May 2006 arXiv papers — page 30

Dmitri E. Nikonov, George I. Bourianoff, Paolo Gargini

Quantum limits of power dissipation in spintronic computing are estimated. A computing element composed of a single electron in a quantum dot is considered. Dynamics of its spin due to external magnetic field and interaction with adjacent dots is described via the Bloch equations. Spin relaxation due to magnetic noise from various sources is described as cou

S. A. Jafari, T. Tohyama, S. Maekawa

We use the method of dynamical mean field thoery, to study the effect of Kondo resonance on optical third harmonic generation (THG) spectra of strongly correlated systems across the metal-insulator transition. We find that THG signals are proportional to the quasiparticle weight $z$ of the Kondo peak, and are precursors of Mott-Hubbard gap formation.

A. Dupuis, D. Marenduzzo, E. Orlandini, J. M. Yeomans

Blue phases of cholesteric liquid crystals offer a spectacular example of naturally occurring disclination line networks. Here we numerically solve the hydrodynamic equations of motion to investigate the response of three types of blue phases to an imposed Poiseuille flow. We show that shear forces bend and twist and can unzip the disclination lines. Under g

Thomas Hennig, Philipp Maass, Junichiro Hayano, Stefan Heinrichs

The statistical properties of heart beat intervals of 130 long-term surface electrocardiogram recordings during atrial fibrillation (AF) are investigated. We find that the distribution of interbeat intervals exhibits a characteristic exponential tail, which is absent during sinus rhythm, as tested in a corresponding control study with 72 healthy persons. The

Sow-Hsin Chen, Li Liu, Xiangqiang Chu, Yang Zhang

We used high-resolution quasielastic neutron scattering spectroscopy to study the single-particle dynamics of water molecules on the surface of hydrated DNA samples. Both H2O and D2O hydrated samples were measured. The contribution of scattering from DNA is subtracted out by taking the difference of the signals between the two samples. The measurement was ma

Zoran Hadzibabic, Peter Krüger, Marc Cheneau, Baptiste Battelier

Any state of matter is classified according to its order, and the kind of order a physical system can posses is profoundly affected by its dimensionality. Conventional long-range order, like in a ferromagnet or a crystal, is common in three-dimensional (3D) systems at low temperature. However, in two-dimensional (2D) systems with a continuous symmetry, true

A. P. Kuprin, D. Qian, Y. -D. Chuang, M. Foo

We report detailed Fermi surface topology and quasiparticle dynamics of the host cobaltate Na0.7CoO2. A direct mapping of the Fermi surface is carried out by angle-resolved photoemission spectroscopy (ARPES). Fermi surface at temperature 16K is a hole-pocket centered around the Gamma-point. The highly correlated nature of the electron liquid is evidenced fro

Tatsuya Nagao, Jun-ichi Igarashi

We study the electric quadrupole (E2) contribution to resonant x-ray scattering (RXS). Under the assumption that the rotational invariance is preserved in the Hamiltonian describing the intermediate state of scattering, we derive a useful expression for the RXS amplitude. One of the advantages the derived expression possesses is the full information of the e

Takayuki Makino, Akira Ohtomo, A. Tsukazaki, M. Kawasaki

A two-band model involving the A- and B-valence bands was adopted to analyze the temperature dependent Hall effect measured on N-doped \textit{p}-type ZnO. The hole transport characteristics (mobilities, and effective Hall factor) are calculated using the ``relaxation time approximation'' as a function of temperature. It is shown that the lattice sca

K. Xu, Y. Liu, D. E. Miller, J. K. Chin

We studied quantum depletion in a gaseous Bose-Einstein condensate. An optical lattice enhanced the atomic interactions and modified the dispersion relation resulting in strong quantum depletion. The depleted fraction was directly observed as a diffuse background in the time-of-flight images. Bogoliubov theory provided a semi-quantitative description for our

Angel J. Moreno, Juan Colmenero

We present simulations on a binary blend of bead-spring polymer chains. The introduction of monomer size disparity yields very different relaxation times for each component of the blend. Competition between two different arrest mechanisms, namely bulk-like dynamics and confinement, leads to an anomalous relaxation scenario for the fast component, characteriz

Naoyuki Sugimoto, Shigeki Onoda, Shuichi Murakami, Naoto Nagaosa

We study the spin Hall effect taking into account the impurity scattering effect as general as possible with the focus on the definition of the spin current. The conserved bulk spin current (Shi et al. [Phys. Rev. Lett. 96, 076604 (2006)]) satisfying the continuity equation of spin is considered in addition to the conventional one defined by the symmetric pr

P. J. Huggins, A. Frank

We discuss the formation of globules in planetary nebulae, typified by those observed in the Helix Nebula. We show that the properties of the globules, their number, mass, separation, and overall geometry strongly support a scenario in which globules are formed by the fragmentation of a swept-up shell as opposed to models in which the knots form in the AGB w

Steven H. Pravdo, Stuart B. Shaklan, Sloane J. Wiktorowicz, Shri Kulkarni

The Stellar Planet Survey (STEPS) is an ongoing astrometric search for giant planets and brown dwarfs around a sample of ~30 M-dwarfs. We have discovered several low-mass companions by measuring the motion of our target stars relative to their reference frames. The highest mass discovery thus far is G 78-28B, a companion to the M-dwarf G 78-28A. The orbital

T. S. R. Babbedge, M. Rowan-Robinson, M. Vaccari, J. A. Surace

We construct rest-frame luminosity functions at 3.6, 4.5, 5.8, 8 and 24 microns over the redshift range 0<z<2 for galaxies and 0<z<4 for optical QSOs, using optical and infrared data from the Spitzer Wide-area InfraRed Extragalactic survey. The 3.6 and 4.5 micron galaxy LFs show evidence for moderate positive luminosity evolution up to z~1.5, consistent with

Gudlaugur Johannesson, Gunnlaugur Bjornsson, Einar H. Gudmundsson

We extend the standard fireball model, widely used to interpret gamma-ray burst (GRB) afterglow light curves, to include energy injections, and apply the model to the afterglow light curves of GRB 990510, GRB 000301C and GRB 010222. We show that discrete energy injections can cause temporal variations in the optical light curves and present fits to the light

R. Carballo, J. I. Gonzalez-Serrano, F. M. Montenegro-Montes, C. R. Benn

We selected from VLA-FIRST a sample of 94 objects starlike in SDSSS, and with APM colour O-E>2, i.e. consistent with their being high-z QSOs. 78 candidates were classified spectroscopically from published data (mainly SDSS) or observations reported here. The fractions of QSOs (51/78) and z > 3 QSOs (23/78) are comparable to those found in other photometric s

G. Altay, J. M. Colberg, R. A. C. Croft

Alignments of galaxy clusters (the Binggeli effect), as well as of galaxies themselves have long been studied both observationally and theoretically. Here we test the influence of large-scales structures and tidal fields on the shapes and alignments of cluster-size and galaxy-size dark matter halos. We use a high-resolution N-body simulation of a $Λ$CDM univ

Kris Beckwith, John F. Hawley, Julian H. Krolik

Simulations of black hole accretion have shown that magnetic stresses are present near and inside the innermost stable circular orbit (ISCO). This finding suggests that such flows may be more luminous than predicted by the standard accretion disk model. Here we apply a prescription for heat dissipation within the simulated accretion flows to estimate their i

Lee Hartmann, Paola D&#39;Alessio, Nuria Calvet, James Muzerolle

Observations of T Tauri stars and young brown dwarfs suggest that the accretion rates of their disks scale strongly with the central stellar mass, approximately $\mdot \propto M_*^2$. No dependence of accretion rate on stellar mass is predicted by the simplest version of the layered disk model of Gammie (1996), in which non-thermal ionization of upper disk l

A. R. Witham, C. Knigge, B. T. Gaensicke, A. Aungwerojwit

We report on the properties of 71 known cataclysmic variables (CVs) in photometric Halpha emission line surveys. Our study is motivated by the fact that the Isaac Newton Telescope (INT) Photometric Halpha Survey of the northern galactic plane (IPHAS) will soon provide r&#39;, i&#39; and narrow-band Halpha measurements down to r&#39; \simeq 20 for all norther

Martin Ilgner, Richard P. Nelson

Context. Recent observations of the X-ray emission from T Tauri stars in the Orion nebula have shown that they undergo frequent outbursts in their X-ray luminosity. These X-ray flares are characterised by increases in luminosity by two orders of magnitude, a typical duration of less than one day, and a significant hardening of the X-ray spectrum. Aims. It is

Guillaume Dubus

LS 5039 and LSI +61 303 are unique amongst high-mass X-ray binaries (HMXB) for their spatially-resolved radio emission and their counterpart at >GeV gamma-ray energies, canonically attributed to non-thermal particles in an accretion-powered relativistic jet. The only other HMXB known to emit very high energy (VHE) gamma-rays, PSR B1259-63, harbours a non-acc

Akira Imada, Kaori Kubota, Taichi Kato, Daisaku Nogami

We report on the time-resolved CCD photometry of a newly discovered variable star, TSS J022216.4+412259.9 during the outburst in 2005 November-December brightening. The obtained light curves unambiguously showed 0.2-0.3 mag modulations, which we confirmed to be the superhump observed among SU UMa-type dwarf novae. We also performed a period search for the da

Jeremy Shears, David Boyd, Gary Poyner

Several brief outbursts were detected in the dwarf nova V1316 Cyg during 2005. These events have an average amplitude of 1.4 magnitude and a duration of <1 to 2 days. Whilst no outburst period could be confirmed, the shortest period between detected events is 10 days. These curious brief outbursts appear to be the normal pattern of behaviour for this system.

J. C. Carson, S. S. Eikenberry, J. J. Smith, J. M. Cordes

In this second of a two-paper sequence, we present Monte Carlo population simulation results of brown dwarf companion data collected during the Cornell High-order Adaptive Optics Survey for brown dwarf companions (CHAOS). Making reasonable assumptions of orbital parameters (random inclination, random eccentricity and random longitude of pericentre) and age d

Anil Bhardwaj

Jupiter, Saturn, and Earth - the three planets having dense atmosphere and a well developed magnetosphere - are known to emit X-rays. Recently, Chandra X-ray Observatory has observed X-rays from these planets, and XMM-Newton has observed them from Jupiter and Saturn. These observations have provided improved morphological, temporal, and spectral characterist

Jennifer L. Donovan, Robeson M. Herrnstein, Paul T. P. Ho

Using the NH\3 (6,6) transition, which samples dense ($\sim 10^{5}$) molecular gas with an energy above ground of 412 K, we find hot gas at high velocities (--142 to --210 km s$^{-1}$) associated with the central 2 pc of the Galactic center. This material may be either infalling gas due to shocks or tidal stripping, or possibly gas swept from the nuclear reg

Sarah Brough, Duncan Forbes, Virginia Kilborn, Warrick Couch

Here we present an investigation of the properties of 16 nearby galaxy groups and their constituent galaxies. The groups are selected from the Group Evolution Multi-wavelength Study (GEMS) and all have X-ray as well as wide-field neutral hydrogen (HI) observations. Group membership is determined using a friends-of-friends algorithm on the positions and veloc

L. Amati, F. Frontera, N. Auricchio, E. Caroli

Lobster-ISS is an X-ray all-sky monitor experiment selected by ESA two years ago for a Phase A study (now almost completed) for a future flight (2009) aboard the Columbus Exposed Payload Facility of the International Space Station. The main instrument, based on MCP optics with Lobster-eye geometry, has an energy passband from 0.1 to 3.5 keV, an unprecedented

Leonardo A. Pachon, Jorge A. Rueda

We dispose of some objections raised by Manko et al. (gr-qc/0604091) on a recently published paper on the role of Poynting vector in the ocurrence of vorticity in electrovaccum spacetimes (2006, Class. Quantum Grav. 23, 2395)

Vyacheslav M. Abramov

The interest to retrial queueing systems is due to their application to telephone systems. The paper studies multiserver retrial queueing systems with $n$ servers. Arrival process is a quite general point process. An arriving customer occupies one of free servers. If upon arrival all servers are busy, then the customer waits for his service in orbit, and aft

Kevin S. McFarland

MINERvA is a dedicated neutrino cross-section experiment planned for the near detector hall of the NuMI neutrino beam at Fermilab. I summarize the detector design and physics capabilities of the experiment.

Rafał Kulik

In this paper, we establish the Bahadur--Kiefer representation for sample quantiles for a class of weakly dependent linear processes. The rate of approximation is the same as for i.i.d. sequences and is thus optimal.

Hael Collins, R. Holman

An effective description of an initial state is a method for representing the signatures of new physics in the short-distance structure of a quantum state. The expectation value of the energy-momentum tensor for a field in such a state contains new divergences that arise when summing over this new structure. These divergences occur only at the initial time a

Tiago C. Ribeiro, Alexander Seidel, Jung Hoon Han, Dung-Hai Lee

We study the effect of Coulomb interaction between two oppositely doped low-dimensional tJ model systems. We exactly show that, in the one-dimensional case, an arbitrarily weak interaction leads to the formation of charge neutral electron-hole pairs. We then use two different mean-field theories to address the two-dimensional case, where inter-layer excitons

Margarita Tsaousidou, George P. Triberis

We calculate the electronic contribution to the thermal conductance in a quantum dot that is weakly coupled via tunnel barriers to two electrons reservoirs. A linear response model is derived for the calculation of the heat current Q through the quantum dot when a small temperature difference and a small voltage difference are applied between the two reservo

Sean T. Paul, Gang Tian

Based on the Cayley, Grothendieck, Knudsen Mumford theory of determinants we extend the CM polarization to the Hilbert scheme. We identify the weight of this refined line bundle with the generalized Futaki invariant of Donaldson. We are able to conclude that CM stability implies K-Stability. An application of the Grothendieck Riemann Roch Theorem shows that

Gregory Benford

Current-carrying flows, in the laboratory and in astrophysical jets, can form remarkably stable magnetic structures. Decades of experience shows that such flows often build equilibria that reverse field directions, evolving to an MHD Taylor state, which has remarkable stability properties. We model jets and the magnetic bubbles they build as reversed field p

Valeri P. Frolov, David Kubiznak

We demonstrate that the rotating black holes in an arbitrary number of dimensions and without any restrictions on their rotation parameters possess the same `hidden&#39; symmetry as the 4-dimensional Kerr metric. Namely, besides the spacetime symmetries generated by the Killing vectors they also admit the (antisymmetric) Killing-Yano and symmetric Killing te

Kenneth Lane

CDF and D0 each have more than 1 inverse femtobarn of data on tape, and their stores are increasing. This should be sufficient to carry out significant searches for low-scale technicolor in rho_T --> W pi_T and omega_T, rho_T --> gamma pi_T, processes whose cross sections may be as large as several picobarns. In this note we motivate and describe the Technic

C. Firmani, V. Avila-Reese, G. Ghisellini, G. Ghirlanda

Recently, a tight correlation among three quantities that characterize the prompt emission of long Gamma-Ray Bursts (GRBs) with known redshift z, was discovered (Firmani et al. 2006). We use this correlation to construct the Hubble diagram (HD) with a sample of 19 GRBs in the broad range of z=0.17-4.5, and carry out a full statistical analysis to constrain c

Selman Akbulut, Sema Salur

The main purpose of this paper is to give a mathematical definition of ``mirror symmetry&#39;&#39; for Calabi-Yau and G_2 manifolds. More specifically, we explain how to assign a G_2 manifold (M,ϕ,Λ), with the calibration 3-form ϕand an oriented 2-plane field Λ, a pair of parametrized tangent bundle valued 2 and 3-forms of M. These forms can then be used to

Nikodem J. Poplawski

The Einstein-Cartan-Saa theory of torsion modifies the spacetime volume element so that it is compatible with the connection. The condition of connection compatibility gives constraints on torsion, which are also necessary for the consistence of torsion, minimal coupling, and electromagnetic gauge invariance. To solve the problem of positivity of energy asso

Ulf H. Danielsson, Niklas Johansson, Magdalena Larfors

In this letter we consider a charged black hole in a flux compactification of type IIB string theory. Both the black hole and the fluxes will induce potentials for the complex structure moduli. We choose the compact dimensions to be described locally by a deformed conifold, creating a large hierarchy. We demonstrate that the presence of a black hole typicall

Vishnu Jejjala, Djordje Minic

The cosmological constant problem is turned around to argue for a new foundational physics postulate underlying a consistent quantum theory of gravity and matter, such as string theory. This postulate is a quantum equivalence principle which demands a consistent gauging of the geometric structure of canonical quantum theory. We argue that string theory can b

Biplob Bhattacherjee, Anirban Kundu

In the minimal Universal Extra Dimension (mUED) model, there are four physical scalar particles at the n=1 level, two charged and two neutral. Due to the almost degenerate nature of the spectrum, the detection of these scalars is a major challenge, perhaps the greatest experimental challenge if UED-type new physics is observed at the Large Hadron Collider (L

Uri Bader, Alex Furman, Ali Shaker

We propose a new approach to superrigidity phenomena and implement it for lattice representations and measurable cocycles with homeomorphisms of the circle as the target group. We are motivated by Ghys&#39; theorem stating that any representation $\ro:Γ\to\Homeo_+(S^1)$ of an irreducible lattice $Γ$ in a semi-simple real Lie group $G$ of higher rank, either

M. E. J. Newman

We consider the problem of detecting communities or modules in networks, groups of vertices with a higher-than-average density of edges connecting them. Previous work indicates that a robust approach to this problem is the maximization of the benefit function known as &#34;modularity&#34; over possible divisions of a network. Here we show that this maximizat

Anton Dochtermann

We investigate a notion of $\times$-homotopy of graph maps that is based on the internal hom associated to the categorical product in the category of graphs. It is shown that graph $\times$-homotopy is characterized by the topological properties of the $\Hom$ complex, a functorial way to assign a poset (and hence topological space) to a pair of graphs; $\Hom

Dmitry Solenov, Denis Tolkunov, Vladimir Privman

We analyze the indirect exchange interaction between two two-state systems, e.g., spins 1/2, subject to a common finite-temperature environment modeled by bosonic modes. The environmental modes, e.g., phonons or cavity photons, are also a source of quantum noise. We analyze the coherent vs noise-induced features of the two-spin dynamics and predict that for

Javier Ballesteros-Paredes, Lee Hartmann

We discuss problems with some observational estimates indicating long protostellar core lifetimes and large stellar age spreads in molecular clouds. We also point out some additional observational constraints which suggest that protostellar cores do not have long lifetimes before collapsing. For external galaxies, we argue that the widths of spiral arms does

Jim Wiss

We begin with giving some motivation for the study of charm semileptonic and fully leptonic decays. We turn next to a discussion of semileptonic absolution branching fraction results form CLEO-c. Two exciting high statistics results on fully leptonic decays of the D+ -> mu+ nu and Ds+ -> mu+ nu from CLEO-c and BaBar are reviewed. We turn next to a discussion

M. Cinchetti, M. Sánchez Albaneda, D. Hoffmann, T. Roth

The femtosecond magnetization dynamics of a thin cobalt film excited with ultrashort laser pulses has been studied using two complementary pump-probe techniques, namely spin-, energy- and time-resolved photoemission and time-resolved magneto-optical Kerr effect. Combining the two methods it is possible to identify the microscopic electron spin-flip mechanism

A. Hart, G. M. von Hippel, R. R. Horgan

We construct the S-wave part of the electromagnetic vector annihilation current to O(alpha_s v^2)$ on the lattice for heavy quarks whose dynamics are described by the NRQCD action, where v is the non-relativistic quark velocity. The lattice vector current for QQbar annihilation is expressed as a linear combination of lattice operators with quantum numbers L=

Leonardo Biliotti

We consider a connected symplectic manifold $M$ acted on by a connected Lie group $G$ in a Hamiltonian fashion. If $G$ is compact, we prove give an Equivalence Theorem for the symplectic manifolds whose squared moment map $\parallel \mu \parallel^2$ is constant. This result works also in the almost-K\"ahler setting. Then we study the case when $G$ is a non c

A. V. Kuzmin

Quantum channels depending on a number of classical control parameters are considered. Assuming the stochastic fluctuations of the control parameters in the small errors limit it is shown that the channel fidelity is equal to the average value of the channel purities calculated in the cases of the control errors presence and absence respectively. The result

G. E. Volovik

The anisotropic superfluid 3He-A in aerogel provides an interesting example of a system with continuous symmetry in the presence of random anisotropy disorder. Recent NMR experiments allow us to discuss two regimes of the orientational disorder, which have different NMR properties. One of them, the (s)-state, is identified as the pure Larkin-Imry-Ma state. T

Sebastian Goette

We give an optimal upper bound for the first eigenvalue of the untwisted Dirac operator on a compact symmetric space G/H with rk G-rk H\le 1 with respect to arbitrary Riemannian metrics. We also prove a rigidity statement.

A. V. Radyushkin

We study the large-Q^2 behavior of the meson form factor F_M (Q^2) constructed using the holographic light-front wave functions proposed recently by Brodsky and de Teramond. We show that this model can be also obtained within the Migdal&#39;s regularization approach (``meromorphization&#39;&#39;), if one applies it to 3-point function for scalar currents mad

M. Feito, F. J. Cao

We study the threshold control protocol for a collective flashing ratchet. In particular, we analyze the dependence of the current on the values of the thresholds. We have found analytical expressions for the small threshold dependence both for the few and for the many particle case. For few particles the current is a decreasing function of the thresholds, t

James Gilmore, Priyamvada Natarajan

By stacking an ensemble of strong lensing clusters, we demonstrate the feasibility of placing constraints on the dark energy equation of state. This is achieved by using multiple images of sources at two or more distinct redshift planes. The sample of smooth clusters in our simulations is based on observations of massive clusters and the distribution of back

Jacob Sherson, Hanna Krauter, Rasmus K. Olsson, Brian Julsgaard

Quantum teleportation is an important ingredient in distributed quantum networks, and can also serve as an elementary operation in quantum computers. Teleportation was first demonstrated as a transfer of a quantum state of light onto another light beam; later developments used optical relays and demonstrated entanglement swapping for continuous variables. Th

Jeremy Quastel, Benedek Valko

We consider finite-range asymmetric exclusion processes on $\mathbb Z$ with non-zero drift. The diffusivity $D(t)$ is expected to be of ${\mathcal O}(t^{1/3})$. We prove that $D(t)\ge Ct^{1/3}$ in the weak (Tauberian) sense that $\int_0^\infty e^{-λt}tD(t)dt \ge Cλ^{-7/3}$ as $λ\to 0$. The proof employs the resolvent method to make a direct comparison with t

Urs Hartl

In their book Rapoport and Zink constructed rigid analytic period spaces $F^{wa}$ for Fontaine&#39;s filtered isocrystals, and period morphisms from PEL moduli spaces of $p$-divisible groups to some of these period spaces. They conjectured the existence of an étale bijective morphism $F^a \to F^{wa}$ of rigid analytic spaces and of a universal local system o

J. D. Gibbon, G. A. Pavliotis

The tradition in Navier-Stokes analysis of finding estimates in terms of the Grashof number $\bG$, whose character depends on the ratio of the forcing to the viscosity $ν$, means that it is difficult to make comparisons with other results expressed in terms of Reynolds number $\Rey$, whose character depends on the fluid response to the forcing. The first tas

I. M. Suslov

It is demonstrated, that &#39;t Hooft&#39;s renormalization scheme (in which β-function has exactly the two-loop form) is generally in conflict with the natural physical requirements and specifies the type of the field theory in an arbitrary manner. It violates analytic properties in the coupling constant plane and provokes misleading conclusion on accumulat

Alberto Abbondandolo, Pietro Majer

We prove the Morse relations for the set of all geodesics connecting two non-conjugate points on a class of globally hyperbolic Lorentzian manifolds. We overcome the difficulties coming from the fact that the Morse index of every geodesic is infinite, and from the lack of the Palais-Smale condition, by using the Morse complex approach.

Arvind, Gurpreet Kaur, Geetu Narang

We describe a new implementation of the Bernstein-Vazirani algorithm which relies on the fact that the polarization states of classical light beams can be cloned. We explore the possibility of computing with waves and discuss a classical optical model capable of implementing any algorithm (on $n$ qubits) that does not involve entanglement. The Bernstein-Vazi

D. Jayasri, N. Satyavathi, V. S. S. Sastry, K. P. N. Murthy

We investigate Isotropic - Nematic transition in liquid crystal elastomers employing non-Boltzmann Monte Carlo techniques. We consider a lattice model of a liquid elastomer and Selinger-Jeon-Ratna Hamiltonian which accounts for homogeneous/inhomogeneous interactions among liquid crystalline units, interaction of local nematics with global strain, and with in

Motohiko Kusakabe, Toshitaka Kajino, Grant J. Mathews

Recent spectroscopic observations of metal poor stars have indicated that both $^7$Li and $^6$Li have abundance plateaus with respect to the metallicity. Abundances of $^7$Li are about a factor three lower than the primordial abundance predicted by standard big-bang nucleosynthesis (SBBN), and $^6$Li abundances are $\sim 1/20$ of $^7$Li, whereas SBBN predict

Hiroto Ogawa, Nariya Uchida

We study the core structure of the twist-grain-boundary (TGB) phase of chiral liquid crystals by numerically minimizing the Landau-de Gennes free energy. We analyze the morphology of layers at the grain boundary, to better understand the mechanism of frustration between the smectic layer order and chirality. As the chirality increases, the effective bending

Teodor Banica, Julien Bichon, Gaetan Chenevier

We consider circulant graphs having $p$ vertices, with $p$ prime. To any such graph we associate a certain number $k$, that we call type of the graph. We prove that for $p>>k$ the graph has no quantum symmetry, in the sense that the quantum automorphism group reduces to the classical automorphism group.

Shigeki Matsutani

This article investigates local properties of the further generalized Weierstrass relations for a spin manifold $S$ immersed in a higher dimensional spin manifold $M$ from viewpoint of study of submanifold quantum mechanics. We show that kernel of a certain Dirac operator defined over $S$, which we call submanifold Dirac operator, gives the data of the immer

Philippe Gris

Recent results from searches for non-supersymmetric particles by the CDF and D0 collaborations are reported. The sample taken during the RunII of the Fermilab T eVatron collider at Ecms=1.96 TeV is used. The integrated luminosity analyzed ranges from 300 to 1020 pb-1 depending on the search.}

Audrey Cottet, Mahn-Soo Choi

We study the zero-bias magnetoresistance MR of an interacting quantum dot connected to two ferromagnetic leads and capacitively coupled to a gate voltage source Vg. We investigate the effects of the spin-activity of the contacts between the dot and the leads by introducing an effective exchange field in an Anderson model. This spin-activity makes easier nega

V. A. Khoze, A. D. Martin, M. G. Ryskin

We propose a new variable, R_j, in order to identify exclusive double-diffractive high E_T dijet production. The variable R_j is calculated using the transverse energy E_T and pseudorapidity of the jet with the largest E_T. For a purely exclusive event the value of R_j -> 1, if we were to neglect hadronisaton and the detector resolution effects. To illustrat

Ll. Bel

We introduce in the framework of the linear approximation of General relativity a natural distinction between General gauge transformations generated by any vector field and those Special ones for which this vector field is a gradient. This allows to introduce geometrical objects that are not invariant under General gauge transformations but they are under S

Titus S. van Erp

We analyze the efficiency of different methods for the calculation of reaction rates in the case of two simple analytical benchmark systems. Two classes of methods are considered: the first are based on the free energy calculation along a reaction coordinate and the calculation of the transmission coefficient, the second on the sampling of dynamical pathways

Takeshi Kurimoto

Uncertainty in the PQCD calculation of B decays is investigated in $B\to π$, $B\to D$ transition form factors and $B\to Dπ$ decay amplitudes. $B$ meson distributionamplitude dependence is studied by taking three kinds of distribution amplitude so far suggested. It is found that almost same $q^2$ dependence of the form factors can be obtained irrespective of

Tian Khoon Lim, Cheryl E. Praeger

The generalised Paley graphs are, as their name suggests, a generalisation of the Paley graphs, first defined by Paley in 1933 (see \cite{Paley}). They arise as the relation graphs of symmetric cyclotomic association schemes. However, their automorphism groups may be much larger than the groups of the corresponding schemes. We determine the parameters for wh

Li-Ming Wang, Qing Wang

We add a nonstandard higgs into the traditional bosonic part of electroweak chiral Lagrangian, in purpose of finding out the contribution to EWCL coefficients from processes with internal line higgs particle. To construct the effective Lagrangian with higgs, we use low energy expansion scheme and write down all the independent terms conserving $SU(2)\times U

I. V. Sharf, G. O. Sokhrannyi, A. V. Tykhonov, K. V. Yatkin

We demonstrate a possibility of computation of inelastic scattering cross-section in a multi-peripheral model by application of the Laplace method to multidimensional integral over the domain of physical process. The constrained maximum point of scattering cross-section integral under condition of the energy-momentum conservation has been found. In the vicin

Biswarup Mukhopadhyaya, Raghavendra Srikanth

We consider the possibility of neutrino mass generation in a supersymmetric model where lepton number can be violated by odd units. The different patterns of mixing in the quark and lepton sectors are attributed to the persence of right-chiral neutrino superfields which (a) enter into Yukawa couplings via non-renormalizable interaction with hidden sector fie

Ho Trung Dung, Stefan Yoshi Buhmann, Dirk-Gunnar Welsch

The influence of the size and shape of a dispersing and absorbing dielectric body on the local-field corrected spontaneous-decay of an excited atom embedded in the body is studied on the basis of the real-cavity model. By means of a Born expansion of the Green tensor of the system it is shown that to linear order in the susceptibility of the body the decay r

L. Canet, H. J. Hilhorst

We consider the branching and annihilating random walk $A\to 2A$ and $2A\to 0$ with reaction rates $σ$ and $λ$, respectively, and hopping rate $D$, and study the phase diagram in the $(λ/D,σ/D)$ plane. According to standard mean-field theory, this system is in an active state for all $σ/D>0$, and perturbative renormalization suggests that this mean-field res

Chandrasekhar Chatterjee, Amitabha Lahiri

We revisit Nambu&#39;s model of quark confinement by a tube of magnetic flux, with two additional features. The quarks are taken to be magnetic monopoles external to the tube, which seal the ends, and are also taken to be fermions. This ensures that the model is inconsistent unless there are at least two species of fermions being confined.

Soren Galatius, Ib Madsen, Ulrike Tillmann, Michael Weiss

The embedded cobordism category under study in this paper generalizes the category of conformal surfaces, introduced by G. Segal in order to formalize the concept of field theories. Our main result identifies the homotopy type of the classifying space of the embedded d-dimensional cobordism category for all d. For d=2, our results lead to a new proof of the

Francisco Correa, Mikhail S. Plyushchay

We show that some simple well studied quantum mechanical systems without fermion (spin) degrees of freedom display, surprisingly, a hidden supersymmetry. The list includes the bound state Aharonov-Bohm, the Dirac delta and the Poschl-Teller potential problems, in which the unbroken and broken N=2 supersymmetry of linear and nonlinear (polynomial) forms is re

J. Conrad, F. Tegenfeldt

In this note we give an example application of a recently presented predictive learning method called Rule Ensembles. The application we present is the search for super-symmetric particles at the Large Hadron Collider. In particular, we consider the problem of separating the background coming from top quark production from the signal of super-symmetric parti

Takayuki Tatekawa

We study the behavior of Lagrangian perturbative solutions. For a spherical void model, the higher order the Lagrangian perturbation we consider, the worse the approximation becomes in late-time evolution. In particular, if we stop to improve until an even order is reached, the perturbative solution describes the contraction of the void. To solve this proble

Bomee Lee, Jounghun Lee

The Local Group is a small galaxy cluster with the membership of 62 nearby galaxies including the Milky Way and M31. Although the Local Group has yet to be virialized, it interacts with the surrounding matter as one gravitationally bound system. To understand the formation and evolution of the Local Group as well as its member galaxies, it is important to re

M. L. Walker

It is argued that the ground state of three- and four-colour QCD contains a monopole condensate, necessary for the dual Meissner effect to be the mechanism of confinement, and support its stability on the grounds that it gives the off-diagonal gluons an effective mass sufficient to remove the unstable ground state mode.

David M. -T. Kuo

The time-dependent tunnelling current arising from the electron-hole recombination of exciton state is theoretically studied using the nonequilibrium Green&#39;s function technique and the Anderson model with two energy levels. The charge conservation and gauge invariance are satisfied in the tunnelling current. Apart from the classical capacitive charging a

Gil I. Shamir

Tight bounds on the block entropy of patterns of sequences generated by independent and identically distributed (i.i.d.) sources are derived. A pattern of a sequence is a sequence of integer indices with each index representing the order of first occurrence of the respective symbol in the original sequence. Since a pattern is the result of data processing on

Jian-Zhong Du, Su-Juan Qin, Qiao-Yan Wen, Fu-Chen Zhu

In a recent paper [S. Bagherinezhad and V. Karimipour, Phys. Rev. A 67, 044302 (2003)], a quantum secret sharing protocol based on reusable GHZ states was proposed. However, in this comment, it is shown that this protocol is insecure because a cheater can gain all the secret bits before sharing, while introducing one data bit error at most in the whole commu

Jia-Lin Zhu, Fu-fang Xu, Yu-feng Jia

Quantum transport through the junction between two metallic carbon nanotubes connected by intertube links has been studied within the TB method and Landauer formula. It is found that the conductance oscillates with both of the coupling strength and length. The corresponding local density of states (LDOS) is clearly shown and can be used to explain the reason

Chong-Xing Yue, Shuo Yang, Chao-Hsi Chang

This paper has been withdrawn by the author, due some mistakes in this paper.

A. Ulacia Rey, A. Perez Martinez, Roberto A. Sussman

We consider a magnetized degenerate gas of fermions as the matter source of a homogeneous but anisotropic Bianchi I spacetime with a Kasner--like metric. We examine the dynamics of this system by means of a qualitative and numerical study of Einstein-Maxwell field equations which reduce to a non--linear autonomous system. For all initial conditions and combi

Subhash Kak

Thermodynamic entropy is not an entirely satisfactory measure of information of a quantum state. This entropy for an unknown pure state is zero, although repeated measurements on copies of such a pure state do communicate information. In view of this, we propose a new measure for the informational entropy of a quantum state that includes information in the p