May 2007 arXiv papers — page 7

Michael K. Henry, Chandrasekhar Ramanathan, Jonathan S. Hodges, Colm A. Ryan

We demonstrate coherent control of two logical qubits encoded in a decoherence free subspace (DFS) of four dipolar-coupled protons in an NMR quantum information processor. A pseudo-pure fiducial state is created in the DFS, and a unitary logical qubit entangling operator evolves the system to a logical Bell state. The four-spin molecule is partially aligned

Hendrik Bluhm

The author presents a method for calculating the magnetic fields near a planar surface of a superconductor with a given intrinsic magnetization in the London limit. He computes solutions for various magnetic domain boundary configurations and derives relations between the spectral densities of the magnetization and the resulting field in the vacuum half spac

Weiyong He

In this short note we show that the existence of bilaterally symmetric extremal Kähler metrics on $\mathbb{CP}^2\sharp 2\bar{\mathbb{CP}^2}$.

Gary Shiu, Bret Underwood, Devin G. E. Walker, Kathryn M. Zurek

Warped string compactifications, characterized by non-singular behavior of the metric in the infrared (IR), feature departures from the usual anti-de Sitter warped extra dimensions. We study the implications of the smooth IR cutoff for Randall-Sundrum (RS) type models. We find that the phenomenology of the KK gravitons (including their masses and couplings)

N. Rougemaille, M. Portalupi, A. Brambilla, P. Biagioni

Using spin-polarized low-energy electron microscopy to study magnetization in epitaxial layered systems, we found that the area vs perimeter relationship of magnetic domains in the top Fe layers of Fe/NiO/Fe(100) structures follows a power-law distribution, with very small magnetic domain cutoff radius (about 40 nm) and domain wall thickness. This unusual ma

D. V. Khveshchenko

We study localization properties of two-dimensional Dirac fermions subject to a power-law-correlated random vector potential describing, e.g., the effect of "ripples" in graphene. By using a variety of techniques (low-order perturbation theory, self-consistent Born approximation, replicas, and supersymmetry) we make a case for a possible complete loc

Eun-Ah Kim, Michael J. Lawler, Paul Oreto, Subir Sachdev

We study the character of an Ising nematic quantum phase transition (QPT) deep inside a d-wave superconducting state with nodal quasiparticles in a two-dimensional tetragonal crystal. We find that, within a 1/N expansion, the transition is continuous. To leading order in 1/N, quantum fluctuations enhance the dispersion anisotropy of the nodal excitations, an

F. Camilo, S. M. Ransom, J. Penalver, A. Karastergiou

We have observed the 5.54s anomalous X-ray pulsar XTE J1810-197 at radio, millimeter, and infrared (IR) wavelengths, with the aim of learning about its broad-band spectrum. At the IRAM 30m telescope, we have detected the magnetar at 88 and 144GHz, the highest radio-frequency emission ever seen from a pulsar. At 88GHz we detected numerous individual pulses, w

Mirjam Cvetic, Justin F. Vazquez-Poritz

We construct supergravity solutions describing a stack of D3-branes localized at a point on a blown-up cycle of a resolved L^{a,b,c} cone. The geometry flows from AdS_5 x L^{a,b,c} to AdS_5 x S^5/Z_k. The corresponding quiver gauge theory undergoes an RG flow between two superconformal fixed points, which leads to semi-infinite chains of flows between the va

A. Snarskii, M. Zhenirovskyy

For thermoelectric, galvanomagnetic and some other effects there may simultaneously exist two percolation thresholds, close to which the effective kinetic coefficients of macroscopically disordered media are critically dependent on the proximity to percolation thresholds, their behavior being described by universal critical indexes.

Martina Hentschel, Diego C. B. Valente, Eduardo R. Mucciolo, Harold U. Baranger

We discuss decoherence in charge qubits formed by multiple lateral quantum dots in the framework of the spin-boson model and the Born-Markov approximation. We consider the intrinsic decoherence caused by the coupling to bulk phonon modes. Two distinct quantum dot configurations are studied: (i) Three quantum dots in a ring geometry with one excess electron i

W. Lyra, A. Johansen, H. Klahr, N. Piskunov

We present global 3D MHD simulations of disks of gas and solids, aiming at developing models that can be used to study various scenarios of planet formation and planet-disk interaction in turbulent accretion disks. A second goal is to show that Cartesian codes are comparable to cylindrical and spherical ones in handling the magnetohydrodynamics of the disk s

Petter Holme, Mikael Huss

In a recent paper, Marr, Muller-Linow and Hutt [Phys. Rev. E 75, 041917 (2007)] investigate an artificial dynamic system on metabolic networks. They find a less complex time evolution of this dynamic system in real networks, compared to networks of reference models. The authors argue that this suggests that metabolic network structure is a major factor behin

Rogerio de Sousa

We propose a model for magnetic noise based on spin-flips (not electron-trapping) of paramagnetic dangling-bonds at the amorphous-semiconductor/oxide interface. A wide distribution of spin-flip times is derived from the single-phonon cross-relaxation mechanism for a dangling-bond interacting with the tunneling two-level systems of the amorphous interface. Th

Dorit Aharonov, Daniel Gottesman, Sandy Irani, Julia Kempe

We study the computational strength of quantum particles (each of finite dimensionality) arranged on a line. First, we prove that it is possible to perform universal adiabatic quantum computation using a one-dimensional quantum system (with 9 states per particle). This might have practical implications for experimentalists interested in constructing an adiab

Fabio Bernardoni, Sergio L. Cacciatori, Bianca L. Cerchiai, Antonio Scotti

In this paper we present a construction of the compact form of the exceptional Lie group F4 by exponentiating the corresponding Lie algebra f4. We realize F4 as the automorphisms group of the exceptional Jordan algebra, whose elements are 3 x 3 hermitian matrices with octonionic entries. We use a parametrization which generalizes the Euler angles for SU(2) a

Sandy Irani

We prove that adiabatic computation is equivalent to standard quantum computation even when the adiabatic quantum system is restricted to be a set of particles on a one-dimensional chain. We give a construction that uses a 2-local Hamiltonian on nearest neighbors using particles that can have ten distinct states. This implies a construction of a one-dimensio

Richard S. Garavuso, Francesco Toppan

Chern-Simons AdS supergravity theories are gauge theories for the super-AdS group. These theories possess a fermionic symmetry which differs from standard supersymmetry. In this paper, we study five-dimensional Chern-Simons AdS supergravity in a Randall-Sundrum scenario with two Minkowski 3-branes. After making modifications to the D = 5 Chern-Simons AdS sup

Ian Hambleton, Ozgun Unlu

We construct a non-abelian extension $Γ$ of $S^1$ by $\cy 3 \times \cy 3$, and prove that $Γ$ acts freely and smoothly on $S^{5} \times S^{5}$. This gives new actions on $S^{5} \times S^{5}$ for an infinite family $\cP$ of finite 3-groups. We also show that any finite odd order subgroup of the exceptional Lie group $G_2$ admits a free smooth action on $S^{11

Marco Picariello, João Pulido, S. Andringa, N. F. Barros

Time variability of the solar neutrino flux especially in the low and intermediate energy sector remains an open question and, if it exists, it is likely to be originated from the magnetic moment transition from active to light sterile neutrinos at times of intense solar activity and magnetic field. We examine the prospects for the SNO+ experiment to address

C. Di Franco, M. Paternostro, G. M. Palma, M. S. Kim

We introduce and formalize the concept of information flux in a many-body register as the influence that the dynamics of a specific element receive from any other element of the register. By quantifying the information flux in a protocol, we can design the most appropriate initial state of the system and, noticeably, the distribution of coupling strengths am

I. Sahin

We investigate the constraints on the anomalous quartic $W^{+}W^{-}Zγ$ gauge boson coupling through the process $e^{-}γ\to ν_{e}W^{-}Z$. Considering incoming beam polarizations and the longitudinal and transverse polarization states of the final W and Z boson we find 95% confidence level limits on the anomalous coupling parameter $a_{n}$ with an integrated l

M. Burak Erdogan, Vadim Zharnitsky

It is shown that a large subset of initial data with finite energy ($L^2$ norm)evolves nearly linearly in nonlinear Schr\" odinger equation with periodic boundary conditions. These new solutions are not perturbations of the known ones such as solitons, semiclassical or weakly linear solutions.

J. P. Eisenstein, D. Syphers, L. N. Pfeiffer, K. W. West

The quantum lifetime of two-dimensional holes in a GaAs/AlGaAs double quantum well is determined via tunneling spectroscopy. At low temperatures the lifetime is limited by impurity scattering but at higher temperatures hole-hole Coulomb scattering dominates. Our results are consistent with Fermi liquid theory, at least up to r_s = 11. At the highest temperat

Daniela Tordella, Michele Iovieno, Peter Roger Bailey

The interaction of two isotropic turbulent fields of equal integral scale but different kinetic energy generates the simplest kind of inhomogeneous turbulent field. In this paper we present a numerical experiment where two time decaying isotropic fields of kinetic energies $E_1$ and $E_2$ initially match over a narrow region. Within this region the kinetic e

Andrzej Krasiński, Krzysztof Bolejko

In a previous paper we formulated a set of necessary conditions for the spherically symmetric weakly charged dust to avoid Big Bang/Big Crunch, shell crossing and permanent central singularities. However, we did not discuss the properties of the energy density, some of which are surprising and seem not to have been known up to now. A singularity of infinite

J. William Helton, Jiawang Nie

Let $S =\{x\in \re^n: g_1(x)\geq 0, ..., g_m(x)\geq 0\}$ be a semialgebraic set defined by multivariate polynomials $g_i(x)$. Assume $S$ is convex, compact and has nonempty interior. Let $S_i =\{x\in \re^n: g_i(x)\geq 0\}$, and $\bdS$ (resp. $\bdS_i$) be the boundary of $S$ (resp. $S_i$). This paper discusses whether $S$ can be represented as the projection

A. Galli, L. Piro

We perform a detailed study of inverse Compton (IC) emission for a fireball undergoing external shock (ES) in either a uniform or a wind-like interstellar medium, and assess the relative importance of IC and synchrotron emissions. We determine the primary model parameters driving the IC to synchrotron emission ratio in the case of a short duration central en

Ruy Exel, Artur O. Lopes

We present a detailed exposition (for a Dynamical System audience) of the content of the paper: R. Exel and A. Lopes, $C^*$ Algebras, approximately proper equivalence relations and Thermodynamic Formalism, {\it Erg. Theo. and Dyn. Syst.}, Vol 24, pp 1051-1082 (2004). We show only the uniqueness of the β-KMS (in a certain C*-Algebra obtained from the operator

Artur O. Lopes, M. Sebastiani

We show that for a fixed curve $K$ and for a family of variables curves $L$, the number of $n$-Poncelet pairs is $\frac{e (n)}{2}$, where $e(n)$ is the number of natural numbers $m$ smaller than $n$ and which satisfies mcd $ (m,n)=1$. The curvee $K$ do not have to be part of the family. In order to show this result we consider an associated billiard transfor

Sven Heinemeyer, Yonatan Kahn, Michael Schmitt, Mayda Velasco

Anomalous production of low-energy photons from the galactic center have fueled speculations on the nature and properties of dark matter particles. In particular, it has been proposed that light scalars may be responsible for the bulk of the matter density of the universe, and that they couple to ordinary matter through a light spin-1 boson. If this is the c

Subhayan Mandal, Pankaj Jain

We study the possibility of evading astrophysical bound on light pseudoscalars. We argue that the solar bounds can be evaded if we have a sufficiently strong self-coupling of the pseudoscalars. The required coupling does not conflict with any known experimental bounds. We also show that it is possible to find a coupling range such that the recent PVLAS exper

M. Gomes, T. Mariz, J. R. Nascimento, A. Yu. Petrov

The anomaly found by Callan and Harvey is shown to be cancelled in a three-dimensional noncommutative gauge theory coupled to a fermion with a mass function depending on one spatial coordinate (domain wall mass). This evaluation has been done for the fermion in the fundamental and adjoint representations of the gauge group in the limit of small noncommutativ

D. H. Phong, Jian Song, Jacob Sturm, Ben Weinkove

The limiting behavior of the normalized Kähler-Ricci flow for manifolds with positive first Chern class is examined under certain stability conditions. First, it is shown that if the Mabuchi K-energy is bounded from below, then the scalar curvature converges uniformly to a constant. Second, it is shown that if the Mabuchi K-energy is bounded from below and i

Dragos Ghioca, Thomas J. Tucker

We prove a dynamical version of the Mordell-Lang conjecture for subvarieties of the affine space A^g over a p-adic field, endowed with polynomial actions on each coordinate of A^g. We use analytic methods similar to the ones employed by Skolem, Chabauty, and Coleman for studying diophantine equations.

G. Erkol, M. Oka

We evaluate the pion-nucleon and the pion-Delta sigma terms by employing the method of quantum chromodynamics (QCD) sum rules. The obtained value of the pion-nucleon sigma term is compatible with the larger values already anticipated by the recent calculations. It is also found that the pion-Delta sigma term is as large as the pion-nucleon sigma term.

Thomas M. Eccardt

This paper demonstrates that basic statistics (mean, variance) of the logarithm of the variate itself can be used in the calculation of differential entropy among random variables known to be multiples and powers of a common underlying variate. For the same set of distributions, the variance of the differential self-information is shown also to be a function

Jean-Philippe Bruneton, Gilles Esposito-Farese

Modified Newtonian dynamics (MOND) is a possible way to explain the flat galaxy rotation curves without invoking the existence of dark matter. It is however quite difficult to predict such a phenomenology in a consistent field theory, free of instabilities and admitting a well-posed Cauchy problem. We examine critically various proposals of the literature, a

A. G. Angel, M. R. Evans, E. Levine, D. Mukamel

The Zero-Range Process, in which particles hop between sites on a lattice under conserving dynamics, is a prototypical model for studying real-space condensation. Within this model the system is critical only at the transition point. Here we consider a non-conserving Zero-Range Process which is shown to exhibit generic critical phases which exist in a range

H. Hagman, C. M. Dion, P. Sjolund, S. J. H. Petra

We study the influence of the lattice topography and the coupling between motion in different directions, for a three-dimensional Brownian motor based on cold atoms in a double optical lattice. Due to controllable relative spatial phases between the lattices, our Brownian motor can induce drifts in arbitrary directions. Since the lattices couple the differen

Igor F. Herbut

I consider the Hubbard model of graphene in an external magnetic field and in the Hartree-Fock approximation. In the continuum limit, the ground state energy at half filling becomes nearly symmetric under rotations of the three-component vector (N1,N2,m), with the first two components representing the Neel order parameter orthogonal to and the third componen

Raoul Dillenschneider, Jung Hoon Kim, Jung Hoon Han

A class of exact spin ground states with nonzero averages of vector spin chirality, $<Š_i \times Š_j \cdot \hat{z}>$, is presented. It is obtained by applying non-uniform O(2) rotations of spin operators in the XY plane on the SU(2)-invariant Affleck-Kennedy-Lieb-Tasaki (AKLT) states and their parent Hamiltonians. Excitation energies of the new ground states

A. Toporensky, P. Tretyakov

We consider dynamics of the FRW Universe with a scalar field. Using Maupertuis principle we find a curvature of geodesics flow and show that zones of positive curvature exist for all considered types of scalar field potential. Usually, phase space of systems with the positive curvature contains islands of regular motion. We find these islands numerically for

Julien Tailleur, Jorge Kurchan, Vivien Lecomte

We study a simple transport model driven out of equilibrium by reservoirs at the boundaries, corresponding to the hydrodynamic limit of the symmetric simple exclusion process. We show that a nonlocal transformation of densities and currents maps the large deviations of the model into those of an open, isolated chain satisfying detailed balance, where rare fl

Kwei-Chou Yang

We present the studies of the decays $B\to a_1(1260) π$ and $a_1(1260) K$ within the framework of QCD factorization. Due to the G-parity, unlike the vector meson, the chiral-odd two-parton light-cone distribution amplitudes of the $a_1$ are antisymmetric under the exchange of quark and anti-quark momentum fractions in the SU(2) limit. The branching ratios fo

A. Freitas

In co-annihilation scenarios, the weakly interacting dark matter particle (WIMP) is close in mass to another particle that can decay into the WIMP. As a result, both particles freeze out at roughly the same time in the early universe, and both contribute to the effective dark matter annihilation cross-section. Since the heavier particle does not need to be w

Claude M. Dion, Eric Cances

We present a suite of programs to determine the ground state of the time-independent Gross-Pitaevskii equation, used in the simulation of Bose-Einstein condensates. The calculation is based on the Optimal Damping Algorithm, ensuring a fast convergence to the true ground state. Versions are given for the one-, two-, and three-dimensional equation, using eithe

Hiroki Nakamura, Tadaaki Nasu, Makoto Sakuda, Omar Benhar

We have carried out a calculation of the inclusive electron scattering cross section off oxygen in the kinematical region corresponding to beam energies between 700 and 1200 MeV, where quasielastic scattering and single pion production are the dominant reaction mechanisms. The formalism developed and successfully applied to describe quasielastic scattering h

Yusuke Okame, Mitsuo J. Hayashi

We construct (0,2), D=2 gauged linear sigma model on a supermanifold in both the Abelian gauge group and the non-Abelian gauge group. The $\hat{U}$ operator provides consistency conditions for satisfying the SUSY invariance. Contrary to the Abelian gauge group, it is not essential to introduce the new operator in order to check the exact SUSY invariance of t

Hao Wei, Shuang Nan Zhang

In the present work, we investigate the universe dominated by quintom or hessence energies in Loop Quantum Cosmology (LQC). Interestingly enough, we find that there are some stable attractors in these two cases. In the case of quintom, all stable attractors have the feature of decelerated expansion. In the case of hessence, most of stable attractors have the

Tanuka Chattopadhyay, Ranjeev Misra, Asis Kumar Chattopadhyay, Malay Naskar

Two different multivariate clustering techniques, the K-means partitioning method and the Dirichlet process of mixture modeling, have been applied to the BATSE Gamma-ray burst (GRB) catalog, to obtain the optimum number of coherent groups. In the standard paradigm, GRB are classified in only two groups, the long and short bursts. However, for both the cluste

Vladimir Dzhunushaliev, Vladimir Folomeev, Kairat Myrzakulov, Ratbay Myrzakulov

We consider a thick brane model supported by two interacting scalar fields in 7D and 8D general relativity. Using the special type of a potential energy, we obtain numerically the regular asymptotically flat vacuum solutions. A possibility of obtaining the similar solutions for an arbitrary number of the extra spatial dimensions is estimated.

Hiromi Saida, Tomohiro Harada, Hideki Maeda

We calculate the quantum radiation power of black holes which are asymptotic to the Einstein-de Sitter universe at spatial and null infinities. We consider two limiting mass accretion scenarios, no accretion and significant accretion. We find that the radiation power strongly depends on not only the asymptotic condition but also the mass accretion scenario.

Marius Buliga

Here we prove that for dilatation structures linearity (see arXiv:0705.1440v1) is equivalent to a statement about the inverse semigroup generated by the family of dilatations of the space. The result is new for Carnot groups and the proof seems to be new even for vector spaces.

Z. Kuznetsova, M. Rojas, F. Toppan

We investigate supergroups with Grassmann parameters replaced by odd Clifford parameters. The connection with non-anticommutative supersymmetry is discussed. A Berezin-like calculus for odd Clifford variables is introduced. Fermionic covariant derivatives for supergroups with odd Clifford variables are derived. Applications to supersymmetric quantum mechanic

The BABAR Collaboration, B. Aubert

We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V_{cb}| and of the parameters rho^2, R_1(1), and R_2(1), which fully characterize the form factors for the B0 -> D*- l+ nu_l decay in the framework of heavy-quark effective theory. The results, based on a selected sample of about 52,800 B0 -> D*- l+ nu_l decays, recorded by th

Samy Skander Bahoura

We give blow-up analysis for a Brezis-Merle&#39;s problem on the boundary. Also we give a proof of a compactness result with Lipschitz condition and weaker assumption on the regularity of the domain (smooth domain or $ C^{2,α} $ domain).

Asan Damanik, Mirza Satriawan, Muslim, Pramudita Anggraita

We use the left-right symmetry model based on SU(2)_{L}xSU(2)_{R}xU(1)_{B-L} gauge group with two bidoublets and one doublet Higgs field for electroweak interaction. The lepton fields are represented as a doublet of SU(2)for both left and right fields. By using the pattern of symmetry breaking emerges as the minimum of the Higgs potential for a range of para

C. A. Bertulani, M. S. Hussein

We discuss the geometry of the highly quantal nuclear three-body systems composed of a core plus two loosely bound particles. These Borromean nuclei have no single bound two-body subsystem. Correlation plays a prominent role. From consideration of the $B(E1)$ value extracted from electromagnetic dissociation, in conjunction with HBT-type analysis of the two

Tadashi Wadayama

In this paper, an analysis of the undetected error probability of ensembles of binary matrices is presented. The ensemble called the Bernoulli ensemble whose members are considered as matrices generated from i.i.d. Bernoulli source is mainly considered here. The main contributions of this work are (i) derivation of the error exponent of the average undetecte

Mun Dae Kim, Sam Young Cho

We investigate two types of genuine three-qubit entanglement, known as the Greenberger-Horne-Zeilinger(GHZ) and W states, in a macroscopic quantum system. Superconducting flux qubits are considered theoretically in order to generate such states. A phase coupling is proposed to offer enough strength of interactions between qubits. While an excited state can b

Tadashi Wadayama

In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter symbol interference channels and partial response ch

D. Napoletani, T. Sauer, D. C. Struppa, E. Petricoin

The problem of reconstructing and identifying intracellular protein signaling and biochemical networks is of critical importance in biology today. We sought to develop a mathematical approach to this problem using, as a test case, one of the most well-studied and clinically important signaling networks in biology today, the epidermal growth factor receptor (

Robert Carroll

A short survey of some material related to conformal general relativity (CGR), integrable Weyl geometry, and Dirac-Weyl (DW) theory is given which suggests that CGR is essentially equivalent to DW with quantum mass equivalent to conformal mass, and various actions can be reformulated in terms of the quantum potential.

S. S. Kutateladze

A few remarks on how mathematics quests for freedom.

A. Sandoval-Villalbazo, A. L. Garcia-Perciante

The gravitational instability of a fully ionized gas is analyzed within the framework of linear irreversible thermodynamics. In particular, the presence of a heat flux corresponding to generalized thermodynamic forces is shown to affect the properties of the dispersion relation governing the stability of this kind of system in certain problems of interest.

M. O. Tahim, R. R. Landim, C. A. S. Almeida

In this letter we discuss the possibility of treating the spacetime by itself as a kind of deformable body for which we can define an fundamental lattice, just like atoms in crystal lattices. We show three signs pointing in that direction. We simulate the spacetime manifold by a very specific congruence of curves and use the Landau-Raychadhuri equation to st

Hilmar Forkel, Michael Beyer, Tobias Frederico

An approximate holographic dual of QCD is constructed and shown to reproduce the empirical linear trajectories of universal slope on which the square masses of radially and orbitally excited hadrons join. Conformal symmetry breaking and other IR effects are described exclusively by deformations of the anti-de Sitter background metric. The predictions for the

E. Mukhin, V. Tarasov, A. Varchenko

We show that the following two algebras are isomorphic. The first is the algebra $A_P$ of functions on the scheme of monic linear second-order differential operators on $\C$ with prescribed regular singular points at $z_1,..., z_n, \infty$, prescribed exponents $\La^{(1)}, ..., \La^{(n)}, \La^{(\infty)}$ at the singular points, and having the kernel consisti

S. C. Chapman, J. Penarrubia, R. Ibata, A. McConnachie

We present spectroscopic observations of the AndXII dwarf spheroidal galaxy using DEIMOS/Keck-II, showing it to be moving rapidly through the Local Group (-556 km/s heliocentric velocity, -281 km/s relative to Andromeda from the MW), falling into the Local Group from ~115 kpc beyond Andromeda&#39;s nucleus. AndXII therefore represents a dwarf galaxy plausibl

Ian A. Kash, Eric J. Friedman, Joseph Y. Halpern

We discuss the design of efficient scrip systems and develop tools for empirically analyzing them. For those interested in the empirical study of scrip systems, we demonstrate how characteristics of agents in a system can be inferred from the equilibrium distribution of money. From the perspective of a system designer, we examine the effect of the money supp

M. Baes, E. Van Hese

Both numerical simulations and observational evidence indicate that the outer regions of galaxies and dark matter haloes are typically mildly to significantly radially anisotropic. The inner regions can be significantly non-isotropic, depending on the dynamical formation and evolution processes. In an attempt to break the lack of simple dynamical models that

Artyom V. Yurov, Artyom V. Astashenok, Pedro F. Gonzalez-Diaz

Recently it was found that dark energy in the form of phantom generalized Chaplygin gas may lead to a new form of the cosmic doomsday, the big freeze singularity. Like the big rip singularity, the big freeze singularity would also take place at a finite future cosmic time, but unlike the big rip singularity it happens for a finite scale factor.Our goal is to

R. F. Sobreiro

Some nonperturbative aspects of Euclidean Yang-Mills theories in four dimensions, quantized in the Landau gauge, are analytically studied. In particular, we investigate the dynamical mass generation for the gluons due to the presence of dimension two condensates. This study is performed in the framework of the local composite operator technique in the case o

Tod R. Lauer, Scott Tremaine, Douglas Richstone, S. M. Faber

Programs to observe evolution in the Mbh-sigma or Mbh-L relations typically compare black-hole masses, Mbh, in high-redshift galaxies selected by nuclear activity to Mbh in local galaxies selected by luminosity L, or stellar velocity dispersion sigma. Because AGN luminosity is likely to depend on Mbh, selection effects are different for high-redshift and loc

Eric V. Linder

This Resource Letter provides a guide to the literature on dark energy and the accelerating universe. It is intended to be of use to researchers, teachers, and students at several levels. Journal articles, books, and websites are cited for the following topics: Einstein&#39;s cosmological constant, quintessence or dynamical scalar fields, modified cosmic gra

P. A. Price, A. Songaila, L. L. Cowie, J. Bell Burnell

We describe the properties of the host galaxy of the gamma-ray burst GRB060510B based on a spectrum of the burst afterglow obtained with the Gemini North 8m telescope. The galaxy lies at a redshift of z = 4.941 making it the fourth highest spectroscopically identified burst host. However, it is the second highest redshift galaxy for which the quality of the

D. M. Worrall, M. Birkinshaw, R. A. Laing, W. D. Cotton

We present Chandra X-ray results for the jet, nucleus, and gaseous atmosphere of NGC 315, a nearby radio galaxy whose jet kinematics are known through deep radio mapping. Diffuse X-ray synchrotron emission is detected from the jet out to 30 arcsec from the nucleus, through regions both of fast bulk flow and deceleration. The X-ray to radio flux ratio drops c

Eric j. Friedman, Joseph Y. Halpern, Ian Kash

A model of providing service in a P2P network is analyzed. It is shown that by adding a scrip system, a mechanism that admits a reasonable Nash equilibrium that reduces free riding can be obtained. The effect of varying the total amount of money (scrip) in the system on efficiency (i.e., social welfare) is analyzed, and it is shown that by maintaining the ap

C. Carignan, O. Hernandez, J. E. Beckman, K. Fathi

A new scanning Fabry-Perot system will soon be available at the Nasmyth focus of the 4,2m William Hershell Telescope (WHT). It has been designed by the Laboratoire d&#39;Astrophysique Experimentale (LAE) in Montreal and is being built in collaboration with astronomers at the Instituto de Astrofisica de Canarias (IAC). The instrument will see first light at t

Thomas H. Puzia, Bahram Mobasher, Paul Goudfrooij

We have developed an efficient photometric technique for identifying young early-type galaxy candidates using a combination of photometric redshifts, spectral-type classification, and optical/near-infrared colors. Applying our technique to the GOODS HST/ACS and VLT/ISAAC data we have selected a complete and homogeneous sample of young elliptical candidates a

Andrea Goldwurm

The centre of our galaxy hosts the nearest super-massive black hole to the solar system, identified to the compact radio source Sgr A*. High energy experiments have tried in the past to detect the X/gamma-ray emission expected from the accretion of the surrounding material into this super-massive black hole. Only recently however, thanks to the new generatio

Hari Krovi, Igor Devetak

Local pure states are an important resource for quantum computing. The problem of distilling local pure states from mixed ones can be cast in an information theoretic paradigm. The bipartite version of this problem where local purity must be distilled from an arbitrary quantum state shared between two parties, Alice and Bob, is closely related to the problem

Lei Shu, D. E. MacLaughlin, Y. Aoki, Y. Tunashima

Zero- and longitudinal-field muon spin relaxation (MuSR) experiments have been carried out in the alloy series Pr(Os1-xRux)4Sb12 and Pr1-yLayOs4Sb12 to elucidate the anomalous dynamic muon spin relaxation observed in these materials. The damping rate associated with this relaxation varies with temperature, applied magnetic field, and dopant concentrations x

Wesley Ketchum, E. Baron, David Branch

We present spectral fits to five epochs of the typical Type Ib supernova 1999dn using the generalized, non-LTE, stellar atmospheres code PHOENIX. Our goal is threefold: to determine basic physical properties of the supernova ejecta, such as velocity, temperature, and density gradients; to reproduce He I absorption lines by invoking non-thermal excitation; an

Erik D. Demaine, Francisco Gomez-Martin, Henk Meijer, David Rappaport

We demonstrate relationships between the classic Euclidean algorithm and many other fields of study, particularly in the context of music and distance geometry. Specifically, we show how the structure of the Euclidean algorithm defines a family of rhythms which encompass over forty timelines (\emph{ostinatos}) from traditional world music. We prove that thes

Yuli V. Nazarov

We review the relations between the full counting statistics and the field theory of electric circuits. We demonstrate that for large conductances the counting statistics is determined by non-trivial saddle-point of the field. Coulomb effects in this limit are presented as quantum corrections that can stongly renormalize the action at low energies.

S. Bezuglyi, J. Kwiatkowski, K. Medynets

In the paper we study aperiodic substitutional dynamical systems arisen from non-primitive substitutions. We prove that the Vershik homeomorphism $ϕ$ of a stationary ordered Bratteli diagram is homeomorphic to an aperiodic substitutional system if and only if no restriction of $ϕ$ to a minimal component is homeomorphic to an odometer. We also show that every

Alpan Raval

The number of fixed mutations accumulated in an evolving population often displays a variance that is significantly larger than the mean (the overdispersed molecular clock). By examining a generic evolutionary process on a neutral network of high-fitness genotypes, we establish a formalism for computing all cumulants of the full probability distribution of a

Rahim Moosa, Anand PIllay

A criterion is given for a type in a finite rank stable theory to be (almost) internal to a given nonmodular minimal type. The motivation comes from results of Campana which give criteria for compact complex analytic spaces to be algebraic (namely Moishezon), in terms of the existence of &#34;generating&#34; families of algebraic subvarieties. A model-theore

R. Roth, P. Navratil

We propose an importance truncation scheme for the no-core shell model, which enables converged calculations for nuclei well beyond the p-shell. It is based on an a priori measure for the importance of individual basis states constructed by means of many-body perturbation theory. Only the physically relevant states of the no-core model space are considered,

Pierre Kervella, Paulo J. V. Garcia

Preparing observing proposals is a classical exercise in an observational astronomer&#39;s life. In this paper, we summarize the general requirements to write a good proposal for the ESO telescopes, and eventually obtain telescope time. We detail in particular the different proposal types, how they are evaluated by ESO, what they should contain and what to a

Antoine Meyer

Several types of term rewriting systems can be distinguished by the way their rules overlap. In particular, we define the classes of prefix, suffix, bottom-up and top-down systems, which generalize similar classes on words. Our aim is to study the derivation relation of such systems (i.e. the reflexive and transitive closure of their rewriting relation) and,

Thomas H. Otway

A lemma from elliptic theory is used to improve a recent result by Li concerning the removability of an isolated point singularity from solutions of the coupled Yang-Mills-Dirac equations.

Konstantin Zeldovich, Peiqiu Chen, Eugene Shakhnovich

Classical population genetics a priori assigns fitness to alleles without considering molecular or functional properties of proteins that these alleles encode. Here we study population dynamics in a model where fitness can be inferred from physical properties of proteins under a physiological assumption that loss of stability of any protein encoded by an ess

Alejandra Melfo

Grand Unified Theories based on the group SO(10) generically provide interesting and testable relations between the charged fermions and neutrino sector masses and mixings. In the light of the recent neutrino data, we reexamine these relations both in supersymmetric and non-supersymmetric models, and give a brief review of their present status.

Leonid Friedlander, Michael Solomyak

We derive a two-terms asymptotics for eigenvalues of the Dirichlet Laplacian in a narrow strip of variable width. The asymptotics is taken with respect to a small paprameter that characterizes the width of the strip.

Vinicio Pelino, Filippo Maimone

We study a particular return map for a class of low dimensional chaotic models called Kolmogorov Lorenz systems, which received an elegant general Hamiltonian description and includes also the famous Lorenz63 case, from the viewpoint of energy and Casimir balance. In particular it is considered in detail a subclass of these models, precisely those obtained f

John Franks

In these lectures we consider how algebraic properties of discrete subgroups of Lie groups restrict the possible actions of those groups on surfaces. The results show a strong parallel between the possible actions of such a group on the circle $S^1$ and the measure preserving actions on surfaces. Our aim is the study of the (non)-existence of actions of latt

W. Kausch, M. Gitti, T. Erben, S. Schindler

We present a detailed analysis of the medium redshift (z=0.2906) galaxy cluster Z3146 which is part of the ongoing ARCRAIDER project, a systematic search for gravitational arcs in massive clusters of galaxies. The analysis of Z3146 is based on deep optical wide field observations in the B, V and R bands obtained with the WFI@ESO2.2m, and shallow archival WFP