July 2004 arXiv papers — page 4

M. A. Braun

Inclusive cross-sections for gluon jet production are studied numerically in the perturbative QCD pomeron model for central collisions of identical nuclei at high energies. Two forms for the inclusive cross-sections, with and without emission from the triple pomeron vertex, are compared. The difference was found to reduce to a numerical factor 0.8$÷$ 09 for

Alessandro Bacchetta, Marco Radici

Using the formalism of two-hadron fragmentation functions, we discuss single-spin asymmetries occurring in the production of two hadrons in the current region of deep inelastic scattering, with a particular emphasis on transversity measurements.

Lincoln Wolfenstein

The scattering amplitude of D Pi at the energy of the B mass can be calculated using Regge theory. Recent papers have used this to calculate the final state strong phases in the decays B to D Pi. It is argued that while the Regge amplitude can yield an absorption correction to the decay rate, it is not useful for determining the strong phase.

Ulrich Langenfeld

In my diploma thesis I calculate a lower mass bound of the lightest nutralino assuming an additional supernova cooling mechanism. I consider elektron-positron annihilation and nucleon-nucleon bremsstrahlung as cooling processes. These cooling processes must not be too effective because they would destroy the neutrino signal (SN 1987a). From this requirement

Oliver Brein

A method is presented to exploit adaptive integration algorithms using importance sampling, like VEGAS, for the task of scanning theoretical predictions depending on a multi-dimensional parameter space. Usually, a parameter scan is performed with emphasis on certain features of a theoretical prediction. Adaptive integration algorithms are well-suited to perf

Tomas Brauner, Jiri Hosek

We argue in favor of dynamical mass generation in an SU(2)xU(1) electroweak model with two complex scalar doublets with ordinary masses. The masses of leptons and quarks are generated by ultraviolet-finite non-perturbative solutions of the Schwinger-Dyson equations for full fermion propagators with self-consistently modified scalar boson exchanges. The W and

Robert Kaminski, Leonard Lesniak, Benoit Loiseau

The scalar-isoscalar, scalar-isotensor and vector-isovector pi-pi amplitudes are fitted simultaneously to experimental data and to Roy's equations. The resulting amplitudes are compared with those fitted only to experimental data. No additional constraints for the pi-pi threshold behaviour of the amplitudes are imposed. Threshold parameters are calculate

Luis Gonzalez-Mestres

Using new theoretical tools, which allow to better understand ultra-high energy (UHE) dynamics, several patterns of Lorentz symmetry violation (LSV) are studied and compared with experiment. It is claimed that quadratically deformed relativistic kinematics (QDRK), where the parameter driving LSV varies like the square of the energy scale, remains the best su

Albrecht Kyrieleis

We have performed analytically the transverse momentum integrations in the real corrections to the longitudinal γ^*_L impact factor and carried out numerically the remaining integrations. I outline the analytical integration and present the numerical results: we have performed a numerical test and computed those parts of the impact factor that depend upon th

P. Huber, M. Lindner, W. Winter

We present the GLoBES (``General Long Baseline Experiment Simulator'') software package, which allows the simulation of long-baseline and reactor neutrino oscillation experiments. One part of the software is the abstract experiment definition language to define experiments with beam and full detector descriptions as accurate as possible. Many systema

Felipe J. Llanes-Estrada, Christian S. Fischer, Reinhard Alkofer

We construct a model for the quark-gluon vertex of Landau gauge QCD. This is of twofold interest: on the one hand the quark-gluon interaction is at the heart of quark confinement, on the other hand it is a central element in hadron phenomenology based on QCD Greens functions. We employ the non-Abelian one-loop diagram in perturbation theory, which is of orde

Alakabha Datta

The three body decays $B \to D^{(*)} \bar{D}^{(*)} K_s$ may be used to measure both $\sin{2β}$ and $\cos{2β}$. Crucial to the $\cos{2β}$ measurement is the resonant contribution to the three body decay from p-wave excited $D_s$ states. If these p-wave states are the newly discovered $D_s(2317)$ and $D_s(2460)$ then they are below the $D^{(*)} K$ threshold an

N. Nimai Singh, Mrinal K. Das

We study the implications on an important result on radiative corrections (JM conjecture) which states that the solar mass scale $\bigtriangleup m^2_{21}$ corresponding to the large mixing angle (LMA) MSW solution of the solar neutrino problem, can be generated through radiative corrections in the minimal supersymmetric standard model (MSSM) if two of the ne

A. N. Sissakian, O. Yu. Shevchenko, O. N. Ivanov

The semi-inclusive deep inelastic scattering (SIDIS) process is considered. It is proposed a theoretical procedure allowing the direct extraction from the SIDIS data of the first moments of the polarized valence distributions and of the first moment difference of the light sea quark polarized distributions in the next to leading (NLO) QCD order. The validity

David Atwood, Gudrun Hiller

We investigate a class of models for new physics which could produce a large difference in sin 2 beta between B0-> J/ψK(S) and the ``pure penguin'' mode B0-> phi K(S). In such models, the dominant effect is through a Z-penguin and therefore a pattern of deviation in sin 2beta as measured in B0-> chi(1) K(S); eta(c) K(S); J/ψK(S) and psi-prime K(S) is

Costas G. Strouthos

We study the difficulties associated with detecting chiral singularities in strongly coupled lattice QCD at fixed nonzero tempearture. We show that the behavior of the chiral condensate, the pion mass and the pion decay constant, for small masses, are all consistent with the predictions of Chiral Perturbation Theory. However, the values of the quark masses t

S. Prelovsek, C. Dawson, T. Izubuchi, K. Orginos

This is an exploratory study of the lightest non-singlet scalar $q\bar q$ state on the lattice with two dynamical quarks. Domain Wall fermions are used for both sea and valence quarks on a 16^3*32 lattice with an inverse lattice spacing of 1.7 GeV. We extract the scalar meson mass 1.58(34) GeV from the exponential time-dependence of the dynamical correlators

I. Abt, A. Caldwell, X. Liu, J. Sutiak

The eRHIC facility planned for the Brookhaven National Laboratory will allow detailed studies of the strong hadronic interactions. Among the exciting research topics discussed are the pursuit of the Color Glass Condensate, the three dimensional scan of nucleons and nuclei, and the solution to the mystery of how the proton spin is built up from its constituen

Boaz Klima

Highlights of the experimental results presented at the 39th Rencontres du Moriond on ``QCD and High Energy Hadronic Interactions'', which was held in La Thuile, Italy on Mar. 28 - Apr. 4, 2004 are briefly summarised.

Wei-Tou Ni

As in other parts of physics, we advocate the interaction approach: experiments <--> phenomenology <--> low-energy effective (field) theory <--> microscopic theory to probe the microscopic origin of gravity. Using chi-g phenomenological framework, we discuss the tests of equivalence principles. The only experimentally unconstrained degree of freedom is the a

Anirudh Pradhan, Purnima Pandey

Some Bianchi type I viscous fluid cosmological models with a variable cosmological constant are investigated in which the expansion is considered only in two direction i.e. one of the Hubble parameter $(H_{1} = \frac{A_{4}}{A})$ is zero. The viscosity coefficient of bulk viscous fluid is assumed to be a power function of mass density whereas the coefficient

Peter D. Turney

This paper describes the National Research Council (NRC) Word Sense Disambiguation (WSD) system, as applied to the English Lexical Sample (ELS) task in Senseval-3. The NRC system approaches WSD as a classical supervised machine learning problem, using familiar tools such as the Weka machine learning software and Brill&#39;s rule-based part-of-speech tagger.

Nicola Olivetti, Gian Luca Pozzato, Camilla Schwind

In this paper we present a cut-free sequent calculus, called SeqS, for some standard conditional logics, namely CK, CK+ID, CK+MP and CK+MP+ID. The calculus uses labels and transition formulas and can be used to prove decidability and space complexity bounds for the respective logics. We also present CondLean, a theorem prover for these logics implementing Se

G Gordon Worley

Central to the power of open-source software is bug shallowness, the relative ease of finding and fixing bugs. The open-source movement began with Unix software, so many users were also programmers capable of finding and fixing bugs given the source code. But as the open-source movement reaches the Macintosh platform, bugs may not be shallow because few Maci

A. M. Lacasta, J. M. Sancho, A. H. Romero, I. M. Sokolov

We present a numerical and partially analytical study of classical particles obeying a Langevin equation that describes diffusion on a surface modeled by a two dimensional potential. The potential may be either periodic or random. Depending on the potential and the damping, we observe superdiffusion, large-step diffusion, diffusion, and subdiffusion. Superdi

Sangmoon Park, Yongjae Lee, Thomas Vogt

The structure of a new member of the AxCoO2 x nH2O family (A=Li,Na,K) was determined by high-resolution synchrotron X-ray powder diffraction. Layered lithium cobalt oxide hydrate LixCoO2 x 2H2O crystallizes in a disordered monoclinic structure (space group C2/m) with lattice parameters a = 4.8915(2) A, b = 2.8239(1) A, c = 10.7033(9) A, beta = 112.386(4)deg.

A. M. M. Pruisken, I. S. Burmistrov

It has recently been pointed out that the existence of massless chiral edge excitations has important strong coupling consequences for the topological concept of an instanton vacuum. In the first part of this paper we elaborate on the effective action for ``edge excitations&#39;&#39; in the Grassmannian $U(m+n)/U(m) \times U(n)$ non-linear sigma model in the

Vasudeva Siruguri, S. K. Paranjpe, P. Raj, A. Sathyamoorthy

Uranium manganese germanide, UMn2Ge2, crystallizes in body-centered tetragonal ThCr2Si2 structure with space group I4/mmm, a = 3.993A and c = 10.809A under ambient conditions. Energy dispersive X-ray diffraction was used to study the compression behaviour of UMn2Ge2 in a diamond anvil cell. The sample was studied up to static pressure of 26 GPa and a reversi

J. B. Staunton, S. Ostanin, S. S. A. Razee, B. L. Gyorffy

On the basis of a first-principles, relativistic electronic structure theory of finite temperature metallic magnetism, we investigate the variation of magnetic anisotropy, K, with magnetisation, M, in metallic ferromagnets. We apply the theory to the high magnetic anisotropy material, L1_0-ordered FePt, and find its uniaxial K consistent with a magnetic easy

Przemyslaw Repetowicz, Stefan Hutzler, Peter Richmond

We study the model of interacting agents proposed by Chatterjee et al that allows agents to both save and exchange wealth. Closed equations for the wealth distribution are developed using a mean field approximation. We show that when all agents have the same fixed savings propensity, subject to certain well defined approximations defined in the text, these e

Gilles Zumbach

This paper investigates the scaling dependencies between measures of &#34;activity&#34; and of &#34;size&#34; for companies included in the FTSE 100. The &#34;size&#34; of companies is measured by the total market capitalization. The &#34;activity&#34; is measured with several quantities related to trades (transaction value per trade, transaction value per h

M. Ya. Ovchinnikova

The mean-field study of the stripe phases of t-t&#39;-U Hubbard model confirms formation of the &#34;impurity&#34; subbands of states localized on domain walls. For bond-aligned stripes it is shown that segments of the Fermi surfaces (FS) in antinodal and nodal directions correspond to the &#34;impurity&#34; band or to that delocalized over a whole antiferro

O. Ujsaghy, A. Zawadowski

Following the discovery of the Kondo effect the bulk transport and magnetic behavior of the dilute magnetic alloys have been successfully described. In the last fifteen years new directions have been developed as the study of the systems of reduced dimensions and the artificial atoms so called quantum dots. In this review the first subject is reviewed starti

Vera B. Henriques, Marcia C Barbosa

We present a simple model for an associating liquid in which polymorphism and density anomaly are connected. Our model combines a two dimensional lattice gas with particles interacting through a soft core potential and orientational degrees of freedom represented through thermal \char`\&#34;{}ice variables\char`\&#34;{} . The competition between the directio

V. Z. Cerovski, M. Schreiber, U. Grimm

Spectral properties and anomalous diffusion in the silver-mean (octonacci) quasicrystals in d=1,2,3 are investigated using numerical simulations of the return probability C(t) and the width of the wave packet w(t) for various values of the hopping strength v. In all dimensions we find C(t)\sim t^{-δ}, with results suggesting a crossover from δ<1 to δ=1 when

E. B. Araujo, C. A. Guarany, K. Yukimitu, J. C. S. Moraes

The purpose of the present work is to report studies on structural phase transition for PMN-xPT single crystal, with melt PbTiO3 composition around the MPB (x = 0.35 mol %), using infrared spectroscopy technique. The study was centered on monitoring the behavior of the stretching-(Nb-O), stretching-(Ti-O) and stretching-(Mg-O) stretching modes as a function

Martin Wackenhut, Sean McNamara, Hans Herrmann

We study the shearing of polydisperse and bidisperse media with a size ratio of 10. Simulations are performed with a the two dimensional shear cell using contact dynamics. With a truncated power law for the polydisperse media we find that they show a stronger dilatancy and greater resistance to shearing than bidisperse mixtures. Motivated by the practical pr

I. Brovchenko, A. Geiger, A. Oleinikova

The phase behavior of fluids near weakly attractive substrates is studied by computer simulations of the coexistence curve of a Lennard-Jones (LJ) fluid confined in a slitlike pore. The temperature dependence of the density profiles of the LJ fluid is found to be very similar to the behavior of water near hydrophobic surfaces (Brovchenko et al. J.Phys.: Cond

Xing-Qiu Chen, Shu-Lan Wang, Xue-Yong Ding, Xiang-Xun Xue

Based on density functional calculations, the relationship between magnetism or superconductivity and electronic states around Fermi level were derived, and the location of the Fermi level in nonmagnetic &#34;form&#34; of Laves-phase compounds is very sensitive to determine the presence of nonmagnetism, or ferromagnetism, or antiferromagnetism, or supercondu

Matteo Beccaria, Gian Fabrizio De Angelis

We study a model of strongly correlated fermions in one dimension with extended N=2 supersymmetry. The model is related to the spin $S=1/2$ XXZ Heisenberg chain at anisotropy $Δ=-1/2$ with a real magnetic field on the boundary. We exploit the combinatorial properties of the ground state to determine its exact wave function on finite lattices with up to 30 si

Mayeul d&#39;Avezac, Matteo Calandra, Francesco Mauri

We present a self-interaction-corrected (SIC) density-functional-theory (DFT) approach for the description of systems with an unpaired electron or hole such as spin 1/2 defect-centers in solids or radicals. Our functional is easy-to-implement and its minimization does not require additional computational effort with respect to ordinary DFT functionals. In pa

Alexander Bühler, Götz S. Uhrig, Jaan Oitmaa

A high order series expansion is employed to study the thermodynamical properties of a S=1/2 chain coupled to dispersionless phonons. The results are obtained without truncating the phonon subspace since the series expansion is performed formally in the overall exchange coupling J. The results are used to investigate various parameter regimes, e.g. the adiab

Kazuo Hida

Low energy properties of the S=1/2 antiferromagnetic Heisenberg chains with Fibonacci exchange modulation are studied using the real space renormalization group method for strong exchange modulation. It is found that the ground state of this model belongs to a new universality class with logarithmically divergent dynamical exponent which is neither like Fibo

D. F. Agterberg

This paper has been withdrawn due to the heavy reliance on the fraudulent experiments of Schoen. Note that part of the paper has been published in D.F. Agterberg, Physica C 387, 13 (2003).

Motoyuki Saijo

We investigate the gravitational collapse of rapidly rotating relativistic supermassive stars by means of a 3+1 hydrodynamical simulations in conformally flat spacetime of general relativity. We study the evolution of differentially rotating supermassive stars of $q \equiv J/M^{2} \sim 1$ ($J$ is the angular momentum and $M$ is the gravitational mass of the

Sean N. Raymond, Thomas Quinn, Jonathan I. Lunine

`Hot jupiters,&#39; giant planets with orbits very close to their parent stars, are thought to form farther away and migrate inward via interactions with a massive gas disk. If a giant planet forms and migrates quickly, the planetesimal population has time to re-generate in the lifetime of the disk and terrestrial planets may form (Armitage 2003). We present

S. Boissier, A. Boselli, V. Buat, J. Donas

We have used UV (FOCA) and FIR (IRAS) images of six nearby late type galaxies to study the radial variation of the UV extinction (deduced from the FIR/UV ratio). We compare the UV extinction gradient with other extinction indicators (Balmer decrement) and search for a relation between the extinction, the metallicity and the gas surface density among our gala

S. Falter, H. -J. Roeser, H. Hippelein, E. Bell

As a step towards our understanding of galaxy evolution and for testing predictions of cosmological models we started a survey for galaxy clusters intending to identify candidates out to redshifts of ~1.5: HIROCS (= Heidelberg InfraRed/Optical Cluster Survey) is a multi-color survey (B, R, i, z and H) covering 11 square degrees in four fields on the sky. Our

Daniel Fabrycky

Positions of High-Mass X-ray Binaries are often known precisely enough to unambiguously identify the optical component, and a number of those stars are monitored by the OGLE and MACHO collaborations. The light curves of two such candidates are examined for evidence of Be star behavior and for periodicity. One of the stars exhibits two periods of 6.833 and 15

B. Gendre, L. Piro, M. De Pasquale

We present the XMM-Newton observation of GRB 040106. From the X-ray spectral index and temporal decay, we argue that the afterglow is consistent with a fireball expanding in a wind environment. A constant density environment is excluded by the data. This is one of the very few cases in which this conclusion can be drawn.

S. S. Larsen, T. Richtler

Using new data from the UVES spectrograph on the ESO Very Large Telescope and archive images from the Hubble Space Telescope, we have measured projected velocity dispersions and structural parameters for two bright young star clusters in the nearby spiral galaxy NGC 5236. One cluster is located near the nuclear starburst of NGC 5236, at a projected distance

Daisuke Iono, Min S. Yun, J. Christopher Mihos

(abridged) We investigate the detailed response of gas to the formation of transient and long-lived dynamical structures induced in the early stages of a disk-disk collision, and identify observational signatures of radial gas inflow through a detailed examination of the collision simulation of an equal mass bulge dominated galaxy. Stars respond to the tidal

L. K. Haikala, J. Harju, K Mattila, M Toriseva

The Chamaeleon I dark cloud (Cha I} has been mapped in C18O J=1-0 with an angular resolution of 1 arcmin using the SEST telescope. The large scale structures previously observed with lower spatial resolution in the cloud turn into a network of clumpy filaments. The automatic Clumpfind routine developed by Williams et al. 1994 is used to identify individual c

Olivier Godet, Suzy Collin, Anne-Marie Dumont

In a previous article, with a new code designed for a photoionized thick hot medium using a full transfer treatment of both lines and continuum, we have studied the He-like emission of a medium photoionized by an X-ray source. We considered the influence of density, ionization parameter and column density. We stressed that photoionized media are not uniform

Chien-Jen Tang, Wei-Tou Ni

Due to the high-precision nature of the ASTROD (Astrodynamical Space Test of Relativity using Optical Devices) mission concept, the asteroid perturbations on the ASTROD spacecraft is crucial. These perturbations need to be modelled and determined together with relativistic effects and other solar-system parameters. In a previous investigation (Su et al., Pla

Sandro Villanova, Giovanni Carraro, Raul de la Fuente Marcos, Ruggero Stagni

We present CCD UBVI photometric and medium/high resolution spectroscopic observations obtained in the field of the previously unstudied dissolving open cluster candidates NGC 5385, NGC 2664 and Collinder~21. Our analysis stands on the discussion of star counts, photometry, radial velocity distribution, and proper motions available from the Tycho~2 catalogue.

Carl L. Gardner

The implications of seven popular models of quintessence based on supergravity or M/string theory for the transition from a decelerating to an accelerating universe are explored. All seven potentials can mimic the LambdaCDM model at low redshifts 0 < z < 5. However, for a natural range of initial values of the quintessence field, the SUGRA and Polonyi potent

Luis Gonzalez-Mestres

Non-tachyonic superluminal sectors of matter (superbradyons), with critical speeds in vacuum much larger than the speed of light, can quite naturally exist and play an important role in both cosmic-ray physics (anomalous high-energy events) and cosmology (big-bang physics, alternatives to inflation, dark matter...). They can even be the real &#34;elementary&

D. M. Neumann, S. Majerowicz

Clusters of galaxies contain a hot gas, which emits in X-rays. X-ray telescopes such as XMM-Newton allow to study this plasma to obtain information on physical quantities of these objects. We present here some results on the total mass density distribution of clusters obtained with XMM-Newton based on the hydrostatic approach. These results can be compared t

Takashi Hamana, Matthias Bartelmann, Naoki Yoshida, Christoph Pfrommer

We investigate statistical distributions of differences in gravitational-lensing deflections between two light rays, the so-called lensing excursion angles. A probability distribution function of the lensing excursion angles, which plays a key role in estimates of lensing effects on angular clustering of objects (such as galaxies, QSOs and also the CMB tempe

Axel Brandenburg, Christer Sandin, Petri J. Käpylä

The standard theory of the solar cycle in terms of an alpha-Omega dynamo hinges on a proper understanding of the nonlinear alpha effect. Boundary conditions play a surprisingly important role in determining the magnitude of alpha. For closed boundaries, the total magnetic helicity is conserved, and since the alpha effect produces magnetic helicity of one sig

Hideki Asada, Taketoshi Kasai, Masumi Kasai

The Euclidean algorithm in algebra is applied to a class of gravitational lenses for which the lens equation consists of any set of coupled polynomial equations in the image position. In general, this algorithm allows us to reduce an apparently coupled system to a single polynomial in one variable (say $x$ in Cartesian coordinates) without the other componen

Yutaka Fujita, Craig L. Sarazin, Thomas H. Reiprich, H. Andernach

We use XMM-Newton observations of the cluster of galaxies A133 to study the X-ray spectrum of the intracluster medium (ICM). We find a cold front to the southeast of the cluster core. From the pressure profile near the cold front, we derive an upper limit to the velocity of the core relative to the rest of the cluster of <230 km s^-1. Our previous Chandra im

F. Camilo, B. M. Gaensler, E. V. Gotthelf, J. P. Halpern

We report on a 19 ks observation of the pulsar J1016-5857 with the Chandra X-ray Observatory. This &#34;Vela-like&#34; pulsar has rotation period 107 ms, characteristic age 21 kyr, and spin-down power 2.6e36 ergs/s. A relatively bright centrally peaked source of radius ~25&#34; around the radio pulsar position has a spectrum that is well fitted by an absorbe

Axel Brandenburg, Christer Sandin

A new simulation set-up is proposed for studying mean field dynamo action. The model combines the computational advantages of local cartesian geometry with the ability to include a shear profile that resembles the sun&#39;s differential rotation at low latitudes. It is shown that in a two-dimensional mean field model this geometry produces cyclic solutions w

Robert B. Ellis, Vadim Ponomarenko, Catherine H. Yan

The $q$-round Renyi-Ulam pathological liar game with $k$ lies on the set $[n]:=\{1,...,n\}$ is a 2-player perfect information zero sum game. In each round Paul chooses a subset $A\subseteq [n]$ and Carole either assigns 1 lie to each element of $A$ or to each element of $[n]\setminus A$. Paul wins if after $q$ rounds there is at least one element with $k$ or

Gorazd Cvetic, Igor Kondrashuk, Ivan Schmidt

Based on general considerations such as $R$-operation and Slavnov-Taylor identity we show that the effective action, being understood as Legendre transform of the logarithm of the path integral, possesses particular structure in ${\cal N} =4$ supersymmetric Yang--Mills theory for kernels of the effective action expressed in terms of the dressed effective fie

Tomohiro Harada

Gravitational collapse is one of the most striking phenomena in gravitational physics. The cosmic censorship conjecture has provided strong motivation for researches in this field. In the absence of general proof for the censorship, many examples have been proposed, in which naked singularity is the outcome of gravitational collapse. Recent development has r

Shung-ichi Ando, Chang Ho Hyun

Pionless effective field theory with dibaryon fields is reexamined for observables involving the deuteron. The electromagnetic form factors of the deuteron and the total cross sections of radiative neutron capture on the proton, $np \to dγ$, are calculated. The low energy constants of vector(photon)-dibaryon-dibaryon vertices in the effective lagrangian are

Nikhil Padmanabhan, Tamas Budavari, David J. Schlegel, Terry Bridges

We discuss the construction of a photometric redshift catalogue of Luminous Red Galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS), emphasizing the principal steps necessary for constructing such a catalogue -- (i) photometrically selecting the sample, (ii) measuring photometric redshifts and their error distributions, (iii) and estimating the true red

Andrea Passamonti, Marco Bruni, Leonardo Gualtieri, Carlos F. Sopuerta

Linear perturbation theory is appropriate to describe small oscillations of stars, while a mild non-linearity is still tractable perturbatively but requires to consider mode coupling. It is natural to start to look at this problem by considering the coupling between linear radial and non-radial modes. Radial pulsations of a spherical compact objects do not p

Nadia Benbernou, Patricia Cahn, Joseph O&#39;Rourke

We define a notion for unfolding smooth, ruled surfaces, and prove that every smooth prismatoid (the convex hull of two smooth curves lying in parallel planes), has a nonoverlapping &#34;volcano unfolding.&#34; These unfoldings keep the base intact, unfold the sides outward, splayed around the base, and attach the top to the tip of some side rib. Our result

Antonio Masiero, Sudhir K. Vempati, Oscar Vives

In spite of the large lepton flavour violation (LFV) observed in neutrino oscillations, within the Standard Model, we do \textit{not} expect any visible LFV in the charged lepton sector ($μ\to e, γ$, $τ\to μ, γ$, etc.). On the contrary, the presence of new physics close to the electroweak scale can enhance the amplitudes of these processes. We discuss this i

Simon P Morgan

An ODE variational calculation shows that an image principle curvature ratio factor can raise the lower bound, 2(Image Area), on energy of a harmonic map of a surface into Rn. In certain situations, including all radially symmetry harmonic maps, equality is achieved.

Michael Usher

Continuing the program of math.SG/0012067 and math.SG/0310450, we introduce refinements of the Donaldson-Smith standard surface count which are designed to count nodal pseudoholomorphic curves and curves with a prescribed decomposition into reducible components. In cases where a corresponding analogue of the Gromov-Taubes invariant is easy to define, our inv

R. J. Fries, S. A. Bass, B. Muller

We discuss different sources of hadron correlations in relativistic heavy ion collisions. We show that correlations among partons in a quasi-thermal medium can lead to the correlated emission of hadrons by quark recombination and argue that this mechanism offers a plausible explanation for the dihadron correlations in the few GeV/c momentum range observed in

Allen Lee, Ha Youn Lee, Mehran Kardar

Locomotion of bacteria by actin polymerization, and in vitro motion of spherical beads coated with a protein catalyzing polymerization, are examples of active motility. Starting from a simple model of forces locally normal to the surface of a bead, we construct a phenomenological equation for its motion. The singularities at a continuous transition between m

Paul Butterley, Anthony Sudbery, Jason Szulc

We examine the possible states of subsystems of a system of bits or qubits. In the classical case (bits), this means the possible marginal distributions of a probability distribution on a finite number of binary variables; we give necessary and sufficient conditions for a set of probability distributions on all proper subsets of the variables to be the margi

Fernando Etayo, Rafael Santamar\{&#39;ı}a, Sergiu I. Vacaru

We outline an unified approach to geometrization of Lagrange mechanics, Finsler geometry and geometric methods of constructing exact solutions with generic off-diagonal terms and nonholonomic variables in gravity theories. Such geometries with induced almost symplectic structure are modelled on nonholonomic manifolds provided with nonintegrable distributions

Dean Lee

We prove several inequalities using lowest-order effective field theory for nucleons which give an upper bound on the pressure of asymmetric nuclear matter and neutron matter. We prove two types of inequalities, one based on convexity and another derived from shifting an auxiliary field.

Sandeep Tyagi

A method to sum over logarithmic potential in 2D and Coulomb potential in 3D with periodic boundary conditions in all directions is given. We consider the most general form of unit cells, the rhombic cell in 2D and the triclinic cell in 3D. For the 3D case, this paper presents a generalization of Sperb&#39;s work [R. Sperb, Mol. Simulation, \textbf{22}, 199-

Yan Chen, Paolo Zanardi, Z. D. Wang, F. C. Zhang

Entanglement of the ground states in $XXZ$ and dimerized Heisenberg spin chains as well as in a two-leg spin ladder is analyzed by using the spin-spin concurrence and the entanglement entropy between a selected sublattice of spins and the rest of the system. In particular, we reveal that quantum phase transition points/boundaries may be identified based on t

Eugen Radu, Elizabeth Winstanley

We investigate static axially symmetric black hole solutions in a four-dimensional Einstein-Yang-Mills-SU(2) theory with a negative cosmological constant $Λ$. These solutions approach asymptotically the anti-de Sitter spacetime and possess a regular event horizon. A discussion of the main properties of the solutions and the differences with respect to the as

A. Babic, B. Guberina, R. Horvat, H. Stefancic

For cosmologies including scale dependence of both the cosmological and the gravitational constant, an additional consistency condition dictated by the Bianchi identities emerges, even if the energy-momentum tensor of ordinary matter stays individually conserved. For renormalization-group (RG) approaches it is shown that such a consistency relation ineluctab

Brendan Guilfoyle

It is proven that, under mild physical assumptions, an isolated stationary relativistic perfect fluid consists of a finite number of cells fibred by invariant annuli or invariant tori. For axially symmetric circular flows it is shown that the fluid consists of cells fibred by rigidly rotating annuli or tori.

Kayll Lake

The standard energy conditions of classical general relativity are applied to FLRW cosmologies containing sudden future singularities. Here we show, in a model independent way, that although such cosmologies can satisfy the null, weak and strong energy conditions, they always fail to satisfy the dominant energy condition. They require a divergent spacelike e

F. Gulminelli, Ph. Chomaz, M. D&#39;Agostino

Partial energy fluctuations are known tools to reconstruct microcanonical heat capacities. For experimental applications, approximations have been developed to infer fluctuations at freeze out from the observed fragment partitions. The accuracy of this procedure as well as the underlying independent fragment approximation is under debate already at the level

Heike Mildenberger, Saharon Shelah, Boaz Tsaban

It is consistent (relative to ZFC) that the union of max{b,g} many families in the Baire space which are not finitely dominating is not dominating. In particular, it is consistent that for each nonprincipal ultrafilter U, the cofinality of the reduced ultrapower w^w/U is greater than max{b,g}. The model is constructed by oracle chain condition forcing, to wh

Jiri Bajer, Adam Miranowicz, Mateusz Andrzejewski

Evolutions of quantum noise, characterized by quadrature squeezing parameter and Fano factor, and of mixedness, quantified by quantum von Neumann and linear entropies, of a pumped dissipative non-linear oscillator are studied. The model can describe a signal mode interacting with a thermal reservoir in a parametrically pumped cavity with a Kerr non-linearity

Luca Amendola, Maurizio Gasperini, Federico Piazza

We discuss the possible consistency of the recently discovered Type Ia supernovae at z>1 with models in which dark energy is strongly coupled to a significant fraction of dark matter, and in which an (asymptotic) accelerated phase exists where dark matter and dark energy scale in the same way. Such a coupling has been suggested for a possible solution of the

G. D&#39;Ambrosio, T. Hambye, A. Hektor, M. Raidal

In the supersymmetric triplet (type-II) seesaw model, in which a single SU(2)_L-triplet couples to leptons, the high-energy neutrino flavour structure can be directly determined from the low-energy neutrino data. We show that even with such a minimal triplet content, leptogenesis can be naturally accommodated thanks to the resonant interference between super

Nikolaos I. Katzourakis

We show that every analytic semi-Riemannian manifold can be isometrically embeddded into an Einstein maifold in co-dimension one.

J. Lukierski, P. C. Stichel, W. J. Zakrzewski

We describe a N=2 supersymmetric extension of the nonrelativistic (2+1)-dimensional model describing particles on the noncommutative plane with scalar (electric) and vector (magnetic) interactions. First, we employ the N=2 superfield technique and show that in the presence of a scalar N=2 superpotential the magnetic interaction is implied by the presence of

Miguel A. Sanchis-Lozano

A non-standard light CP-odd Higgs boson could induce a slight (but observable) lepton universality breakdown in Upsilon leptonic decays. Moreover, the mixing between such a pseudoscalar Higgs and $η_b$ states might shift the mass levels of the latter, thereby changing the values of the $m_{Υ(nS)}-m_{η_b(nS)}$ splittings predicted in the standard model. Besid

Koji Nagata, Wieslaw Laskowski, Marcin Wiesniak, Marek Zukowski

Rotational invariance of physical laws is a generally accepted principle. We show that it leads to an additional external constraint on local realistic models of physical phenomena involving measurements of multiparticle spin 1/2 correlations. This new constraint rules out such models even in some situations in which standard Bell inequalities allow for expl

R. S. Ward

This paper describes a natural one-parameter family of generalized Skyrme systems, which includes the usual SU(2) Skyrme model and the Skyrme-Faddeev system. Ordinary Skyrmions resemble polyhedral shells, whereas the Hopf-type solutions of the Skyrme-Faddeev model look like closed loops, possibly linked or knotted. By looking at the minimal-energy solutions

Dimitrios Tsimpis

We examine the theta-expansion of the eleven-dimensional supervielbein. We outline a systematic procedure which can be iterated to any order. We give explicit expressions for the vielbein and three-form potential components up to order ${\cal O}(þ^5)$. Furthermore we show that at each order in the number of supergravity fields, in a perturbative expansion ar

V. Peano, M. Thorwart

We investigate the nonlinear response of a vibrating suspended nanomechanical beam on external periodic driving. The amplitude of the fundamental transverse mode behaves thereby like a weakly damped quantum particle in a driven anharmonic potential. Upon using a Born-Markovian master equation, we calculate the fundamental mode amplitude for varying driving f

Y. G. Zhao, Y. H. Wang, G. M. Zhang, B. Zhang

We report a giant resistance drop induced by dc electrical currents in La0.67Ca0.33MnO3 epitaxial thin films. Resistance of the patterned thin films decreases exponentially with increasing current and a maximum drop shows at the temperature of resistance peak Tp. Variation of resistance with current densities can be scaled below and above Tp, respectively. T

Noriaki Ikeda, K. -I. Izawa

We investigate an extension of 2D nonlinear gauge theory from the Poisson sigma model based on Lie algebroid to a model with additional two-form gauge fields. Dimensional reduction of 3D nonlinear gauge theory yields an example of such a model, which provides a realization of Courant algebroid by 2D nonlinear gauge theory. We see that the reduction of the ba