three-peak structure, presented as evidence of dynamic Jahn-Teller (DJT) effect in the C60+ ion. Those data constitute, along with earlier spectra by the Uppsala group, the best available piece of experimental evidence about the spectrum of a hole in fullerene. DJT m

Masayasu Harada, Koichi Yamawaki

We develop an effective field theory of QCD and QCD-like theories, based on the hidden local symmetry (HLS) model. We formulate the chiral perturbation theory with loops of rho as well as pi and further include quadratic divergences which are crucial to the chiral phase transition. Detailed calculations of the one-loop renormalization-group equation of the p

A. L. Kataev

Using the infrared-renormalon approach, we obtain the constraints on the next-to-leading order non-singlet polarised parton densities. The advocated feature follows from the consideration of the effect revealed in the process of the next-to-leading order fits to the data for the assymetry of polarised lepton-nucleon scattering which result in the approximate

B. C. Allanach, S. Kraml, W. Porod

We estimate the current theoretical uncertainty in sparticle mass predictions by comparing several state-of-the-art computations within the minimal supersymmetric standard model (MSSM). We find that the theoretical uncertainty is comparable to the expected statistical errors from the Large Hadron Collider (LHC), and significantly larger than those expected f

Wang Xiang-bin, Fan Heng

Two remote parties, Alice and Bob initially share some non-maximally entangled states. Through the entanglement concentration by local operation and classical communication(LOCC), they may obtain an outcome of maximally entangled states in the price of decreasing the number of pairs shared by them. Recently, entanglement concentration have been experimently

P. Süle, M. Menyhárd, K. Nordlund

Molecular dynamics simulations have been used to obtain the three-dimensional distribution of interfacial mixing and cascade defects in Ti/Pt multilayer system due to single 1 keV $Ar^+$ impacts at grazing angle of incidence. The Ti/Pt system was chosen because of its relatively high heat of mixing in the binary alloy and therefore a suitable candidate for t

Yoshiaki Himemoto, Misao Sasaki

We review a viable alternative scenario of the inflationary universe in the context of the Randall-Sundrum (RS) braneworld. In this scenario, the dynamics of a 5-dimensional scalar field, which we call a bulk scalar field, plays the central role. Focusing on the second (single-brane) RS model, we discuss braneworld inflation driven by a bulk scalar field wit

R. Aurich, F. Steiner

We study quintessence models with a constant (effective) equation of state. It is investigated whether such quintessence models are consistent with a negative spatial curvature of the Universe with respect to the anisotropy of the cosmic microwave background radiation measured by the WMAP mission. If the reionization is negligibly small, it is found that suc

Michael Maziashvili

It is shown that, to the lowest order in $\hbar,$ the particle production related to the tunneling that leads to the false vacuum decay is described by the orthogonal part of fluctuation field with respect to the bounce solution. As a simple example the spatially homogeneous tunneling is considered in order to illustrate the consequences coming from such a r

Michael Thies, Konrad Urlichs

We confirm earlier hints that the conventional phase diagram of the discrete chiral Gross-Neveu model in the large N limit is deficient at non-zero chemical potential. We present the corrected phase diagram constructed in mean field theory. It has three different phases, including a kink-antikink crystal phase. All transitions are second order. The driving m

L. Benfatto, A. Toschi, S. Caprara

The derivation of the effective theory for the phase degrees of freedom in a superconductor is still, to some extent, an open issue. It is commonly assumed that the classical XY model and its quantum generalizations can be exploited as effective phase-only models. In the quantum regime, however, this assumption leads to spurious results, such as the violatio

V. N. Russkikh, Yu. B. Ivanov, E. G. Nikonov, W. Noerenberg

A 3-fluid hydrodynamic model is introduced for simulating heavy-ion collisions at incident energies between few and about 200 AGeV. In addition to the two baryon-rich fluids of 2-fluid models, the new model incorporates a third, baryon-free (i.e. with zero net baryonic charge) fluid which is created in the mid-rapidity region. Its evolution is delayed due to

K. E. Arinstein, V. F. Dmitriev, I. B. Khriplovich

We demonstrate that there is no appreciable enhancement of the anapole moment of $^{11}$Be. The effect of small energy intervals is compensated for by a small overlap of the halo neutron wave function with core.

S. Wanajo, M. Tamamura, N. Itoh, K. Nomoto

We examine r-process nucleosynthesis in a &#34;prompt supernova explosion&#34; from an 8-10 Msun progenitor star, as an alternative scenario to the &#34;neutrino wind&#34; mechanism. In the present model, the progenitor star has formed an oxygen-neon-magnesium core at its center. The core-collapse simulations are performed with a one-dimension, Newtonian hyd

Chandan Singh Dalawat

We determine the Chow group of zero-cycles on a rational surface X defined over a finite extension K of the field of p-adic numbers (p a prime) when X is split by an unramified extension of K.

Kiyoshi Higashijima, Etsuko Itou

The Wilsonian renormalization group (WRG) equation is used to derive a new class of scale invariant field theories with nonvanishing anomalous dimensions in 2-dimensional ${\cal N}=2$ supersymmetric nonlinear sigma models. When the coordinates of the target manifolds have nontrivial anomalous dimensions, vanishing of the $β$ function suggest the existence of

Takashi Uchino, Izumi Tsutsui

We provide a systematic study on the possibility of supersymmetry (SUSY) for one dimensional quantum mechanical systems consisting of a pair of lines $\R$ or intervals [-l, l] each having a point singularity. We consider the most general singularities and walls (boundaries) at $x = \pm l$ admitted quantum mechanically, using a U(2) family of parameters to sp

Melvyn B. Nathanson

Let A be a set of nonnegative integers. For every nonnegative integer n and positive integer h, let r_{A}(n,h) denote the number of representations of n in the form n = a_1 + a_2 + ... + a_h, where a_1, a_2,..., a_h are elements of A and a_1 \leq a_2 \leq ... \leq a_h. The infinite set A is called a basis of order h if r_{A}(n,h) \geq 1 for every nonnegative