December 2003 arXiv papers — page 3

Yoshinobu Habara, Holger B. Nielsen, Masao Ninomiya

We consider the long standing problem in field theories of bosons that the boson vacuum does not consist of a `sea', unlike the fermion vacuum. We show with the help of supersymmetry considerations that the boson vacuum indeed does also consist of a sea in which the negative energy states are all "filled", analogous to the Dirac sea of the fermio

Roman Bezrukavnikov, Michael Finkelberg, Victor Ginzburg

We prove a localization theorem for the type A rational Cherednik algebra H_c=H_{1,c} over an algebraic closure of the finite field F_p. In the most interesting special case where the parameter c takes values in F_p, we construct an Azumaya algebra A_c on Hilb^n, the Hilbert scheme of n points in the plane, such that the algebra of global sections of A_c is

Hans Lindblad, Igor Rodnianski

We prove global stability of Minkowski space for the Einstein vacuum equations in harmonic (wave) coordinate gauge for the set of restricted data coinciding with Schwartzschild solution in the neighborhood of space-like infinity. The result contradicts previous beliefs that wave coordinates are "unstable in the large" and provides an alternative appr

JM Geremia, Herschel A. Rabitz

Optimal Identification (OI) is a recently developed procedure for extracting optimal information about quantum Hamiltonians from experimental data using shaped control fields to drive the system in such a manner that dynamical measurements provide maximal information about its Hamiltonian. However, while optimal, OI is computationally expensive as initially

S. H. Myrskog, J. K. Fox, M. W. Mitchell, A. M. Steinberg

Quantum process tomography is used to fully characterize the evolution of the quantum vibrational state of atoms. Rubidium atoms are trapped in a shallow optical lattice supporting only two vibrational states, which we charcterize by reconstructing the 2x2 density matrix. Repeating this process for a complete set of inputs allows us to completely characteriz

Masaki Owari, Keiji Matsumoto, Mio Murao

Based on set theoretic ordering properties, a general formulation for constructing a pair of convertibility monotones, which are generalizations of distillable entanglement and entanglement cost, is presented. The new pair of monotones do not always coincide for pure bipartite infinite dimensional states under SLOCC (stochastic local operations and classical

Gerardo Adesso, Fabrizio Illuminati, Silvio De Siena

We qualify the entanglement of arbitrary mixed states of bipartite quantum systems by comparing global and marginal mixednesses quantified by different entropic measures. For systems of two qubits we discriminate the class of maximally entangled states with fixed marginal mixednesses, and determine an analytical upper bound relating the entanglement of forma

Peng-Ye Wang, Ping Xie, Hua-Wei Yin

We propose a travelling-wave perturbation method to control the spatiotemporal dynamics in a cardiac model. It is numerically demonstrated that the method can successfully suppress the wave instability (alternans in action potential duration) in the one-dimensional case and convert spiral waves and turbulent states to the normal travelling wave states in the

M. Alvioli, C. Ciofi degli Atti, L. P. Kaptari, H. Morita

The exclusive electro-disintegration processes 2H(e,e'p)n, 3He(e,e'p)2H, 3He(e,e'p)pn, 3He(e,e'pp)n and 4He(e,e'p)3H have been calculated using realistic few-body wave functions and treating final state interaction (FSI) effects within a generalized eikonal approach. The semi-inclusive scattering A(e,e'p)X off complex nuclei has been

C. Hartnack, J. Aichelin

We study the reaction Au+Au at 1.48 AGeV and analyze the influence of the KN optical potential on cm spectra and azimuthal distributions at mid-rapidity. We find a significant change of the yields but only slight changes in the shapes of the distributions when turning off the optical potential. However, the spectra show contributions from different reaction

Dennis Bonatsos, D. Lenis, N. Minkov, D. Petrellis

Davidson potentials of the form $β^2 +β_0^4/β^2$, when used in the original Bohr Hamiltonian for $γ$-independent potentials bridge the U(5) and O(6) symmetries. Using a variational procedure, we determine for each value of angular momentum $L$ the value of $β_0$ at which the derivative of the energy ratio $R_L=E(L)/E(2)$ with respect to $β_0$ has a sharp max

Dennis Bonatsos, D. Lenis, N. Minkov, P. P. Raychev

It is proved that the potentials of the form $β^{2n}$ (with $n$ being integer) provide a ``bridge'' between the U(5) symmetry of the Bohr Hamiltonian with a harmonic oscillator potential (occuring for $n=1$) and the E(5) model of Iachello (Bohr Hamiltonian with an infinite well potential, materialized for infinite $n$). Parameter-free (up to overall

W. Liu, C. M. Ko

The cross sections for production of pentaquark $Ξ^+_5$ from the reaction $γp\to K^0K^0Ξ^+_5$ and $Ξ^{--}_5$ from the reaction $γn\to K^+K^+Ξ^{--}_5$ are evaluated in a hadronic model that includes their couplings to both $Σ\bar K$ and $Σ\bar K^*$. With these coupling constants determined from the empirical $πNN(1710)$ and $ρNN(1710)$ coupling constants by a

Michael Mitrovski

A non-monotonic energy dependence of the $K^{+} / π^{+}$ ratio with a sharp maximum close to 30 A$\cdot$GeV is observed in central Pb+Pb collisions. Within a statistical model of the early stage, this is interpreted as a sign of the phase transition to a QGP, which causes a sharp change in the energy dependence of the strangeness to entropy ratio. This obser

Luc Rey-Bellet, Lawrence E. Thomas

We consider a system of stochastic partial differential equations modeling heat conduction in a non-linear medium. We show global existence of solutions for the system in Sobolev spaces of low regularity, including spaces with norm beneath the energy norm. For the special case of thermal equilibrium, we also show the existence of an invariant measure (Gibbs

A. V. Razumov, Yu. G. Stroganov

Using determinant representations for partition functions of the corresponding square ice models and the method proposed recently by one of the authors, we investigate refined enumerations of vertically symmetric alternating-sign matrices, off-diagonally symmetric alternating-sign matrices and alternating-sign matrices with U-turn boundary. For all these cas

J. Garcia-Escudero, M. Lorente

In a recent paper ([1],[2]) we have classified explicitely all the unitary highest weight representations of non compact real forms of semisimple Lie Algebras on Hermitian symmetric space. These results are necessary in order to construct all the unitary highest weight representations of affine Kac-Moody Algebras following some theorems proved by Jakobsen an

J. Garcia-Escudero, M. Lorente

The study of unitarization of representations for non compact real forms of simple Lie Algebras has been achieved in the past decade by Jakobsen (JA81, JA83) and by Enright, Howe and Wallach (EH83) following different paths but arriving at the same final results. In order to discuss unitarity we need to introduce a scalar product. This is done in sections II

S. V. Ivanov, A. M. Storozhev

To solve two problems of Bergman stated in 1981, we construct a group $G$ such that $G$ contains a free noncyclic subgroup (hence, $G$ satisfies no group identity) and $G$, as a group, is generated by its subsemigroup that satisfies a nontrivial semigroup identity.

S. V. Ivanov, A. M. Storozhev

To solve a number of problems on varieties of groups, stated by Kleiman, Kuznetsov, Ol'shanskii, Shmel'kin in the 1970's and 1980's, we construct continuously many varieties of groups in which all periodic groups are abelian and whose pairwise intersections are the variety of all abelian groups.

S. V. Ivanov, A. M. Storozhev

To solve problems of Gilbert Baumslag and Hanna Neumann, posed in the 1960's, we construct a nontrivial variety of groups all of whose noncyclic free groups are non-hopfian.

Sonia Stanciu

We construct the energy operator for particles obeying infinite statistics defined by a q-deformation of the Heisenberg algebra. (This paper appeared published in CMP in 1992, but was not archived at the time.)

B. Plotkin

In every variety of algebras $Θ$ we can consider its logic and its algebraic geometry. In the previous papers geometry in equational logic, i.e., equational geometry has been studied. Here we describe an extension of this theory towards the First Order Logic (FOL). The algebraic sets in this geometry are determined by arbitrary sets of FOL formulas. The prin

R. Aharoni, E. Berger, R. Meshulam

Let X(G) denote the flag complex of a graph G=(V,E) on n vertices. We study relations between the first eigenvalues of successive higher Laplacians of X(G). One consequence is the following result: Let λ_2(G) denote the second smallest eigenvalue of the Laplacian of G. If λ_2(G)> \frac{kn}{k+1} then the real k-th reduced cohomology group H^k(X(G)) is zero. A

Rahul Roy, Hideki Tanemura

Sticks at one of different orientation are placed in an i.i.d. fashion at points of a Poisson point process of intensity $λ$. Sticks of the same direction have the same length, while sticks in different directions may have different lengths. We study the geometry of finite cluster as $λ\to \infty$. The asymptotic shape of the custer being determined by the p

Rinat Kedem

This paper explains the relation between the fusion product of symmetric power sl(n) evaluation modules, as defined by Feigin and Loktev, and the graded coordinate ring R(mu), which describes the cohomology ring of the flag variety Fl(mu) of GL(N). The graded multiplicity spaces appearing in the decomposition of the fusion product into irreducible sl(n)-modu

Pawel Kroeger

Although there are many simple proofs of Jordan's decomposition theorem in the literature (see [1], the references mentioned there, and [2]), our proof seems to be even more elementary. In fact, all we need is the theorem on the dimensions of rang and kernel and the existence of eigenvalues of a linear transformation on a nontrivial finite dimensional co

Elmas Irmak

Let R be a compact, connected, orientable surface of genus g with p boundary components. Let C(R) be the complex of curves on R and Mod_R^* be the extended mapping class group of R. Suppose that either g = 2 and p > 1 or g > 2 and p >= 0. We prove that a simplicial map lambda from C(R) to C(R) is superinjective if and only if it is induced by a homeomorphism

Timothy Y. Chow, Philip J. Lin

The problem of minimizing the number of bidirectional SONET rings required to support a given traffic demand has been studied by several researchers. Here we study the related ``ring grooming problem'' of minimizing the number of add/drop locations instead of the number of rings; in a number of situations this is a better approximation to the true eq

Alessandra Agostini

We have investigated some issues relevant for the possibility to construct physical theories on the $κ$-Minkowski noncommutative spacetime. The notion of field in $κ$-Minkowski has been introduced by generalizing the Weyl system/map formalism and a comparative study of the star products arising from this generalization has been done. A line of analysis of th

Martin Cederwall, Henric Larsson

We consider supermembranes ending on M5-branes, with the aim of deriving the appropriate matrix theories describing different situations. Special attention is given to the case of non-vanishing (selfdual) C-field. We identify the relevant deformation of the six-dimensional super-Yang-Mills theory whose dimensional reduction is the matrix theory for membranes

V. A. Abramovsky, A. V. Dmitriev

Single diffraction processes was usually treated in the triple-reggeon framework, but this formalism is inconsistent with CDF data. In this paper we show, that multipomeron quasi-eikonal model gives agreement with these data. Cross-section of single diffraction processes at LHC energy is estimated.

J. Gasser

I present introductory lectures on the use of effective field theory methods in QCD at low energies.

Craig N. Burrell, Michael E. Luke, Alexander R. Williamson

We study the O(Lambda/mb) corrections to the singly and doubly differential hadronic invariant mass spectra dΓ/dsH and dΓ/dsH dq^2 in b -> u decays, and discuss the implications for the extraction of the CKM matrix element |Vub|. Using simple models for the subleading shape functions, the effects of subleading operators are estimated to be at thefew percent

Cornelius C. Noack

Parton cascade models have been surprisingly successful in describing heavy-ion reactions at RHIC energies -- surprising because in spite of their QCD bells and whistles, they essentially embody classical many-particle dynamics. The procedure to determine the sequence of the binary parton interactions, however -- an essential aspect of all such models -- is

Oleg. V. Utyuzh, Grzegorz Wilk

The role of BEC for photons and neutral pions is briefly discussed and illustrated by means of new method of numerical modelling of BEC proposed by us recently.

B. Ananthanarayan, P. N. Pandita

We carry out an analysis of the non-universal supersymmetry breaking scalar masses arising in SO(10) supersymmetric unification. By considering patterns of squark and slepton masses, we derive a set of sum rules for the sfermion masses which are independent of the manner in which SO(10) breaks to the Standard Model gauge group via its SU(5) subgroups. The ph

Charles A. Nelson

For the observed t --> W b decay, an intensity-ratio equivalence-theorem for two Lorentz-invariant couplings is shown to be related to symmetries of tWb-transformations. Three explicit tWb-transformations, A_{+}=M A_{SM}, ... relate the four standard model's helicity amplitudes, A_{SM}, and the amplitudes A_{+} in the case of an additional t_R --> b_L we

Vladimir K. Petrov

We study the possibility to reconstruct the primordial function for some periodic function. The procedure includes an analytical continuation of a discrete function for Fourier coefficients computation, that introduces an ambiguity. To establish conditions under which no ambiguity appears, the modification of Carlson theorem is suggested. In a case when no s

M. Lorente

We explore the connection between the symmetry transformations and conservation laws for the Klein-Gordon and Dirac fields on the lattice. The generators of the space time translations and Lorentz boost (defined on the lattice) are constants of motion and satisfy the standard commutation relations.

G. P. Zeller

Charged and neutral current low energy neutrino cross section predictions from a variety of Monte Carlo generators in present use are compared against existing experimental data. Comparisons are made to experimental data on quasi-elastic, resonant and coherent single pion production, multiple pion production, single kaon production, and total inclusive cross

Tanmay Vachaspati

If certain conditions are met, a propagating phase boundary can be a sonic horizon. Sonic Hawking radiation from such a phase boundary is expected in the quantum theory. The Hawking temperature for typical values of system parameters can be as large as $\sim 0.04$ K. Since the setup does not require the physical transport of material, it evades the seemingly

Timir Datta, Ming Yin, and Michael Bleiweiss

We address the researchers studying the magneto-transport properties of unconventional systems such as bulk samples and new materials or those working in the soft quantum limit. We have developed a procedure for the analysis of experimental data, so as to increase the confidence level about the presence of quantum hall effect in these data. It is shown that

Prashant Sharma

We study the response of a two-channel Kondo quantum dot device proposed by Y. Oreg and D. Goldhaber-Gordon [Phys. Rev. Lett. {\bf 90}, 136602 (2003)] to a spin-bias applied across one of its channels formed by Fermi liquid reservoirs weakly coupled to a spin-1/2 quantum dot. When the temperature $T<T_K$, the Kondo temperature of the device, the spin conduct

W. Vincent Liu, Frank Wilczek

Motivated by the energetic advantage of achieving coherent enhancement of effective spin-dependent interactions through approximate nesting, we propose specific forms of spin ordering, whose form varies over the Fermi surface, for the cuprate superconductors. Competing &#34;spin-orbit&#34; orderings involving order parameters in spatial $d_{x^2-y^2}$ and $d_

Ernesto P. Borges, Ugur Tirnakli

The sensitivity to initial conditions and relaxation dynamics of two-dimensional maps are analyzed at the edge of chaos, along the lines of nonextensive statistical mechanics. We verify the dual nature of the entropic index for the Henon map, one ($q_{sen}<1$) related to its sensitivity to initial conditions properties, and the other, graining-dependent ($q_

J. -P. Onnela, K. Kaski, J. Kertesz

Networks of companies can be constructed by using return correlations. A crucial issue in this approach is to select the relevant correlations from the correlation matrix. In order to study this problem, we start from an empty graph with no edges where the vertices correspond to stocks. Then, one by one, we insert edges between the vertices according to the

N. Stefanakis

We examine the effect of the magnetic field on the proximity effect in nanostructures, self consistently using the Bogoliubov-deGennes formalism within the two dimensional extended Hubbard model. We calculate the local density of states and the pair amplitude. We study several nanostructures: superconductor - two dimensional electron gas, superconductor - fe

L. V. Nomerovannaya, A. A. Makhnev, S. V. Streltsov, I. A. Nekrasov

Optical properties of the isoelectronic compounds LaCoO$_3$ and HoCoO$_3$ has been experimentally and theoretically investigated. We&#39;ve measured the real $ε_1(ω)$ and imaginary $ε_2(ω)$ parts of the dielectric function, reflectance $R(ω)$ and optical conductivity at room temperature. The shift of the most pronounced spectral features to the high energy r

Adolfo Avella, Ferdinando Mancini

A fully self-consistent calculation of the bosonic dynamics of the Hubbard model is developed within the Composite Operator Method. From one side we consider a basic set of fermionic composite operators (Hubbard fields) and calculate the retarded propagators. On the other side we consider a basic set of bosonic composite operators (charge, spin and pair) and

Corrado Di Guilmi, Edoardo Gaffeo, Mauro Gallegati

Dynamical systems with components whose sizes evolve according to multiplicative stochastic rules have been recently combined with entry and exit processes. We show that the assumptions usually made in modeling exits are at odds with the available evidence. We discuss a recently proposed macroeconomic model with random multiplicative shocks and a mechanism f

Shinji Watanabe, Masatoshi Imada

A new numerical algorithm for interacting fermion systems to treat the grand-canonical ensemble is proposed and examined by extending the path-integral renormalization group method. To treat the grand-canonical ensemble, the particle-hole transformation is applied to the Hamiltonian and basis states. In the interaction-term projection, the Stratonovich-Hubba

J. Androulakis, P. Migiakis, J. Giapintzakis

We present measurements of electrical resistivity, thermal conductivity and thermopower of polycrystalline Sr-doped LaCoO3 with composition La0.95Sr0.05CoO3. Our data show that the investigated compound exhibits a very respectable room temperature thermoelectric figure of merit value of 0.18. Our results not only show that oxides are promising candidates for

E. Cappelluti, B. Cerruti, L. Pietronero

In this paper we employ a gaussian expansion within the finite-$U$ slave-bosons formalism to investigate the momentum structure of the electron-phonon vertex function in the Hubbard model as function of $U$ and $n$. The suppression of large momentum scattering and the onset a small-${\bf q}$ peak structure, parametrized by a cut-off $q_c$, are shown to be es

Jesper Ferkinghoff-Borg, Mogens H. Jensen, Joachim Mathiesen, Poul Olesen

We investigate systems of nature where the common physical processes diffusion and fragmentation compete. We derive a rate equation for the size distribution of fragments. The equation leads to a third order differential equation which we solve exactly in terms of Bessel functions. The stationary state is a universal Bessel distribution described by one para

Chay Goldenberg, Isaac Goldhirsch

Recent experimental results on the static or quasistatic response of granular materials have been interpreted to suggest the inapplicability of the traditional engineering approaches, which are based on elasto-plastic models (which are elliptic in nature). Propagating (hyperbolic) or diffusive (parabolic) models have been proposed to replace the `old&#39; mo

J. Androulakis, Z. Viskadourakis, N. Katsarakis, J. Giapintzakis

A detailed study of the zero-field electrical resistivity and magnetoresistance for the metallic members of the LaNi_{1-x}Co{x}O3 solid solution with 0.3<=x<=0.6 is reported. The low temperature resistivity of the compounds with 0.3<=x<=0.5 exhibits a logarithmic dependence that is characteristic of systems with spin fluctuations. It is suggested that the ef

I. A. Nekrasov, G. Keller, D. E. Kondakov, A. V. Kozhevnikov

We present parameter-free LDA+DMFT results for the many-particle density of states of cubic SrVO3 and orthorhombic CaVO3. Both systems are found to be strongly correlated metals, but em not on the verge of a metal-insulator transition. In spite of the considerably smaller V-O-V bonding angle in CaVO3 the photoemission spectra of the two systems are very simi

Dominik Rogula

Dense distributions of string-like objects in material media are considered in terms of continuum field theory. The strings are assumed to carry a quantized abelian topological charge, such as the Burgers vector of dislocations in solids or magnetic flux of supercurrent vortices in type-II supercondoctors. Within this common framework the facts known from di

Viktor Zubko, Eli Dwek, Richard G. Arendt

We present new interstellar dust models which have been derived by simultaneously fitting the far-ultraviolet to near-infrared extinction, the diffuse infrared (IR) emission and, unlike previous models, the elemental abundance constraints on the dust for different interstellar medium abundances, including solar, F and G star, and B star abundances. The fitti

Massimiliano Bonamente, W. Van Dyke Dixon

We present the far-ultraviolet spectrum of the Seyfert 1 galaxy 2MASX J21362313-6224008 obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). The spectrum features absorption from Galactic OVI at two velocities and redshifted HI Lyman beta and gamma, CII, CIII, and O VI. The redshifted absorption features represent a single kinematic component blu

Godfrey Louis, A. Santhosh Kumar

This paper reports the extraordinary biology of the microorganisms from the mysterious red rain of Kerala, India. These chemosynthetic organisms grow optimally at an extreme high temperature of 300 degrees C in hydrothermal conditions and can metabolize inorganic and organic compounds including hydrocarbons. Stages found in their life cycle show reproduction

Mirel Birlan, Schelte J. Bus, Irina Belskaya, Sonia Fornasier

In the frame of the international campaign to observe potential target asteroids for the Rosetta mission, remote observations have been carried out between Observatoire de Paris, in Meudon-France, and the NASA Infrared Telescope Facility on Mauna Kea. The SpeX instrument was used in the 0.8-2.5 microns spectral region, for two observing runs in March and Jun

Sangwook Park, John P. Hughes, Patrick O. Slane, David N. Burrows

We continue our analysis of the Galactic oxygen-rich supernova remnant (SNR) G292.0+1.8, which was observed with the {\it Chandra X-ray Observatory}. The high angular resolution {\it Chandra} data resolve metal-rich ejecta knots as well as the shocked circumstellar medium. X-ray emission from the ejecta material in G292.0+1.8 is dominated by highly ionized O

T. Gleissner, J. Wilms, G. G. Pooley, M. A. Nowak

We analyze simultaneous radio-X-ray data of Cygnus X-1 from the Ryle telescope (RT) and RXTE over more than 4 a. We show that apparent correlations on short time scales in the lightcurves of Cyg X-1 are probably the coincidental outcome of white noise statistics.

P. Capak, L. L. Cowie, E. M. Hu, A. J. Barger

We have conducted a deep multi-color imaging survey of 0.2 degrees^2 centered on the Hubble Deep Field North (HDF-N). We shall refer to this region as the Hawaii-HDF-N. Deep data were collected in U, B, V, R, I, and z&#39; bands over the central 0.2 degrees^2 and in HK&#39; over a smaller region covering the Chandra Deep Field North (CDF-N). The data were re

Eli Livne, Adam Burrows, Rolf Walder, Itamar Lichtenstadt

We have developed a time-dependent, multi-energy-group, and multi-angle (S$_n$) Boltzmann transport scheme for radiation hydrodynamics simulations, in one and two spatial dimensions. The implicit transport is coupled to both 1D (spherically-symmetric) and 2D (axially-symmetric) versions of the explicit Newtonian hydrodynamics code VULCAN. The 2D variant, VUL

K. Abe, M. Honda, K. Kasahara, T. Kajita

Precise knowledge of the hadronic interaction between primary cosmic rays and atmospheric nuclei is very important and fundamental to study atmospheric neutrinos and their oscillations. We studied hadronic interaction models using the data of primary and secondary cosmic rays observed by BESS experiments. By comparing the observed spectra with the ones calcu

V. G. Vakulik, R. E. Schild, V. N. Dudinov, A. A. Minakov

Photometry of the Q2237+0305gravitational lens in VRI spectral bands with the 1.5-m telescope of the high-altitude Maidanak observatory in 1995-2000 is presented. Monitoring of Q2237+0305 in July-October 2000, made at nearly daily basis, did not reveal rapid (night-to-night and intranight) variations of brightness of the components during this time period. R

U. Ertan, K. S. Cheng

We show that the observed pulsed optical emission of the anomalous X-ray pulsar 4U 0142+61 can be accounted for by both the magnetar outer gap models and the disk-star dynamo gap models, therefore is not an evidence in favor of one of these models as its responsible mechanism. Nevertheless, the estimated high energy gamma-ray spectra from these models have d

Ivan K. Kostov

The 2D quantum gravity on a disc, or the non-critical theory of open strings, is known to exhibit an integrable structure, the boundary ground ring, which determines completely the boundary correlation functions. Inspired by the recent progress in boundary Liouville theory, we extend the ground ring relations to the case of non-vanishing boundary Liouville i

J. M. Link

Using data from the FOCUS experiment we analyze the $D^+π^-$ and $D^0π^+$ invariant mass distributions. We measure the $D_2^{*0}$ mass $M_{D_2^{*0}} = (2464.5 \pm 1.1 \pm 1.9) \mev$ and width $Γ_{D_2^{*0}} = (38.7 \pm 5.3 \pm 2.9) \mev$, and the $D_2^{*+}$ mass $ M_{D_2^{*+}} = (2467.6 \pm 1.5 \pm 0.76) \mev$ and width $ Γ_{D_2^{*+}} = (34.1 \pm 6.5 \pm 4.2)

Masafumi Fukuma, Yuji Kono, Akitsugu Miwa

We present a mechanism through which a certain class of short-distance cutoff affects the CMB anisotropies at large angular scales. Our analysis is performed in two steps. The first is given in an intuitive way, using the property of the inflationary universe that quantum fluctuations of an inflaton field become classical after crossing the Hubble horizon. W

W. H. Zurek, F. M. Cucchietti, J. P. Paz

We examine an exactly solvable model of decoherence - a spin-system interacting with a collection of environment spins. We show that in this model (introduced some time ago to illustrate environment-induced superselection) generic assumptions about the coupling strengths lead to a universal (Gaussian) suppression of coherence between pointer states. We explo

Ryuichi Shindou

In this paper, we propose the quantum spin pumping in quantum spin systems where an applied electric field ($E$) and magnetic field ($H$) cause a finite spin gap to its critical ground state. When these systems are subject to alternating electromangetic fields; $(E,H)=(\sin\frac{2πt}{T},\cos\frac{2πt}{T})$ and travel along the {\it{loop}} $Γ_{\rm{loop}}$ whi

Bin Zhang, Donald L. Johnson

Centrality dependence of J/psi production in Au-Au collisions at 200 GeV nucleon-nucleon center of mass energy is studied using the Glauber model plus the kinetic formation model. Initial J/psi production and destruction by incoming nucleons are described by the Glauber model. J/psi-charm equilibration in the gluon plasma is described by the kinetic formatio

G. S. Agarwal, P. K. Pathak

We demonstrate how spontaneous emission in a cavity can be controlled by the application of a dc field. The method is specially suitable for Rydberg atoms. We present a simple argument for the control of emission.

Maosen Fang, Stephen Fenner, Frederic Green, Steven Homer

We prove several new lower bounds for constant depth quantum circuits. The main result is that parity (and hence fanout) requires log depth circuits, when the circuits are composed of single qubit and arbitrary size Toffoli gates, and when they use only constantly many ancillæ. Under this constraint, this bound is close to optimal. In the case of a non-const

M. Wendeker, G. Litak, M. Krupa

We examine a simple, fuel-air, model of combustion in spark ignition (si) engine with indirect injection. In our two fluid model, variations of fuel mass burned in cycle sequences appear due to stochastic fluctuations of a fuel feed amount. We have shown that a small amplitude of these fluctuations affects considerably the stability of a combustion process s

T. Kaminski, M. Wendeker, K. Urbanowicz, G. Litak

We analyse the experimental time series of internal pressure in a four cylinder spark ignition engine. In our experiment, performed for different spark advance angles, apart from usual cyclic changes of engine pressure we observed oscillations. These oscillations are with longer time scales ranging from one to several hundred engine cycles depending on engin

Ljubisa D. R. Kocinac

We investigate two closure-type properties, the Reznichenko property and the Pytkeev property, in hyperspace topologies.

Adrian Duma, Cristian Vladmirescu

In this paper is presented a new approach to the axiomatic homotopy theory in categories, which offers a simpler and more useful answer to this old question: how two objects in a category (without any topological feature) can be deformed each in other?

B. Klartag

Here we show that any n-dimensional centrally symmetric convex body K has an n-dimensional perturbation T which is convex and centrally symmetric, such that the isotropic constant of T is universally bounded. T is close to K in the sense that the Banach-Mazur distance between T and K is O(log n). If K has a non-trivial type then the distance is universally b

B. Balcar, T. Jech, T. Pazák

It is consistent that every weakly distributive complete ccc Boolean algebra carries a strictly positive Maharam submeasure.

E. Kiritsis, C. Kounnas, P. M. Petropoulos, I. Rizos

Decoupling limits of physical interest occur in regions of space--time where the string coupling diverges. This is illustrated in the celebrated example of five-branes. There are several ways to overcome this strong-coupling problem. We review those which are somehow related to two-dimensional conformal field theories. One method consists of distributing the

J. W. Moffat

The cosmological constant problem is reviewed and a possible quantum gravity resolution is proposed. A space satellite Eötvös experiment for zero-point vacuum energy is proposed to see whether Casimir vacuum energy falls in a gravitational field at the same rate as ordinary matter.

Eran Bouchbinder, Joachim Mathiessen, Itamar Procaccia

Post mortem analysis of fracture surfaces of ductile and brittle materials on the $μ$m-mm and the nm scales respectively, reveal self affine graphs with an anomalous scaling exponent $ζ\approx 0.8$. Attempts to use elasticity theory to explain this result failed, yielding exponent $ζ\approx 0.5$ up to logarithms. We show that when the cracks propagate via pl

Matteo Merlo, Nicodemo Magnoli, Maura Sassetti, Bernhard Kramer

The effects of interactions in a 2D electron system in a strong magnetic field of two degenerate Landau levels with opposite spins and at filling factors 1/2 are studied. Using the Chern-Simons gauge transformation, the system is mapped to Composite Fermions. The fluctuations of the gauge field induce an effective interaction between the Composite Fermions w

Grzegorz Litak

We show that superconductors with inhomogeneous order parameters can show similar features as anisotropic ones. In this paper we study the low temperature specific heat dependence in such a system and we show that the disorder associated with randomly distributed attractive centers convert the BCS temperature exponential behaviour into a power law formula. T

G. Litak, J. F. Annett, B. L. Gyorffy, K. I. Wysokinski

We analyze the possibilities of triplet pairing in Sr2RuO4 based upon an idea of interlayer coupling. We have considered two models differing by the effective interactions. In one model the quasi-particle spectra have horizontal line nodes on all three Fermi surface sheets, while in the other the spectra have line or point nodes on the alpha and beta sheets

S. P. Gabuda, S. G. Kozlova, S. B. Erenburg, N. V. Bausk

Mixed-valence compound Pb3O4 (minium) has been studied using X-ray absorption near-edge structure (XANES) spectroscopy and DFT calculations. In spite of presence of two valence states of lead [Pb(II) and Pb(IV)], the XANES spectrum of studied system is corresponding to apparently unified, an intermediate valence state of Pb. On the other hand, the 207Pb NMR

P. Zheng, N. L. Wang, J. L. Luo, R. Jin

We present optical conductivity spectra for $Pb_{2}Ru_{2}O_{7-δ}$ single crystal at different temperatures. Among reported pyrochlore ruthenates, this compound exhibits metallic behavior in a wide temperature range and has the least resistivity. At low frequencies, the optical spectra show typical Drude responses, but with a knee feature around 1000 \cm. Abo

Richard H. Cyburt, Brian D. Fields, Keith A. Olive

Using the recent WMAP determination of the baryon-to-photon ratio, 10^{10} η= 6.14 to within a few percent, big bang nucleosynthesis (BBN) calculations can make relatively accurate predictions of the abundances of the light element isotopes which can be tested against observational abundance determinations. At this value of η, the Li7 abundance is predicted

Han-Dong Chen, Sylvain Capponi, Fabien Alet, Shou-Cheng Zhang

The high Tc cuprates have a complex phase diagram with many competing phases. We propose a bosonic effective quantum Hamiltonian based on the projected SO(5) model with extended interactions, which can be derived from the microscopic models of the cuprates. The global phase diagram of this model is obtained using mean-field theory and the Quantum Monte Carlo

Giovanni Gallavotti

Entropy might be a not well defined concept if the system can undergo transformations involving stationary nonequilibria. It might be analogous to the heat content (once called ``caloric&#39;&#39;) in transformations that are not isochoric (i.e. which involve mechanical work): it could be just a quantity that can be transferred or created, like heat in equil

R. R. Metsaev

Free totally symmetric arbitrary spin massive bosonic and fermionic fields propagating in AdS(d) are investigated. Using the light cone formulation of relativistic dynamics we study bosonic and fermionic fields on an equal footing. Light-cone gauge actions for such fields are constructed. Interrelation between the lowest eigenvalue of the energy operator and

Sergej A. Choroszavin

This paper is a didactic commentary (a transcription with variations) to the paper of S.R. Foguel {\it Finite Dimensional Perturbations in Banach Spaces}. Addressed, mainly: postgraduates and related readers. Subject: Suppose we have two linear operators, A, B, so that B - A is rank one. Let λ_o be an {\it isolated} point of the spectrum of A. In addition, l

Masakiyo Kitazawa, Tomoi Koide, Teiji Kunihiro, Yukio Nemoto

We show that the pseudogap of the quark density of states is formed in hot quark matter as a precursory phenomenon of the color superconductivity on the basis of a low-energy effective theory. We clarify that the soft mode of the di-quark pair field gives rise to a peculiar behavior of the quark dispersion relation and a short life-time of the quasiparticles

A. Cappelli, G. D&#39;Appollonio, M. Zabzine

The Virasoro minimal models with boundary are described in the Landau-Ginzburg theory by introducing a boundary potential, function of the boundary field value. The ground state field configurations become non-trivial and are found to obey the soliton equations. The conformal invariant boundary conditions are characterized by the reparametrization-invariant

P. Aurenche, Rahul Basu, M. Fontannaz, R. M. Godbole

We present a Next-to-Leading Order calculation of the cross section for the leptoproduction of large-$E_{\bot}$ hadrons and we compare our predictions with H1 data on the forward production of $π^0$. We find large higher order corrections and an important sensitivity to the renormalization and factorization scales. These large corrections are shown to arise