September 2006 arXiv papers — page 40

E. Katzav, M. Adda-Bedia, R. Arias

The problem of dynamic symmetric branching of an initial single brittle crack propagating at a given speed under plane loading conditions is studied within a continuum mechanics approach. Griffith's energy criterion and the principle of local symmetry are used to determine the cracks paths. The bifurcation is predicted at a given critical speed and at a

The HAPPEX Collaboration

We report new measurements of the parity-violating asymmetry A_PV in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with <theta_lab>~6.0 degrees. The 4He result is A_PV = (+6.40 +/- 0.23 (stat) +/- 0.12 (syst)) x10^-6. The hydrogen result is A_PV = (-1.58 +/- 0.12 (stat) +/- 0.04 (syst)) x10^-6. These results significantly improve constra

Victor A. Nicholson

Laundry surfaces for closed braid diagrams are presented. It is shown that braid diagrams are characterized by linking matrices obtained by lifting cycles from these surfaces. Oriented link types are then characterized by equivalence classes of linking matrices. Similar equivalence classes can be composed of Gordon and Litherland forms or Seifert matrices.

Claudia Polini, Bernd Ulrich, Marie A. Vitulli

The core of an ideal is the intersection of all its reductions. We describe the core of a zero-dimensional monomial ideal I as the largest monomial ideal contained in a general reduction of I. This provides a new interpretation of the core in the monomial case as well as an efficient algorithm for computing it. We relate the core to adjoints and first coeffi

Kari Enqvist, Teppo Mattsson

We consider an inhomogeneous but spherically symmetric Lemaitre-Tolman-Bondi model to demonstrate that spatial variations of the expansion rate can have a significant effect on the cosmological supernova observations. A model with no dark energy but a local Hubble parameter about 15% larger than its global value fits the supernova data better than the homoge

Dmitrii L. Maslov, Andrey V. Chubukov, Ronojoy Saha

We study the nonanalytic behavior of the static spin susceptibility of 2D fermions as a function of temperature and magnetic field. For a generic Fermi liquid, χ_s (T, H)= const+c_1 max (T,μ_B|H|), where c_1 is shown to be expressed via complicated combinations of the Landau parameters, rather than via the backscattering amplitude, contrary to the case of th

The BABAR Collaboration, B. Aubert

We present measurements of the total production rates and momentum distributions of the charmed baryon $Λ_c^+$ in $e^+e^- \to$ hadrons at a center-of-mass energy of 10.54 GeV and in $Υ(4S)$ decays. In hadronic events at 10.54 GeV, charmed hadrons are almost exclusively leading particles in $e^+e^- \to c\bar{c}$ events, allowing direct studies of $c$-quark fr

Tomasz Ciszkowski, Zbigniew Kotulski

The pervasiveness of wireless communication recently gave mobile ad hoc networks (MANET) a significant researchers&#39; attention, due to its innate capabilities of instant communication in many time and mission critical applications. However, its natural advantages of networking in civilian and military environments make them vulnerable to security threats.

J. J. Hopfield

The algorithms that simple feedback neural circuits representing a brain area can rapidly carry out are often adequate to solve only easy problems, and for more difficult problems can return incorrect answers. A new excitatory-inhibitory circuit model of associative memory displays the common human problem of failing to rapidly find a memory when only a smal

Juan C. Migliore, Fabrizio Zanello

The purpose of this note is to characterize the finite Hilbert functions which force all of their artinian algebras to enjoy the Weak Lefschetz Property (WLP). Curiously, they turn out to be exactly those (characterized by Wiebe in $[Wi]$) whose Gotzmann ideals have the WLP. This implies that, if a Gotzmann ideal has the WLP, then all algebras with the same

Kazuhito Fujiwara

We study the N=1 U(N) gauge model obtained by spontaneous breaking of N=2 supersymmetry. The Fayet-Iliopoulos term included in the N=2 action does not appear in the action on the N=1 vacuum and the superpotential is modified to break discrete R symmetry. We take a limit in which the Kahler metric becomes flat and the superpotential preserves non-trivial form

Anne M. Green, Ben Morgan

We study the dependence of the exposure required to directly detect a WIMP directional recoil signal on the capabilities of a directional detector. Specifically we consider variations in the nuclear recoil energy threshold, the background rate, whether the detector measures the recoil momentum vector in 2 or 3 dimensions and whether or not the sense of the m

Kentaro Hori, David Tong

We study various aspects of N=(2,2) supersymmetric non-Abelian gauge theories in two dimensions, with applications to string vacua. We compute the Witten index of SU(k) SQCD with N>0 flavors with twisted masses; the result is presented as the solution to a simple combinatoric problem. We further claim that the infra-red fixed point of SU(k) gauge theory with

Patricia Ball, Roman Zwicky

We calculate the dominant Standard Model contributions to the time-dependent CP asymmetry in B0->K*0 gamma, which is O(1/mb) in QCD factorisation. We find that, including all relevant hadronic effects, in particular from soft gluons, the asymmetry S is very small, S=-0.022\pm 0.015^{+0}_{-0.01}, and smaller than suggested recently from dimensional arguments

Stefano Actis, Michal Czakon, Janusz Gluza, Tord Riemann

Recent developments in the computation of two-loop master integrals for massive Bhabha scattering are briefly reviewed. We apply a method based on expansions of exact Mellin-Barnes representations and evaluate all planar four-point master integrals in the approximation of small electron mass at fixed scattering angle for the one-flavor case. The same techniq

Aaron Pierce, Jesse Thaler, Lian-Tao Wang

New physics near the TeV scale can generate dimension-six operators that modify the production rate and branching ratios of the Higgs boson. Here, we show how Higgs boson pair production can yield complementary information on dimension-six operators involving the gluon field strength. For example, the invariant mass distribution of the Higgs boson pair can s

Roger Colbeck

In the literature, strong coin tossing protocols based on bit commitment have been proposed. Here we examine a protocol that instead tries to achieve the task by sharing entanglement securely. The protocol uses only qubits, and has bias 1/4. This is equal to the best known bias for bit commitment based schemes.

Raul Cordovil, Manoel Lemos, Claudia Linhares Sales

We introduce the notion of k-hyperclique complexes, i.e., the largest simplicial complexes on the set [n] with a fixed k-skeleton. These simplicial complexes are a higher-dimensional analogue of clique (or flag) complexes (case k=2) and they are a rich new class of simplicial complexes. We show that Dirac&#39;s theorem on chordal graphs has a higher-dimensio

William D. Banks, Igor E. Shparlinski

We obtain asymptotic formulae for the number of primes $p\le x$ for which the reduction modulo $p$ of the elliptic curve $$ \E_{a,b} : Y^2 = X^3 + aX + b $$ satisfies certain ``natural&#39;&#39; properties, on average over integers $a$ and $b$ with $|a|\le A$ and $|b| \le B$, where $A$ and $B$ are small relative to $x$. Specifically, we investigate behavior

Martin Forde

This paper has been withdrawn

Luca Ferretti, Stephen F. King, Andrea Romanino

We consider a new approach to fermion masses and mixings in which no special &#34;horizontal&#34; dynamics is invoked to account for the hierarchical pattern of charged fermion masses and for the peculiar features of neutrino masses. The hierarchy follows from the vertical, family-independent structure of the model, in particular from the breaking pattern of

Frédéric Blanqui, Colin Riba

In a previous work, the first author extended to higher-order rewriting and dependent types the use of size annotations in types, a termination proof technique called type or size based termination and initially developed for ML-like programs. Here, we go one step further by considering conditional rewriting and explicit quantifications and constraints on si

C. Emary, L. J. Sham

We describe an interaction mechanism between electron spins in a vertically-stacked double quantum dot that can be used for controlled two-qubit operations. This interaction is mediated by excitons confined within, and delocalized over, the double dot. We show that gates equivalent to the SQRT-SWAP gate can be obtained in times much less than the exciton rel

Bruno Nietlispach

This paper has been withdrawn by the author; a revised version is part of the author&#39;s phd-thesis &#34;Quasi-logarithmic structures&#34; (Zurich, 2007).

Tanay K. Dey, Sudipta Mukherji, Subir Mukhopadhyay, Swarnendu Sarkar

This paper deals with black holes, bubbles and orbifolds in Gauss-Bonnet theory in five dimensional anti de Sitter space. In particular, we study stable, unstable and metastable phases of black holes from thermodynamical perspective. By comparing bubble and orbifold geometries, we analyse associated instabilities. Assuming AdS/CFT correspondence, we discuss

E. Burgos, H. Ceva, R. Perazzo, M. Devoto

We investigate the relationship between the nested organization of mutualistic systems and their robustness against the extinction of species. We establish that a nested pattern of contacts is the best possible one as far as robustness is concerned, but only when the least linked species have the greater probability of becoming extinct. We introduce a coeffi

C. S. Kochanek, X. Dai, C. Morgan, N. Morgan

Microlensing of gravitationally lensed quasars by the stars in the foreground lens galaxy can be used to probe the nature of dark matter, to determine the mean stellar mass in the lens galaxy, and to measure the internal structure of quasar accretion disks. Until recently, little progress has been made toward using microlensing for these purposes because of

Evgeny Kh. Akhmedov, Michele Frigerio

Type I and type II seesaw contributions to the mass matrix of light neutrinos are inherently related if left-right symmetry is realized at high energy scales. We investigate implications of such a relation for the interpretation of neutrino data. We proved recently that the left-right symmetric seesaw equation has eight solutions, related by a duality proper

Seungjoon Hyun, Sang-Heon Yi

We consider non-compact branes in topological string theories on a class of Calabi-Yau spaces including the resolved conifold and its mirror. We compute the amplitudes of the insertion of non-compact Lagrangian branes in the A-model on the resolved conifold in the context of the topological vertex as well as the melting crystal picture. They all agree with e

Ralf Hofmann

We argue that a selfconsistent spatial coarse-graining, which involves interacting (anti)calorons of unit topological charge modulus, implies that real-time loop expansions of thermodynamical quantities in the deconfining phase of SU(2) and SU(3) Yang-Mills thermodynamics are, modulo 1PI resummations, determined by a finite number of connected bubble diagram

T. Padmanabhan

The equations of motion for matter fields are invariant under the shift of the matter lagrangian by a constant. Such a shift changes the energy momentum tensor of matter by T^a_b --> T^a_b +\rho \delta^a_b. In the conventional approach, gravity breaks this symmetry and the gravitational field equations are not invariant under such a shift of the energy momen

Christof Geiss, Bernard Leclerc, Jan Schröer

Let L be a preprojective algebra of Dynkin type, and let G be the corresponding complex semisimple simply connected algebraic group. We study rigid modules in subcategories sub(Q) for Q an injective L-module, and we introduce a mutation operation between complete rigid modules in sub(Q). This yields cluster algebra structures on the coordinate rings of the p

Martin Schumacher

The $t$-channel contribution to the difference of electromagnetic polarizabilities of the nucleon, $(α-β)^t$, can be quantitatively understood in terms of a $σ$-meson pole in the complex $t$-plane of the invariant scattering amplitude $A_1(s,t)$ with properties of the $σ$ meson as given by the quark-level Nambu--Jona-Lasinio model (NJL). Equivalently, this q

Davoud Kamani

In this manuscript we consider the transformations of the oscillators of the bosonic fields of the superstring in terms of the fermions oscillators and vice versa. We demand the exchange of the commutation and anti-commutation relations of the oscillators. Therefore, we obtain some conditions on the Grassmannian matrices that appear in these transformations.

K. Ebrahimi-Fard, J. M. Gracia-Bondia, F. Patras

Motivated by recent work of Connes and Marcolli, based on the Connes-Kreimer approach to renormalization, we augment the latter by a combinatorial, Lie algebraic point of view. Our results rely both on the properties of the Dynkin idempotent, one of the fundamental Lie idempotents in the theory of free Lie algebras, and on properties of Hopf algebras encapsu

S. Antusch, S. F. King, A. Riotto

We study thermal leptogenesis in classes of neutrino mass models based on the seesaw mechanism with three right-handed neutrinos and sequential right-handed neutrino dominance. The flavour-dependent Boltzmann equations are solved appropriate to both the Standard Model and the Minimal Supersymmetric Standard Model. Within these classes of models we investigat

Tomoaki Matsumoto

A new numerical code, called SFUMATO, for solving self-gravitational magnetohydrodynamics (MHD) problems using adaptive mesh refinement (AMR) is presented. A block-structured grid is adopted as the grid of the AMR hierarchy. The total variation diminishing (TVD) cell-centered scheme is adopted as the MHD solver, with hyperbolic cleaning of divergence error o

S. Iblisdir, J. I. Latorre, R. Orus

An analytical expression for the von Neumann entropy of the Laughlin wave function is obtained for any possible bipartition between the particles described by this wave function, for filling fraction nu=1. Also, for filling fraction nu=1/m, where m is an odd integer, an upper bound on this entropy is exhibited. These results yield a bound on the smallest pos

C. Coronnello, M. Tumminello, F. Lillo, S. Micciche`

We review some methods recently used in the literature to detect the existence of a certain degree of common behavior of stock returns belonging to the same economic sector. Specifically, we discuss methods based on random matrix theory and hierarchical clustering techniques. We apply these methods to a set of stocks traded at the New York Stock Exchange. Th

David Martinez-Delgado, Jorge Penarrubia, Mario Juric, Emilio J. Alfaro

The recently discovered Virgo stellar over-density, which expands over \~1000deg^2 perpendicularly to the Galactic disk plane (7< Z <15 kpc, R~7 kpc), is the largest clump of tidal debris ever detected in the outer halo and is likely related with the accretion of a nearby dwarf galaxy by the Milky Way. We carry out N-body simulations of the Sagittarius strea

Bruno Nietlispach

This paper has been withdrawn by the author; a revised version is part of the author&#39;s phd-thesis &#34;Quasi-logarithmic structures&#34; (Zurich, 2007).

P. G. Radaelli, L. C. Chapon

The symmetry conditions for the development of a macroscopic electrical polarization as a secondary order parameter to a magnetic ordering transition, and the constraints on the direction of the polarization vector, are determined by a non-conventional application of the theory of irreducible co-representations. In our approach, which is suitable for both ma

Stefan Fredenhagen, Matthias R. Gaberdiel, Christoph A. Keller

The influence of closed string moduli on the D-brane moduli space is studied from a worldsheet point of view. Whenever a D-brane cannot be adjusted to an infinitesimal change of the closed string background, the corresponding exactly marginal bulk operator ceases to be exactly marginal in the presence of the brane. The bulk perturbation then induces a renorm

Andrzej P. Kisielewicz, Krzysztof Przesławski

A non-empty subset A of X = X_1 x...x X_d is a (proper) box if A = A_1 x...x A_d and A_i is a (proper) subset of X_i for each i. Suppose that for each pair of boxes A, B and each i, one can only know which of the three states takes place: A_i = B_i, A_i = X_i\setminus B_i, A_i is different from each of the sets B_i, X_i\setminus B_i. Let F and G be two syste

Takahiro Sagawa, Masahito Ueda

We propose a new thermodynamic equality and several inequalities concerning the relationship between work and information for an isothermal process with Maxwell&#39;s demon. Our approach is based on the formulation a la Jarzynski of the thermodynamic engine and on the quantum information-theoretic characterization of the demon. The lower bound of each inequa

Koenraad M. R. Audenaert

We prove a matrix inequality for matrix monotone functions, and apply it to prove a singular value inequality for Heinz means recently conjectured by X. Zhan.

Yehuda Pinchover, Achilles Tertikas, Kyril Tintarev

In this paper we prove a sufficient condition, in terms of the behavior of a ground state of a singular p-Laplacian problem with a potential term, such that a nonzero subsolution of another such problem is also a ground state. Unlike in the linear case (p=2), this condition involves comparison of both the functions and of their gradients.

Christoph Simon, Yann-Michel Niquet, Xavier Caillet, Joel Eymery

Single electron spins in quantum dots are attractive for quantum communication because of their expected long coherence times. We propose a method to create entanglement between two remote spins based on the coincident detection of two photons emitted by the dots. Local nodes of several qubits can be realized using the dipole-dipole interaction between trion

Chien-Wen Hwang, Zheng-Tao Wei

The light-front approach is a relativistic quark model and offers many insights to the internal structures of the hadronic bound states. In this study, we apply the covariant light-front approach to ground-state heavy quarkonium. The pesudoscalar and vector meson decay constants are discussed. We present a detailed study of two-photon annihilation P \to γγan

S. Pirzada, T. A. Naikoo, F. A. Dar

A signed bipartite graph G(U, V) is a bipartite graph in which each edge is assigned a positive or a negative sign. The signed degree of a vertex x in G(U, V) is the number of positive edges incident with x less the number of negative edges incident with x. The set S of distinct signed degrees of the vertices of G(U, V) is called its signed degree set. In th

Yutaka Hosotani

In the dynamical gauge-Higgs unification the 4D Higgs field is unified with gauge fields and the electroweak symmetry is dynamically broken by the Hosotani mechanism. Interesting phenomenology is obtained in the Randall-Sundrum warped spacetime. (i) The Higgs boson mass is predicted at the LHC energies. (ii) The hierarchy in the fermion mass spectrum is natu

Y. Meurice

We define the non-perturbative part of a quantity as the difference between its numerical value and the perturbative series truncated by dropping the order of minimal contribution and the higher orders. For the anharmonic oscillator, the double-well potential and the single plaquette gauge theory, the non-perturbative part can be parametrized as A (lambda)^B

C. Alexandrou, Ph. de Forcrand, B. Lucini

Diquarks may play an important role in hadron spectroscopy, baryon decays and color superconductivity. We investigate the existence of diquark correlations in lattice QCD by considering systematically all the lowest energy diquark channels in a color gauge-invariant setup. We measure mass differences between the various channels and show that the positive pa

Hirohito Hayashi, Masashi Chiba

We investigate the dynamical interaction between a galactic disk and surrounding numerous dark subhalos as expected for a galaxy-sized halo in the cold dark matter (CDM) models. Our particular interest is to what extent accretion events of subhalos into a disk are allowed in light of the observed thinness of a disk. Several models of subhalos are considered

Dragos Ghioca, Thomas J. Tucker

We prove that the local height of a point on a Drinfeld module can be computed by averaging the logarithm of the distance to that point over the torsion points of the module. This gives rise to a Drinfeld module analog of a weak version of Siegel&#39;s integral points theorem over number fields and to an analog of a theorem of Schinzel&#39;s regarding the or

Jian-Ming Cai, Zheng-Wei Zhou, Guang-Can Guo

We investigate the dynamics of information in isolated multi-qubit systems. It is shown that information is in not only local form but also nonlocal form. We apply a measure of local information based on fidelity, and demonstrate that nonlocal information can be directly related to some appropriate well defined entanglement measures. Under general unitary tr

Jian-Ming Cai, Zheng-Wei Zhou, Xing-Xiang Zhou, Guang-Can Guo

We consider pure quantum states of N qubits and study the genuine N-qubit entanglement that is shared among all the N qubits. We introduce an information-theoretic measure of genuine N-qubit entanglement based on bipartite partitions. When N is an even number, this measure is presented in a simple formula, which depends only on the purities of the partially

Eric Pop, David Mann, Kenneth Goodson, Hongjie Dai

We analyze transport in metallic single-wall carbon nanotubes (SWNTs) on insulating substrates over the bias range up to electrical breakdown in air. To account for Joule self-heating, a temperature-dependent Landauer model for electrical transport is coupled with the heat conduction equation along the nanotube. The electrical breakdown voltage of SWNTs in a

Jiangbin Gong, Paul Brumer

A simple model of quantum ratchet transport that can generate unbounded linear acceleration of the quantum ratchet current is proposed, with the underlying classical dynamics fully chaotic. The results demonstrate that generic acceleration of quantum ratchet transport can occur with any type of classical phase space structure. The quantum ratchet transport w

Viv Kendon

The development of quantum algorithms based on quantum versions of random walks is placed in the context of the emerging field of quantum computing. Constructing a suitable quantum version of a random walk is not trivial: pure quantum dynamics is deterministic, so randomness only enters during the measurement phase, i.e., when converting the quantum informat

Nicolai B. Grosse, Thomas Symul, Magdalena Stobińska, Timothy C. Ralph

We present a technique for measuring the second-order coherence function $g^{(2)}(τ)$ of light using a Hanbury-Brown Twiss intensity interferometer modified for homodyne detection. The experiment was performed entirely in the continuous variable regime at the sideband frequency of a bright carrier field. We used the setup to characterize $g^{(2)}(τ)$ for the

Carl M. Bender, Dorje C. Brody, Hugh F. Jones, Bernhard K. Meister

Given an initial quantum state |psi_I> and a final quantum state |psi_F> in a Hilbert space, there exist Hamiltonians H under which |psi_I> evolves into |psi_F>. Consider the following quantum brachistochrone problem: Subject to the constraint that the difference between the largest and smallest eigenvalues of H is held fixed, which H achieves this transform

E. Persson, S. Fürthauer, S. Wimberger, J. Burgdörfer

We investigate the long-time limit of quantum localization of the kicked Rydberg atom. The kicked Rydberg atom is shown to possess in addition to the quantum localization time $τ_L$ a second cross-over time $t_D$ where quantum dynamics diverges from classical dynamics towards increased instability. The quantum localization is shown to vanish as either the st

N. K. Solovarov

Pedagogical introduction into the problem of the mathematical description of the quantum correlation (entanglement) of composite quantum systems is represented. The notion is substantiated about the fact that the conventional algorithm of the reduction of von Neumann in the description of the dynamics of the observed subsyatem is not universal and correspond

Dan Kenigsberg, Tal Mor

Several protocols for controlled teleportation were suggested by Yang, Chu, and Han [PRA 70, 022329 (2004)]. In these protocols, Alice teleports qubits (in an unknown state) to Bob iff a controller allows it. We view this problem in the perspective of secure multi-party quantum computation. We show that the suggested entanglement-efficient protocols for $m$-

Kia Manouchehri, J. B. Wang

To study the ballistic transport of charge carriers in nano-structured quantum devices, a highly efficient numerical technique is developed, which provides continuous transmission spectra for arbitrarily complex potential geometries in two dimensions. We apply the proposed method to single and double barrier structures and compare the results with those obta

Wolfgang Menges

Resistive Plate Chambers (RPCs) were used for the instrumentation of the iron flux return of the BABAR detector as a muon system. Unfortunately the efficiency of the original RPCs degraded rapidly with time. Limited Streamer Tubes (LSTs) were chosen for an upgrade of the barrel portion of the detector. The phased installation started in summer 2004 with repl

V. Alfi, A. De Martino, L. Pietronero, A. Tedeschi

Price dynamics is analyzed in terms of a model which includes the possibility of effective forces due to trend followers or trend adverse strategies. The method is tested on the data of a minority-majority model and indeed it is capable of reconstructing the prevailing traders&#39; strategies in a given time interval. Then we also analyze real (NYSE) stock-p

D. Van Neck, S. Verdonck, G. Bonny, P. W. Ayers

We propose a framework to construct the ground-state energy and density matrix of an N-electron system by solving selfconsistently a set of single-particle equations. The method can be viewed as a non-trivial extension of the Kohn-Sham scheme (which is embedded as a special case). It is based on separating the Green&#39;s function into a quasi-particle part

Adi Taflia, David Holcman

The time spent by an interacting Brownian molecule inside a bounded microdomain has many applications in cellular biology, because the number of bounds is a quantitative signal, which can initiate a cascade of chemical reactions and thus has physiological consequences. In the present article, we propose to estimate the mean time spent by a Brownian molecule

Matteo Conforti, Fabio Baronio, Antonio Degasperis, Stefan Wabnitz

We study the excitation, decay and interactions of novel, velocity locked three-wave parametric solitons in a medium with quadratic nonlinearity and dispersion. We analytically describe the particle-like scattering between stable or unstable soliton triplets with linear waves in terms of explicit solutions featuring accelerated or decelerated solitons.

A. M. Stewart

A decomposition of the angular momentum of the classical electromagnetic field into orbital and spin components that is manifestly gauge invariant and general has been obtained. This is done by decomposing the electric field into its longitudinal and transverse parts by means of the Helmholtz theorem. The orbital and spin components of the angular momentum o

Wing Yim Tam

Optical interference holography has been proved to be a useful technique in fabricating periodic photonic crystals in which electromagnetic waves are forbidden in certain frequency bandgaps. Compared to periodic crystals quasicrystals, having higher point group symmetry, are more favourable in achieving complete bandgaps. In this report, we propose two seven

Edward Shuryak

Starting with a reminder of what is strongly coupled Quark-Gluon Plasma (sQGP), we proceed to recent advances in jet quenching and heavy quark diffusion, with a brief summary of various results based on AdS/CFT correspondence. The conical flow is a hydrodynamical phenomenon created by energy and entropy deposited by high energy jets propagating in matter, si

Simon Hands, Seyong Kim, Jon-Ivar Skullerud

Results are presented from a numerical study of lattice QCD with gauge group SU(2) and two flavors of Wilson fermion at non-zero quark chemical potential mu >> T. Studies of the equation of state, the superfluid condensate, and the Polyakov line all suggest that in addition to the low density phase of Bose-condensed diquark baryons, there is a deconfined pha

Edward Shuryak

We start with a discussion of a phase diagram and three special collision energies: (i) the first touching of the mixed phase; (ii) the softest point; (iii) the critical point. We then proceed to more details about the role a massless critical mode should play in the particle interaction and the elliptic flow. We then enter a discussion of whether high densi

Alberto Accardi

Beside its intrinsic interest for the insights it can give into color confinement, knowledge of the space-time evolution of hadronization is very important for correctly interpreting jet-quenching data in heavy ion collisions and extracting the properties of the produced medium. On the experimental side, the cleanest environment to study the space-time evolu

Takuya Shoji, Yoshifumi R. Shimizu

The nuclear wobbling motion in the Lu region is studied by the microscopic cranked mean-field plus RPA method. The Woods-Saxon potential is used as a mean-field with a new parameterization which gives reliable description of rapidly rotating nuclei. The prescription of symmetry-preserving residual interaction makes the calculation of the RPA step parameter-f

D. Zhang, F. Huang, L. R. Dai, Y. W. Yu

The N Omega-bar systems with spin S=1 and S=2 are dynamically investigated within the framework of the chiral SU(3) quark model and the extended chiral SU(3) quark model by solving the resonating group method (RGM) equation. The model parameters are taken from our previous work, which gave a good description of the energies of the baryon ground states, the b

P. Thorngren Engblom, S. Negasi Keleta, F. Cappellaro, B. Hoistad

The reaction pp -> pp pi0 was studied with the WASA detector at the CELSIUS storage ring. The center of mass angular distribution of the pi0 was obtained by detection of the gamma decay products together with the two outgoing protons, and found to be anisotropic with a negative second derivative slope, in agreement with the theoretical predictions from a mic

Xiaopeng Zhao, David G. Schaeffer, Carolyn M. Berger, Daniel J. Gauthier

Various authors have shown that, near the onset of a period-doubling bifurcation, small perturbations in the control parameter may result in much larger disturbances in the response of the dynamical system. Such amplification of small signals can be measured by a gain defined as the magnitude of the disturbance in the response divided by the perturbation amp

O. Bayrak, G. Kocak, I. Boztosun

In this article, we present the analytical solution of the radial Schrödinger equation for the Hulthén potential within the framework of the asymptotic iteration method by using an approximation to the centrifugal potential for any $l$ states. We obtain the energy eigenvalues and the corresponding eigenfunctions for different screening parameters. The wave f

G. I. Garas&#39;ko, D. G. Pavlov

The space of the associative commutative hyper complex numbers, H_4, is a 4-dimensional metric Finsler space with the Berwald-Moor metric. It provides the possibility to construct the tensor fields on the base of the analytical functions of the H_4 variable and also in case when this analyticity is broken. Here we suggest a way to construct the metric tensor

Eldar Straume

A n n-body system is a labelled collection of n point masses in Euclidean space, and their congruence and internal symmetry properties involve a rich mathematical structure which is investigated in the framework of equivariant Riemannian geometry. Some basic concepts are n-configuration, configuration space, internal space, shape space, Jacobi transformation

Delia Ionescu, Juergen Scheurle

We present a formulation of general nonlinear LC circuits within the framework of Birkhoffian dynamical systems on manifolds. We develop a systematic procedure which allows, under rather mild non-degeneracy conditions, to write the governing equations for the mathematical description of the dynamics of an LC circuit as a Birkhoffian differential system. In o

Delia Ionescu

The aim of this paper is to give a formulation of the dynamics of nonlinear RLC circuits as a geometric Birkhoffian system and to discuss in this context the concepts of regularity, conservativeness, dissipativeness. An RLC circuit, with no assumptions placed on its topology, will be described by a family of Birkhoffian systems, parameterized by a finite num

Srikanth Iyengar

These notes are an introduction to basic properties of Andre-Quillen homology for commutative algebras. They are an expanded version of my lectures at the summer school: Interactions between homotopy theory and algebra, University of Chicago, 26th July - 6th August, 2004. The aim is to give fairly complete proofs of characterizations of smooth homomorphisms

Maria Joita

We prove a covariant version of the KSGNS (Kasparov, Stinespring, Gel&#39;fand,Naimark,Segal) construction for completely positive linear maps between locally $C^{*}$-algebras. As an application of this construction, we show that a covariant completely positive linear map $ρ$ from a locally $C^{*}$-algebra $A$ to another locally $C^{*}$ -algebra $B$ with res

Martin Edjvet, James Howie

A Magnus subgroup of a one-relator group is the free subgroup freely generated by a proper subset of the generators. Two such subgroups can intersect in the obvious way or in a larger, exceptional way. The condition of non-exceptional intersection of Magnus subgroups of a one-relator group is applied to give criteria for the resulting cyclically presented gr

Stephen J. Pride

Recently Alonso and Hermiller introduced a homological finiteness condition\break $bi{-}FP_n$ (here called {\it weak} $bi{-}FP_n$) for monoid rings, and Kobayashi and Otto introduced a different property, also called $bi{-}FP_n$ (we adhere to their terminology). From these and other papers we know that: $bi{-}FP_n \Rightarrow$ left and right $FP_n \Rightarro

Andrew Comech

We derive damping estimates and asymptotics of $L^p$ operator norms for oscillatory integral operators with finite type singularities. The methods are based on incorporating finite type conditions into $L^2$ almost orthogonality technique of Cotlar-Stein.

Michael Dettweiler, Stefan Reiter

We prove new instances of Simpson&#39;s rigidity conjecture which states that quasi-unipotent rigid local systems should be motivic. We construct new relative motives over the fourfold punctured Riemann sphere which give rise to $G_2$-rigid local systems which are not rigid in the group $\GL_7.$

Michael Farber, Dirk Schuetz

In this paper we study a new notion of category weight of homology classes developing further the ideas of E. Fadell and S. Husseini. In the case of closed smooth manifolds the homological category weight is equivalent to the cohomological category weight of E. Fadell and S. Husseini but these two notions are distinct already for Poincaré complexes. An impor

Michael Farber, Dirk Schuetz

In this paper we study topology of the variety of closed planar polygons with given side lengths. We describe the Betti numbers of the moduli spaces as functions of the length vector. We also find sharp upper bounds on the sum of Betti numbers of the moduli space depending only on the number of links n. Our method is based on an observation of a remarkable i

Anne Quéguiner-Mathieu

The `transcendental methods&#39; in the algebraic theory of quadratic forms are based on two major results, proved in the 60&#39;s by Cassels and Pfister, and known as the representation and the subform theorems. A generalization of the representation theorem was proven by Jean-Pierre Tignol in 1996, in the setting of central simple algebras with involution.

F. San Segundo, J. R. Sendra

In this paper we present several formulae for computing the partial degrees of the defining polynomial of the offset curve to an irreducible affine plane curve given implicitly, and we see how these formulae particularize to the case of rational curves. In addition, we present a formula for computing the degree w.r.t the distance variable.

Ravi Bapna, Paulo Goes, Ram Gopal, James R. Marsden

Widespread e-commerce activity on the Internet has led to new opportunities to collect vast amounts of micro-level market and nonmarket data. In this paper we share our experiences in collecting, validating, storing and analyzing large Internet-based data sets in the area of online auctions, music file sharing and online retailer pricing. We demonstrate how

S. Pirzada, T. A. Naikoo, T. A. Chishti

The set A of distinct scores of the vertices of an oriented bipartite graph D(U, V) is called its score set. We consider the following question: given a finite, nonempty set A of positive integers, is there an oriented bipartite graph D(U, V) such that score set of D(U, V) is A? We conjecture that there is an affirmative answer, and verify this conjecture wh

S. Pirzada, T. A. Chishti, T. A. Naikoo

Given non-negative integers m, n, h and k with $ m\geq h>1 $ and $ n\geq k>1, $an [h-k]-bipartite hypertournament on $ m+n$ vertices is a triple $(U,V,A) $, where U and V are two sets of vertices with $| U| =m$ and $ | V| =n,$ and $A$ is a set of $(h+k) -$ tuples of vertices, called arcs, with exactly $h$ vertices from $U$ and exactly $k$ vertices from $V$,

Kim Knudsen, Mikko Salo

We extend results of Dos Santos Ferreira-Kenig-Sjoestrand-Uhlmann (math.AP/0601466) to less smooth coefficients, and we show that measurements on part of the boundary for the magnetic Schroedinger operator determine uniquely the magnetic field related to a Hoelder continuous potential. We give a similar result for determining a convection term. The proofs in