April 2006 arXiv papers — page 20

A. A. Bogush, V. V. Kisel, N. G. Tokarevskaya, V. M. Red'kov

20-component Petras theory of 1/2-spin particle with anomalous magnetic momentum in presence of external electromagnetic and gravitational fields is investigated. The gravitation field is described as space-time curvature. Correctness of the constructed equations in the sense of general relativity and gauge local Lorentz symmetry is proved in detail. Tetrad

Guillaume Belanger, Regis Terrier, Okkie De Jager, Andrea Goldwurm

We present the highly significant detection of a quasi-periodic flux modulation with a period of 22.2 min seen in the X-ray data of the Sgr A* flare of 2004 August 31. This flaring event, which lasted a total of about three hours, was detected simultaneously by EPIC on XMM-Newton and the NICMOS near-infrared camera on the HST. Given the inherent difficulty i

B. Kaviraj, S. K. Ghatak

The magneto-impedance (MI) in amorphous ribbon of nominal composition Fe73.5Nb3Cu1Si13.5B9 has been measured at 1MHz and at room temperature for different configurations of exciting a.c and biasing d.c. fields. A large drop in both resistance and reactance is observed as a function of d.c magnetic field. When the d.c and a.c fields are parallel but normal to

Masanao Ozawa

In 1981, Takeuti introduced quantum set theory as the quantum counterpart of Boolean valued models of set theory by constructing a model of set theory based on quantum logic represented by the lattice of closed subspaces in a Hilbert space and showed that appropriate quantum counterparts of ZFC axioms hold in the model. Here, Takeuti's formulation is ext

B. Kaviraj, S. K. Ghatak

A two-core transducer assembly using a Fe73.5Nb3Cu1Si13.5B9 ribbon to detect a change of magnetic field is proposed and tested for displacement (linear and angular) and current sensor. Two identical inductors, with the ribbon as core, are a part of two series resonance network, and are in high impedance state when excited by a small a.c field of 1MHz in abse

Toshihiko Masuda, Reiji Tomatsu

We show the uniqueness of minimal actions of a compact Kac algebra with amenable dual on the AFD factor of type II$_1$. This particularly implies the uniqueness of minimal actions of a compact group. Our main tools are a Rohlin type theorem, the 2-cohomology vanishing theorem, and the Evans-Kishimoto type intertwining argument.

Kevin O'Bryant

Zhi-Wei Sun conjectures if k congruence classes are disjoint, then two of the moduli have greatest common divisor at least as large as k. We prove this conjecture for k strictly less than 21.

Efrain J. Ferrer, Vivian de la Incera

We investigate the effects of an external magnetic field in the gluon dynamics of a color superconductor with three massless quark flavors. In the framework of gluon mean-field theory at asymptotic densities, we show that the long-range component $\widetilde{H}$ of the external magnetic field that penetrates the CFL phase produces an instability when its str

J. F. Kanem, S. Maneshi, M. Partlow, M. Spanner

Quantum resonances in the kicked rotor are characterized by a dramatically increased energy absorption rate, in stark contrast to the momentum localization generally observed. These resonances occur when the scaled Planck's constant hbar=(r/s)*4pi, for any integers r and s. However only the hbar=r*2pi resonances are easily observable. We have observed hi

Auromeet Saha, P. Pant, U. C. Dumka, P. Hegde

During the second land campaign (LC-II) organised by ISRO-GBP, extensive ground-based measurements of aerosol characteristics were carried out over Manora Peak (29.4oN; 79.5oE; 1951 metres above mean sea level), Nainital (a high altitude station located in the Shivalik ranges of Central Himalayas) during the dry, winter season (December) of 2004. These measu

Bin-Guang Ma

The present work provides a new conceptual framework for GUT (Grand Unified Theory) based on a picture of fractal universe. Under a hypothesis of multi-scaled matter structure, we find new clues for the conciliation of quantum and relativity and for the unification of fundamental interactions. A new interpretation for matter wave is proposed as the trajector

G. Brodin, L. Stenflo, P. K. Shukla

The resonant interaction between kinetic Alfvén and ion-acoustic waves is considered using the Hall-MHD theory. The results of previous authors are generalized to cover both finite Larmor radius as well as the ideal MHD results. It is found that the three wave coupling is strongest when the wavelength is comparable to the ion-sound gyroradius. Applications o

S. E. Emelin, A. L. Pirozerski, N. N. Vassiliev

Main results of researches of the electric erosive discharge afterglow plasma, of the fireballs being formed by this plasma and having some particular but deep similarities to the ball lightning are given. The analysis of our results and results of some other authors has allowed to specify the nature of radiation and stability of the shape for a dust-gas che

Mark MacLean, Paul Terwilliger

We consider a bipartite distance-regular graph $G$ with diameter at least 4 and valency at least 3. Fix a vertex of $G$ and let $T$ denote the corresponding subconstituent algebra. We give a detailed description of a certain type of irreducible $T$-module, said to be thin with endpoint 2.

Chandan Singh Dalawat

We show that the characteristic homomorphism of Colliot-Th{é}l{è}ne and Sansuc from the Chow group of 0-cycles of degree~0 is compatible with restriction and corestriction maps.

Patrick Brosnan, Gregory J. Pearlstein

We prove that the zero locus of an admissible normal function over an algebraic parameter space S is algebraic in the case where S is a curve.

Akira Ishii, Hokuto Uehara

In this article, we study the group of autoequivalences of derived categories of coherent sheaves on the minimal resolution of $A_n$-singularities on surfaces. Our main result is to find generators of this group.

Tanvir Rahman

This paper has been withdrawn due to the use of some incorrect neutrino parameter space ranges.

Brandon Carter

Although implicit in the discovery of the Schwarzschild solution 40 years earlier, the issues raised by the theory of what are now known as black holes were so unsettling to physicists of Einstein's generation that the subject remained in a state of semiclandestine gestation until his demise. That turning point -- just half a century after Einstein's

Krzysztof Wohlfeld

We formulate the double exchange (DE) model for systems with $t_{2g}$ orbital degeneracy, relevant for hole-doped cubic vanadates. In the relevant regime of strong on-site Coulomb repulsion $U$ we solve the model using two distinct mean-field approximations: Hartree-Fock, and mean-field applied to the formulation of the model in the Kotliar-Ruckenstein slave

Krzysztof Wohlfeld, Andrzej M. Oles

We investigate the role of the double exchange mechanism for stability of the metallic C-type antiferromagnetic (C-AF) phase, which was observed experimentally in hole doped La$_{1-x}$Sr$_x$VO$_3$. The double exchange model treats localized electrons in xy orbitals as classical S=1/2 spins, which interact by Hund's exchange $J_H$ with yz/zx electrons in

Chul-Sung Choi, Tadayasu Dotani

We present the results of analyzing the XMM-Newton data obtained in 2001 November 7 - 8. A flare is observed simultaneously in X-ray and UV together with a quiescence. We find that during the flare event X-ray flux varies with UV with no significant time lag, indicating a close correlation of flux variation for X-ray and UV flares. An upper limit of the lag

Remigiusz Augusiak, Maciej Demianowicz, Pawel Horodecki

We construct a single observable measurement of which mean value on four copies of an {\it unknown} two-qubit state is sufficient for unambiguous decision whether the state is separable or entangled. In other words, there exists a universal collective entanglement witness detecting all two-qubit entanglement. The test is directly linked to a function which c

Xiao-Feng Qian, Z. Song

The concepts of concurrence and mode concurrence are the measures of entanglement for spin-1/2 and spinless fermion systems respectively. Based on the Jordan-Wigner transformation, any spin-1/2 system is always associated with a fermion system (called counterpart system). The comparison of concurrence and mode concurrence can be made with the aid of the Mars

Kazumasa Takeuchi

Universality classes of Ising-like phase transitions are investigated in series of two-dimensional synchronously updated probabilistic cellular automata (PCAs), whose time evolution rules are either of Glauber type or of majority-vote type, and degrees of anisotropy are varied. Although early works showed that coupled map lattices and PCAs with synchronously

J F McCann, Liang-You Peng, I D Williams, K T Taylor

We simulate the dynamics of H2+ and HD+ by direct solution of the time-dependent Schroedinger equation for the electronic and nuclear motion for the interaction of intense femtosecond pulses. On these timescales the rotational motion, even for such light molecules, is frozen. Therefore it is a reasonable assumption that the nuclear alignment is fixed during

Graeme Smith, John A. Smolin

A striking feature of quantum error correcting codes is that they can sometimes be used to correct more errors than they can uniquely identify. Such degenerate codes have long been known, but have remained poorly understood. We provide a heuristic for designing degenerate quantum codes for high noise rates, which is applied to generate codes that can be used

B. Kyung, A. -M. S. Tremblay

We study the Mott transition, antiferromagnetism and superconductivity in layered organic conductors using Cellular Dynamical Mean Field Theory for the frustrated Hubbard model. A d-wave superconducting phase appears between an antiferromagnetic insulator and a metal for $t^{\prime}/t=0.3-0.7 $, or between a nonmagnetic Mott insulator (spin liquid) and a met

Uros Seljak, Anze Slosar, Patrick McDonald

We combine the Ly-alpha forest power spectrum (LYA) from the Sloan Digital Sky Survey (SDSS) and high resolution spectra with cosmic microwave background (CMB) including 3-year WMAP, and supernovae (SN) and galaxy clustering constraints to derive new constraints on cosmological parameters. The existing LYA power spectrum analysis is supplemented by constrain

A. V. Chubukov, D. V. Khveshchenko

We discuss the effect of Fermi surface curvature on long-distance/time asymptotic behaviors of two-dimensional fermions interacting via a gapless mode described by an effective gauge field-like propagator. By comparing the predictions based on the idea of multi-dimensional bosonization with those of the strong- coupling Eliashberg approach, we demonstrate th

The BABAR Collaboration, B. Aubert

A study of the $D_{sJ}^*(2317)^+$ and $D_{sJ}(2460)^+$ mesons in inclusive $c\bar{c}$ production is presented using 232 ${\rm fb}^{-1}$ of data collected by the BaBar experiment near $\sqrt{s} = 10.6$ \gev. Final states consisting of a $D_s^+$ meson along with one or more $π^0$, $π^\pm$, or $γ$ particles are considered. Estimates of the mass and limits on th

Carl J. Grillmair, Odysseas Dionatos

We report on the detection in Sloan Digital Sky Survey data of a 63 degree-long tidal stream of stars, extending from Ursa Major to Cancer. The stream has no obvious association with the orbit of any known cluster or galaxy. The contrast of the detected stream is greatest when using a star count filter that is matched to the color-magnitude distribution of s

Martin Centurion, Mason A. Porter, P. G. Kevrekidis, Demetri Psaltis

We conduct an experimental investigation of nonlinearity management in optics using femtosecond pulses and layered Kerr media consisting of glass and air. By examining the propagation properties over several diffraction lengths, we show that wave collapse can be prevented. We corroborate these experimental results with numerical simulations of the (2 + 1)-di

R. Bellazzini, G. Spandre, M. Minuti, L. Baldini

We report on a large active area (15x15mm2), high channel density (470 pixels/mm2), self-triggering CMOS analog chip that we have developed as pixelized charge collecting electrode of a Micropattern Gas Detector. This device, which represents a big step forward both in terms of size and performance, is the last version of three generations of custom ASICs of

M. Vuckovic, S. D. Kawaler

PG 0014+067 is one of the most promising pulsating subdwarf B stars for seismic analysis, as it has a rich pulsation spectrum. The richness of its pulsations, however, poses a fundamental challenge to understanding the pulsations of these stars, as the mode density is too complex to be explained only with radial and nonradial low degree (l < 3) p-modes witho

Shidong Jiang, Minzhong Xu

The second hyperpolarizability $γ_N(-3ωω,ω,ω)$ of $N$ double-bond finite chain of trans-polyactylene is analyzed using the Su-Schrieffer-Heeger model to explain qualitative features of the size-dependence behavior of $γ_N$. Our study shows that $γ_N/N$ is {\it nonmonotonic} with $N$ and that the nonmonotonicity is caused by the dominant contribution of the i

D0 Collaboration, V. Abazov

The results of a search for squarks and gluinos using data from ppbar collisions recorded at a center-of-mass energy of 1.96 TeV by the D0 detector at the Fermilab Tevatron Collider are reported. The topologies analyzed consist of acoplanar-jet and multijet events with large missing transverse energy. No evidence for the production of squarks or gluinos was

Viviane Baladi, Aïcha Hachemi

For large $N$, we consider the ordinary continued fraction of $x=p/q$ with $1\le p\le q\le N$, or, equivalently, Euclid&#39;s gcd algorithm for two integers $1\le p\le q\le N$, putting the uniform distribution on the set of $p$ and $q$s. We study the distribution of the total cost of execution of the algorithm for an additive cost function $c$ on the set $\m

G. E. Volovik

We discuss the main myths related to the vacuum energy and cosmological constant, such as: ``unbearable lightness of space-time&#39;&#39;; the dominating contribution of zero point energy of quantum fields to the vacuum energy; non-zero vacuum energy of the false vacuum; dependence of the vacuum energy on the overall shift of energy; the absolute value of en

Melvyn B. Nathanson

Problems in additive number theory related to sum and difference sets, more general binary linear forms, and representation functions of additive bases for the integers and nonnegative integers.

S. Kraus, Y. Balega, M. Elitzur, K. -H. Hofmann

NGC 7538 IRS1 is a high-mass (approx. 30 M_sun) protostar with a CO outflow, an associated UCHII region, and a linear methanol maser structure, which might trace a Keplerian-rotating circumstellar disk. The directions of the various associated axes are misaligned with each other. We investigate the near-infrared morphology of the source to clarify the relati

Ahmad Ghodsi

We show that in IIB string theory and for D1D5p black holes in ten dimensions the method of entropy function works. Despite the more complicated Wald formula for the entropy of D1D5p black holes in ten dimensions, their entropy is given by entropy function at its extremum point. We use this method for computing the entropy of the system both at the level of

Jean-Michel Levy

It is argued that systematically unbiassing estimators is not always justified and can be counter-productive. On the contrary, a general rule is given to build a (slightly) biased but consistent estimator which is always closer to the value being estimated than the unbiased estimator from which one has started.

Frank Simon

We present preliminary measurements of the cross section and the double longitudinal spin asymmetry in inclusive jet production in polarized p+p collisions at Sqrt(s) = 200 GeV. The measured cross section agrees well with NLO pQCD calculations over seven orders of magnitude. The observed spin asymmetries are consistent with theoretical evaluations based on d

Juan B. Gil, Paul A. Loya

We study the structure and asymptotic behavior of the resolvent of elliptic cone pseudodifferential operators acting on weighted Sobolev spaces over a compact manifold with boundary. We obtain an asymptotic expansion of the resolvent as the spectral parameter tends to infinity, and use it to derive corresponding heat trace and zeta function expansions as wel

Aftab Alam, Abhijit Mookerjee

In this paper we shall discuss the effect of disorder induced configuration fluctuations on single particle and two-particle phonon Green functions in substitutional random binary alloys. The randomness of the system will be dealt within the augmented space theorem, introduced by one of us [J. Phys. C : Solid State Phys. 6, L205(1973)]. This will be combined

Marek Szydlowski, Aleksandra Kurek, Adam Krawiec

Recent astronomical observations indicate that the Universe is presently almost flat and undergoing a period of accelerated expansion. Basing on Einstein&#39;s general relativity all these observations can be explained by the hypothesis of a dark energy component in addition to cold dark matter (CDM). Because the nature of this dark energy is unknown, it was

V. Berejnov, A. Leshansky

In a recent Letter (Y. Sumino et al., PRL 94, 068301 (2005)) a spontaneous motion of an oil droplet in the surrounding aqueous media along a glass surface was reported. The authors suggested that the self-locomotion is driven by a difference in wettability between the front and the rear of a droplet sustained by its translational motion. We disagree with the

Valdir B. Bezerra, Cristine N. Ferreira, Herman J. Mosquera Cuesta

The early Universe might have undergone phase transitions at energy scales much higher than the one corresponding to the Grand Unified Theories (GUT) scales. At these higher energy scales, the transition at which gravity separated from all other interactions; the so-called Planck era, more massive strings called supermassive cosmic strings, could have been p

Brian D. Boe, Markus Hunziker

In this paper the authors investigate infinite-dimensional representations $L$ in blocks of the relative (parabolic) category ${\mathcal O}_S$ for a complex simple Lie algebra, having the property that the cohomology of the nilradical with coefficients in $L$ ``looks like&#39;&#39; the cohomology with coefficients in a finite-dimensional module, as in Kostan

Tsuguhiko Asakawa, So Matsuura, Kazutoshi Ohta

We investigate the D-brane bound states from the viewpoint of the unstable D/\bar{D}-system and their tachyon condensation. We consider two systems; a system of k D(-1)-branes and N D3-branes with open strings connecting them and a system of N D3-branes with open strings corresponding to the k-instanton flux, both of which are realized through the tachyon co

Yuri Rylov

It is proved the mathematical theorem, that the wave function describes the statistical ensemble of particles, but not a single particle. Supposition, that the wave function describes a single particle appears to be incompatible with formalism of quantum mechanics.

Jianya Liu, Emmanuel Royer, Jie Wu

In this paper, we prove a weaker form of a conjecture of Montgomery-Vaughan on extreme values of automorphic L-functions at 1.

Omar Mustafa, S. Habib Mazharimousavi

Exact solvability of some non-Hermitian $η$-weak-pseudo-Hermitian Hamiltonians is explored as a byproduct of $η$-weak-pseudo-Hermiticity generators. A class of V_{eff}(x)=V(x)+iW(x) potentials is considered, where the imaginary part W(x) is used as an $η$-weak-pseudo-Hermiticity generator to obtain exactly solvable $η$-weak-pseudo-Hermitian Hamiltonian model

Attila Andai

The volume of the quantum mechanical state space over $n$-dimensional real, complex and quaternionic Hilbert-spaces with respect to the canonical Euclidean measure is computed, and explicit formulas are presented for the expected value of the determinant in the general setting too. The case when the state space is endowed with a monotone metric or a pull-bac

Takashi Saitou

We study matrix models as a new approach to formulate massless higher spin gauge field theory. As a first step in this direction, we show that the free equation of motion of bosonic massless higher spin gauge fields can be derived from that of a matrix model.

Janine Splettstoesser, Michele Governale, Jürgen König, Rosario Fazio

We present a diagrammatic real-time approach to adiabatic pumping of electrons through interacting quantum dots. Performing a systematic perturbation expansion in the tunnel-coupling strength, we compute the charge pumped through a single-level quantum dot per pumping cycle. The combination of Coulomb interaction and quantum fluctuations, accounted for in co

Manas Patra

It is known that mutually unbiased bases, whenever they exist, are optimal in an information theoretic sense for the determination of unknown state of a quantum ensemble. These bases may not exist in most dimensions and some suboptimal choices have to be made. The present paper deals with estimates of the information loss in suboptimal choice of bases. The i

Manas Patra

In this paper we introduce a projective invarinat measure on the special unitary group. It is directly related to transition probabilities. It has some interesting connection with convex geometry. Applications to approximation of quantum circuits and entanglement are given.

Jian Fu

We propose a novel interferometer by using optical transverse modes in multimode waveguide that can beat the standard quantum limit. In the scheme, the classical simulation of $N$-partical quantum entangled states is generated by using $N$ independent classical fields and linear optical elements. Similar to the quantum-enhanced measurements, the classical si

Soo-Jong Rey, Yasuaki Hikida

We investigate emergent holography of weakly coupled two-dimensional hyperKähler sigma model on cotangent bundle of (N-1)-dimensional complex projective space at zero and finite temperature. The sigma model is motivated by the spacetime conformal field theory dual to the near-horizon geometry of Q1 D1-brane bound to Q5 D5-brane wrapped on four-torus times ci

A. G. Ramm

Let $f\in L^2(S^2)$ be an arbitrary fixed function with small norm on the unit sphere $S^2$, and $D\subset \R^3$ be an arbitrary fixed bounded domain. Let $k>0$ and $α\in S^2$ be fixed. It is proved that there exists a potential $q\in L^2(D)$ such that the corresponding scattering amplitude $A(α&#39;)=A_q(α&#39;)=A_q(α&#39;,α,k)$ approximates $f(α&#39;)$ wit

Salah A. Aly, Andreas Klappenecker, Pradeep Kiran Sarvepalli

Classical BCH codes that contain their (Euclidean or Hermitian) dual codes can be used to construct quantum stabilizer codes; this correspondence studies the properties of such codes. It is shown that a BCH code of length n can contain its dual code only if its designed distance d=O(sqrt(n)), and the converse is proved in the case of narrow-sense codes. Furt

Kimikazu Kato, Mayumi Oto, Hiroshi Imai, Keiko Imai

1-qubit quantum states form a space called the three-dimensional Bloch ball. To compute Holevo capacity, Voronoi diagrams in the Bloch ball with respect to the quantum divergence have been used as a powerful tool. These diagrams basically treat mixed quantum states corresponding to points in the interior of the Bloch ball. Due to the existence of logarithm i

Jian Fu, Xun Zhang

We numerically demonstrate that &#34;mode-entangled states&#34; based on the transverse modes of classical optical fields in multimode waveguides violate Bell&#39;s inequality. Numerically simulating the correlation measurement scheme of Bell&#39;s inequality, we obtain the normalized correlation functions of the intensity fluctuations for the two entangled

Y. D. Wang, Y. Li, Z. Song, C. P. Sun

We propose a solid state based protocol to implement the universal quantum storage for electronic spin qubit. The quantum memory in this scheme is the spin wave excitation in the ring array of nuclei in a quantum dot. We show that the quantum information carried by an arbitrary state of the electronic spin can be coherently mapped onto the spin wave excitati

Akira R. Kinjo, Ken Nishikawa

Protein one-dimensional (1D) structures such as secondary structure and contact number provide intuitive pictures to understand how the native three-dimensional (3D) structure of a protein is encoded in the amino acid sequence. However, it has not been clear whether a given set of 1D structures contains sufficient information for recovering the underlying 3D

Rainer W. Kuehne

Steven Jones et al. reported to have observed nuclear fusion at room temperature. They observed this &#34;cold fusion&#34; by electrolyzing heavy water. Later experiments confirmed these observations. These experiments confirmed the generation of strong electric fields within the deuterided metals. These electric fields accelerate the deuterons to keV energi

J F McCann, Liang-You Peng, I D Williams

In our model the electron dynamics are described by a two-state approximation. This might appear a rough approximation since it neglects coupling through excited electronic states and ionization channels. However at high intensity (laser fields equivalent to the Coulomb force) and long wavelength (photon energy much lower than the ionization potential) the d

Michael C. Wittmann

English abstract: In the "Intuitive Quantum Physics" course, we use graphical interpretations of mathematical equations and qualitative reasoning to develop and teach a simplified model of quantum physics. Our course contains three units: Wave physics, Development of a conceptual toolbox, and quantum physics. It also contains three key themes: wave-particle

Holger Mueller, Achim Peters, Claus Braxmaier

We present a simple method to stabilize the optical path length of an optical fiber to an accuracy of about 1/100 of the laser wavelength. We study the dynamic response of the path length to modulation of an electrically conductive heater layer of the fiber. The path length is measured against the laser wavelength by use of the Pound-Drever-Hall method; nega

A. Deltuva, A. C. Fonseca, P. U. Sauer

The Coulomb interaction between the protons is included in the description of proton-deuteron scattering using the screening and renormalization approach in the framework of momentum-space integral equations. Two new calculational schemes are presented that confirm the reliability of the perturbative approach for treating the screened Coulomb interaction in

R. Skibinski, H. Witala, J. Golak

We extended the study of relativistic effects in neutron-deuteron scattering to the exclusive breakup. To this aim we solved the three-nucleon Faddeev equation including such relativistic features as relativistic kinematics and boost effects at incoming neutron lab. energies E_n^{lab}=65 MeV, 156 MeV and 200 MeV. As dynamical input a relativistic nucleon-nuc

V. Bradnova, M. M. Chernyavsky, A. Sh. Gaitinov, L. A. Goncharova

We give an overview of results and prospects of nuclear clustering studies on the grounds of the observations of interactions of light stable and radioactive nuclei with an initial energy above 1 A GeV in nuclear emulsions. Thank to the best spatial resolution and the full solid angle acceptance provided by nuclear emulsions, such an approach allows one to o

Gian Michele Graf, Alessio Vaghi

In the context of the Anderson model, Minami proved a Wegner type bound on the expectation of 2 by 2 determinant of Green&#39;s functions. We generalize it so as to allow for a magnetic field, as well as to determinants of higher order.

Attila Andai

The aim of the paper is to extend the notion of $α$-geometry in the classical and in the noncommutative case by introducing a more general class of pull-back metrics and to give concrete formulas for the scalar curvature of these Riemannian manifolds. We introduce a more general class of pull-back metrics of the noncommutative state spaces, we pull back the

Aravind Asok

We give a concrete description of the category of G-equivariant vector bundles on certain affine G-varieties (where G is a reductive linear algebraic group over an algebraically closed field of characteristic 0) in terms of linear algebra data.

Ilya Kapovich, Paul Schupp

We show that for any positive integer $m\ge 1$, $m$-relator quotients of the modular group $M = PSL(2,\mathbb{Z})$ generically satisfy a very strong Mostow-type \emph{isomorphism rigidity}. We also prove that such quotients are generically &#34;essentially incompressible&#34;. By this we mean that their &#34;absolute $T$-invariant&#34;, measuring the smalles

Elemer E Rosinger

It is argued that Goedel&#39;s incompleteness theorem should be seen as self-evident, rather than unexpected or surprising.

Chandan Singh Dalawat

We compute the Chow group of a Ch{â}telet surface over a dyadic field. Combined with the previous work of Bloch, Colliot-Th{é}l{è}ne, Coray, Ischebeck, Sansuc, Swinnerton-Dyer, and the author, this allows one to compute the Chow group of any Ch{â}telet surface over any number field.

Tom Wilde

Let χbe an irreducible character of the finite group G. If g is an element of G and χ(g) is not zero, then we conjecture that the order of g divides |G|/χ(1). The conjecture is a generalization of the classical fact that irreducible p-projective characters vanish on p-singular elements, since the latter is equivalent to saying that if χ(g) is not zero then t

Jan M. Swart

This paper considers contact processes with additional voter model dynamics. For such models, results of Lloyd and Sudbury can be applied to find a self-duality, as well as dualities and thinning relations with systems of random walks with annihilation, branching, coalescence, and deaths. We show that similar relations, which are known from the literature fo

V. I. Danilov, A. V. Karzanov, G. A. Koshevoy

We show that a connected regular $A_2$-crystal (the crystal graph of an irreducible representation of $sl_3$) can be produced from two half-grids by replicating them and glying together in a certain way. Also some extensions and related aspects are discussed.

François Bolley, José Antonio Carrillo

We show that the Euclidean Wasserstein distance is contractive for inelastic homogeneous Boltzmann kinetic equations in the Maxwellian approximation and its associated Kac-like caricature. This property is as a generalization of the Tanaka theorem to inelastic interactions. Consequences are drawn on the asymptotic behavior of solutions in terms only of the E

Ali Akhavi, Jean-François Marckert, Alain Rouault

For $g < n$, let $b\_1,...,b\_{n-g}$ be $n - g$ independent vectors in $\mathbb{R}^n$ with a common distribution invariant by rotation. Considering these vectors as a basis for the Euclidean lattice they generate, the aim of this paper is to provide asymptotic results when $n\to +\infty$ concerning the property that such a random basis is reduced in the sens

Yuichi Nohara

In this thesis we study asymptotic behavior of projective embeddings of abelian varieties and their amoebas. The projective embeddings are given by theta functions. It is known that a Lagrangian fibration of the abelian variety determines a basis of theta functions. After reviewing the relation from the viewpoint of geometric quantization and mirror symmetry

Yuichi Nohara

In this paper, we study asymptotic behavior of projective embeddings of Kummer varieties given by theta functions, and their amoebas. We prove that a Lagrangian fibration of the Kummer variety can be approximated by moment maps of the projective spaces.

Mariya Vorobets, Yaroslav Vorobets

We introduce two series of finite automata starting from the so-called Aleshin and Bellaterra automata. We prove that each automaton in the first series defines a free non-Abelian group while each automaton in the second series defines the free product of groups of order 2. Furthermore, these properties are shared by disjoint unions of any number of distinct

Fausto Gozzi, Francesco Russo

This paper is devoted to present a method of proving verification theorems for stochastic optimal control of finite dimensional diffusion processes without control in the diffusion term. The value function is assumed to be continuous in time and once differentiable in the space variable ($C^{0,1}$) instead of once differentiable in time and twice in space ($

Fausto Gozzi, Francesco Russo

The motivation of this paper is to prove verification theorems for stochastic optimal control of finite dimensional diffusion processes without control in the diffusion term, in the case that the value function is assumed to be continuous in time and once differentiable in the space variable ($C^{0,1}$) instead of once differentiable in time and twice in spa

Fabrizio Catanese

Given a smooth complex surface S, and a compact connected global normal crossings divisor $D = \cup_i D_i$, we consider the local fundamental group, i.e., the fundamental group Gamma of T-D, where T is a good tubular neighbourhood of D. One has a surjection of Gamma onto the fundamental group of D, and the kernel $\sK$ is normally generated by geometric loop

A. Tsurkov

This research was motivated by universal algebraic geometry. One of the central questions of universal algebraic geometry is: when two algebras have the same algebraic geometry? For answer of this question (see [Pl],[Ts]) we must consider the variety, to which our algebras belongs, the category K of all finitely generated free algebras of our variety and res

Michael McGuigan

In this paper we extend the Cosmological Constant Seesaw treatment of hep-th/0602112 to String/M-Theory where the cosmological constant is finite. We discuss how transitions between different $λ$, one of Planckian vacuum energy, can give rise to a large $M_{Pl}^4$ denominator in the Cosmological Constant Seesaw relation discussed by Banks, Motl and Carroll.

Ching-Ming Chen, Tianjun Li, Dimitri V. Nanopoulos

On Type IIA orientifolds with flux compactifications in supersymmetric AdS vacua, we for the first time construct SU(5) models with three anti-symmetric {\bf 10} representations and without symmetric {\bf 15} representations. We show that all the pairs of the anti-fundamental {\bf \bar 5} and fundamental {\bf 5} representations can obtain GUT/string-scale ve

Hristu Culetu

The entropy S of the horizon $theta = pi/2$ of the Hawking wormhole written in spherical Rindler coordinates is computed in this letter. Using Padmanabhan&#39;s prescription,we found that the surface gravity of the horizon equals the proper acceleration of the Rindler observer. S is a monotonic function of the radial coordinate $xi$ and vanishes when $xi$ eq

Mark G. Alford, Krishna Rajagopal, Sanjay Reddy, Andrew Steiner

We construct strangelets, taking into account electrostatic effects, including Debye screening, and arbitrary surface tension sigma of the interface between vacuum and quark matter. We find that there is a critical surface tension sigma_crit below which large strangelets are unstable to fragmentation and below which quark star surfaces will fragment into a c

Takehiko Asaka, Shuntaro Nakamura, Masahiro Yamaguchi

Cosmological issues of the gravitino production by the decay of a heavy scalar field $X$ are examined, assuming that the damped coherent oscillation of the scalar once dominates the energy of the universe. The coupling of the scalar field to a gravitino pair is estimated both in spontaneous and explicit supersymmetry breaking scenarios, with the result that

Jan-e Alam, Pradip Roy, Abhee K. Dutt-Mazumder

We argue that in the measured $p_T$ domain of RHIC, collisional rather than the radiative energy loss is the dominant mechanism for jet quenching. Accordingly we calculate nuclear suppression factor for light hadrons by taking only the elastic energy loss in sharp contrast with the previous calculations where only the radiative loss are considered.

K. Sasaki, T. Ueda, T. Uematsu

We present the next-to-next-to-leading order ($alpha alpha_s^2$) corrections to the first moment of the polarized virtual photon structure function $g_1^gamma(x,Q^2,P^2)$ in the kinematical region $Lambda^2 ll P^2 ll Q^2$, where $-Q^2(-P^2)$ is the mass squared of the probe (target) photon and $Lambda$ is the QCD scale parameter. In order to evaluate the thr

A. V. Luchinsky

The decays $χ_{b0,2}\toψψ$ and $χ_{b0,2}\toψψ\to2(μ^+μ^-)$ are considered. It is shown that with the help of $ψ$-meson angular distributions and the distributions by final muon kinematical variables it is possible to determine the spin of the decaying $χ_b$-meson. These distributions can also give an additional information about $ψ$-meson wave functions.