December 2002 arXiv papers

I. V. Kanatchikov

Precanonical quantization of pure Yang-Mills fields, which is based on the covariant De Donder-Weyl (DW) Hamiltonian formalism, and its connection with the functional Schrodinger representation in the temporal gauge are discussed. The YM mass gap problem is related to a finite dimensional spectral problem for a generalized Clifford-valued magnetic Schrödinge

Brandon C. Kelly, Philip A. Hughes, Hugh D. Aller, Margo F. Aller

We introduce an algorithm for applying a cross-wavelet transform to analysis of quasiperiodic variations in a time-series, and introduce significance tests for the technique. We apply a continuous wavelet transform and the cross-wavelet algorithm to the Pearson-Readhead VLBI survey sources using data obtained from the University of Michigan 26-m parabloid at

Frank Wilczek

Some important problems in quantitative QCD will certainly yield to hard work and adequate investment of resources, others appear difficult but may be accessible, and still others will require essentially new ideas. Here I identify several examples in each class.

G. G. Barnafoldi, P. Levai, G. Papp, G. Fai

Perturbative QCD results on pion production are presented in proton-proton, proton-nucleus and nucleus-nucleus collisions from CERN SPS up to RHIC energy. A K_{jet}(s, p_T, Q) factor obtained from jet production is applied to perform next-to-leading order calculations. Using the intrinsic transverse momentum (k_T) we determined transverse momentum spectra fo

Jeeva Anandan, Naresh Dadhich, Parampreet Singh

We present an action principle formulation for the study of motion of an extended body in General Relativity in the limit of weak gravitational field. This gives the classical equations of motion for multipole moments of arbitrary order coupling to the gravitational field. In particular, a new force due to the octupole moment is obtained. The action also yie

Beatriz Gato-Rivera

This is a brief introduction to the subject of Conformal Field Theory on surfaces with boundaries and crosscaps, which describes the perturbative expansion of open string theory.

Pierre Henry-Labordere, Bernard Julia, Louis Paulot

The correspondence between del Pezzo surfaces and field theory models over the complex numbers or for split real forms is extended to other real forms, in particular to those compatible with supersymmetry. Specifically, all theories of the Magic triangle that reduce to the pure supergravities in four dimensions correspond to singular real del Pezzo surfaces

S. K. Sahay

We investigate the matching of continuous gravitational wave (CGW) signals in an all sky search with reference to Earth based laser interferometric detectors. We consider the source location as the parameters of the signal manifold and templates corresponding to different source locations. It has been found that the matching of signals from locations in the

Lev Vaidman, Zion Mitrani

Methods for measuring an integral of a classical field via local interaction of classical bits or local interaction of qubits passing through the field one at a time are analyzed. A quantum method, which has an exponentially better precision than any classical method we could see, is described.

P. Vielva, E. Martinez-Gonzalez, J. E. Gallegos, L. Toffolatti

We present an estimation of the point source (PS) catalogue that could be extracted from the forthcoming ESA Planck mission data. We have applied the Spherical Mexican Hat Wavelet (SMHW) to simulated all-sky maps that include CMB, Galactic emission (thermal dust, free-free and synchrotron), thermal Sunyaev-Zel'dovich effect and PS emission, as well as in

Matt Mackie, Anssi Collin, Juha Javanainen

Collective two-color photoassociation of a freely-interacting 87Rb Bose-Einstein condensate is theoretically examined, focusing on stimulated Raman adiabatic passage (STIRAP) from an atomic to a stable molecular condensate. In particular, Drummond et al. [Phys. Rev. A 65, 063619 (2002); cond-mat/0110578] have predicted that particle-particle interactions can

M. Jourdan, N. Blümer, H. Adrian

Superconducting SrTiO_{3-δ} was obtained by annealing single crystalline SrTiO_3 samples in ultra high vacuum. An analysis of the V(I) characteristics revealed very small critical currents I_c which can be traced back to a unavoidable doping inhomogeneity. R(T) curves were measured for a range of magnetic fields B at I<<I_c, thereby probing only the sample r

Miao Li

We discuss the sizes of a black hole in the M theory pp-wave background, and how the transverse size can be reproduced in the matrix model.

Kiyoshi Tamaki, Masato Koashi, Nobuyuki Imoto

We prove the unconditional security of the Bennett 1992 protocol, by using a reduction to an entanglement distillation protocol initiated by a local filtering process. The bit errors and the phase errors are correlated after the filtering, and we can bound the amount of phase errors from the observed bit errors by an estimation method involving nonorthogonal

Seungjoon Hyun, Jaemo Park, Hyeonjoon Shin

We work out boundary conditions for the covariant open string in the type IIA plane wave background, which corresponds to the D-branes in the type IIA theory. We use the kappa symmetric string action and see what kind of boundary conditions should be imposed to retain kappa symmetry. We find half BPS as well as quarter BPS branes and the analysis agrees with

Harry J. Lipkin

The past leaves the surprising experimental successes of the simple constituent quark model to be expained by QCD. Surprising agreement with experiment from simple Sakharov-Zeldovich model (1966) having quarks with effective masses and hyperfine interaction. Nambu&#39;s (1966) Colored quarks with gauge gluons gave mass spectrum with only $qqq$ and $\bar q$ b

Kiyoshi Igusa

This paper gives a short summary of the central role played by Ed Brown&#39;s &#34;twisting cochains&#34; in higher Franz-Reidemeister (FR) torsion and higher analytic torsion. Briefly, any fiber bundle gives a twisting cochain which is unique up to fiberwise homotopy equivalence. However, when they are based, the difference between two of them is a higher a

Mark Walker, Masaki Mori, Michiko Ohishi

Cold, dense gas clouds have been proposed as a major component of the Galactic dark matter; such clouds can be revealed by the gamma-ray emission which arises from cosmic-rays interacting with the gas. If this dark matter component is clustered then highly luminous GeV sources result, preferentially at low to mid Galactic latitudes where they lie within the

A. B. Souchkov, J. R. Simpson, H. D. Drew, M. Quijada

We have measured the optical conductivity of single crystal LuMnO3 from 10 to 45000 cm-1 at temperatures between 4 and 300 K. A symmetry allowed on-site Mn $d$-$d$ transition near 1.7 eV is observed to blue shift (~0.1 eV) in the antiferromagnetic state due to Mn-Mn superexchange interactions. Similar anomalies are observed in the temperature dependence of t

R. Loll

In these lecture notes, I describe the motivation behind a recent formulation of a non-perturbative gravitational path integral for Lorentzian (instead of the usual Euclidean) space-times, and give a pedagogical introduction to its main features. At the regularized, discrete level this approach solves the problems of (i) having a well-defined Wick rotation,

J. Berges, Sz. Borsanyi, J. Serreau

We solve the nonequilibrium dynamics of a 3+1 dimensional theory with Dirac fermions coupled to scalars via a chirally invariant Yukawa interaction. The results are obtained from a systematic coupling expansion of the 2PI effective action to lowest non-trivial order, which includes scattering as well as memory and off-shell effects. The dynamics is solved nu

V. V. Flambaum, E. V. Shuryak

We follow our previous paper on possible cosmological variation of weak scale (quark masses) and strong scale, inspired by data on cosmological variation of the electromagnetic fine structure constant from distant quasar (QSO) absorption spectra. In this work we identify the {\em strange quark mass} $m_s$ as the most important quantity, and the {\em sigma me

Antonina N. Fedorova, Michael G. Zeitlin

We present an application of variational-wavelet analysis to quasiclassical calculations of solutions of Wigner equations related to nonlinear (polynomial) dynamical problems. (Naive) deformation quantization, multiresolution representations and variational approach are the key points. Numerical calculations demonstrates pattern formation from localized eige

Arun K. Pati

Quantum information theory has revolutionized the way in which information is processed using quantum resources such as entangled states, local operations and classical communications. Two important protocols in quantum communications are quantum teleportation and remote state preparation. In quantum teleportation neither the sender nor the receiver know the

R. Passante, F. Persico

A time-dependent Casimir-Polder force is shown to arise during the time evolution of a partially dressed two-level atom. The partially dressed atom is obtained by a rapid change of an atomic parameter such as its transition frequency, due to the action of some external agent. The electromagnetic field fluctuations around the atom, averaged over the solid ang

Kiyoshi Tamaki, Masato Koashi, Nobuyuki Imoto

The security of two-state quantum key distribution against individual attack is estimated when the channel has losses and noises. We assume that Alice and Bob use two nonorthogonal single-photon polarization states. To make our analysis simple, we propose a modified B92 protocol in which Alice and Bob make use of inconclusive results and Bob performs a kind

V. S. Starovoitov

A random matrix theory approach is applied in order to analyze the localization properties of local spectral density for a generic system of coupled quantum states with strong static imperfection in the unperturbed energy levels. The system is excited by an external periodic field, the temporal profile of which is close to monochromatic one. The shape of loc

Dominic Mayers

It is believed that superselection rules in quantum mechanics can restrict the possible operation on a qbit. If this was true, the model used by Mayers for the impossibility of bit commitment and by Kitaev for the impossibility of coin flipping would be inadequate. We explain why this is not the case. We show that a charge superselection rule implies no rest

Robert A. Herrmann

Using the accepted methods to extract natural system behavior from the Einstein-Hilbert gravitational field tensor equation, a new coordinate transformation is analyzed. It is demonstrated that these extraction methods yield specific contradictions. Two such contradictions are that for an electrically neutral (non-rotating) Schwarzschild configuration there

Antonina N. Fedorova, Michael G. Zeitlin

We consider an application of variational-wavelet approach to nonlinear collective models of beam/plasma physics: Vlasov/Boltzmann-like reduction from general BBGKY hierachy. We obtain fast convergent multiresolution representations for solutions which allow to consider polynomial and rational type of nonlinearities. The solutions are represented via the mul

Elad Schneidman, William Bialek, Michael J. Berry

A population of neurons typically exhibits a broad diversity of responses to sensory inputs. The intuitive notion of functional classification is that cells can be clustered so that most of the diversity is captured in the identity of the clusters rather than by individuals within clusters. We show how this intuition can be made precise using information the

Blaise Aguera y Arcas, Adrienne L. Fairhall, William Bialek

A spiking neuron ``computes&#39;&#39; by transforming a complex dynamical input into a train of action potentials, or spikes. The computation performed by the neuron can be formulated as dimensional reduction, or feature detection, followed by a nonlinear decision function over the low dimensional space. Generalizations of the reverse correlation technique w

H. Marion, F. Pereira Dos Santos, M. Abgrall, S. Zhang

Over five years we have compared the hyperfine frequencies of 133Cs and 87Rb atoms in their electronic ground state using several laser cooled 133Cs and 87Rb atomic fountains with an accuracy of ~10^{-15}. These measurements set a stringent upper bound to a possible fractional time variation of the ratio between the two frequencies : (d/dt)ln(nu_Rb/nu_Cs)=(0

S. Bize, S. A. Diddams, U. Tanaka, C. E. Tanner

Over a two-year duration, we have compared the frequency of the 199Hg+ 5d106s 2S 1/2 (F=0)<-> 5d9 6s2 2D 5/2 (F=2) electric-quadrupole transition at 282 nm with the frequency of the ground-state hyperfine splitting in neutral 133Cs. These measurements show that any fractional time variation of the ratio nu(Cs)/nu(Hg) between the two frequencies is smaller th

I. T. Obukhovsky, V. I. Kukulin, M. M. Kaskulov, P. Grabmayr

The impact of the short-range $NΔ$ interaction on the pion photoproduction processes off the deuteron in the $Δ$-resonance region is studied in the framework of recently proposed dressed-bag model. A common dressing procedure for bare three- and six-quark states is used to describe both the pion decay widths of baryon resonances and the effective $NN$ (or $N

Petr Alexa

Possible theoretical electromagnetic paths between the ground state and the isomeric state at 75.3 keV in 180Ta are discussed in the framework of the two-quasiparticle-plus-phonon model and the standard axially-symmetric rotor model including Coriolis mixing. Experimental transition rates from the isomeric state to the ground state via observed mediating sta

Dirk Hundertmark, Werner Kirsch, Simone Warzel

We determine the leading low-energy fall-off of the integrated density of states of a magnetic Schroedinger operator with repulsive Poissonian random potential in case its single impurity potential has a slow anisotropic decay at infinity. This so-called magnetic Lifshits tail is shown to coincide with the one of the corresponding classical integrated densit

Clifford Henry Taubes

This article describes various moduli spaces of pseudoholomorphic curves on the symplectization of a particular overtwisted contact structure on S^1 x S^2. This contact structure appears when one considers a closed self dual form on a 4-manifold as a symplectic form on the complement of its zero locus. The article is focussed mainly on disks, cylinders and t

Eric L Swenson

We give sufficient conditions for a group of homeomorphisms of a Peano continuum X without cut-points to be a convergence group. The condition is that there is a collection of convergence subgroups whose limit sets `cut up&#39; X in the correct fashion. This is closely related to the result in [E Swenson, Axial pairs and convergence groups on S^1, Topology 3

Mikhail Lyubich

The goal of this technical note is to show that the geometry of generalized parabolic towers cannot be essentially bounded. It fills a gap in author&#39;s paper &#34;Combinatorics, geomerty and attractors of quasi-quadratic maps&#34;, Annals of Math., 1992.

Jonathan P. McCammond, Daniel T. Wise

A group is coherent if all its finitely generated subgroups are finitely presented. In this article we provide a criterion for positively determining the coherence of a group. This criterion is based upon the notion of the perimeter of a map between two finite 2-complexes which is introduced here. In the groups to which this theory applies, a presentation fo

Rutwig Campoamor-Stursberg

We finish the determination of the invariants of the coadjoint representation of six dimensional real Lie algebras, by determining a fundamental set of invariants for the 99 isomorphism classes of solvable Lie algebras with five dimensional nilradical. We also give some results on the invariants of solvable Lie algebras in arbitrary dimension whose nilradica

Ron M. Adin, Avital Frumkin, Yuval Roichman

The hook components of $V^{\otimes n}$ interpolate between the symmetric power $\sym^n(V)$ and the exterior power $\wedge^n(V)$. When $V$ is the vector space of $k\times m$ matrices over $\bbc$, we decompose the hook components into irreducible $GL_k(\bbc)\times GL_m(\bbc)$-modules. In particular, classical theorems are proved as boundary cases. For the alge

Jose A. de Azcarraga, Jose M. Izquierdo, Moises Picon, Oscar Varela

We study how to generate new Lie algebras $\mathcal{G}(N_0,..., N_p,...,N_n)$ from a given one $\mathcal{G}$. The (order by order) method consists in expanding its Maurer-Cartan one-forms in powers of a real parameter $λ$ which rescales the coordinates of the Lie (super)group $G$, $g^{i_p} \to λ^p g^{i_p}$, in a way subordinated to the splitting of $\mathcal

R. Brustein, S. P. de Alwis, E. G. Novak

We conduct a systematic search for a viable string/M-theory cosmology, focusing on cosmologies that include an era of slow-roll inflation, after which the moduli are stabilized and the Universe is in a state with an acceptably small cosmological constant. We observe that the duality relations between different cosmological backgrounds of string/M-theory modu

P. Baseilhac, M. Stanishkov

Exact vacuum expectation values of the third level descendent fields $<(\partialϕ)^3({\bar\partial}ϕ)^3e^{aϕ}>$ in the Bullough-Dodd model are proposed. By performing quantum group restrictions, we obtain $<L_{-3}{\bar L}_{-3}Φ_{lk}>$ in perturbed minimal conformal field theories.

F. Loran

We show that after mapping each element of a set of second class constraints to the surface of the other ones, half of them form a subset of abelian first class constraints. The explicit form of the map is obtained considering the most general Poisson structure. We also introduce a proper redefinition of second class constraints that makes their algebra symp

Axel Krause

We review a recent proposal towards a microscopic understanding of the entropy of non-supersymmetric spacetimes -- with emphasis on the Schwarzschild black hole. The approach is based at an intermediate step on the description of the non-supersymmetric spacetime in terms of dual Euclidean brane pairs of type-II string-theory or M-theory. By counting specific

Zheng Yin

N=1 and 2 superconformal boundary conditions are shown to be the consequence of a boundary on the worldsheet superspace with positive codimension in the anticommuting subspace. In addition to the well-known boundary conditions, I also find two new infinite series of N=2 boundary states. Their free field realizations are given. A self-contained development of

J. Blümlein, H. Böttcher

In this talk we summarize main results of a recent determination of the polarized deeply inelastic parton distributions to NLO from the world data. In the analysis the LO and NLO parton densities and their $1σ$ statistical errors were derived and parameterized. The strong coupling constant $α_s(M_Z^2)$ is determined $α_s(M_Z^2) = 0.113 \pm 0.004 {\rm (stat.)

T. V. Shishkina, I. B. Marfin

The cross section for deep inelastic lepton-nucleon scattering with arbitrary polarized scattering fermions is calculated within the electroweak Standard Model and non-minimal gauge models with additional neutral boson. The Lorentz-invariant formulas for cross section and all types of electroweak asymmetries, polarized, charge-polarized, charged, including t

Zvi Bern

In this talk, the recent breakthrough in two-loop perturbative calculations is reviewed, with emphasis on the applications to phenomenological studies. The recent precision measurement of the anomalous magnetic moment of the muon by the Brookhaven g-2 collaboration is also used as an illustrative example of the importance of Standard Model precision perturba

Masayasu Harada

In this talk I summarize main features of the vector manifestation (VM) which was recently proposed as a novel manifestation of the Wigner realization of chiral symmetry in which the symmetry is restored at the critical point by the massless degenerate pion (and its flavor partners) and the rho meson (and its flavor partners) as the chiral partner. I show ho

A. N. Mitra

A new approach to the non-perturbative regime of QCD is proposed by introducing a (non-hermitian) field $B$ related to the usual gluon field $A$ by $B_μ$ = $(1+ σ\partial_m) A_μ$ where $m$ goes to zero after differentiation, and $σ$ is a parameter which `runs&#39; with momentum ($k$). An exact treatment yields a structure $[1/k^2 + 2μ^2/k^4]$ for the gluon p

Hong Liu, Gregory Moore, Nathan Seiberg

In this talk we discuss the cosmic singularity. We motivate the need to correct general relativity in the study of singularities, and mention the kind of corrections provided by string theory. We review how string theory resolves time-like singularities with two examples. Then, a simple toy model with lightlike singularities is presented, and studied in clas

A. A. Bytsenko, Yu. P. Goncharov

The natural extension of Schwarzschild metric to the case of nonzero cosmological constant $Λ$ known as the Kottler metric is considered and it is discussed under what circumstances the given metric could describe the Schwarzschild black hole immersed in a medium with nonzero energy density. Under the latter situation such an object might carry topologically

P. Nalbach

The dielectric constant of amorphous solids at low temperatures is governed by the dynamics of tunneling systems, small groups of atoms which tunnel between quasi equivalent potential minima. Recent experiments showed that at temperatures below 20 mK various glasses exhibit memory for a previously applied electric bias field. A first sweep of an electric bia

M. F. DeCamp, D. A. Reis, A. Cavalieri, P. H. Bucksbaum

We study coherent strain in (001) Ge generated by an ultrafast laser-initiated high density electron-hole plasma. The resultant coherent pulse is probed by time-resolved x-ray diffraction through changes in the anomalous transmission. The acoustic pulse front is driven by ambipolar diffusion of the electron-hole plasma and propagates into the crystal at supe

P. Coleman, C. Pepin

Although the concept of a quantum phase transition has been known since the nineteen seventies, their importance as a source of radical transformation in metallic properties has only recently been appreciated. A quantum critical point forms an essential singularity in the phase diagram of correlated matter. We discus new insights into the nature of this phen

T. A. Costi

We study electronic transport through a strongly interacting quantum dot by using the finite temperature extension of Wilson&#39;s numerical renormalization group (NRG) method. This allows the linear conductance to be calculated at all temperatures and in particular at very low temperature where quantum fluctuations and the Kondo effect strongly modify the t

Serguei Ktitorov

The problem of the vortex structure in the lattice modele of superconductors has been reduced to the nonlinear map problem characteristic for the fractal theory.

Pierre Del Moral, Arnaud Doucet

This paper shows how one can use Sequential Monte Carlo methods to perform what is typically done using Markov chain Monte Carlo methods. This leads to a general class of principled integration and genetic type optimization methods based on interacting particle systems.

Y. J. Uemura

Extensive muon spin relaxation measurements have been performed to determine the magnetic field penetration depth in high-Tc cuprate superconductors with simple hole doping, Zn-doping, overdoping, and formation of static SDW nano islands. System dependence of $n_{s}/m^{*}$ (superconducting carrier density / effective mass) reveals universal correlations betw

M. Ausloos, K. Ivanova

We generalize the momentum indicator idea taking into account the volume of transactions as a multiplicative factor. We compare returns obtained following strategies based on the classical or the generalized technical analysis, taking into account a sort of risk investor criterion.

Harry I. Teplitz, Nicholas R. Collins, Jonathan P. Gardner, Robert S. Hill

We present the luminosity function of [OII]-emitting galaxies at a median redshift of z=0.9, as measured in the deep spectroscopic data in the STIS Parallel Survey (SPS). The luminosity function shows strong evolution from the local value, as expected. By using random lines of sight, the SPS measurement complements previous deep single field studies. We calc

Frederick M. Walter, Tracy L. Beck, Jon A. Morse, Scott J. Wolk

The 3&#34; pair of B9 stars, HD 28867, is one of the brightest X-ray sources in the Taurus-Auriga star forming region. In this multi-wavelength study, we attempt to deduce the source of the X-ray emission. We show that the East component is the X-ray source. The East component has a near-IR excess and displays narrow absorption lines in the optical, both of

Andrew Gould

I test the completeness of USNO-B detections of high proper-motion (mu>0.18&#34;/yr) stars and the accuracy of its measurements by comparing them to the revised NLTT (rNLTT) catalog of Salim & Gould. For 14.5<V<18.5, only 6% of such stars are missing from USNO-B while another 4% have large errors, mostly too large to be useful. Including both classes, incomp

M. Y. Poon, D. Merritt

We construct models of triaxial galactic nuclei containing central black holes using the method of orbital superposition, then verify their stability by advancing N-body realizations of the models forward in time. We assume a power-law form for the stellar density, rho ~ 1/r and 1/r^2; these correspond approximately to the nuclear density profiles of bright

Javier Ballesteros-Paredes

Molecular clouds (MC) are the densest and coldest component of the interstellar gas, and the sites of star formation. They are also turbulent and fractal and their masses and sizes span several orders of magnitude. It is also generally believed that they are close to Virial equilibrium (VE). Since this statement has been questioned by a number of authors, wi

R. S. Singh, B. K. Sinha, N. K. Lohani

It is found from Maxwell&#39;s equations that the magnetic field lines are good analogues of relativistic strings. It is shown that the super-conducting current in the neutron star&#39;s interior causes local rotation of magnetic flux tubes carrying quantized flux.

Long-Long Feng, Chi-Wang Shu, Meng-Ping Zhang

We describe a newly developed cosmological hydrodynamics code based on the weighted essentially non-oscillatory (WENO) schemes for hyperbolic conservation laws. High order finite difference WENO schemes are designed for problems with piecewise smooth solutions containing discontinuities, and have been successful in applications for problems involving both sh

Harry I. Teplitz, Nicholas R. Collins, Jonathan P. Gardner, Robert S. Hill

In the first three years of operation STIS obtained slitless spectra of approximately 2500 fields in parallel to prime HST observations as part of the STIS Parallel Survey (SPS). The archive contains almost 300 fields at high galactic latitude (|b|>30) with spectroscopic exposure times greater than 3000 seconds. This sample contains 220 fields (excluding spe

Manuel I. Marques, Jose M. Borreguero, H. Eugene Stanley, Nikolay V. Dokholyan

We study cold denaturation of proteins at high pressures. Using multicanonical Monte Carlo simulations of a model protein in a water bath, we investigate the effect of water density fluctuations on protein stability. We find that above the pressure where water freezes to the dense ice phase ($\approx2$ kbar), the mechanism for cold denaturation with decreasi

Massimo Blasone, Paulo Pires Pacheco, Hok Wan Chan Tseung

By resorting to recent results on the relativistic currents for mixed (flavor) fields, we calculate a space-time dependent neutrino oscillation formula in Quantum Field Theory. Our formulation provides an alternative to existing approaches for the derivation of space dependent oscillation formulas and it also accounts for the corrections due to the non-trivi

M. Nishimura, Y. Tanii

In the context of the AdS/CFT correspondence the general form of a three-form flux perturbation to the AdS_5 x S^5 solution in the type IIB supergravity which preserves N=2 supersymmetry is obtained. The arbitrary holomorphic function appearing in the N=1 case studied by Grana and Polchinski is restricted to a quadratic function of the coordinates transverse

T. Padmanabhan, T. Roy Choudhury

Current cosmological observations show a strong signature of the existence of a dark energy component with negative pressure. The most obvious candidate for this dark energy is the cosmological constant (with the equation of state w_X=p/ρ=-1), which, however, raises several theoretical difficulties. This has led to models for dark energy component which evol

Vladimir Pestov

Let $F\subseteq H\subseteq G$ be closed subgroups of a locally compact group. In response to a 1972 question by Eymard, we construct an example where the homogeneous factor-space $G/F$ is amenable in the sense of Eymard-Greenleaf, while $H/F$ is not. (In our example, $G$ is discrete.) As a corollary which answers a 1990 question by Bekka, the induced represe

Yu-xi Liu, Adam Miranowicz, Masato Koashi, Nobuyuki Imoto

The entanglement of excitonic states in a system of $N$ spatially separated semiconductor microcrystallites is investigated. The interaction among the different microcrystallites is mediated by a single-mode cavity field. It is found that the symmetric sharing of the entanglement (measured by the concurrence) between any pair of the excitonic state with $N$

S. L. Sessions, D. Belitz

An effective field theory is derived that describes the quantum critical behavior of itinerant ferromagnets as the transition is approached from the ferromagnetic phase. This complements a recent study of the critical behavior on the paramagnetic side of the phase transition, and investigates the role of the ferromagnetic Goldstone modes near criticality. We

Alejandro Corichi

Loop quantum gravity can account for the Bekenstein-Hawking entropy of a black hole provided a free parameter is chosen appropriately. Recently, it was proposed that a new choice of the Immirzi parameter could predict both black hole entropy and the frequencies of quasinormal modes in the large $n$ limit, but at the price of changing the gauge group of the t

M. Ciuchini, E. Franco, A. Masiero, L. Silvestrini

The present unitarity triangle fit, whose essential input is represented by the s to d and b to d transition processes, fully agrees with the SM. However, most of the phenomena involving b to s transitions are still largely unexplored and hence b to s phenomenology still constitutes a place for new physics manifestations, in spite of the tremendous experimen

M. B. Altaie

The back reaction effect of the neutrino field at finite temperature in the background of the static Einstein universe is investigated. A relationship between the temperature of the universe and its radius is found. As in the previously studied cases of the massless scalar field and the photon field, this relation exhibit a minimum radius below which no self

Alexander Kling, Olaf Lechtenfeld, Alexander D. Popov, Sebastian Uhlmann

It is argued that the (NS-sector) superstring field equations are integrable, i.e. their solutions are obtainable from linear equations. We adapt the 25-year-old solution-generating &#34;dressing&#34; method and reduce the construction of nonperturbative superstring configurations to a specific cohomology problem. The application to vacuum superstring field

C. P. Buszello, I. Fleck, P. Marquard, J. J. van der Bij

A possibility to prove spin and CP-eigenvalue of a Standard Model (SM) Higgs boson is presented. We exploit angular correlations in the subsequent decay H -> ZZ -> 4l (muons or electrons) for Higgs masses above 200 GeV. We compare the angular distributions of the leptons originating from the SM Higgs with those resulting from decays of hypothetical particles

Frauke Liers, Matteo Palassini, Alexander K. Hartmann, Michael Juenger

We study the Ising spin glass on random graphs with fixed connectivity z and with a Gaussian distribution of the couplings, with mean μand unit variance. We compute exact ground states by using a sophisticated branch-and-cut method for z=4,6 and system sizes up to N=1280 for different values of μ. We locate the spin-glass/ferromagnet phase transition at μ= 0

Costas G. Strouthos, Ioannis N. Tziligakis

We present results from numerical studies of the finite temperature phase transition of the $(3+1)d$ O(N)-symmetric non-linear sigma model for $N=1,2$ and 3. We study the dependence of the width of the 3d critical region on $N$ and we show that the broken phase scaling region is much wider for N=2 and 3 than for N=1. We also compare the widths of the critica

G. Domokos, Andrea Erdas, S. Kovesi-Domokos

In theories which require a space of dimension d>4, there is a natural mechanism of suppressing neutrino masses: while Standard Model fields are confined to a 3-brane, right handed neutrinos live in the bulk. Due to Kaluza-Klein excitations, the effective magnetic moments of neutrinos are enhanced. The effective magnetic moment is a monotonically growing fun

Saurya Das, Gabor Kunstatter

Recent astrophysical observations suggest that the value of fine structure constant $α=e^2/\hbar c$ may be slowly increasing with time. This may be due to an increase of $e$ or a decrease of $c$, or both. In this article, we argue from model independent considerations that this variation should be considered adiabatic. Then, we examine in detail the conseque

S. Blinnikov, N. Chugai, P. Lundqvist, D. Nadyozhin

We simulate shock propagation in a wide range of core-collapsing presupernovae: from compact WR stars exploding as SNe Ib/c through very extended envelopes of the narrow-line SNe IIn. We find that the same physical phenomenon of radiating shocks can produce outbursts of X-ray radiation (with photon energy $3kT \sim 1$ keV) lasting only a second in SNe Ib/c,

A. Lobanov, A. Studenikin

A new type of electromagnetic radiation by a neutrino with non-zero magnetic (and/or electric) moment moving in background matter and electromagnetic field is considered. This radiation originates from the quantum spin flip transitions and we have named it as &#34;spin light of neutrino&#34;($SLν$). The neutrino initially unpolarized beam (equal mixture of $

T. Falter, K. Gallmeister, U. Mosel

In the present paper we investigate incoherent rho^0 electroproduction off complex nuclei. We derive a novel, simple expression for the incoherent electroproduction cross section in which one can clearly separate the final state interactions of the reaction products from the &#39;initial state interactions&#39; of the photon that give rise to nuclear shadowi

Christian Raabe, Ludwig Knöll, Dirk-Gunnar Welsch

Recently the influence of dielectric and geometrical properties on the Casimir force between dispersing and absorbing multilayered plates in the zero-temperature limit has been studied within a 1D quantization scheme for the electromagnetic field in the presence of causal media [R. Esquivel-Sirvent, C. Villarreal, and G.H. Cocoletzi, Phys. Rev. Lett. 64, 052

S. Recksiegel, Y. Sumino

We compare the perturbatively calculated QCD potential to that obtained from lattice calculations in the theory without light quark flavours. We examine E_tot(r) = 2 m_pole + V_QCD(r) by re-expressing it in the MSbar mass m = m^MSbar(m^MSbar) and by choosing specific prescriptions for fixing the scale mu (dependent on r and m). By adjusting m so as to maximi

Wen-Tai Chiang, Shin Nan Yang, L. Tiator, M. Vanderhaeghen

A reggeized model for ηand η&#39; photoproduction on the nucleon is presented. In this model, t-channel vector meson exchanges are described in terms of Regge trajectories to comply with the correct high energy behavior. We compare this reggeized model with an isobar model (η-MAID), where the t-channel exchanges are described by ρand ωpoles. Both models cont

JLQCD Collaboration, S. Aoki, R. Burkhalter, M. Fukugita

We present a high statistics study of the light hadron spectrum and quark masses in QCD with two flavors of dynamical quarks. Numerical simulations are carried out using the plaquette gauge action and the O(a)-improved Wilson quark action at β=5.2, where the lattice spacing is found to be a=0.0887(11)fm from ρmeson mass, on a 20^3\times 48 lattice. At each o

Kamiokande collaboration, Y. Gando

We present the results of a search for low energy $\barν_e$ from the Sun using 1496 days of data from Super-Kamiokande-I. We observe no significant excess of events and set an upper limit for the conversion probability to $\barν_e$ of the $^8$B solar neutrino. This conversion limit is 0.8% (90% C.L.) of the standard solar model&#39;s neutrino flux for total

Robin Blume-Kohout, Wojciech H. Zurek

Chaotic evolutions exhibit exponential sensitivity to initial conditions. This suggests that even very small perturbations resulting from weak coupling of a quantum chaotic environment to the position of a system whose state is a non-local superposition will lead to rapid decoherence. However, it is also known that quantum counterparts of classically chaotic

Matt Visser, David L. Wiltshire

Stellar structure in braneworlds is markedly different from that in ordinary general relativity. As an indispensable first step towards a more general analysis, we completely solve the ``on brane&#39;&#39; 4-dimensional Gauss and Codazzi equations for an arbitrary static spherically symmetric star in a Randall--Sundrum type II braneworld. We then indicate ho

Tetsuya Shiromizu, Kazuya Koyama, Keitaro Takahashi

We discuss the effective theory for the close limit of two branes in a covariant way. To do so we solve the five dimensional Einstein equation along the direction of the extra dimension. Using the Taylor expansion we solve the bulk spacetimes and derive the effective theory describing the close limit. We also discuss the radion dynamics and braneworld black

J. Bajer, A. Miranowicz, R. Tanas

It is well known that the optical Kerr effect can be a source of highly squeezed light, however the analytical limit of the noise suppression has not been found yet. The process is reconsidered and an analytical estimation of the optimal quadrature noise level is presented. The validity of the new scaling law is checked numerically and analytically.