November 2005 arXiv papers — page 24

Andrey V. Zhiglo

Various flame tracking techniques are often used in hydrodynamic simulations. Their use is indispensable when resolving actual scale of the flame is impossible. We show that parameters defining "artificial flame" propagation found from model systems may yield flame velocities several times distinct from the required ones, due to matter expansion bein

Shai Kaspi, Ehud Behar

We present and discuss high-resolution grating spectra of the quasar PG1211+143 obtained over three years. Based on an early observation from 2001, we find an outflow component of about 3000 km/s in contrast with the much higher velocity of about 24000 km/s reported earlier for this source, and based on the same data set. Subsequent grating spectra obtained

Matthew R. Francis, Rachel Bean, Arthur Kosowsky

Future high-resolution microwave background measurements hold the promise of detecting galaxy clusters throughout our Hubble volume through their Sunyaev-Zel'dovich (SZ) signature, down to a given limiting flux. The number density of galaxy clusters is highly sensitive to cluster mass through fluctuations in the matter power spectrum, as well as redshift

Benjamin J. Owen

I make the first estimates of maximum elastic quadrupole deformations sustainable by alternatives to conventional neutron stars. Solid strange quark stars might sustain maximum ellipticities (dimensionless quadrupoles) up to a few times $10^{-4}$ rather than a few times $10^{-7}$ for conventional neutron stars, and hybrid quark-baryon or meson-condensate sta

P. J. Käpylä, M. J. Korpi, M. Stix, I. Tuominen

We study the mixing length concept in comparison to three-dimensional numerical calculations of convection with rotation. In a limited range, the velocity and temperature fluctuations are linearly proportional to the superadiabaticity, as predicted by the mixing length concept and in accordance with published results. The effects of rotation are investigated

A. J. S. Hamilton, C. D. Rimes, R. Scoccimarro

We show how to estimate the covariance of the power spectrum of a statistically homogeneous and isotropic density field from a single periodic simulation, by applying a set of weightings to the density field, and by measuring the scatter in power spectra between different weightings. We recommend a specific set of 52 weightings containing only combinations o

C. D. Rimes, A. J. S. Hamilton

We measure the covariance of the non-linear matter power spectrum from N-body simulations using two methods. In the first case, the covariance of power is estimated from the scatter over many random realizations of the density field. In the second, we use a novel technique to measure the covariance matrix from each simulation individually by re-weighting the

Estia J. Eichten, Kenneth Lane, Chris Quigg

We revise and extend expectations for the properties of charmonium states that lie above charm threshold, in light of new experimental information. We refine the Cornell coupled-channel model for the coupling of c-cbar levels to two-meson states, defining resonance masses and widths by pole positions in the complex energy plane, and suggest new targets for e

Arni S. R. Srinivasa Rao

A mid-point theorem is proved in an elementary way for the U type shape of functions that arise out of exponential quadratic functions. These results are inspired from epidemic patterns and growth over a time period. Key words: natural numbers mapping, mean value theorem.

S. H. Cohen, R. E. Ryan, A. N. Straughn, N. P. Hathi

We present a photometric search for objects with point-source components that are optically variable on timescales of weeks--months in the Hubble Ultra Deep Field (HUDF) to i'(AB)=28.0 mag. The data are split into four sub-stacks of approximately equal exposure times. Objects exhibiting the signature of optical variability are selected by studying the ph

Saul Barshay, Georg Kreyerhoff

We present aspects of a model which attempts to unify the creation of cold dark matter, a CP-violating baryon asymmetry, and also a small, residual vacuum energy density, in the early universe. The model contains a primary scalar (inflaton) field and a primary pseudoscalar field, which are initially related by a cosmological, chiral symmetry. The nonzero vac

Bin Wang

This is the part II of our series of two papers, "Clemens' conjecture: part I", "Clemens' conjecture: part II". Continuing from part I, in this paper we turn our attention to general quintic threefolds. In a universal quintic threefold X, we construct a family of quasi-regular deformation B_b such that the generic member in this famil

Chethan Krishnan, Edoardo Di Napoli

With a view towards applications for de Sitter, we construct the multi-parametric $q$-deformation of the $so(5,\IC)$ algebra using the Faddeev-Reshetikhin-Takhtadzhyan (FRT) formalism.

Predrag Nikolic, Subir Sachdev

We describe the influence of the gapless, nodal, fermionic quasiparticles of a two-dimensional d-wave superconductor on the motion of vortices. A continuum, functional formalism is used to obtain the effective vortex action, after the fermions have been integrated out. At zero temperture (T), the leading terms in the vortex action retain their original form,

Claudia de Rham, Andrew J. Tolley

We consider the propagation of gravitational waves in six dimensions induced by sources living on 3-branes in the context of a recent exact solution hep-th/0506050. The brane geometries are de Sitter and the bulk is a warped geometry supported by a positive cosmological constant as well as a 2-form flux. We show that at low energies ordinary gravity is repro

Tina Kahniashvili, Tanmay Vachaspati

Magnetic fields in various astrophysical settings may be helical and, in the cosmological context, may provide a measure of primordial CP violation during baryogenesis. Yet it is difficult, even in principle, to devise a scheme by which magnetic helicity may be detected, except in some very special systems. We propose that charged cosmic rays originating fro

Bin Wang

This is a series of two papers in which we solve the Clemens conjecture: there are only finitely many smooth rational curves of each degree in a generic quintic threefold. In this first paper, we deal with a family of smooth Calabi-Yau threefolds f_εfor a small complex number ε. We give an geometric obstruction, deviated quasi-regular deformations B_b of c_ε

Tetsufumi Hirano

We can establish a new picture, the perfect fluid sQGP core and the dissipative hadronic corona, of the space-time evolution of produced matter in relativistic heavy ion collisions at RHIC. It is also shown that the picture works well also in the forward rapidity region through an analysis based on a new class of the hydro-kinetic model and that this is a ma

Dean Lee

We present lattice results for the ground state energy of a spin-1/2 fermion system in the unitary limit, where the effective range of the interaction is zero and the scattering length is infinite. We compute the ground state energy for a system of 6, 10, 14, 18, and 22 particles, with equal numbers of up and down spins in a periodic cube. We estimate that i

I. F. Bikmaev, R. A. Sunyaev, M. G. Revnivtsev, R. A. Burenin

We present first results of a campaign of optical identifications of X-ray sources discovered by RXTE and INTEGRAL observatories during their sky surveys. In this work we study six newly discovered nearby active galactic nuclei at z<0.1. The optical spectrophotometric data were obtained with Russian-Turkish 1.5-m telescope (RTT150). We present their redshift

Fabrizio Di Marco, Alessio Notari

We show that Inflation in a False Vacuum becomes viable in the presence of a spectator scalar field non minimally coupled to gravity. The field is unstable in this background, it grows exponentially and slows down the pure de Sitter phase itself, allowing then fast tunneling to a true vacuum. We compute the constraint from graceful exit through bubble nuclea

Scott J. Thompson, Steven P. Lewis

A detailed reexamination of the (110) surface structure of rutile TiO2 has been carried out using first-principles total-energy methods. This investigation is in response to a recent high-precision LEED-IV measurement revealing certain significant quantitative discrepancies between experiment and previous theoretical calculations. We have been able to resolv

R. D. Davies, C. Dickinson, A. J. Banday, T. R. Jaffe

WMAP data when combined with ancillary data on free-free, synchrotron and dust allow an improved understanding of the spectrum of emission from each of these components. Here we examine the sky variation at intermediate latitudes using a cross-correlation technique. In particular, we compare the observed emission in 15 selected sky regions to three ``standar

Charalampos Anastasiou, Alejandro Daleo

We present a new method for the numerical evaluation of arbitrary loop integrals in dimensional regularization. We first derive Mellin-Barnes integral representations and apply an algorithmic technique, based on the Cauchy theorem, to extract the divergent parts in the epsilon->0 limit. We then perform an epsilon-expansion and evaluate the integral coefficie

Igor Nikolaev

An AF-algebra is assigned to each cusp form f of weight two; we study properties of this operator algebra, when f is a Hecke eigenform.

Julien Sopik, Clement Sire, Pierre-Henri Chavanis

We consider the dynamics of a gas of free bosons within a semi-classical Fokker-Planck equation for which we give a physical justification. In this context, we find a striking similarity between the Bose-Einstein condensation in the canonical ensemble, and the gravitational collapse of a gas of classical self-gravitating Brownian particles. The paper is main

Marino Gran, Tim Van der Linden

We develop some new aspects of cohomology in the context of semi-abelian categories: we establish a Hochschild-Serre 5-term exact sequence extending the classical one for groups and Lie algebras; we prove that an object is perfect if and only if it admits a universal central extension; we show how the second Barr-Beck cohomology group classifies isomorphism

Vitor Araujo, Maria Jose Pacifico, Enrique Pujals, Marcelo Viana

We prove that a singular-hyperbolic attractor of a 3-dimensional flow is chaotic, in two strong different senses. Firstly, the flow is expansive: if two points remain close for all times, possibly with time reparametrization, then their orbits coincide. Secondly, there exists a physical (or Sinai-Ruelle-Bowen) measure supported on the attractor whose ergodic

Sara Jabbari-Farouji, Daisuke Mizuno, Maryam Atakhorrami, Fred C. MacKintosh

We provide a direct experimental test of the Stokes-Einstein relation as a special case of the fluctuation-dissipation theorem (FDT) in an aging colloidal glass. The use of combined active and passive microrheology allows us to independently measure both the correlation and response functions in this non-equilibrium situation. Contrary to previous reports, w

T. Clifton, John D. Barrow

We determine the general conditions for the existence of Godel, Einstein static, and de Sitter universes in gravity theories derived from a Lagrangian that is an arbitrary function of the scalar curvature and Ricci and Riemann curvature invariants. Explicit expressions for the solutions are found in terms of the parameters defining the Lagrangian. We also de

Adan Cabello

We introduce two two-player quantum pseudo-telepathy games based on two recently proposed all-versus-nothing (AVN) proofs of Bell&#39;s theorem [A. Cabello, Phys. Rev. Lett. 95, 210401 (2005); Phys. Rev. A 72, 050101(R) (2005)]. These games prove that Broadbent and Methot&#39;s claim that these AVN proofs do not rule out local-hidden-variable theories in whi

A. -K. Jappsen, S. C. O. Glover, R. S. Klessen, M. -M. Mac Low

We study the influence of low levels of metal enrichment on the cooling and collapse of ionized gas in small protogalactic halos using three-dimensional, smoothed particle hydrodynamics simulations. Our initial conditions represent protogalaxies forming within a fossil HII region -- a previously ionized HII region which has not yet had time to cool and recom

V. Paschalidis, A. M. Khokhlov, I. D. Novikov

We present an analysis of well-posedness of constrained evolution of 3+1 formulations of GR. In this analysis we explicitly take into account the energy and momentum constraints as well as possible algebraic constraints on the evolution of high-frequency perturbations of solutions of Einstein&#39;s equations. In this respect, our approach is principally diff

I. I. Bigi, N. Uraltsev, R. Zwicky

We address the nonperturbative effects associated with soft charm quarks in inclusive B decays. Such corrections are allowed by the OPE, but have largely escaped attention so far. The related four-quark `double heavy&#39; expectation values of the form <B|\bar{b}c \bar{c}b|B> are computed in the 1/m_c expansion by integrating out the charm field to one and t

R. Silva, G. S. Franca, C. S. Vilar, J. S. Alcaniz

We have revisited the fragment-asperity interaction model recently introduced by Sotolongo-Costa and Posadas (Physical Review Letters 92, 048501, 2004) by considering a different definition for mean values in the context of Tsallis nonextensive statistics and introducing a new scale between the earthquake energy and the size of fragment $ε\propto r^3$. The e

Ursula Hamenstaedt

Let S be an oriented surface of genus g with m punctures. If 3g-3+m is at least 4 then we construct for every compact subset K of moduli space a closed Teichmueller geodesic not intersecting K.

Alessandro Sergi, Paolo V. Giaquinta

We analyze the equilibrium statistical mechanics of canonical, non-canonical and non-Hamiltonian equations of motion by throwing light into the peculiar geometric structure of phase space. Some fundamental issues regarding time translation and phase space measure are clarified. In particular, we emphasize that a phase space measure should be defined by means

C. E. Thomas

Branching ratios and polarization amplitudes for B decaying to all allowed pseudoscalar, vector, axial-vector, scalar and tensor combinations of D_s and D mesons are calculated in the Isgur Scora Grinstein Wise (ISGW) quark model after assuming factorization. We find good agreement with other models in the literature and the limited experimental data and mak

Mohammad A. Ganjali

Recently, it was shown that half BPS Supergravity solution of theories with SU(2$|$4) symmetry algebra is given uniformly by determining a single function which obeys three dimensional continuous Toda equation. In this paper, we study the scale invariant solution of Toda equation. Our motivation is that some solutions of half BPS sector of IIB supergravity,

Simon Portegies Zwart, Holger Baumgardt, Stephen L. W. McMillan, Junichiro Makino

We simulate the inner 100pc of the Milky-Way Galaxy to study the formation and evolution of the population of star clusters and intermediate mass black holes. For this study we perform extensive direct N-body simulations of the star clusters which reside in the bulge, and of the inner few tenth of parsecs of the super massive black hole in the Galactic cente

Harald Dimmelmeier, Nikolaos Stergioulas, Jose A. Font

We study non-linear axisymmetric pulsations of rotating relativistic stars using a general relativistic hydrodynamics code under the assumption of a conformal flatness. We compare our results to previous simulations where the spacetime dynamics was neglected. The pulsations are studied along various sequences of both uniformly and differentially rotating rel

Xavier Garcia i Tormo, Joan Soto

We argue that the photon spectra in radiative decays of various heavy quarkonium states provide important information on their nature. If two of these states are in the strong coupling regime, we are able to produce a parameter-free model independent formula, which holds at next-to-leading order and includes both direct and fragmentation contributions. When

Ricardo E. Gamboa Saravi

We describe the exact solution of Einstein&#39;s equation corresponding to a static homogenous distribution of matter with plane symmetry lying below $z=0$. We study the geodesics in it and we show that this simple spacetime exhibits very curious properties. In particular, it has a repelling singular boundary and all geodesics bounce off it.

Regine Frank, Andreas Lubatsch, Johann Kroha

We present a systematical theory for the interplay of strong localization effects and absorption or gain of classical waves in 3-dimensional, disordered dielectrics. The theory is based on the selfconsistent Cooperon resummation, implementing the effects of energy conservation and its absorptive or emissive corrections by an exact, generalized Ward identity.

A. -M. S. Tremblay, B. Kyung, D. Sénéchal

This is a short review of the theoretical work on the two-dimensional Hubbard model performed in Sherbrooke in the last few years. It is written on the occasion of the twentieth anniversary of the discovery of high-temperature superconductivity. We discuss several approaches, how they were benchmarked and how they agree sufficiently with each other that we c

G. S. Bisnovatyi-Kogan

The most precise measurements are done at present by timing of radiopulsars in binary systems with two neutron stars. The timing measurements of the Taylor-Hulse pulsar B1913+16 gave the most precise results on testing of general relativity (GR), finding implicit proof of existence of gravitational waves. We show that available results of existing measuremen

Keisuke Okamura, Yastoshi Takayama, Kentaroh Yoshida

We consider open spinning string solutions on an AdS_4 x S^2-brane (D5-brane) in the bulk AdS_5 x S^5 background. By taking account of the breaking of SO(6)_R to SO(3)_H x SO(3)_V due to the presence of the AdS-brane, the open rotating string ansatz is discussed. We construct the elliptic folded/circular open string solutions in the SU(2) and the SL(2) secto

K. Maeda, P. A. Mazzali, K. Nomoto

A fully 3D Monte Carlo scheme is applied to compute optical bolometric light curves for aspherical (jet-like) supernova explosion models. Density and abundance distributions are taken from hydrodynamic explosion models, with the energy varied as a parameter to explore the dependence. Our models show initially a very large degree ($\sim 4$ depending on model

Sonny Ben-Shimon, Michael Krivelevich

In this work we show that with high probability the chromatic number of a graph sampled from the random regular graph model $\Gnd$ for $d=o(n^{1/5})$ is concentrated in two consecutive values, thus extending a previous result of Achlioptas and Moore. This concentration phenomena is very similar to that of the binomial random graph model $\Gnp$ with $p=\frac{

S. Longhi, M. Marangoni, M. Lobino, R. Ramponi

We report on a direct experimental observation of dynamic localization (DL) of light in sinusoidally-curved Lithium-Niobate waveguide arrays which provides the optical analog of DL for electrons in periodic potentials subjected to ac electric fields as originally proposed by Dunlap and Kenkre [D.H. Dunlap and V.M. Kenkre, Phys. Rev. B 34, 3625 (1986)]. The t

Venelin Kozhuharov

An experimental proposal to measure Br($K^+ \to \pi^+ \nu \bar{\nu}$) has been submitted at the CERN SPSC. The goal is to collect ~80 $K^+\to \pi^+ \nu \bar{\nu}$ events with signal to background ratio of 10:1 in two years of data taking. This will allow determination of the CKM parameter $V_{td}$ with ~10% accuracy.

Tomoaki Nogawa, Koji Nemoto

We propose a model for charge density waves in ring shaped crystals, which depicts frustration between intra- and inter-chain couplings coming from cylindrical bending. It is then mapped to a three dimensional uniformly frustrated XY model with one dimensional anisotropy in connectivity. The nonequilibrium relaxation dynamics is investigated by Monte Carlo s

V. V. Abramov, P. I. Goncharov, A. Yu. Kalinin, A. V. Khmelnikov

The single spin asymmetry for charge hadron production off nuclei (C, Cu) has been measured using 40 GeV/c polarized proton beam. The measurements were carried out using FODS-2 experimental setup at IHEP. The data are presented in the central region and the forward region with respect to the incident protons.

Jae-Suk Yang, Seungbyung Chae, Woo-Sung Jung, Hie-Tae Moon

In this paper, we studied the dynamics of the log-return distribution of the Korean Composition Stock Price Index (KOSPI) from 1992 to 2004. Based on the microscopic spin model, we found that while the index during the late 1990s showed a power-law distribution, the distribution in the early 2000s was exponential. This change in distribution shape was caused

A. Gal, E. Friedman

Evidence for excitation of exotic S=+1 pentaquark degrees of freedom is presented by studying optical-potential fits to K^+ - nucleus total, reaction and elastic-differential cross section data at p(lab) = 500 - 700 MeV/c. Estimates of the underlying two-nucleon absorption K^+ n N --> Theta^+ N reaction cross section are made and are used for discussing the

Dan Mangoubi

Let M be a closed Riemannian manifold. We consider the inner radius of a nodal domain for a large eigenvalue λ. We give upper and lower bounds on the inner radius of the type C/λ^k. Our proof is based on a local behavior of eigenfunctions discovered by Donnelly and Fefferman, and a Poincaré type inequality proved by Maz&#39;ya. Sharp lower bounds are known o

P. Kroll

It is reported on an analysis of Phi-meson electroproduction at small Bjorken-x within the handbag approach. The amplitudes factorize into generalized parton distributions and a partonic subprocess, electroproduction off gluons. Cross sections and spin density matrix elements are evaluated for Phi-meson electroproduction and found to be in fair agreement wit

Masato Tsujii

We consider suspension semi-flows of angle-multiplying maps on the circle. Under a $C^r$generic condition on the ceiling function, we show that there exists an anisotropic Sobolev space contained in the $L^2$ space such that the Perron-Frobenius operator for the time-$t$-map acts on it and that the essential spectral radius of that action is bounded by the s

Gioacchino Ranucci

The experimental issue of the search for new particles of unknown mass poses the challenge of exploring a wide interval to look for the usual signatures represented by excess of events above the background. A side effect of such a broad range quest is that the traditional significance calculations valid for signals of known location are no more applicable wh

Daniel I. Goldman, Harry L. Swinney

We demonstrate that a fluidized bed of hard spheres during defluidization displays properties associated with formation of a glass. The final state is rate dependent, and as this state is approached, the bed exhibits heterogeneity with increasing time and length scales. The formation of a glass results in the loss of fluidization and an arrest of macroscopic

E. Anderson

This paper concerns the absolute versus relative motion debate. The Barbour and Bertotti 1982 work may be viewed as an indirectly set up relational formulation of a portion of Newtonian mechanics. I consider further direct formulations of this and argue that the portion in question -- universes with zero total angular momentum, that are conservative and with

E. Anderson

Relational particle models are employed as toy models for the study of the Problem of Time in quantum geometrodynamics. These models&#39; analogue of the thin sandwich is resolved. It is argued that the relative configuration space and shape space of these models are close analogues from various perspectives of superspace and conformal superspace respectivel

E. Anderson

The conventional spacetime formulation of general relativity may be recast as a dynamics of spatial 3-geometries (geometrodynamics). Furthermore, geometrodynamics can be derived from first principles. I investigate two distinct sets of these: (i) Hojman, Kuchař and Teitelboim&#39;s, which presuppose that the spatial 3-geometries are embedded in spacetime. (i

Kazuo Fujikawa

It is sometimes stated in the literature that the quantum anomaly is regarded as an example of the geometric phase. Though there is some superficial similarity between these two notions, we here show that the differences bewteen these two notions are more profound and fundamental. As an explicit example, we analyze in detail a quantum mechanical model propos

Jonas Soderholm, Keiichi Hirano, Shigehiko Mori, Shuichiro Inoue

The process of spontaneous parametric down-conversion (SPDC) in nonlinear crystals makes it fairly easy to generate entangled photon states. It has been known for some time that the conversion efficiency can be improved by employing quasi-phase-matching in periodically poled crystals. Using two single-photon detectors, we have analyzed the photon pairs gener

Sadollah Nasiri

The behavior of the quantum potential is studied for a particle in a linear and a harmonic potential by means of an extended phase space technique. This is done by obtaining an expression for the quantum potential in momentum space representation followed by the generalization of this concept to extended phase space. It is shown that there exists an extended

L. A. Tracy, J. P. Eisenstein, L. N. Pfeiffer, K. W. West

Resistively-detected NMR measurements on 2D electron systems near the $ν= 1$ quantum Hall state are reported. In contrast to recent results of Gervais \emph{et al.} [Phys. Rev. Lett. $\bf 94$, 196803 (2005)], a dispersive lineshape is found at all RF powers studied and Korringa-like nuclear spin-lattice relaxation is observed. The shape of the unexplained di

Ali Nayeri, Robert H. Brandenberger, Cumrun Vafa

We study the generation of cosmological perturbations during the Hagedorn phase of string gas cosmology. Using tools of string thermodynamics we provide indications that it may be possible to obtain a nearly scale-invariant spectrum of cosmological fluctuations on scales which are of cosmological interest today. In our cosmological scenario, the early Hagedo

Man-Duen Choi, Frederic Latremoliere

We study the C*-algebra crossed-product of the closed unit disk by the action of one of its conformal automorphisms. After classifying the conformal automorphisms up to topological conjugacy, we investigate, for each class, the irreducible representations of the full C*-crossed-products, and derive their spectrum and a complete desciption of the algebras.

Huisheng Wang, Xin Liu, Zhenjun Xiao, Libo Guo

We calculate the branching ratios and CP-violating asymmetries for $B^0 \to π^0 η^{(\prime)}$ and $B^+\to π^+ η^{(\prime)}$ decays in the perturbative QCD (pQCD) factorization approach here. We not only calculate the usual factorizable contributions, but also evaluate the non-factorizable and annihilation type contributions. Besides the current-current opera

S. Ole Warnaar

A new type of sl_3 basic hypergeometric series based on Macdonald polynomials is introduced. Besides a pair of Macdonald polynomials attached to two different sets of variables, a key-ingredient in the sl_3 basic hypergeometric series is a bisymmetric function related to Macdonald&#39;s commuting family of q-difference operators, to the sl_3 Selberg integral

Haibao Duan, Xuezhi Zhao

Based on the Basis theorem of Bruhat--Chevalley [C] and the formula for multiplying Schubert classes obtained in [D\QTR{group}{u}] and programed in [DZ$_{\QTR{group}{1}}$], we introduce a new method computing the Chow rings of flag varieties (resp. the integral cohomology of homogeneous spaces). The method and results of this paper have been extended in [DZ$

Christian Grosche

In this contribution I show that it is possible to construct three-dimensional spaces of non-constant curvature, i.e. three-dimensional Darboux-spaces. Two-dimensional Darboux spaces have been introduced by Kalnins et al., with a path integral approach by the present author. In comparison to two dimensions, in three dimensions it is necessary to add a curvat

Jeremy L. Fellows

The phenomenon of quantum entanglement is explained in a way which is fully consistent with Einstein&#39;s Special Theory of Relativity. A subtle flaw is identified in the logic supporting the view that Bell&#39;s Inequality precludes all local hidden-variable theories, and it is shown how EPR-type experiments can be constructed to produce statistical correl

Fei Gao, Fenzhuo Guo, Qiaoyan Wen, Fu-Chen Zhu

With the help of a simple quantum key distribution (QKD) scheme, we discuss the relation between BB84-type protocols and two-step-type ones. It is shown that they have the same essence, i.e., information-splitting. More specifically, the similarity between them includes (1) the carrier state is split into two parts which will be sent one by one; (2) the poss

Fei Gao, Fenzhuo Guo, Qiaoyan Wen, Fuchen Zhu

A quantum key distribution protocol based on entanglement swapping is proposed. Through choosing particles by twos from the sequence and performing Bell measurements, two communicators can detect eavesdropping and obtain the secure key. Because the two particles measured together are selected out randomly, we need neither alternative measurements nor rotatio

Noam Erez

The relative phase between spatially separated component waves of a single photon can be measured by joint interference with a second photon emitted by a known source. In the case of a single such phase (i.e. two component waves), the probability for a successful measurement is one half. This method can be implemented with current experimental techniques.

S. Nasiri, S. Khademi, S. Bahrami, F. Taati

A generalized quantum distribution function is introduced. The corresponding ordering rule for non-commuting operators is given in terms of a single parameter. The origin of this parameter is in the extended canonical transformations that guarantees the equivalence of different distribution functions obtained by assuming appropriate values for this parameter

S. Khademi, S. Nasiri, S. Fathi, F. Taati

Recently, it is shown that the extended phase space formulation of quantum mechanics is a suitable technique for studying the quantum dissipative system. Here, as an application of this formalism, we consider a dissipative system of charged particles interacting with an external time dependent electric field. Such a system has been investigating by Buch and

S. Khademi, S. Nasiri

Recently, it is shown that the extended phase space formulation of quantum mechanics is a suitable technique for studying the quantum dissipative systems. Here, as a further application of this formalism, we consider a dissipative system of charged particles interacting with an external time dependent electric field. Such a system has been investigated by Bu

H. Y. Fan Y. L. Yang

The generating entangled state by using a 50/50 beamsplitter has been discussed in the literature before . In this paper we explore how to use an asymmetric beam-splitter to produce a new kind of entangled state. We construct such kind of states theoretically and then prove that they make up a complete and orthonormal representation in two-mode Fock space. I

Xiong-Jun Liu, Hui Jing, Xin Liu, Ming-Sheng Zhan

Entanglement of remote atom lasers is obtained via quantum state transfer technique from lights to matter waves in a five-level $M$-type system. The considered atom-atom collisions can yield an effective Kerr susceptibility for this system and lead to the self- and cross- phase modulation between the two output atom lasers. This effect results in generation

Josh Mitteldorf

r-selection refers to evolutionary competition in the rate of a population&#39;s exponential increase. This is contrasted with K-selection, in which populations in steady-state compete in efficiency of resource conversion. Evolution in nature is thought to combine these two in various proportions. But in modeling the evolution of life histories, theorists ha

Uri Einav, Yuval Tabach, Gad Getz, Assif Yitzhaky

On the basis of epidemiological studies, infection was suggested to play a role in the etiology of human cancer. While for some cancers such a role was indeed demonstrated, there is no direct biological support for the role of viral pathogens in the pathogenesis of childhood leukemia. Using a novel bioinformatic tool, that alternates between clustering and s

T. Rozovskaia, O. Ravid-Amir, S. Tillib, G. Getz

The ALL-1 gene is directly involved in 5-10% of ALLs and AMLs by fusion to other genes or through internal rearrangements. DNA microarrays were utilized to determine expression profiles of ALLs and AMLs with ALL-1 rearrangements. These profiles distinguish those tumors from other ALLs and AMLs. The expression patterns of ALL-1-associated tumors, in particula

N. Hamedani Radja, R. R. Farzami, M. R. Ejtehadi

We show that the hydrophobicity of sequences is the leading term in Miyazawa-Jernigan interactions. Being the source of additive (solvation) terms in pair-contact interactions, they were used to reduce the energy parameters while resulting in a clear vector manipulation of energy. The reduced (additive) potential performs considerably successful in predictin

Wiliam Ferreira da Cunha, Luiz Fernando Roncaratti, Ricardo Gargano, Geraldo Magela e Silva

In this work, we present a new fitting of the Na+HF potential energy surface (PES) utilizing a new optmization method based in Genetic Algorithm. Topology studies, such as isoenergetic contours and Minimum Energy Path(MEP), show that the quality of this new PES is comparable to the best PES of literature. These facts, suggests that this new approach can be u

Alex Kentsis

In his interviews with Eckermann in the 1820s, Goethe referred to his Theory of Colors as his greatest and ultimate achievement. Its reception following publication in 1810 and subsequent reviews throughout the history of physical science did not reflect this self-assessment. Even Hermann von Helmholtz, who in part modeled his scientific work after Goethe&#3

Zi-Gang Huang, Yong Chen, Yong Zhang, Ying-Hai Wang

We present a time-dependent Langevin description of dynamics of stock prices. Based on a simple sliding-window algorithm, the fluctuation of stock prices is discussed in the view of a time-dependent linear restoring force which is the linear approximation of the drift parameter in Langevin equation estimated from the financial time series. By choosing suitab

Danuta Makowiec, Wieslaw Miklaszewski

Effects of large value assigned to the maximal car velocity on the fundamental diagrams in the Nagel-Schreckenberg model are studied by extended simulations. The function relating the flow in the congested traffic phase with the car density and deceleration probability is found numerically. Properties of the region of critical changes, so-called jamming tran

Ramazan Koc, Hayriye Tutunculer, Mehmet Koca

It is now well known that electron (hole)-vibron coupling and hence Jahn-Teller (JT) effect is important understanding the properties of $C_{60}$ and related molecules. In this paper, we study $H\otimes (2h\oplus g)$ coupling case to find the potential energy surfaces for the positively charged $C_{60}$ molecule due to distortion. The $H\otimes (2h\oplus g)$

M. -C. Firpo

It is shown that the critical layer analysis, involved in the linear theory of internal modes, can be extended continuously into the early nonlinear regime. For the m=1 resistive mode, the dynamical analysis involves two small parameters: the inverse of the magnetic Reynolds number S and the m=1 mode amplitude A, that measures the amount of nonlinearities in

François Hild, Stéphane Roux

The current development of digital image correlation, whose displacement uncertainty is well below the pixel value, enables one to better characterise the behaviour of materials and the response of structures to external loads. A general presentation of the extraction of displacement fields from the knowledge of pictures taken at different instants of an exp

Damien Claire, François Hild, Stéphane Roux

It is proposed to identify damage variables and their growth with loading in two dimensions by only using full-field displacement measurements. The equilibrium gap method is used to estimate the damage field during a biaxial experiment on a sample made of a composite material. From the analysis of a sequence of measurements, a proposed form of constitutive l

Gustavo Rigolin, Andres A. Rieznik

We show in details the four quantum key distribution protocols which initiated the important field of quantum cryptography, using an accessible language for undergraduate students. We begin presenting the BB84 protocol, which uses polarization states of photons in order to transmit cryptographic keys. Thereupon we show the E91 protocol, whose security is bas

X. Q. Li, S. Q. Liu

It is shown that under the post-Newtonian approximation the Einstein equations can be reduced to the standard Maxwell-type field equations in a medium; in such a context the Cerenkov emission by a neutralparticle gives large energy loss while the particle moves at faster than the phase speed of waves in the medium.

Marco V. Tognetti, Helder M. Crespo

We present what is to our knowledge the most complete 1-D numerical analysis of the evolution and the propagation dynamics of an ultrashort laser pulse in a Ti:Sapphire laser oscillator. This study confirms the dispersion managed model of mode-locking, and emphasizes the role of the Kerr nonlinearity in generating mode-locked spectra with a smooth and well-b

Jian-Miin Liu

In the framework of the solvable model of cosmology constructed in the Earth-related coordinate system, we derive the modified Hubble law. This law carries the slowly time-varying Hubble parameter. The modified Hubble law eliminates the need for dark energy.

Andreas Bierwage, Sadruddin Benkadda, Satoshi Hamaguchi, Masahiro Wakatani

Configurations with nearby multiple resonant surfaces have broad spectra of linearly unstable coupled tearing modes with dominant high poloidal mode numbers m. This was recently shown for the case of multiple q = 1 resonances [Bierwage et al., Phys. Rev. Lett. 94 (6), 65001 (2005)]. In the present work, similar behavior is found for double tearing modes (DTM

Yang Sun, Michael Wiescher, Ani Aprahamian, Jacob L. Fisker

Isomeric states in the nuclei along the rapid proton capture process path are studied by the projected shell model. Emphasis is given to two waiting point nuclei Se-68 and Kr-72 that are characterized by shape coexistence. Energy surface calculations indicate that the ground state of these nuclei corresponds to an oblate-deformed minimum, while the lowest st