March 2006 arXiv papers — page 15

Gong-Bo Zhao, Jun-Qing Xia, Bo Feng, Xinmin Zhang

Using the Markov chain Monte Carlo (MCMC) method we perform a global analysis constraining the dynamics of dark energy in light of the supernova (Riess "Gold" samples), galaxy clustering (SDSS 3D power spectra and SDSS lyman-αforest information) and the latest three-year Wilkinson Microwave Anisotropy Probe (WMAP) observations. We have allowed the da

Georg Feulner, Ulrich Hopp, Christine S. Botzler

Aims: We investigate the build-up of stellar mass through star formation in field galaxies, galaxy groups, and clusters in order to better understand the physical processes regulating star formation in different haloes. Methods: In order to do so we relate ongoing star formation activity to the stellar mass by studying the integrated specific star formation

Aurélien A. Fraisse

We compare the predictions of hybrid inflationary models that produce both adiabatic fluctuations and topological defects to first year WMAP results. We use a Markov Chain Monte Carlo method to constrain the contribution of cosmic strings and textures to the CMB angular power spectrum. Marginalizing this contribution over the cosmological parameters of a pow

Diego Dominici

We extend the usual definition of the derivative in a way that Calculus I students can easily comprehend and which allows calculations at branch points.

Thomas Brady, Jose Burillo, Sean Cleary, Melanie Stein

We describe pure braided versions of Thompson's group F. These groups, $BF$ and $\hat{BF}$, are subgroups of the braided versions of Thompson's group V, introduced by Brin and Dehornoy. Unlike V, elements of F are order-preserving self-maps of the interval and we use pure braids together with elements of F thus preserving order. We define these group

Gaston Giribet, Julio Oliva, Ricardo Troncoso

We look for the existence of asymptotically flat simple compactifications of the form $M_{D-p}\times T^{p}$ in $D$-dimensional gravity theories with higher powers of the curvature. Assuming the manifold $M_{D-p}$ to be spherically symmetric, it is shown that the Einstein-Gauss-Bonnet theory admits this class of solutions only for the pure Einstein-Hilbert or

Marek Nowakowski, Andres Balaguera-Antolinez

We explore local consequences of a non-zero cosmological constant on astrophysical structures. We find that the effects are not only sensitive to the density of the configurations but also to the geometry. For non-homogeneous configurations, we calculate the effects for a polytropic configurations and the isothermal sphere. Special emphasis is put on the fac

A. N. Gorban, N. R. Sumner, A. Y. Zinovyev

A method of {\it topological grammars} is proposed for multidimensional data approximation. For data with complex topology we define a {\it principal cubic complex} of low dimension and given complexity that gives the best approximation for the dataset. This complex is a generalization of linear and non-linear principal manifolds and includes them as particu

Wolter Siemons, Gertjan Koster, Hideki Yamamoto, Walter A. Harrison

We have made very thin films of LaAlO3 on TiO2 terminated SrTiO3 and have measured the properties of the resulting interface in various ways. Transport measurements show a maximum sheet carrier density of 1016 cm-2 and a mobility around 104 cm2 V-1 s-1. In situ ultraviolet photoelectron spectroscopy (UPS) indicates that for these samples a finite density of

Philip Sternberg

Let $\mathfrak{g}$ be a Lie algebra all of whose regular subalgebras of rank 2 are type $A_{1}\times A_{1}$, $A_{2}$, or $C_{2}$, and let $B$ be a crystal graph corresponding to a representation of $\mathfrak{g}$. We explicitly describe the local structure of $B$, confirming a conjecture of Stembridge.

Kei Iida, Kenji Fukushima

We systematically apply density functional theory to determine the kind of inhomogeneities that spontaneously develop in a homogeneous gapless phase of neutral two-flavor superfluid quark matter. We consider inhomogeneities in the quark and electron densities and in the phases and amplitude of the order parameter. These inhomogeneities are expected to lead t

Michel Gondran, Alexandre Gondran

The standard quantum theory has not taken into account the size of quantum particles, the latter being implicitly treated as material points. The recent interference experiments of Zeilinger [3] with large molecules like fullerenes and the thought experiments of Bozic et al [7] with asymmetrical Young slits make it possible today to take into account the par

Alexander Scholz, Ray Jayawardhana, Kenneth Wood

We have carried out sensitive 1.3 mm observations of 20 young brown dwarfs in the Taurus star-forming region, representing the largest sample of young substellar objects targeted in a deep millimeter continuum survey to date. Under standard assumptions, the masses of brown dwarf disks range from ~<0.4 to several Jupiter masses. Their relative disk masses are

Vinu Lukose, R. Shankar, G. Baskaran

A single graphene layer exhibits an anomalous Landau level spectrum. A massless Dirac like low energy electronic spectrum underlies this anomaly. We study, analytically and numerically, the effect of a uniform electric field $(E)$ on the anomalous Landau levels. We solve the problem exactly within the Dirac cone approximation and find an interesting scaling

Stefan Wenger

In a recent paper Chatterji and Niblo proved that a geodesic metric space is Gromov hyperbolic if and only if the intersection of any two closed balls has uniformly bounded eccentricity. In their paper, the authors raise the question whether a geodesic metric space with the property that the intersection of any two closed balls has eccentricity 0, is necessa

Aurélien A. Fraisse

We confront the predicted effects of hybrid inflationary models on the Cosmic Microwave Background (CMB) with three years of Wilkinson Microwave Anisotropy Probe (WMAP) observations. Using model selection, we compare the ability of a simple flat power-law LCDM model to describe the data to that of hybrid inflationary models involving global or local cosmic s

Zdzislaw Burda, Andrzej Goerlich, Bartlomiej Waclaw

We present an analytic method for calculating spectral densities of empirical covariance matrices for correlated data. In this approach the data is represented as a rectangular random matrix whose columns correspond to sampled states of the system. The method is applicable to a class of random matrices with radial measures including those with heavy (power-l

Tao Hong, M. Kenzelmann, M. M. Turnbull, C. P. Landee

Inelastic neutron scattering measurements are reported for a powder sample of the spin-1/2 quantum paramagnet $\rm Cu(Quinoxaline)Br_2$. Magnetic neutron scattering is identified above an energy gap of 1.9 meV. Analysis of the sharp spectral maximum at the onset indicates that the material is magnetically quasi-one-dimensional. Consideration of the wave vect

Sabir Umarov, Constantino Tsallis, Stanly Steinberg

The standard central limit theorem plays a fundamental role in Boltzmann-Gibbs statistical mechanics. This important physical theory has been generalized \cite{Tsallis1988} in 1988 by using the entropy $S_q = \frac{1-\sum_i p_i^q}{q-1}$ (with $q \in \mathcal{R}$) instead of its particular BG case $S_1=S_{BG}= -\sum_i p_i \ln p_i$. The theory which emerges is

Joseph A. Minahan

It was recently observed that the one dimensional half-filled Hubbard model reproduces the known part of the perturbative spectrum of planar N=4 super Yang-Mills in the SU(2) sector. Assuming that this identification is valid beyond perturbation theory, we investigate the behavior of this spectrum as the &#39;t Hooft parameter λbecomes large. We show that th

Fernando Muro, Andrew Tonks

We give a small functorial algebraic model for the 2-stage Postnikov section of the K-theory spectrum of a Waldhausen category and use our presentation to describe the multiplicative structure with respect to biexact functors.

J. Martorell, D. W. L. Sprung

The confinement mechanism of electrons in gated circular quantum dots is studied in a sequence of models, from self-consistent 3D Hartree calculations to the semiclassical model of Shikin et al. Separation of the vertical from transverse confinement allows accurate 2D Hartree calculations. For moderate size dots containing $\sim 50$ electrons, 2D Thomas-Ferm

Robert C. Helling, Peter Schupp, Tiberiu Tesileanu

A simple algorithm which gives the multipole vectors in terms of the roots of a polynomial is given. We find that the reported alignmet of the low l multipole vectors can be summarised as an anti-alignmet of these with the dipole direction. This anti-alignment is not only present in l=2 and 3 but also for l=5 and higher. This alignment is likely due to non-l

S. M. Bilenky, M. D. Mateev, S. T. Petcov

We discuss the physics potential of future tritium beta-decay experiments having a sensitivity to a neutrino mass ~\sqrt{|Δm^{2}_{23}|}~5x10^{-2} eV. The case of three-neutrino mixing is analised. A negative result of such an experiment would imply that the neutrino mass spectrum is of normal hierarchical type. The interpretation of a positive result would d

Carlos Gershenson

This paper proposes self-organization as a method to improve the efficiency and adaptability of bureaucracies and similar social systems. Bureaucracies are described as networks of agents, where the main design principle is to reduce local &#34;friction&#34; to increase local and global &#34;satisfaction&#34;. Following this principle, solutions are proposed

Lawrence M. Ioannou

Ever since entanglement was identified as a computational and cryptographic resource, researchers have sought efficient ways to tell whether a given density matrix represents an unentangled, or separable, state. This paper gives the first systematic and comprehensive treatment of this (bipartite) quantum separability problem, focusing on its deterministic (a

Klaus Helbing

In the confinement regime at Q^2=0 the Gerasimov-Drell-Hearn (GDH) Sum Rule connects static properties of the nucleon with the difference of spin dependent doubly polarized total absorption cross sections of real photons. Now, for the first time this fundamental sum rule is verified by the GDH-Collaboration with circularly polarized real photons and longitud

Stuart Zoble

There is a well-known global equivalence between Σ^1_2 sets having the Universal Baire property, two-step Σ^1_3 generic absoluteness, and the closure of the universe under the sharp operation. In this note, we determine the exact consistency strength of Σ^1_2 sets being (2^ω)^{+}-cc Universally Baire, which is below 0^{#}. In a model obtained, there is a Σ^1

Michael E. Wall

Although the importance of protein dynamics in protein function is generally recognized, the role of protein fluctuations in allosteric effects scarcely has been considered. To address this gap, the Kullback-Leibler divergence (Dx) between protein conformational distributions before and after ligand binding was proposed as a means of quantifying allosteric e

D. Heath Jones, Bruce A. Peterson, Matthew Colless, Will Saunders

Luminosity functions and their integrated luminosity densities are presented for the 6dF Galaxy Survey (6dFGS). This ongoing survey ultimately aims to measure around 150,000 redshifts and 15,000 peculiar velocities over almost the entire southern sky at |b|>10 deg. The main target samples are taken from the 2MASS Extended Source Catalog and the SuperCOSMOS S

K. Kordonis, A. V. Sologubenko, T. Lorenz, S. -W. Cheong

We have measured the thermal conductivity of the spin S=1 chain compound Y2BaNiO5. Analyzing the anisotropy of the thermal transport allows to identify a definite spin-mediated thermal conductivity κ_s along the chain direction. The calculated spin-related energy diffusion constant D_E(T) shows a broad peak around 120 K. Close to room temperature, D_E(T) app

Helge Glockner, Ralf Köhl, Tobias Hartnick

We study final group topologies and their relations to compactness properties. In particular, we are interested in situations where a colimit or direct limit is locally compact, a k_ω-space, or locally k_ω. As a first application, we show that unitary forms of complex Kac-Moody groups can be described as the colimit of an amalgam of subgroups (in the categor

Igor Bayak

A model aimed at understanding quantum gravity in terms of Birkhoff&#39;s approach is discussed. The geometry of this model is constructed by using a winding map of Minkowski space into a $\mathbb{R}^{3} \times S^{1}$-cylinder. The basic field of this model is a field of unit vectors defined through the velocity field of a flow wrapping the cylinder. The deg

Zoltan Szabo, Barnabas Poczos, Andras Lorincz

Here, a separation theorem about Independent Subspace Analysis (ISA), a generalization of Independent Component Analysis (ICA) is proven. According to the theorem, ISA estimation can be executed in two steps under certain conditions. In the first step, 1-dimensional ICA estimation is executed. In the second step, optimal permutation of the ICA elements is se

S. Dye, S. J. Warren, N. C. Hambly, N. J. G. Cross

This paper defines the UKIRT Infrared Deep Sky Survey (UKIDSS) Early Data Release (EDR). UKIDSS is a set of five large near-infra-red surveys defined by Lawrence et al. (2006), being undertaken with the UK Infra-red Telescope (UKIRT) Wide Field Camera (WFCAM). The programme began in May 2005 and has an expected duration of seven years. Each survey uses some

Inyong Cho, Eung Jin Chun, Hang Bae Kim, Yoonbai Kim

We analyze homogeneous anisotropic cosmology driven by the dilaton and the self-interacting ``massive&#39;&#39; antisymmetric tensor field which are indispensable bosonic degrees with the graviton in the NS-NS sector of string theories with D-branes. We found the attractor solutions for this system, which show the overall features of general solutions, and c

GianCarlo Ghirardi, Luca Marinatto

We generalize the Greenberger-Horne-Zeilinger nonlocality without inequalities argument to cover the case of arbitrary mixed statistical operators associated to three-qubits quantum systems. More precisely, we determine the radius of a ball (in the trace distance topology) surrounding the pure GHZ state and containing arbitrary mixed statistical operators wh

J. R. Castrejon-Pita, H. Ohadi, D. R. Crick, D. F. A. Winters

We present a number of alternative designs for Penning ion traps suitable for quantum information processing (QIP) applications with atomic ions. The first trap design is a simple array of long straight wires which allows easy optical access. A prototype of this trap has been built to trap Ca+ and a simple electronic detection scheme has been employed to dem

Michael Creutz

A popular approximation in lattice gauge theory is an extrapolation in the number of fermion species away from the four fold degeneracy natural with the staggered fermions formulation. I show that at finite lattice spacing and for an odd number of flavors this extrapolation misses terms which, on general principles, must be present in the continuum theory. F

Brendan Guilfoyle, Wilhelm Klingenberg

We study the geodesic flow on the normal line congruence of a minimal surface in ${\Bbb{R}}^3$ induced by the neutral K\"ahler metric on the space of oriented lines. The metric is lorentz with isolated degenerate points and the flow is shown to be completely integrable. In addition, we give a new holomorphic description of minimal surfaces in ${\Bbb{R}}^3$ a

Torbjorn Sjostrand, Stephen Mrenna, Peter Skands

The PYTHIA program can be used to generate high-energy-physics `events', i.e. sets of outgoing particles produced in the interactions between two incoming particles. The objective is to provide as accurate as possible a representation of event properties in a wide range of reactions, within and beyond the Standard Model, with emphasis on those where strong i

Gernot Münster, Tobias Sudmann

Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term is considered in the framework of chiral perturbation theory. For two and three numbers of quark flavours, respectively, with non-degenerate quark masses the pseudoscalar meson masses and decay constants are calculated in next-to-leading order including lattice effects

Guillermo Cortiñas, Andreas Thom

We show how methods from K-theory of operator algebras can be applied in a completely algebraic setting to define a bivariant, matrix-stable, homotopy-invariant, excisive K-theory of algebras over a fixed unital ground ring H, kk_*(A,B), which is universal in the sense that it maps uniquely to any other such theory. It turns out kk is related to C. Weibel&#3

Markus Schwarz, Ralf Hofmann, Francesco Giacosa

We postulate that the U(1)$_Y$ factor of the Standard Model is an effective manifestation of SU(2) gauge dynamics being dynamically broken by nonperturbative effects. The modified propagation properties of the photon at low temperatures and momenta are computed. As a result of strong screening, the presence of a sizable gap in the spectral power of a black b

Sara R. Hastings-Simon, Matthias U. Staudt, Mikael Afzelius, Pascal Baldi

We present measurements of the linear Stark effect on the $^{4}$I$_{15/2} \to$ $^{4}$I$_{13/2}$ transition in an Er$^{3+}$-doped proton-exchanged LiNbO$_{3}$ crystalline waveguide and an Er$^{3+}$-doped silicate fiber. The measurements were made using spectral hole burning techniques at temperatures below 4 K. We measured an effective Stark coefficient $(Δμ_

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

We establish a general relation between dispersion forces. First, based on QED in causal media, leading-order perturbation theory is used to express both the single-atom Casimir-Polder and the two-atom van der Waals potentials in terms of the atomic polarizabilities and the Green tensor for the body-assisted electromagnetic field. Endowed with this geometry-

Julia Hinkel, Reinhard Mahnke

The presented explanations are provided for the one--dimensional diffusion process with constant drift by using forward Fokker--Planck technique. We are interested in the outflow probability in a finite interval, i.e. first passage time probability density distribution taking into account reflecting boundary on left hand side and absorbing border on right ha

Tristan Meunier, Arnaud Le Diffon, Clément Rueff, Pascal Degiovanni

We investigate the behavior of N atoms resonantly coupled to a single electromagnetic field mode sustained by a high quality cavity, containing a mesoscopic coherent field. We show with a simple effective hamiltonian model that the strong coupling between the cavity and the atoms produces an atom-field entangled state, involving N+1 nearly-coherent component

I. Stefan, F. de Oliveira Santos, M. G. Pellegriti, G. Dumitru

We propose the sequential reaction process $^{15}$O($p$,$γ)(β^{+}$)$^{16}$O as a new pathway to bypass of the $^{15}$O waiting point. This exotic reaction is found to have a surprisingly high cross section, approximately 10$^{10}$ times higher than the $^{15}$O($p$,$β^{+}$)$^{16}$O. These cross sections were calculated after precise measurements of energies

Leonor Ferrer, Francisco Martin, Masaaki Umehara, Kotaro Yamada

We construct a complete bounded immersed null holomorphic curve in C^3, which is a recovery of the previous version of the paper Calc. Var. and PDE&#39;s vol 36 (2009); Erratum: to appear in Calc. Var. and PDE&#39;s, doi:10.1007/s00526-009-0226-5 by the last three authors on this subject.

A. Ali, A. V. Borisov, M. V. Sidorova

We discuss rare meson decays $K^ + \to π^ - \ell ^ + \ell &#39;^ + $ and $D^ + \to K^ - \ell ^ + \ell &#39;^ +$ ($\ell, \ell&#39;=e, μ$) in a supersymmetric extension of the Standard Model with R-parity violation. Estimates of the branching ratios for these decays are presented.

J. E. Campagne, M. Maltoni, M. Mezzetto, T. Schwetz

We consider the physics potential of CERN based neutrino oscillation experiments consisting of a Beta Beam (BB) and a Super Beam (SPL) sending neutrinos to MEMPHYS, a 440 kt water Čerenkov detector at Frejus, at a distance of 130 km from CERN. The $θ_{13}$ discovery reach and the sensitivity to CP violation are investigated, including a detailed discussion o

David Bailin, Alex Love

We construct N=1 supersymmetric fractional branes on the Z_6&#39; orientifold. Intersecting stacks of such branes are needed to build a supersymmetric standard model. If a,b are the stacks that generate the SU(3)_c and SU(2)_L gauge particles, then, in order to obtain just the chiral spectrum of the (supersymmetric) standard model (with non-zero Yukawa coupl

Z. Bajnok, L. Palla, G. Takacs

Boundary form factor axioms are derived for the matrix elements of local boundary operators in integrable 1+1 dimensional boundary quantum field theories using the analyticity properties of correlators via the boundary reduction formula. Minimal solutions are determined for the integrable boundary perturbations of the free boson, free fermion (Ising), Lee-Ya

A. I. Sidorov, B. J. Dalton, S. M. Whitlock, F. Scharnberg

We consider the evolution of a single-atom wavefunction in a time-dependent double-well interferometer in the presence of a spatially asymmetric potential. We examine a case where a single trapping potential is split into an asymmetric double well and then recombined again. The interferometer involves a measurement of the first excited state population as a

Jonathan K. Adams, Basheer N. Bristow

Basic role based access control [RBAC] provides a mechanism for segregating access privileges based upon a user&#39;s hierarchical roles within an organization. This model doesn&#39;t scale well when there is tight integration of multiple hierarchies. In a case where there is joint-tenancy and a requirement for different levels of disclosure based upon a use

CDF Collaboration

We present a measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96 TeV which uses events with an inclusive signature of significant missing transverse energy and jets. This is the first measurement which makes no explicit lepton identification requirements, so that sensitivity to W --> tau nu decays is maintained. Hea

Jinshuang Jin, Xin-Qi Li, YiJing Yan

The quantum coherence control of a solid-state charge qubit is studied by using a suboptimal continuous feedback algorithm within the Bayesian feedback scheme. For the coherent Rabi oscillation, the present algorithm suggests a simple bang-bang control protocol, in which the control parameter is modulated between two values. For the coherence protection of i

Youssef El-Khatib

We consider a stochastic volatility model with jumps where the underlying asset price is driven by the process sum of a 2-dimensional Brownian motion and a 2-dimensional compensated Poisson process. The market is incomplete, resulting in infinitely many equivalent martingale measures. We find the set equivalent martingale measures, and we hedge by minimizing

R. Kaminski, J. R. Pelaez, F. J. Yndurain

We improve, in the energy region between $\bar{K}K$ threshold and $\sim~1.4$ GeV, the energy-dependent phase shift analysis of $ππ$ scattering presented in a previous paper. For the S0 wave we have included more data above $\bar{K}K$ threshold and we have taken into account systematically the elasticity data on the reaction $ππ\to\bar{K}K$. We here made a co

R. Pugatch, N. Bar-gill, N. Katz, E. Rowen

Introducing disorder into the Bose-Hubbard model at integer fillings leads to a Bose glass phase, along with the Mott insulator and superfluid phases. We suggest a new order parameter: the determinant of the one body density matrix, which is nonzero only within the Mott-insulator phase. Alongside the superfluid fraction, it is then possible to distinguish th

Amit Agarwal, Diptiman Sen

We use the equations of motion of non-interacting electrons in a one-dimensional system to numerically study different aspects of charge pumping. We study the effects of the pumping frequency, amplitude, band filling and finite bias on the charge pumped per cycle, and the Fourier transforms of the charge and energy currents in the leads. Our method works for

Jinshuang Jin, Xin-Qi Li, YiJing Yan

The optical manipulation of electron spins is of great benefit to solid-state quantum information processing. In this letter, we provide a comparative study on the ultrafast optical manipulation of single electron spin in the doped and undoped quantum dots. The study indicates that the experimental breakthrough can be preliminarily made in the undoped quantu

Hang-Hyun Jo, Woo-Sung Jung, Hie-Tae Moon

To investigate an effect of social interaction on the bystanders&#39; intervention in emergency situations a rescue model was introduced which includes the effects of the victim&#39;s acquaintance with bystanders and those among bystanders from a network perspective. This model reproduces the experimental result that the helping rate (success rate in our mod

S. K. Srivastava

It is obtained that dark energy emerges from higher-derivative gravity with anon-linear terms proportional to $R^2$ and $R^3$ with $R$ being the Ricci scalar curvature. Interestingly, it is found that the universe begins with acceleration, which continues for a short period. Later on,it decelerates driven by radiation and subsequently by matter. Two componen

Thoudam Satyendra

Observations of diffuse Galactic gamma-ray spectrum by the EGRET instrument reveal an excess above ~ 1 GeV over the expected gamma-ray spectrum calculated under the assumption that the locally observed cosmic-ray (CR) spectra represent the galactic CR spectra. Assuming that Galactic CRs of energy below ~ 100 TeV are accelerated by supernova remnant (SNR) sho

Jihong Qin, Feng Yuan, Shiping Feng

Within the t-J ladder model, superconductivity with a modified d-wave symmetry in doped two-leg ladder cuprates is investigated based on the kinetic energy driven superconducting mechanism. It is shown that the spin-liquid ground-state at the half-filling evolves into the superconducting ground-state upon doping. In analogy to the doping dependence of the su

Liang Sun

The general stability criteria of inviscid Taylor-Couette flows with angular velocity $Ω(r)$ are obtained analytically. First, a necessary instability criterion for centrifugal flows is derived as $ξ&#39;(Ω-Ω_s)<0$ (or $ξ&#39;/(Ω-Ω_s)<0$) somewhere in the flow field, where $ξ$ is the vorticitiy of profile and $Ω_s$ is the angular velocity at the inflection p

Panagiota Daskalopoulos, Natasa Sesum

We provide the classification of eternal (or ancient) solutions of the two-dimensional Ricci flow, which is equivalent to the fast diffusion equation $ \frac{\partial u}{\partial t} = Δ\log u $ on $ \R^2 \times \R.$ We show that, under the necessary assumption that for every $t \in \R$, the solution $u(\cdot, t)$ defines a complete metric of bounded curvatur

A. E. Meyerovich, V. V. Nesvizhevsky

A theory of gravitational quantum states of ultracold neutrons in waveguides with absorbing/scattering walls is presented. The theory covers recent experiments in which the ultracold neutrons were beamed between a mirror and a rough scatterer/absorber. The analysis is based on a recently developed theory of quantum transport along random rough walls which is

Olaf Dreyer

The transition from the quantum to the classical is governed by randomizing devices (RD), i.e., dynamical systems that are very sensitive to the environment. We show that, in the presence of RDs, the usual arguments based on the linearity of quantum mechanics that lead to the measurement problem do not apply. RDs are the source of probabilities in quantum me

Marek Zukowski

A derivation method is given which leads to a series of tight Bell inequalities for experiments involving N parties, with binary observables, and three possible local settings. The approach can be generalized to more settings. Ramifications are presented.

G. Burlak, A. Klimov

We study evolution of entanglement of two two-level atoms placed inside a multilayered microsphere. We show that due to inhomogeneity of the field modes this entanglement essentially depends on the atomic positions (asymmetrical entanglement) and also on the detuning between the atomic transitions and field frequencies. The robust and complete entanglement c

Aurelien Dantan, Jean Cviklinski, Elisabeth Giacobino, Michel Pinard

We show that high squeezing and entanglement can be generated at the output of a cavity containing atoms interacting with two fields in a Coherent Population Trapping situation, on account of a non-linear Faraday effect experienced by the fields close to a dark-state resonance in a cavity. Moreover, the cavity provides a feedback mechanism allowing to reduce

Matthias U. Staudt, Sara R. Hastings-Simon, Mikael Afzelius, Didier Jaccard

We studied optical coherence properties of the 1.53 $μ$m telecommunication transition in an Er$^{3+}$-doped silicate optical fiber through spectral holeburning and photon echoes. We find decoherence times of up to 3.8 $μ$s at a magnetic field of 2.2 Tesla and a temperature of 150 mK. A strong magnetic-field dependent optical dephasing was observed and is bel

Zheng-Yao Su

A scheme to perform the Cartan decomposition for the Lie algebra su(N) of arbitrary finite dimensions is introduced. The schme is based on two algebraic structures, the conjugate partition and the quotient algebra, that are easily generated by a Cartan subalgebra and generally exist in su(N). In particular, the Lie algebras su(2^p) and every su(2^{p-1} < N <

Dominic W. Berry, Howard M. Wiseman

We have previously [Phys. Rev. A 65, 043803 (2002)] analyzed adaptive measurements for estimating the continuously varying phase of a coherent beam, and a broadband squeezed beam. A real squeezed beam must have finite photon flux N and hence can be significantly squeezed only over a limited frequency range. In this paper we analyze adaptive phase measurement

Shahid Iqbal, Qurat-ul-Ann, Farhan Saif

The recurrence phenomena of an initially well localized wave packet are studied in periodically driven power-law potentials. For our general study we divide the potentials in two kinds, namely tightly binding and loosely binding potentials. In the presence of an external periodically modulating force, these potentials may exhibit classical and quantum chaos.

Peter J. Love, Alec Maassen van den Brink, A. Yu. Smirnov, M. H. S. Amin

We define a set of $2^{n-1}-1$ entanglement monotones for $n$ qubits and give a single measure of entanglement in terms of these. This measure is zero except on globally entangled (fully inseparable) states. This measure is compared to the Meyer-Wallach measure for two, three, and four qubits. We determine the four-qubit state, symmetric under exchange of qu

Mark A. Rubin

Stapp claims that, when spatial degrees of freedom are taken into account, Everett quantum mechanics is ambiguous due to a &#34;core basis problem.&#34; To examine an aspect of this claim I generalize the ideal measurement model to include translational degrees of freedom for both the measured system and the measuring apparatus. Analysis of this generalized

Thomas Konrad, Artur Scherer, Michael Nock, Juergen Audretsch

We propose a setup for a heralded, i.e. announced generation of a pure single-photon state given two imperfect sources whose outputs are represented by mixtures of the single-photon Fock state $\ket{1}$ with the vacuum $\ket{0}$. Our purification scheme uses beam splitters, photodetection and a two-photon-absorbing medium. The admixture of the vacuum is full

Tathagat Tulsi, Lov Grover, Apoorva Patel

The standard quantum search lacks a feature, enjoyed by many classical algorithms, of having a fixed point, i.e. monotonic convergence towards the solution. Recently a fixed point quantum search algorithm has been discovered, referred to as the Phase-$π/3$ search algorithm, which gets around this limitation. While searching a database for a target state, thi

Eric J. Deeds, Eugene I. Shakhnovich

Proteins, by virtue of their central role in most biological processes, represent one of the key subjects of the study of molecular evolution. Inherent to the indispensability of proteins for living cells is the fact that a given protein can adopt a specific three-dimensional shape that is specified solely by the proteins sequence of amino acids. Over the pa

Azi Lipshtat, Adiel Loinger, Nathalie Q. Balaban, Ofer Biham

Genetic switch systems with mutual repression of two transcription factors are studied using deterministic and stochastic methods. Numerous studies have concluded that cooperative binding is a necessary condition for the emergence of bistability in these systems. Here we show that for a range of biologically relevant conditions, a suitable combination of net

D. C. Clarke, M. D. Betterton, X. Liu

Transforming Growth Factor-beta (TGF-beta) signalling is an important regulator of cellular growth and differentiation. The principal intracellular mediators of TGF-beta signalling are the Smad proteins, which upon TGF-beta stimulation accumulate in the nucleus and regulate transcription of target genes. To investigate the mechanisms of Smad nuclear accumula

I. A. Stepanow

The traditional method of finding the average value of a physical quantity often gives wrong results. Another formula of averaging is derived which gives correct results. It is applied to calculation of the average radius of tapering tube and the average flow velocity in the tube. The new formula is applicable to many other processes.

Mogens V. Melander, Bruce R. Fabijonas

We consider equilibrium statistics for high Reynolds number isotropic turbulence in an incompressible flow driven by steady forcing at the largest scale. Motivated by shell model observations, we develop a similarity theory for the inertial range from clearly stated assumptions. In the right variables, the theory is scaling invariant, but in traditional vari

M. L. Jones, G. J. Wilkes, B. T. H. Varcoe

We report on a scheme for highly efficient detection of single microwave photons, with application to detecting certain exotic particles such as the axion. This scheme utilises an experiment known as the micromaser and the phenomenon of trapping states to amplify the signal and produce a cascade of detector counts in a field ionization detector. The cascade

Michel Versluis, Cor Blom, Devaraj van der Meer, Ko van der Weele

Shear-thinning fluids exhibit surprisingly rich behaviour. One example is the Kaye effect which occurs when a thin stream of a solution of polyisobutylene in Decalin is poured into a dish of the fluid. As pouring proceeds, a small stream of liquid occasionally leaps upward from the heap. This surprising effect, which lasts only a second or so, is named after

Bernhard Rothenstein

We present a thought experiment that involves a high sensitivity balance initially in a state of mechanical equilibrium but not in a state of thermal equilibrium. After reaching the state of thermal equilibrium it is no longer in a state of mechanical equilibrium.

Lucian-Cornel Crasovan, Osamu Takayama, David Artigas, Steffen Kjaer Johansen

We theoretically investigate the existence and properties of hybrid surface waves forming at interfaces between left-handed materials and dielectric birefringent media. The existence conditions of such waves are found to be highly relaxed in comparison to the original hybrid surface waves, discovered by Dyakonov, in configurations involving birefringent mate

Monia Cheikh, Ha Lien Nghiem, Dominique Ettori, Eric Tinet

We report in this paper what is to our knowledge the first observation of a time-resolved diffusing wave spectroscopy signal recorded by transillumination through a thick turbid medium: the DWS signal is measured for a fixed photon transit time, which opens the possibility of improving the spatial resolution. This technique could find biomedical applications

Soo Yong Kim, Chung Hyun Park, Kyungsik Kim

We have presented a numerical model of a collective opinion formation procedure to explain political phenomena such as two-party and multi-party systems in politics, political unrest, military coup d&#39;etats and netizen revolutions. Nonlinear interaction with binary and independent decision making processes can yield various collective behaviors or collect

Aidan S Arnold, Matthew J Pritchard, David A Smith, Ifan G Hughes

We have theoretically investigated 3D focusing of a launched cloud of cold atoms using a pair of magnetic lens pulses (the alternate-gradient method). Individual lenses focus radially and defocus axially or vice-versa. The performance of the two possible pulse sequences are compared and found to be ideal for loading both &#39;pancake&#39; and &#39;sausage&#3

Parongama Sen, Anjan Kumar Chandra, Kamalika Basu Hajra, Pratap Kumar Das

An important aspect of a Euclidean network is its link length distribution, studied in a few real networks so far. We compute the distribution of the link lengths between collaborators whose papers appear in the PhysicalReview Letters (PRL) in several years within a range of four decades. The distribution is non-monotonic; there is a peak at nearest neighbou

Seong-Dong Kim

Based on a physical monism, which holds that the matter and space are classified by not a difference of their kind but a difference of magnitude of their density, I derive the most fundamental equation of motion, which is capable of providing a deeper physical understanding than the known physics. For example, this equation answers to the substantive reason

G. K. Nie

The alpha-cluster model is based on two assumptions that the proton-neutron pair interactions are responsible for adherence between alpha-clusters and that the NN-interaction in the alpha-clusters is isospin independent. It allows one to estimate the Coulomb energy and the short range inter-cluster bond energy in dependence on the number of clusters. The cha

Maria V. Demina, Nikolai A. Kudryashov

Special polynomials associated with rational solutions of the second Painlevé equation and other members of its hierarchy are discussed. New approach, which allows one to construct each polynomial is presented. The structure of the polynomials is established. Formulas of their coefficients are found. Correlations between the roots of every polynomial are obt

Niels Sondergaard, Predrag Cvitanovic, Andreas Wirzba

The scattering determinant for the scattering of waves from several obstacles is considered in the case of elastic solids with voids. The multi-scattering determinant displays contributions from periodic ray-splitting orbits. A discussion of the weights of such orbits is presented.

Juerg Froehlich, Sandro Graffi, Simon Schwarz

We present a new proof of the convergence of the N-particle Schroedinger dynamics for bosons towards the dynamics generated by the Hartree equation in the mean-field limit. For a restricted class of two-body interactions, we obtain convergence estimates uniform in the Planck constant , up to an exponentially small remainder. For h=0, the classical dynamics i