June 2005 arXiv papers — page 2

B. Altschul, Don Colladay

We consider the role of the velocity in Lorentz-violating fermionic quantum theory, especially emphasizing the nonrelativistic regime. Information about the velocity will be important for the kinematical analysis of scattering and other problems. Working within the minimal standard model extension, we derive new expressions for the velocity. We find that gen

Frank Daniel Steffen

The axino and the gravitino are extremely weakly interacting candidates for the lightest supersymmetric particle (LSP). We demonstrate that either of them could provide the right amount of cold dark matter. Assuming that a charged slepton is the next-to-lightest supersymmetric particle (NLSP), we discuss how NLSP decays into the axino/gravitino LSP can provi

A. Birkedal, R. C. Group, K. Matchev

We first discuss the motivation for measuring slepton masses at the LHC, emphasizing their importance for cosmology. Next we investigate the possibility of making slepton mass determinations at the LHC in neutralino decays. We demonstrate that by studying the shape of the dilepton invariant mass distribution in the decay neutralino_2 -> neutralino_1 + l^+ +

Vincenzo Cirigliano, Benjamin Grinstein, Gino Isidori, Mark B. Wise

We extend the notion of Minimal Flavor Violation to the lepton sector. We introduce a symmetry principle which allows us to express lepton flavor violation in the charged lepton sector in terms of neutrino masses and mixing angles. We explore the dependence of the rates for flavor changing radiative charged lepton decays (ell(i) -> ell(j) + gamma) and mu-to-

Gustavo Burdman, Bogdan A. Dobrescu, Eduardo Ponton

We construct gauge theories in two extra dimensions compactified on the chiral square, which is a simple compactification that leads to chiral fermions in four dimensions. Stationarity of the action on the boundary specifies the boundary conditions for gauge fields. Any six-dimensional gauge field decomposed in Kaluza-Klein modes includes a tower of heavy sp

O. Linnyk, S. Leupold, U. Mosel

We predict the triple differential cross section of the unpolarized Drell-Yan process at sqrt(S)=6 GeV. The model incorporates primordial parton transverse momentum and quark off-shellness effects caused by the initial state interaction.

G. Pancheri, O. Shekhovtsova, G. Venanzoni

In this paper we consider the possibility to test the FSR model in the reaction $e^+e^-\toπ^+π^-γ$ at DA$Φ$NE. We propose to consider the low $Q^2$ region ($Q^2$ is the invariant mass squared of the di-pion system) to study the different models describing $gamma^*\toπ^+π^-γ$ interaction. As illustration we compare the scalar QED and Resonance Perturbation Th

G. Peter Lepage

"Preprint" of paper from 1989 that wasn't arxiv'ed at the time. Abstract: Our understanding of quantum field theories, and, in particular, of renomalization has changed radically in recent years; renormalization is no longer a deeply mysterious procedure for hiding embarrassing infinities. This talk is a non-technical presentation of modern a

K. Kovarik, W. Oeller, C. Weber

Recent high precision calculations for production processes of the SUSY particles at the next linear collider are reviewed. Special attention is paid to the input parameter definition. Numerical results for the SPS1a' benchmark point as proposed in the SPA project, are presented.

Jörg Ruppert

The wake induced in a hot QCD medium by a high momentum parton (jet precursor) is calculated in the framework of linear response theory. Two different scenarios are discussed: a weakly coupled quark gluon plasma (pQGP) as described by hard-thermal loop (HTL) perturbation theory and a strongly cupled QGP (sQGP) with the properties of a quantum liquid. In the

A. Daleo, D. de Florian, R. Sassot

We compute the order alpha_s^2 corrections to the one particle inclusive electroproduction cross section of hadrons with non vanishing transverse momentum. We compare our results with H1 data on forward production of pi^0, and conclude that the data is well described by the DGLAP approach. within the theoretical uncertainties.

D. de Florian, G. A. Navarro, R. Sassot

We present results on the quark and gluon polarization in the nucleon obtained in a combined next to leading order analysis to the available inclusive and semi-inclusive polarized deep inelastic scattering data.

P. Artoisenet, J. -M. Gerard, J. Weyers

We extend the simple scenario for $Ψ'$ decays suggested a few years ago. The $c\bar c$ pair in the $Ψ'$ does not annihilate directly into three gluons but rather survives before annihilating. An interesting prediction is that a large fraction of all $Ψ'$ decays could originate from the $Ψ' \to η_{c} (3π)$ channel which we urge experimentalist

A. P. Martynenko

In the framework based on the quasipotential method and relativistic quark model a new covariant expression for the heavy quark fragmentation amplitude to fragment into the pseudoscalar and vector S-wave heavy mesons is obtained. It contains all possible relativistic corrections including the terms connected with the transformation law of the bound state wav

H. Burkhardt, B. Pietrzyk

Recent improvements in the low energy e+e- annihilation data and their influence on the determination of the hadronic contribution to the running of the QED fine structure constant at m_Z are discussed. Using CMD-2 and KLOE measurements in the rho region we obtain Delta alpha(5)_had(s) = 0.02758 +/- 0.00035 at s = m_Z^2.

L. Bravina, K. Tywoniuk, E. Zabrodin

The production and freeze-out conditions of strange particles, produced in Au+Au collisions at RHIC energies, are studied within microscopic transport model. The system of final particles can be represented as a core, containing the particles which are still interacting with each other, and a halo, in which the particles have already decoupled from the syste

Nicolas Cosme, Laura Lopez Honorez, Michel H. G. Tytgat

We investigate the possibility that dark matter and the baryon asymmetry of the Universe are generated by the same mechanism, following an idea initially proposed by V.A. Kuzmin and recently discussed by R. Kitano and I. Low. In our model, based on a left-right extension of the Standard Model, the baryon asymmetry is generated through leptogenesis and dark m

P. Giovannangeli

The goal of this paper is two-fold. The first aim is to present a detailed version of the computation of the two-loop renormalization of the magnetic coupling in hot QCD. The second is to compare with lattice simulations the string tension of a spatial Wilson loop using the result of our two-loop computation

A. Mukherjee, M. Stratmann, W. Vogelsang

We present a calculation of the next-to-leading order QCD corrections to the partonic cross sections contributing to single-inclusive high-p_T hadron production in collisions of transversely polarized hadrons. We use a recently developed projection technique for treating the phase space integrals in the presence of the cos(2Phi) azimuthal-angular dependence

G. Peter Lepage

This is the "preprint" for a paper that came out in 1998 but for some reason wasn't posted then. Abstract:These lectures are for novices to lattice QCD. They introduce a set of simple ideas and numerical techniques that can be implemented in a short period of time and that are capabable of generating nontrivial, nonperturbative results from latti

Yasha Shnir

The Zirnbauer's color-flavor transformation is applied to the $U(N_c)$ lattice gauge model, in which the gauge theory is induced by a heavy chiral scalar field sitting on lattice sites. The flavor degrees of freedom can encompass several `generations' of the auxiliary field, and for each generation, remaining indices are associated with the elementar

Asit K. De, Tilak Sinha

We have verified various proposals that were suggested in our last paper concerning the continuum limit of a compact formulation of the lattice U(1) pure gauge theory in 4 dimensions using a nonperturbative gauge-fixed regularization. Our study reveals that most of the speculations are largely correct. We find clear evidence of a continuous phase transition

Masahiro Imachi, Yasuhiko Shinno, Hiroshi Yoneyama

We study the sign problem in lattice field theory with a $θ$ term. We apply the maximum entropy method (MEM) to flattening phenomenon of the free energy density $f(θ)$, which originates from the sign problem. In our previous paper, we applied the MEM by employing the Gaussian topological charge distribution $P(Q)$ as mock data. In the present paper, we consi

Christiane Risler

We report on the observation of a narrow resonance in D^{*-}p and D^{*+} pbar invariant mass combinations in deep-inelastic ep scattering at centre-of-mass energies of 300 and 320 GeV at HERA. The mass of the resonance is measured to be 3099 +- 3 (stat.) +- 5 (syst.) MeV, the Gaussian width of 12 +- 3 (stat.) MeV is compatible with the experimental resolutio

M. N. Achasov, K. I. Beloborodov, A. V. Berdyugin, A. G. Bogdanchikov

The cross section of the process e^+e^-\to π^+π^- was measured in the SND experiment at the VEPP-2M collider in the energy region 400<\sqrt[]{s}<1000 MeV. This measurement was based on about 12.4 \times 10^6 selected collinear events, which include 7.4\times 10^6 e^+e^-\to e^+e^-, 4.5\times 10^6 e^+e^-\toπ^+π^- and 0.5\times 10^6 e^+e^-\toμ^+μ^- selected eve

The Pioneer Explorer Collaboration, H. Dittus, S. G. Turyshev, C. Lämmerzahl

The Pioneer 10 and 11 spacecraft yielded the most precise navigation in deep space to date. These spacecraft had exceptional acceleration sensitivity. However, analysis of their radio-metric tracking data has consistently indicated that at heliocentric distances of $\sim 20-70$ astronomical units, the orbit determinations indicated the presence of a small, a

Ding-fang Zeng, Hai-jun Zhao

In 1+1 dimensional case, Einstein equation cannot give us any information on the evolution of the universe because the Einstein tensor of the system is identically zero. We study such a 1+1 dimensional cosmology and find the metric of it according to cosmological principle and special relativity, but the results contradict the usual expression of cosmologica

Ren-Chiun Wang, Chou-Chen Yang, Kun-Ru Mo

Some protected password change protocols were proposed. However, the previous protocols were easily vulnerable to several attacks such as denial of service, password guessing, stolen-verifier and impersonation atacks etc. Recently, Chang et al. proposed a simple authenticated key agreement and protected password change protocol for enhancing the security and

Z. Lonc, M. Truszczynski

We propose and study algorithms to compute minimal models, stable models and answer sets of t-CNF theories, and normal and disjunctive t-programs. We are especially interested in algorithms with non-trivial worst-case performance bounds. The bulk of the paper is concerned with the classes of 2- and 3-CNF theories, and normal and disjunctive 2- and 3-programs

Tobias Herman, John Beamish

Fluid phase transitions in porous media are a powerful probe of the effect of confinement and disorder on phase transitions. Aerogel may provide a model system in which to study the effect of dilute impurities on a variety of phase transitions. In this paper we present a series of low frequency acoustic experiments on the effect of aerogel on the liquid-vapo

V. M. Apalkov, Tapash Chakraborty, C. Schuller

We report on our investigation of the low-lying energy spectra and charge density of a two-dimensional quantum Hall liquid at $ν=\frac25$ that is Coulomb coupled to a quantum dot. The dot contains a hole and two/three electrons. We found that any external perturbation (caused by the close proximity of the quantum dot) locally changes the spin polarization of

Jorge Viamontes, Jay X. Tang

We show that the isotropic to nematic liquid crystalline phase transition of F-actin can be either continuous or discontinuous, depending critically on the filament length. For F-actin with average filament length > 3 um, we confirm that the transition is continuous in both filament alignment and local concentration. In contrast, for filament length < 2 um t

H. Steinberg, O. M. Auslaender, A. Yacoby, J. Qian

The many-body wave-function of an interacting one-dimensional electron system is probed, focusing on the low-density, strong interaction regime. The properties of the wave-function are determined using tunneling between two long, clean, parallel quantum wires in a GaAs/AlGaAs heterostructure, allowing for gate-controlled electron density. As electron density

Andrej Zorko, Denis Arcon, Alexandross Lappas, Zvonko Jaglicic

A study of an impurity driven phase-transition into a magnetically ordered state in the spin-liquid Haldane chain compound PbNi2V2O8 is presented. Both, macroscopic magnetization as well as 51V nuclear magnetic resonance (NMR) measurements reveal that the spin nature of dopants has a crucial role in determining the stability of the induced long-range magneti

Viktor Kaufman, Tamara Mihaljev, Barbara Drossel

We derive mostly analytically the scaling behavior of the number of nonfrozen and relevant nodes in critical Kauffman networks (with two inputs per node) in the thermodynamic limit. By defining and analyzing a stochastic process that determines the frozen core we can prove that the mean number of nonfrozen nodes scales with the network size N as N^{2/3}, wit

Olaf Strelcyk, Thomas Korb, Herbert Schoeller

We study the nonequilibrium spin current through a quantum dot consisting of two localized spin-1/2 coupled to two ferromagnetic insulators. The influence of an intra-dot magnetic field and exchange coupling, different dot-reservoir coupling configurations, and the influence of magnon chemical potential differences vs. magnetic field gradients onto the spin

J. C. Flores

A solvable quantum $LC$ circuit with charge discreteness is studied. Two discrete spectral branches are obtained: (i) the normal branch corresponding to a charged capacitor with integer effective charge $k=q_{e}n$ ($q_{e}$ elementary charge, $n$ integer) and (ii) the anomalous branch where the energy is related to non-integer effective charge $k=q_{e}(n-x)$

M. W. C. Dharma-wardana

The exchange and correlation $E_{xc}$ of strongly correlated electrons in 2D layers of finite width are studied as a function of the density parameter $r_s$, spin-polarization $ζ$ and the temperature $T$. We explicitly treat strong-correlation effects via pair-distribution functions, and introduce an equivalent constant-density approximation (CDA) applicable

Takahiro Sakaue, Elie Raphael

We revisit the classical problem of the behavior of an isolated linear polymer chain in confined spaces, introducing the distinction between two different confinement regimes (the {\it weak} and the {\it strong} confinement regimes, respectively). We then discuss some recent experimental findings concerning the partitioning of individual polymers into protei

E. A. Brener, S. V. Iordanskiy, R. B. Saptsov

The mechanism for the transition of a Bose gas to the superfluid state via thermal fluctuations is considered. It is shown that in the process of external cooling some critical fluctuations (instantons) are formed above the critical temperature. The probability of the instanton formation is calculated in the three and two-dimensional cases. It is found that

I. L. Drichko, A. M. Diakonov, I. Yu. Smirnov, A. V. Suslov

Complex AC-conductance, $σ^{AC}$, in the systems with dense Ge$_{0.7}$Si$_{0.3}$ quantum dot (QD) arrays in Si has been determined from simultaneous measurements of attenuation, $ΔΓ=Γ(H)-Γ(0)$, and velocity, $ΔV /V=(V(H)-V(0)) / V(0)$, of surface acoustic waves (SAW) with frequencies $f$ = 30-300 MHz as functions of transverse magnetic field $H \leq$ 18 T in

Tobias Herman, James Day, John Beamish

Aerogels are very compliant materials - even small stresses can lead to large deformations. In this paper we present measurements of the linear deformation of high porosity aerogels during adsorption of low surface tension fluids, performed using a Linear Variable Differential Transformer (LVDT). We show that the degree of deformation of the aerogel during c

Marcin Kostur, Peter Hänggi, Peter Talkner, José L. Mateos

We investigate anticipated synchronization between two periodically driven deterministic, dissipative inertia ratchets that are able to exhibit directed transport with a finite velocity. The two ratchets interact through an unidirectional delay coupling: one is acting as a master system while the other one represents the slave system. Each of the two dissipa

Yariv Kafri, David R. Nelson

The effect of sequence heterogeneity on the dynamics of molecular motors is reviewed and analyzed using a set of recently introduced lattice models. First, we review results for the influence of heterogenous tracks such as a single-strand of DNA or RNA on the dynamics of the motors. We stress how the predicted behavior might be observed experimentally in ano

Mathieu Renouf, Daniel Bonamy, Frederic Dubois, Pierre Alart

The rheology of 2D steady surface flow of cohesionless cylinders in a rotating drum is investigated through {\em Non Smooth Contact Dynamics} simulations. Profile of volume fraction, translational and angular velocity, rms velocity, strain rate and stress tensor were measured at the midpoint along the length of the surface flowing layer where the flow is gen

V. R. Shaginyan, K. G. Popov, S. A. Artamonov

Experimental studies of the antiferromagnetic (AF) heavy fermion metal $\rm YbRh_2Si_2$ in a magnetic field $B$ indicate the presence of a jump in the Hall coefficient at a magnetic-field tuned quantum state in the zero temperature limit. This quantum state occurs at $B\geq B_{c0}$ and induces the jump even though the change of the magnetic field at $B=B_{c0

N. Bergeal, X. Grison, J. Lesueur, G. Faini

Reproducible high-Tc Josephson junctions have been made in a rather simple two-step process using ion irradiation. A microbridge (1 to 5 ?m wide) is firstly designed by ion irradiating a c-axis-oriented YBa2Cu3O7-? film through a gold mask such as the non-protected part becomes insulating. A lower Tc part is then defined within the bridge by irradiating with

Evgeni Sh. Mamasakhlisov, Artem V. Badasyan, Artyom V. Tsarukyan, Arsen V. Grigoryan

In this paper we summarize some results of our theoretical investigations of helix-coil transition both in single-strand (polypeptides) and two-strand (polynucleotides) macromolecules. The Hamiltonian does not contain any parameter designed especially for helix-coil transition and uses pure molecular microscopic parameters. To calculate averages we evaluate

Anna Painelli

An approach is presented to calculate characteristic current vs voltage curves for isolated molecules without explicit description of leads. The Hamiltonian for current-carrying molecules is defined by making resort to Lagrange multipliers, while the potential drop needed to sustain the current is calculated from the dissipated electrical work. Continuity co

Manabu Kiguchi, Tatsuya Konishi, Kei Murakoshi

We have studied conductance characteristics of mechanically fabricated Ni nanoconstrictions under controlling electrochemical potential and pH of the electrolyte. Conductance histogram showed clear feature peaked at 1-1.5 $G_{0}$ (=$2e^{2}/h$) when the potential of the constriction was kept at more negative potential than -900 mV vs. Ag/AgCl in pH=3.7. Compa

Y. Kuramoto, J. Otsuki, A. Kiss, H. Kusunose

Theoretical account is given of 4f-electron dynamics and multipole orders in Pr skutterudites with particular attention to (i) mechanism of the crystalline electric field (CEF) splitting leading to a pseudo-quartet ground state;(ii) Kondo effect due to exchange interactions involving the pseudo-quartet;(iii) multipole orders in the lattice of the pseudo-quar

N. T. Moore, A. Y. Grosberg

The work addresses the analogy between trivial knotting and excluded volume in looped polymer chains of moderate length, $N<N_0$, where the effects of knotting are small. A simple expression for the swelling seen in trivially knotted loops is described and shown to agree with simulation data. Contrast between this expression and the well known expression for

Akihiro Fujihara, Toshiya Ohtsuki, Hiroshi Yamamoto

We consider stochastic processes where randomly chosen particles with positive quantities x, y (> 0) interact and exchange the quantities asymmetrically by the rule x&#39; = c{(1-a) x + b y}, y&#39; = d{a x + (1-b) y} (x \ge y), where (0 \le) a, b (\le 1) and c, d (> 0) are interaction parameters. Noninteger power-law tails in the probability distribution fu

Hiroko Yokota, Taeko Ohyama, Yoshiaki Uesu

Incipient ferroelectric KTaO3 with off-center Li impurity of the critical concentration of 2.8 mol% was investigated in order to clarify the dipole glass state under electric field. Using optical second-harmonic generation (SHG) microscope, we observed a marked history dependence of SHG intensity through zero-field cooling (ZFC), zero-field heating (ZFH), fi

C. Reichhardt, C. J. Olson Reichhardt

Using numerical simulations we examine the static and dynamic properties of the recently proposed vortex liquid crystal state. We confirm the existence of a smectic-A phase in the absence of pinning. Quenched disorder can induce a smectic state even at T=0. When an external drive is applied, a variety of anisotropic dynamical flow states with distinct voltag

Emil A. Yuzbashyan, Vadim B. Kuznetsov, Boris L. Altshuler

We study the mean-field dynamics of a fermionic condensate interacting with a single bosonic mode (a generalized Dicke model). This problem is integrable and can be mapped onto a corresponding BCS problem. We derive the general solution and a full set of integrals of motion for the time evolution of coupled Fermi-Bose condensates. The present paper complemen

W. Yang, K. Chang

Electron spin relaxation induced by phonon-mediated s-d exchange interaction in a II-VI diluted magnetic semiconductor quantum dot is investigated theoretically. The electron-acoustic phonon interaction due to piezoelectric coupling and deformation potential is included. The resulting spin lifetime is typically on the order of microseconds. The effectiveness

Kiyosi Terao

A comment on Yoshimori&#39;s helical spin structure theory.

P. Coleman, I. Paul, J. Rech

We derive a generalized Luttinger-Ward expression for the Free energy of a many body system involving a constrained Hilbert space. In the large $N$ limit, we are able to explicity write the entropy as a functional of the Green&#39;s functions. Using this method we obtain a Luttinger sum rule for the Kondo lattice. One of the fascinating aspects of the sum ru

Ping Sun, Gabriel Kotliar

We solve the 3D periodic Anderson model via two impurity DMFT. We obtain the temperature v.s. hybridization phase diagram. In approaching the quantum critical point (QCP) both the Neel and lattice Kondo temperatures decrease and they do not cross at the lowest temperature we reached. While strong ferromagnetic spin fluctuation on the Kondo side is observed,

L. P. Oliveira, Henrik Jeldtoft Jensen, Mario Nicodemi, Paolo Sibani

We use Monte Carlo simulations of a coarse grained three dimensional model to demonstrate that the experimentally observed approximate temperature independence of the magnetic creep rate for a broad range of temperatures may be explained in terms of record dynamics, {\it viz.} the dynamical properties of the times at which a stochastic fluctuating signal est

B. Sato, D. A. Fischer, G. W. Henry, G. Laughlin

Doppler measurements from Subaru and Keck have revealed radial velocity variations in the V=8.15, G0IV star HD 149026 consistent with a Saturn-Mass planet in a 2.8766 day orbit. Photometric observations at Fairborn Observatory have detected three complete transit events with depths of 0.003 mag at the predicted times of conjunction. HD 149026 is now the seco

E. Peeters, A. L. Mattioda, F. Kemper, D. M. Hudgins

We present 14--21 um emission spectra of star forming regions and compare them with the PAH spectra from the Ames PAH database. We show that while the emission in this region can be quite variable, the bulk of these variations can be accommodated by variations in the IS PAH population.

David Makovoz, Francine R. Marleau

MOPEX (MOsaicking and Point source EXtraction) is a package developed at the Spitzer Science Center for astronomical image processing. We report on the point source extraction capabilities of MOPEX. Point source extraction is implemented as a two step process: point source detection and profile fitting. Non-linear matched filtering of input images can be per

L. S. Matthews, K. Qiao, T. W. Hyde

A self-consistent three-dimensional model for a complex (dusty) plasma is used to study the effects of multiple-sized dust grains in a dust crystal. In addition to the interparticle forces, which interact through a Yukawa potential, the model includes the effects of gravity, the variation of the sheath potential above the powered electrode, and a radial conf

F. J. Robinson, P. Demarque, D. B. Guenther, Y. -C. Kim

Compared to the Sun, the atmospheric structure and convective flow in Procyon A exhibit the following characteristics: (1) the highly superadiabatic transition layer (SAL) is located at much shallower optical depth; it is in a dynamically active region, and its outer region is located part of the time in the optically thin atmosphere; (2) the outer region of

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

The ``minimum-mass solar nebula&#39;&#39; (MMSN) model estimates the surface density distribution of the protoplanetary disk by assuming the planets to have formed in situ. However, significant radial migration of the giant planets likely occurred in the Solar system, implying a distortion in the values derived by the MMSN method. The true density profiles o

Zuzana Srostlik, Joanna M. Rankin

The paper provides a new analysis of this famous five-component ({\bf M}) pulsar. In addition to the star&#39;s core-active ``abnormal&#39;&#39; mode, we find two distinct behaviors within its ``normal&#39;&#39; mode, a ``quiet-normal&#39;&#39; mode with regular 2.8-period subpulse modulation and little or no core activity, and a ``flare-normal&#39;&#39; mod

P. Ocvirk, C. Pichon, A. Lancon, E. Thiebaut

We introduce STECKMAP (STEllar Content and Kinematics via Maximum A Posteriori), a method to recover the kinematical properties of a galaxy simultaneously with its stellar content from integrated light spectra. It is an extension of STECMAP (astro-ph/0505209) to the general case where the velocity distribution of the underlying stars is also unknown. %and ca

J. Marvin Herndon

The principles of Whole-Earth Decompression Dynamics are disclosed leading to a new way to interpret whole-Earth dynamics. Whole-Earth Decompression Dynamics incorporates elements of and unifies the two seemingly divergent dominant theories of continential displacement, plate tectonics theory and Earth expansion theory. Whole-Earth decompression is the conse

D. Espada, A. Bosma, L. Verdes-Montenegro, E. Athanassoula

We present a HI synthesis imaging study of NGC 864 (CIG 96), a spiral galaxy well isolated from similarly sized companions, yet presenting an intriguing asymmetry in its integral HI spectrum. The asymmetry in the HI profile is associated with a strong kinematical perturbation in the gaseous envelope of the galaxy, where at one side the decay of the rotation

Marc Sauvage, Richard J. Tuffs, Cristina C. Popescu

Following on from IRAS, ISO has provided a huge advancement in our knowledge of the phenomenology of the infrared (IR) emission of normal galaxies and the underlying physical processes. Highlights include: the discovery of an extended cold dust emission component, present in all types of gas-rich galaxies and carrying the bulk of the dust luminosity; the def

M. Ammler, V. Joergens, R. Neuhaeuser

We show how the assumption of coeval formation can be used to constrain the effective temperatures of the components of young eclipsing double-lined spectroscopic binaries. Our method extends the approach of White et al. (1999) to a two-step analysis. The first step compares evolutionary models to the observed masses and radii and selects those models that p

Jun Cui, Jill Bechtold, Jian Ge, David M. Meyer

We used HST/STIS to obtain the spectrum of molecular hydrogen associated with the damped Ly$α$ system at $z_{\rm abs}=1.7765$ toward the quasar Q1331+170 at $z_{\rm em}=2.084$. Strong ${\rm H}_2$ absorption was detected, with a total ${\rm H}_2$ column density of $N({\rm H}_2)=(4.45\pm 0.36)\times 10^{19} {\rm cm^{-2}}$.The molecular hydrogen fraction is $f_

V. V. Smith, K. Cunha, I. I. Ivans, J. C. Lattanzio

We present fluorine abundances in seven red-giant members of the globular cluster M4 (NGC 6121). These abundances were derived from the HF (1--0) R9 line at 2.3357 microns in high-resolution infrared spectra obtained with the Phoenix spectrograph on Gemini-South. Many abundances in the target stars have been studied previously, so that their overall abundanc

E. Jimenez-Bailon, M. Santos-Lleo, M. Dahlem, M. Ehle

Earlier observations of NGC 1808 in various wavebands (X-ray, optical, near-infrared, radio) provided evidence for the existence of either a starburst or a Seyfert 2 nucleus. We here present the results of multiwavelength XMM-Newton and Chandra observations, which directly prove the co-existence of thermal diffuse plasma and non-nuclear unresolved point-like

G. Trinchieri, J. Sulentic, W. Pietsch, D. Breitschwerdt

The prototype compact group known as Stephan&#39;s Quintet (SQ) was observed with XMM-Newton in order to complement the excellent resolution of Chandra with high sensitivity to extended emission. SQ is a dynamic environment whose main effect, at both X-ray and optical wavelengths, appears to be ISM stripping. This is manifested by: 1) secular evolution of mo

A. J. Grocholski, A. Sarajedini, K. A. G. Olsen, G. P. Tiede

We report preliminary results from our near-infrared JHK survey of star clusters in the LMC. The primary goals of the survey are to study the three-dimensional structure and distance of the LMC. In 2003 and 2004 we used the Infrared Side Port Imager (ISPI) on the CTIO 4m to obtain near infrared photometry for a sample of populous LMC clusters. We utilize the

R. van Boekel, C. P. Dullemond, C. Dominik

We present simulations of the interferometric visibilities of Herbig Ae star disks. We investigate whether interferometric measurements in the 10 micrometer atmospheric window are sensitive to the presence of an increased scale height at the inner disk edge, predicted by recent models. Furthermore, we investigate whether such measurements can discriminate be

T. V. Zaqarashvili, G. Belvedere

We suggest that the observed long-period Alfv{é}n waves in the solar wind may be generated in the solar interior due to the pulsation of the Sun in the fundamental radial mode. The period of this pulsation is about 1 hour. The pulsation causes a periodical variation of density and large-scale magnetic field, this affecting the Alfv{é}n speed in the solar int

Olivier Chesneau, R. Van Boekel, T. Herbst, P. Kervella

The core of the nebula surrounding Eta Carinae has recently been observed with VLT/NACO, VLTI/VINCI, VLTI/MIDI and VLTI/AMBER in order to spatially and spectrally constrain the warm dusty environment and the central object. Narrow-band images at 3.74 and 4.05 micron reveal the structured butterfly-shaped dusty environment close to the central star with an un

C. Meurer, J. Bluemer, R. Engel, A. Haungs

Using CORSIKA for simulating extensive air showers, we study the relation between the shower characteristics and features of hadronic multiparticle production at low energies. We report about investigations of typical energies and phase space regions of secondary particles which are important for muon production in extensive air showers. Possibilities to mea

W. J. G. de Blok

A recent study has claimed that the rotation curve shapes and mass densities of Low Surface Brightness (LSB) galaxies are largely consistent with $Λ$CDM predictions, in contrast to a large body of observational work. I demonstrate that the method used to derive this conclusion is incapable of distinguishing the characteristic steep CDM mass-density distribut

E. O. Vasiliev, Yu. A. Shchekinov

The conditions for the fragmentation of the baryonic component during merging of dark matter halos in the early Universe are studied. We assume that the baryonic component undergoes a shock compression. The characteristic masses of protostellar molecular clouds and the minimum masses of protostars formed in these clouds decrease with increasing halo mass. Th

M. R. Mokiem, A. de Koter, J. Puls, A. Herrero

We present the first automated fitting method for the quantitative spectroscopy of O- and early B-type stars with stellar winds. The method combines the non-LTE stellar atmosphere code FASTWIND from Puls et al. (2005) with the genetic algorithm based optimizing routine PIKAIA from Charbonneau (1995), allowing for a homogeneous analysis of upcoming large samp

N. Panchapakesan

Recent results indicate the presence of a cosmological constant (or related dark energy) in the universe. It has been conjectured recently that the interaction parameters of physical theories may be dependant on the size parameter of the universe, related to the cosmological constant. We investigate whether such effects will help in explaining baryogenesis i

J. A. McSaveney, K. R. Pollard, P. L. Cottrell

In this paper we examine the problems of phasing using light curves and offer an alternate technique using the changes in acceleration to establish the zero point. We give astrophysical justification as to why this technique is useful and apply the technique to a selection of Type II Cepheids. We then examine some limitations of the technique which qualify i

Judith G. Cohen, Stephen Shectman, Ian Thompson, Andrew McWilliam

We demonstrate that there are systematic scale errors in the [Fe/H] values determined by the Hamburg/ESO Survey (and by the HK Survey by inference) for certain extremely metal poor (EMP) highly C-enhanced giants. The consequences of these scale errors are that a) the fraction of carbon stars at extremely low metallicities has been substantially overestimated

Luis G. Cabral-Rosetti, Tonatiuh Matos, Darío Núñez, Roberto A Sussman

We present an alternative for the description of galactic halos based on Tsallis&#39; non--extensive entropy formalism; on this scheme, halos are stellar polytropes characterized by three parameters, the central density, $ρ_c$, the central velocity dispersion, $σ_c$ and the polytropic index, $n$. To evaluate these parameters we take the Navarro-Frenk-White p

Zhongyuan Zhou, Shih-I Chu, Siyuan Han

We demonstrate that in a coupled two-qubit system any single-qubit gate can be decomposed into two conditional two-qubit gates and that any conditional two-qubit gate can be implemented by a manipulation analogous to that used for a controlled two-qubit gate. Based on this we present a unified approach to implement universal single-qubit and two-qubit gates

J. A. Nieto

We discuss the Ashtekar formalism from the point of view of twelve dimensions. We first focus on the 2+10 spacetime signature and then we consider the transition $2+10\to (2+2)+(0+8)$. We argue that both sectors 2+2 and 0+8, which are exceptional signatures, can be analyzed from the point of view of a self-dual action associated with the Ashtekar formalism.

Tao Han, Heather E. Logan, Lian-Tao Wang

Little Higgs models predict new gauge bosons, fermions and scalars at the TeV scale that stabilize the Higgs mass against quadratically divergent one-loop radiative corrections. We categorize the many little Higgs models into two classes based on the structure of the extended electroweak gauge group and examine the experimental signatures that identify the l

John Little, Ryan Schwarz

Toric codes are a class of $m$-dimensional cyclic codes introduced recently by J. Hansen. They may be defined as evaluation codes obtained from monomials corresponding to integer lattice points in an integral convex polytope $P \subseteq \R^m$. As such, they are in a sense a natural extension of Reed-Solomon codes. Several authors have used intersection theo

J. T. Padding, H. Löwen, A. Wysocki, A. A. Louis

We show how to implement stick boundary conditions for a spherical colloid in a solvent that is coarse-grained by the method of stochastic rotation dynamics. This allows us to measure colloidal rotational velocity auto-correlation functions by direct computer simulation. We find quantitative agreement with Enskog theory for short times and with hydrodynamic

Maria Brzozowska, Tomasz M. Brzozowski, Jerzy Zachorowski, Wojciech Gawlik

Highly sensitive, non-destructive, real-time spectroscopic determination of the 2D kinetic momentum distribution of a cold-atom sample is performed with the three-beam measurement of the recoil-induced resonances. The measurements performed with an operating magneto-optical trap reveal slow velocity drifts within a stationary atomic cloud and strong anisotro

Pengjie Zhang, Ue-Li Pen

We develop a new tool to generate statistically precise dark matter maps from the cosmic magnification of galaxies with distance estimates. We show how to overcome the intrinsic clustering problem using the slope of the luminosity function, because magnificability changes strongly over the luminosity function, while intrinsic clustering only changes weakly.

Yuri Fedorov

We propose a simple method of explicit description of families of closed geodesics on a triaxial ellipsoid $Q$ that are cut out by algebraic surfaces in ${\mathbb R}^3$. Such geodesics are either connected components of spatial elliptic curves or rational curves. Our approach is based on elements of the Weierstrass--Poncaré reduction theory for hyperelliptic

R. L. Greenblatt, J. L. Lebowitz

We establish necessary and sufficient conditions for the existence of factorizable steady states of the Generalized Zero Range Process. This process allows transitions from a site $i$ to a site $i+q$ involving multiple particles with rates depending on the content of the site $i$, the direction $q$ of movement, and the number of particles moving. We also sho

F. Nerling, J. Blümer, R. Engel, M. Risse

The shower simulation code CORSIKA has been used to investigate the electron energy and angular distributions in high-energy showers. Based on the universality of both distributions, we develop an analytical description of Cherenkov light emission in extensive air showers, which provides the total number and angular distribution of photons. The parameterisat

Oliver DeWolfe

We give a construction of type IIB flux vacua with discrete R-symmetries and vanishing superpotential for hypersurfaces in weighted projective space with any number of moduli. We find that the existence of such vacua for a given space depends on properties of the modular group, and for Fermat models can be determined solely by the weights of the projective s