January 2006 arXiv papers — page 27

Valerii Dryuma

The examples of ten-dimensional vacuum Einstein spaces composed of four-dimensional Einstein spaces and six-dimensional Ricci-flat base space defined by the solutions of the Korteveg de-Vries equation are constructed.

German Izquierdo

In this thesis, we have reviewed how the expansion of the Universe amplifies the quantum vacuum fluctuations, and how the relic GWs spectrum is related with the scale factor. We have evaluated the spectrum in different scenarios: a model of expanding universe with an era dominated by mini black holes and radiation right after the inflation and a model with a

Ujjal Debnath, Subenoy Chakraborty

In this work, gravitational collapse of a spherical cloud, consists of both dark matter and dark energy in the form of modified Chaplygin gas is studied. It is found that dark energy alone in the form of modified Chaplygin gas forms black hole. Also when both components of the fluid are present then the collapse favors the formation of black hole in cases th

R. A. Daishev, S. M. Kozyrev, A. V. Lukin, A. I. Lubimov

The article deals with the results of the research on the realization of the scientific and technical project Dulkyn for detection of low frequency periodic gravitational radiation from the double relativistic astrophysical objects, done by the Scientific Centre of Gravitational-Wave Research Dulkyn of the Academy of Sciences of the Tatarstan Republic (SC GW

Z. Ya. Turakulov, A. T. Muminov

It is shown that geometric optical description of electromagnetic wave with account of its polarization in curved space-time can be obtained straightforwardly from the classical variational principle for electromagnetic field. For this end the entire functional space of electromagnetic fields must be reduced to its subspace of locally plane monochromatic wav

Oscar Y. Takeshita

An interleaver is a critical component for the channel coding performance of turbo codes. Algebraic constructions are important because they admit analytical designs and simple, practical hardware implementation. The spread factor of an interleaver is a common measure for turbo coding applications. Maximum-spread interleavers are interleavers whose spread fa

Lourdes Araujo, Juan J. Merelo

This paper presents an evolutionary algorithm for modeling the arrival dates of document streams, which is any time-stamped collection of documents, such as newscasts, e-mails, IRC conversations, scientific journals archives and weblog postings. This algorithm assigns frequencies (number of document arrivals per time unit) to time intervals so that it produc

Ribhu K. Kaul, Gergely Zaránd, Shailesh Chandrasekharan, Denis Ullmo

Motivated by experiments on double quantum dots, we study the problem of a single magnetic impurity confined in a finite metallic host. We prove an exact theorem for the ground state spin, and use analytic and numerical arguments to map out the spin structure of the excitation spectrum of the many-body Kondo-correlated state, throughout the weak to strong co

Marcelo D. S. de Meneses, Sharon D. da Cunha, D. J. B. Soares, L. R. da Silva

We introduce a network growth model in which the preferential attachment probability includes the fitness vertex and the Euclidean distance between nodes. We grow a planar network around its barycenter. Each new site is fixed in space by obeying a power law distribution.

T. Kiessling, A. V. Platonov, G. V. Astakhov, T. Slobodskyy

We report on a complex nontrivial behavior of the optical anisotropy of quantum dots that is induced by a magnetic field in the plane of the sample. We find that the optical axis either rotates in the opposite direction to that of the magnetic field or remains fixed to a given crystalline direction. A theoretical analysis based on the exciton pseudospin Hami

Edmond Orignac, Roberta Citro

We study 1D fermions with photoassociation or with a narrow Fano-Feshbach resonance described by the Boson-Fermion resonance model. Using thebosonization technique, we derive a low-energy Hamiltonian of the system. We show that at low energy, the order parameters for the Bose Condensation and fermion superfluidity become identical, while a spin gap and a gap

M. Y. Veillette, J. T. Chalker

We present calculations of the magnetic ground state of Cs_2CuCl_4 in an applied magnetic field, with the aim of understanding the commensurately ordered state that has been discovered in recent experiments. This layered material is a realization of a Heisenberg antiferromagnet on an anisotropic triangular lattice. Its behavior in a magnetic field depends on

Luca Dall'Asta

In reason of the strongly non-ergodic dynamical behavior, universality properties of deterministic Fixed-Energy Sandpiles are still an open and debated issue. We investigate the one-dimensional model, whose microscopical dynamics can be solved exactly, and provide a deeper understanding of the origin of the non-ergodicity. By means of exact arguments, we pro

Alejandro B. Kolton, A. Rosso, Thierry Giamarchi

We study the relaxation of an elastic string in a two dimensional pinning landscape using Langevin dynamics simulations. The relaxation of a line, initially flat, is characterized by a growing length, $L(t)$, separating the equilibrated short length scales from the flat long distance geometry that keep memory of the initial condition. We find that, in the lo

Erik Van der Straeten, Jan Naudts

In this paper we compare two polymer stretching experiments. The outcome of both experiments is a force-extension relation. We use a one-dimensional model to show that in general the two quantities are not equal. In certain limits, however, both force-extension relations coincide.

M. Dudka, R. Folk, Yu. Holovatch, G. Moser

The critical dynamics of model C in the presence of disorder is considered. It is known that in the asymptotics a conserved secondary density decouples from the nonconserved order parameter for disordered systems. However couplings between order parameter and secondary density cause considerable effects on non-asymptotic critical properties. Here, a general

Gerhard Schmid, Peter Hanggi

We investigate the potential for controlling the effect of nonlinear Stochastic Resonance (SR) by use of harmonic mixing signals for an overdamped Brownian dynamics in a symmetric double well potential. The periodic forcing for harmonic mixing consists of a first signal with a basic frequency $Ω$ and a second, superimposed signal oscillating at twice the bas

E. V. Vakarin, Yurko Duda, J. P. Badiali

The role of a matrix response to a fluid insertion is analyzed in terms of a perturbation theory and Monte Carlo simulations applied to a hard sphere fluid in a slit of fluctuating density-dependent width. It is demonstrated that a coupling of the fluid-slit repulsion, spatial confinement and the matrix dilatation acts as an effective fluid-fluid attraction,

T. A. Zaleski, T. K. Kopec

We study a model of YBa2Cu3O(6+y) to investigate the influence of oxygen ordering and doping imbalance on the critical temperature Tc(y) and to elucidate a possible origin of well-known feature of YBCO phase diagram: the 60-K plateau. Focusing on "phase only" description of the high-temperature superconducting system in terms of collective variables

E. Diez, Y. P. Chen, S. Avesque, M. Hilke

We designed and performed low temperature DC transport characterization studies on two-dimensional electron gases confined in lattice-matched In$_{0.53}$Ga$_{0.47}$As/In$_{0.52}$Al$_{0.48}$As quantum wells grown by molecular beam epitaxy on InP substrates. The nearly constant mobility for samples with the setback distance larger than 50nm and the similarity

Qiuping A. Wang, Laurent Nivanen, Alain Le Méhauté

This is a study of composition rule and temperature definition for nonextensive systems containing different $q$ subsystems. The physical meaning of the multiplier $β$ associated with the energy expectation in the optimization of Tsallis entropy is investigated for the formalism with normalized expectation given by escort probability. This study is carried o

E. Rico

A simple and efficient method for calculating the ground state for a class of antiferromagnet systems is presented. It combines the valence bond structure of the ground state for this class of systems and real space renormalization group. As an example, the entire Haldane phase for a spin-1 chain is described, from the AKLT model through to the Heisenberg mo

Wei Li, Qiuping A. Wang, Laurent Nivanen, Alain Le Méhauté

It is known that the nonextensive statistics was originally formulated for the systems composed of subsystems having same $q$. In this paper, the existence of composite system with different $q$ subsystems is investigated by fitting the power law degree distribution of air networks with $q$-exponential distribution. Then a possible extension the nonextensive

N. S. Averkiev, L. E. Golub, A. S. Gurevich, V. P. Evtikhiev

Spin relaxation of two-dimensional electrons in asymmetrical (001) AlGaAs quantum wells are measured by means of Hanle effect. Three different spin relaxation times for spins oriented along [110], [1-10] and [001] crystallographic directions are extracted demonstrating anisotropy of D'yakonov-Perel' spin relaxation mechanism. The relative strengths o

Fei Liu, Zhong-can Ou-Yang, Mitsumasa Iwamoto

Recently experiments showed that some biological noncovalent bonds increase their lifetimes when they are stretched by an external force, and their lifetimes will decrease when the force increases further. Several specific quantitative models have been proposed to explain the intriguing transitions from the "catch-bond" to the "slip-bond". Di

G. Pellicane, F. Saija, C. Caccamo, P. V. Giaquinta

We study the thermodynamic stability of fluid-fluid phase separation in binary nonadditive mixtures of hard-spheres for moderate size ratios. We are interested in elucidating the role played by small amounts of nonadditivity in determining the stability of fluid-fluid phase separation with respect to the fluid-solid phase transition. The demixing curves are

Bingbing Wang, Panming Fu, Jie Liu, Biao Wu

The self-trapping phenomenon of Bose-Einstein condensates (BECs) in optical lattices is studied extensively by numerically solving the Gross-Pitaevskii equation. Our numerical results not only reproduce the phenomenon that was observed in a recent experiment [Anker {\it et al.}, Phys. Rev. Lett. {\bf 94} (2005)020403], but also find that the self-trapping br

Yu. V. Knyazev, A. V. Lukoyanov, Yu. I. Kuz'min, A. G. Kuchin

In this paper we report comprehensive experimental and theoretical investigation of magnetic and electronic properties of the intermetallic compounds Pr2Fe17 and Gd2Fe17. For the first time electronic structure of these two systems was probed by optical measurements in the spectral range of 0.22-15 micrometers. On top of that charge carriers parameters (plas

C. G. Yang, E. Eherenfreund, Z. V. Vardeny

In a recent Letter Lee et al. studied the spin 1/2 photoluminescence-detected magnetic resonance (PLDMR) of a soluble derivative of poly-phenylene vinylene [MEH-PPV] and argued that it originates from the interaction of triplet excitons with polarons. We show that in MEH-PPV as well as in other conjugated polymers the spin 1/2 PLDMR does not depend on the tr

Kerson Huang

CSAW (conditioned self-avoiding walk) is a model of protein folding that combines SAW (self-avoiding walk) with Monte-Carlo. It simulates the Brownian motion of a chain molecule in the presence of interactions, both among chain residues, and with the environment. In a first model that includes the hydrophobic effect and hydrogen bonding, a chain of 30 residu

Haruhisa Kitano, Takeyoshi Ohashi, Atsutaka Maeda, Ichiro Tsukada

We report a systematic study of the dynamic microwave conductivity near $T_c$ for La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) thin films with $x$=0.07 to 0.16. The strong frequency dependence of the phase stiffness together with scaling analysis of the ac fluctuating conductivity of superconductivity provide direct evidence for the 2D-XY behavior of nearly decoupled CuO$

Dan Bohr, Peter Schmitteckert, Peter Woelfle

In this paper we present a novel approach combining linear response theory (Kubo) for the conductance and the Density Matrix Renormalization Group (DMRG). The system considered is one-dimensional and consists of non-interacting tight binding leads coupled to an interacting nanostructure via weak links. Electrons are treated as spinless fermions and two diffe

Soumen Roy, Dibyendu Das

We study the motion of a random walker in one longitudinal and d transverse dimensions with a quenched power law correlated velocity field in the longitudinal x-direction. The model is a modification of the Matheron-de Marsily (MdM) model, with long-range velocity correlation. For a velocity correlation function, dependent on transverse co-ordinates y as 1/(

A. Carbone, B. K. Kotowska, D. Kotowski

Low-frequency current fluctuations are investigated over a bias range covering {\em ohmic}, {\em trap-filling} and {\em space-charge-limited current} regimes in polycrystalline polyacenes. The relative current noise power spectral density ${\cal S}(f)$ is constant in the {\em ohmic} region, steeply increases at the {\em trap-filling transition} region and de

Fei Ye, Bing-Shen Wang, JiZhong Lou, Zhao-Bin Su

In this paper, we report the applicability of the density matrix renormalization group(DMRG) approach to the cylindrical single wall carbon nanotube (SWCN) for purpose of its correlation effect. By applying the DMRG approach to the $t$+$U$+$V$ model, with $t$ and $V$ being the hopping and Coulomb energies between the nearest neighboring sites, respectively,

C. N. Veenstra, W. van Dijk, D. W. L. Sprung, J. Martorell

Time delay in electron propagation through a finite periodic system such as a semiconductor superlattice is studied by direct numerical solution of the time-dependent Schrödinger equation. It is found that addition of an anti-reflection coating significantly reduces the time delay, in addition to increasing the transmissivity.

Alan P. Boss

A new suite of three dimensional radiative, gravitational hydrodynamical models is used to show that gas giant planets are unlikely to form by the disk instability mechanism at distances of ~100 AU to ~200 AU from young stars. A similar result seems to hold for the core accretion mechanism. These results appear to be consistent with the paucity of detections

Victor P. Debattista

I review recent progress from $N$-body simulations in our understanding of the secular evolution of isolated disk galaxies. I describe some of the recent controversies in the field which have been commonly attributed to numerics. The numerical methods used are widely used in computational astronomy and the problems encountered are therefore of wider interest

K. Schreyer, D. Semenov, Th. Henning, J. Forbrich

We observed the embedded, young 8--10 Msun star AFGL 490 at subarcsecond resolution with the Plateau de Bure Interferometer in the C17O (2--1) transition and found convincing evidence that AFGL 490 is surrounded by a rotating disk. Using two-dimensional modeling of the physical and chemical disk structure coupled to line radiative transfer, we constrain its

B. Varga, I. Horváth, L. G. Balázs

We estimated the Txx quantiles of the cumulative GRB light curves using our recalculated background. The basic information of the light curves was extracted by multivariate statistical methods. The possible classes of the light curves are also briefly discussed.

S. Capozziello, V. F. Cardone, G. Lambiase, A. Troisi

We investigate the possibility that part of the dark matter is not made out of the usual cold dark matter (CDM) dustlike particles, but is under the form of a fluid of strings with barotropic factor $w_s = -1/3$ of cosmic origin. To this aim, we split the dark matter density parameter in two terms and investigate the dynamics of a spatially flat universe fil

Simon Goodwin, David Hubber, Estelle Moraux, Anthony Whitworth

We examine the spatial distribution of brown dwarfs produced by the decay of small-N stellar systems as expected from the embryo ejection scenario. We model a cluster of several hundred stars grouped into 'cores' of a few stars/brown dwarfs. These cores decay, preferentially ejecting their lowest-mass members. Brown dwarfs are found to have a wider s

S. Woosley, H. -T. Janka

Supernovae are nature's grandest explosions and an astrophysical laboratory in which unique conditions exist that are not achievable on Earth. They are also the furnaces in which most of the elements heavier than carbon have been forged. Scientists have argued for decades about the physical mechanism responsible for these explosions. It is clear that the

A. M. Sobolev, A. B. Ostrovskii, M. S. Kirsanova, O. V. Shelemei

Methanol masers which are traditionally divided into two classes provide possibility to study important parts of the star forming regions: Class~II masers trace vicinities of the massive YSOs while class~I masers are likely to trace more distant parts of the outflows where newer stars can form. There are many methanol transitions which produce observed maser

Carlo Burigana, Andrea Zizzo

We investigated the role of the cyclotron emission (CE) associated to cosmic magnetic fields (MF) on the evolution of cosmic microwave background (CMB) spectral distortions. We computed the photon and energy injection rates by including spontaneous and stimulated emission and absorption. These CE rates have been compared with those of bremsstrahlung (BR) and

Lilia Ferrario, Dayal Wickramasinghe

We explore the hypothesis that the magnetic fields of neutron stars are of fossil origin. For parametrised models of the distribution of magnetic flux on the Main Sequence and of the birth spin period of the neutron stars, we calculate the expected properties of isolated radio pulsars in the Galaxy using as our starting point the initial mass function and st

Pedro Lacerda, Jane Luu

We use optical data on 10 Kuiper Belt objects (KBOs) to investigate their rotational properties. Of the 10, three (30%) exhibit light variations with amplitude delta_m >= 0.15 mag, and 1 out of 10 (10%) has delta_m >= 0.40 mag, which is in good agreement with previous surveys. These data, in combination with the existing database, are used to discuss the rot

J. Melendez, N. G. Shchukina, I. E. Vasiljeva, I. Ramirez

We use high quality VLT/UVES published data of the permitted OI triplet and FeII lines to determine oxygen and iron abundances in unevolved (dwarfs, turn-off, subgiants) metal-poor halo stars. The calculations have been performed both in LTE and NLTE, employing effective temperatures obtained with the new infrared flux method (IRFM) temperature scale by Rami

Mark Lacy

This review attempts to describe developments in the fields of quasar and quasar host galaxies in the past five. In this time period, the Sloan and 2dF quasar surveys have added several tens of thousands of quasars, with Sloan quasars being found to z>6. Obscured, or partially obscured quasars have begun to be found in significant numbers. Black hole mass es

Carolyn Sealfon, Licia Verde, Raul Jimenez

We show how to place constraints on cluster physics by stacking the weak lensing signals from multiple clusters found through the Sunyaev-Zeldovich (SZ) effect. For a survey that covers about 200 sq. deg. both in SZ and weak lensing observations, the slope and amplitude of the mass vs. SZ luminosity relation can be measured with few percent error for cluster

Keitaro Takahashi, Kiyotomo Ichiki, Hiroshi Ohno, Hidekazu Hanayama

We discuss generation of magnetic field from cosmological perturbations. We consider the evolution of three component plasma (electron, proton and photon) evaluating the collision term between elecrons and photons up to the second order. The collision term is shown to induce electric current, which then generate magnetic field. There are three contributions,

Joydev Lahiri, Gautam Bhattacharya

We analyze cosmological perturbations to the linear order in the context of inflation with an arbitrary number of scalar fields. The fields take values on a non-trivial manifold with a positive-definite metric and are non-minimally coupled to Einstein gravity. The perturbations are decomposed into three different types. The scalar-type perturbations are pres

L. Chayes, H. K. Lei

We introduce and study a family of 2D percolation systems which are based on the bond percolation model of the triangular lattice. The system under study has local correlations, however, bonds separated by a few lattice spacings act independently of one another. By avoiding explicit use of microscopic paths, it is first established that the model possesses t

Nicolas Yunes, Wolfgang Tichy

We construct approximate initial data for non-spinning black hole binary systems by asymptotically matching the 4-metrics of two tidally perturbed Schwarzschild solutions in isotropic coordinates to a resummed post-Newtonian 4-metric in ADMTT coordinates. The specific matching procedure used here closely follows the calculation in gr-qc/0503011, and is perfo

Xiao-Song Lin, Hao Zheng

The colored HOMFLY polynomial is the quantum invariant of oriented links in $S^3$ associated with irreducible representations of the quantum group $U_q(\mathrm{sl}_N)$. In this paper, using an approach to calculate quantum invariants of links via cabling-projection rule, we derive a formula for the colored HOMFLY polynomial in terms of the characters of the

Cameron McA Gordon, John Luecke

For a knot K in S^3, let T(K) be the characteristic toric sub-orbifold of the orbifold (S^3,K) as defined by Bonahon and Siebenmann. If K has unknotting number one, we show that an unknotting arc for K can always be found which is disjoint from T(K), unless either K is an EM-knot (of Eudave-Munoz) or (S^3,K) contains an EM-tangle after cutting along T(K). As

Nicolas Chatillon, Cosmin Macesanu, Aleksandr Pinzul, Mark Trodden

It has recently been suggested that in a brane world scenario with large extra dimensions, short distance gravitational interactions can enhance the dark matter scattering cross-section in a velocity dependent way. Such a modification may then help to address possible problems with non-interacting cold dark matter on galactic and sub-galactic scales. We argu

Metod Saniga, Michel Planat

The paper deals with a particular type of a projective ring plane defined over the ring of double numbers over Galois fields, R\_{\otimes}(q) \equiv GF(q) \otimes GF(q) \cong GF(q)[x]/(x(x-1)). The plane is endowed with (q^2 + q + 1)^2 points/lines and there are (q + 1)^2 points/lines incident with any line/point. As R\_{\otimes}(q) features two maximal idea

Tony Rothman, Stephen Boughn

Freeman Dyson has questioned whether any conceivable experiment in the real universe can detect a single graviton. If not, is it meaningful to talk about gravitons as physical entities? We attempt to answer Dyson's question and find it is possible concoct an idealized thought experiment capable of detecting one graviton; however, when anything remotely r

A. A. Schekochihin, S. C. Cowley

Observations of galaxy clusters show that the intracluster medium (ICM) is likely to be turbulent and is certainly magnetized. The properties of this magnetized turbulence are determined both by fundamental nonlinear magnetohydrodynamic interactions and by the plasma physics of the ICM, which has very low collisionality. Cluster plasma threaded by weak magne

S. Ryu, Y. Hatsugai

The entanglement entropy (von Neumann entropy) has been used to characterize the complexity of many-body ground states in strongly correlated systems. In this paper, we try to establish a connection between the lower bound of the von Neumann entropy and the Berry phase defined for quantum ground states. As an example, a family of translational invariant latt

Gandalf Lechner

A new approach to the construction of interacting quantum field theories on two-dimensional Minkowski space is discussed. In this program, models are obtained from a prescribed factorizing S-matrix in two steps. At first, quantum fields which are localized in infinitely extended, wedge-shaped regions of Minkowski space are constructed explicitly. In the seco

Roberto Iengo, Jorge G. Russo

We explain simple semi-classical rules to estimate the lifetime of any given highly-excited quantum state of the string spectrum in flat spacetime. We discuss both the decays by splitting into two massive states and by massless emission. As an application, we study a solution describing a rotating and pulsating ellipse which becomes folded at an instant of t

Enrico Nardi, Yosef Nir, Esteban Roulet, Juan Racker

We study leptogenesis from the out-of-equilibrium decays of the lightest heavy neutrino $N_1$ in the medium (low) temperature regime, $T\lsim 10^{12}$ GeV ($10^{10}$ GeV), where the rates of processes mediated by the $τ$ (and $μ$) Yukawa coupling are non negligible, implying that the effects of lepton flavors must be taken into account. We find important qua

I. G. Koprinkov

Phase sensitive adiabatic states for a quantum system interacting with an electromagnetic field have been derived taking into account all material phase factors of the initial bare states. The adiabatic states so obtained show a traceable phase behavior, causally depending on the initial conditions and the relevant physical processes. Experimental appearance

P. Castelo Ferreira, P. Vargas Moniz

Withdrawn: The solutions presented in this work are not compatible with the equation of motion for g_{00}, which we did not properly verify. In the framework of this work, the only bulk solutions compatible with periodicity of the fifth dimension are constant fields. Also for a scalar field only constant solutions are obtained.

Marco Cadoli, Toni Mancini

The goal of this paper is to provide a strong integration between constraint modelling and relational DBMSs. To this end we propose extensions of standard query languages such as relational algebra and SQL, by adding constraint modelling capabilities to them. In particular, we propose non-deterministic extensions of both languages, which are specially suited

V. I. Afonso, D. Bazeia, L. Losano

This work deals with braneworld scenarios in the presence of real scalar field with standard dynamics. We show that the first-order formalism, which exists in the case of flat brane, can be extended to bent brane, for both de Sitter and anti-de Sitter geometry. We illustrate the results with some examples of current interest to high energy physics.

Matthias Blau, George Thompson

We study Chern-Simons theory on 3-manifolds $M$ that are circle-bundles over 2-dimensional surfaces $Σ$ and show that the method of Abelianisation, previously employed for trivial bundles $Σ\times S^1$, can be adapted to this case. This reduces the non-Abelian theory on $M$ to a 2-dimensional Abelian theory on $Σ$ which we identify with q-deformed Yang-Mills

V. Bosch-Ramon, J. M. Paredes, G. E. Romero, D. F. Torres

Among unidentified gamma-ray sources in the galactic plane, there are some that present significant variability and have been proposed to be high-mass microquasars. To deepen the study of the possible association between variable low galactic latitude gamma-ray sources and microquasars, we have applied a leptonic jet model based on the microquasar scenario t

R. J. Barber, J. Tennyson, G. J. Harris, R. N. Tolchenov

A computed list of H$_{2}$$^{16}$O infra-red transition frequencies and intensities is presented. The list, BT2, was produced using a discrete variable representation two-step approach for solving the rotation-vibration nuclear motions. It is the most complete water line list in existence, comprising over 500 million transitions (65% more than any other list

Leonardo Pisani, Tulika Maitra, Roser Valenti

We present a density functional study of Fe doped into the tetrahedral and octahedral cation sites of the wide band gap spinel ZnGa$_2$O$_4$. We calculate the electronic structure for different substitutions and discuss the magnetic and transport properties for each case considering different approximations for the exchange-correlation potential. We show tha

Pasquale Calabrese, John Cardy

We show that the time-dependence of correlation functions in an extended quantum system in d dimensions, which is prepared in the ground state of some hamiltonian and then evolves without dissipation according to some other hamiltonian, may be extracted using methods of boundary critical phenomena in d+1 dimensions. For d=1 particularly powerful results are

A. Abada, S. Davidson, F-X. J. Michaux, M. Losada

We study the impact of flavour in thermal leptogenesis, including the quantum oscillations of the asymmetries in lepton flavour space. In the Boltzmann equations we find different numerical factors and additional terms which can affect the results significantly. The upper bound on the CP asymmetry in a specific flavour is weaker than the bound on the sum. Th

Iain Moffatt

We use a simple geometric argument and small cancellation properties of link groups to prove that alternating links are non-trivial. This proof uses only classic results in topology and combinatorial group theory.

S. Castelletto, I. P. Degiovanni, V. Schettini, A. Migdall

We explore the feasibility of using high conversion-efficiency periodically-poled crystals to produce photon pairs for photon-counting detector calibrations at 1550 nm. The goal is the development of an appropriate parametric down-conversion (PDC) source at telecom wavelengths meeting the requirements of high-efficiency pair production and collection in sing

C. Adami, G. Ver Steeg

If black holes were able to clone quantum states, a number of paradoxes in black hole physics would disappear. However, the linearity of quantum mechanics forbids exact cloning of quantum states. Here we show that black holes indeed clone incoming quantum states with a fidelity that depends on the black hole's absorption coefficient, without violating th

Christopher M. Dawson, Henry L. Haselgrove, Michael A. Nielsen

In this paper we do a detailed numerical investigation of the fault-tolerant threshold for optical cluster-state quantum computation. Our noise model allows both photon loss and depolarizing noise, as a general proxy for all types of local noise other than photon loss noise. We obtain a threshold region of allowed pairs of values for the two types of noise.

Feng-Kun Guo, Peng-Nian Shen, Huan-Qing Jiang

The $ψ'\to J/ψπ^+π^-$ decay process provides a new way to extract the $ππ$ $S$ wave phase shifts up to $0.59GeV$. In this paper we derive the formulae for extracting the $ππ$ $S$ wave phase shifts from the invariant mass spectrum of $ππ$ in the $ψ'\to J/ψπ^+π^-$ decay.

T. Kappeler, P. Perry, M. Shubin, P. Topalov

In 1974 P. Lax introduced an algebro-analytic mechanism similar to the Lax L-A pair. Using it we prove global existence and uniqueness for solutions of the initial value problem for mKdV in classes of smooth functions which can be unbounded at infinity, and may even include functions which tend to infinity with respect to the space variable. Moreover, we est

Y. Z. Zhang, J. X. Wang, Y. Q. Hu

Time-dependent resistive magnetohydrodynamic simulations are carried out to study a flux rope eruption caused by magnetic reconnection with implication in coexistent flare-CME (coronal mass ejection) events. An early result obtained in a recent analysis of double catastrophe of a flux rope system is used as the initial condition, in which an isolated flux ro

Shao-You Zhao, Wen-Li Yang, Yao-Zhong Zhang

We review the recent progress on the construction of the determinant representations of the correlation functions for the integrable supersymmetric fermion models. The factorizing $F$-matrices (or the so-called $F$-basis) play an important role in the construction. In the $F$-basis, the creation (and the annihilation) operators and the Bethe states of the in

Takahiro Kubota

The one-loop QED and electroweak radiative corrections to neutrino-deuteron scattering induced by the neutral current are reexamined, paying a particular attention to the constant term which has never been treated properly in literature. This problem is closely related to the definition of the axial-vector coupling constant $g_{A}$ and requires thorough calc

Xiang-Yu Wang, Zhuo Li, Peter Meszaros

The recent detection of delayed X-ray flares during the afterglow phase of gamma-ray bursts (GRBs) suggests an inner-engine origin, at radii inside the deceleration radius characterizing the beginning of the forward shock afterglow emission. Given the observed temporal overlapping between the flares and afterglows, there must be inverse Compton (IC) emission

W. C. Lim, R. J. Deeley, J. Wainwright

We derive the late-time behaviour of tilted Bianchi VII_0 cosmologies with an irrotational radiation fluid as source, and give the asymptotic form of the general solution as $t \to +\infty$, making comparisons with the dust-filled models. At first sight the radiation-filled models appear to approximate the flat FL model at late times, since the Hubble-normal

Fernando M. Cucchietti, Caio H. Lewenkopf, Horacio M. Pastawski

We study the decay rate of the Loschmidt echo or fidelity in a chaotic system under a time-dependent perturbation $V(q,t)$ with typical strength $\hbar/τ_{V}$. The perturbation represents the action of an uncontrolled environment interacting with the system, and is characterized by a correlation length $ξ_0$ and a correlation time $τ_0$. For small perturbati

Detlef Duerr, Sheldon Goldstein, James Taylor, Roderich Tumulka

We derive for Bohmian mechanics topological factors for quantum systems with a multiply-connected configuration space Q. These include nonabelian factors corresponding to what we call holonomy-twisted representations of the fundamental group of Q. We employ wave functions on the universal covering space of Q. As a byproduct of our analysis, we obtain an expl

I. G. Koprinkov

We present theoretical and experimental evidences showing that the material phase of the state vector is causally related with the dynamic of quantum system and may have observable physical consequences.

I. G. Koprinkov

We present theoretical and experimental evidences, which show that the material phase of the state vector is causally related with the dynamic of the quantum system and becomes carrier of physical information.

Anna Jencova

We show a relation between a quantum channel $Φ$ and its conjugate $Φ^C$, which implies that the $p\to p$ Schatten norm of the channel is the same as the $1\to p$ completely bounded norm of the conjugate. This relation is used to give an alternative proof of the multiplicativity of both norms.

Thiago R. Oliveira, A. O. Caldeira

The possibility of obtaining the initial pure state in a usual Stern-Gerlach experiment through the recombination of the two emerging beams is investigated. We have extended the previous work of Englert, Schwinger and Scully \cite{ISG1} including the fluctuations of the magnetic field generated by a properly chosen magnet. As a result we obtained an attenuat

Er'el Granot, Avi Marchewka

We investigate the short-time dynamics of a delta-function potential barrier on an initially confined wave-packet. There are mainly two conclusions: A) At short times the probability density of the first particles that passed through the barrier is unaffected by it. B) When the barrier is absorptive (i.e., its potential is imaginary) it affects the transmitt

William Boucher, Thierry Debuisschert

We have implemented an experimental set-up in order to demonstrate the feasibility of time-coding protocols for quantum key distribution. Alice produces coherent 20 ns faint pulses of light at 853 nm. They are sent to Bob with delay 0 ns (encoding bit 0) or 10 ns (encoding bit 1). Bob directs at random the received pulses to two different arms. In the first

Wei-Long She

Very recently we present a theory [Wei-long She, Chin. Phys. 14, 2514(2005); Online: http://www.jop.org/journals/cp; http://arxiv.org/abs/quant-ph/0512097] to show that the quantization of light energy in vacuum can be derived directly from classical electromagnetic theory through the consideration of statistics based on classical physics and reveal that the

Renato Renner

We propose various new techniques in quantum information theory, including a de Finetti style representation theorem for finite symmetric quantum states. As an application, we give a proof for the security of quantum key distribution which applies to arbitrary protocols.

Hwayean Lee, Jongin Lim, HyungJin Yang

We propose a quantum key distribution protocol with quantum based user authentication. Our protocol is the first one in which users can authenticate each other without previously shared secret and then securely distribute a key where the key may not be exposed to even a trusted third party. The security of our protocol is guaranteed by the properties of the

G. A. Enciso

Two complementary analyses of a cyclic negative feedback system with delay are considered in this paper. The first analysis applies the work by Sontag, Angeli, Enciso and others regarding monotone control systems under negative feedback, and it implies the global attractiveness towards an equilibrium for arbitrary delays. The second one concerns the existenc

Jose E. Gonzalez, Robersy Sanchez, Aminael Sanchez

Motivation: Its well known the use of electric current in the cleaning of viral diseases in plants instead a deep knowledge of this phenomenas theoretical basis is not yet available. The description of the real causes of nucleoprotein inactivation, will contribute to the optimization of further experiments in order to obtain more and more efficient cleaning

Gerhard Schmid, Igor Goychuk, Peter Hanggi

The influence of intrinsic channel noise on the spontaneous spiking activity of poisoned excitable membrane patches is studied by use of a stochastic generalization of the Hodgkin-Huxley model. Internal noise stemming from the stochastic dynamics of individual ion channels is known to affect the collective properties of the whole ion channel cluster. For exa

Matteo Dell'Omodarme, Giada Valle

Despite several deficiencies, the use of spreadsheets in statistics courses is increasingly common. In this paper we discuss many shortcomings resulting from this approach. We suggest a technique integrating a spreadsheet and a dedicated software package (R), that takes advantage of the characteristics of both programs. We also present a simple protocol of t