January 2007 arXiv papers

Michal Horodecki, Seth Lloyd, Andreas Winter

We prove direct quantum coding theorem for random quantum codes. The problem is separated into two parts: proof of distinguishability of codewords by receiver, and that of indistinguishability of codewords by environment (privacy). For a large class of codes, only privacy has to be checked.

S. I. Denisov, K. Sakmann, P. Talkner, P. Hänggi

We present an analytical method of calculating the mean first-passage times (MFPTs) for the magnetic moment of a uniaxial nanoparticle which is driven by a rapidly rotating, circularly polarized magnetic field and interacts with a heat bath. The method is based on the solution of the equation for the MFPT derived from the two-dimensional backward Fokker-Plan

Yi-Zhong Fan, Da-Ming Wei, Dong Xu

A possible birefringence effect that arises in quantum gravity leads to a frequency-dependent rotation of the polarization angle of linearly polarized emission from distant sources. Here we use the UV/optical polarization data of the afterglows of GRB 020813 and GRB 021004 to constrain this effect. We find an upper limit on the Gambini & Pulin birefringence

Andrea Nerozzi

Wave extraction plays a fundamental role in the binary black hole simulations currently performed in numerical relativity. Having a well defined procedure for wave extraction, which matches simplicity with efficiency, is critical especially when comparing waveforms from different simulations. Recently, progress has been made in defining a general technique w

L. Dabrowski, T. Hadfield, P. M. Hajac, R. Matthes

In this overview, we study how to reduce the index pairing for a fibre-product C*-algebra to the index pairing for the C*-algebra over which the fibre product is taken. As an example we analyze the case of suspensions and apply it to noncommutative instanton bundles of arbitrary charges over the suspension of quantum deformations of the 3-sphere.

Gerardo Adesso, Ivette Fuentes-Schuller

We investigate the Hawking effect on entangled fields. By considering a scalar field which is in a two-mode squeezed state from the point of view of freely falling (Kruskal) observers crossing the horizon of a Schwarzschild black hole, we study the degradation of quantum and classical correlations in the state from the perspective of Schwarzschild observers

D. G. Levkov, A. G. Panin, S. M. Sibiryakov

We develop the semiclassical method of complex trajectories in application to chaotic dynamical tunneling. First, we suggest a systematic numerical technique for obtaining complex tunneling trajectories by the gradual deformation of the classical ones. This provides a natural classification of the tunneling solutions. Second, we present a heuristic procedure

Daniel P. Stark, Abraham Loeb, Richard S. Ellis

[Abridged] We develop a simple star formation model whose goal is to interpret the emerging body of observational data on star-forming galaxies at z>~6. The efficiency and duty cycle of the star formation activity within dark matter halos are determined by fitting the luminosity functions of Lya emitter and Lyman-break galaxies at redshifts z~5-6. Using our

K. G. Noeske, B. J. Weiner, S. M. Faber, C. Papovich

We analyze star formation (SF) as a function of stellar mass (M*) and redshift z in the All Wavelength Extended Groth Strip International Survey (AEGIS). For 2905 field galaxies, complete to 10^10(10^10.8) Msun at z<0.7(1), with Keck spectroscopic redshifts out to z=1.1, we compile SF rates (SFR) from emission lines, GALEX, and Spitzer MIPS 24 micron photome

Aurel Bulgac, Joaquin E. Drut, Piotr Magierski

We present the first model-independent comparison of recent measurements of the entropy and of the critical temperature of a unitary Fermi gas, performed by Luo et al., with the most complete results currently available from finite temperature Monte Carlo calculations. The measurement of the critical temperature in a cold fermionic atomic cloud is consistent

Nikodem J. Poplawski

The Ferraris-Kijowski purely affine Lagrangian for the electromagnetic field, that has the form of the Maxwell Lagrangian with the metric tensor replaced by the symmetrized Ricci tensor, is dynamically equivalent to the metric Einstein-Maxwell Lagrangian, except the zero-field limit, for which the metric tensor is not well-defined. This feature indicates tha

William Beckner

Sharp error estimates in terms of the fractional Laplacian and a weighted Besov norm are obtained for Pitt&#39;s inequality by using the spectral representation with weights for the fractional Laplacian due to Frank, Lieb and Seiringer and the sharp Stein-Weiss inequality. Dilation invariance, group symmetry on a non-unimodular group and a nonlinear Stein-We

Morris L. Eaton, James P. Hobert, Galin L. Jones, Wen-Lin Lai

We consider evaluation of proper posterior distributions obtained from improper prior distributions. Our context is estimating a bounded function $ϕ$ of a parameter when the loss is quadratic. If the posterior mean of $ϕ$ is admissible for all bounded $ϕ$, the posterior is strongly admissible. We give sufficient conditions for strong admissibility. These con

Congjun Wu, Doron Bergman, Leon Balents, S. Das Sarma

We study the ground states of cold atoms in the tight-binding bands built from p-orbitals on a two dimensional honeycomb optical lattice. The band structure includes two completely flat bands. Exact many-body ground states with on-site repulsion can be found at low particle densities, for both fermions and bosons. We find crystalline order at n=1/6 with a $\

Heather Armstrong, Bradley Forrest, Karen Vogtmann

We study the action of the group Aut(F_n) of automorphisms of a finitely generated free group on the degree 2 subcomplex of the spine of Auter space. Hatcher and Vogtmann showed that this subcomplex is simply connected, and we use the method described by K. S. Brown to deduce a new presentation of Aut(F_n).

L. Alvarez-Ruso, L. S. Geng, S. Hirenzaki, M. J. Vicente Vacas

We analyze the neutrino induced charged current coherent pion production at the energies of interest for recent experiments like K2K and MiniBooNE. Medium effects in the production mechanism and the distortion of the pion wave function, obtained solving the Klein Gordon equation with a microscopic optical potential, are included in the calculation. We find a

Mark A. Rubin, Sumanth Kaushik

The formalism for computing the signal-to-noise ratio (SNR) for laser radar is reviewed and applied to the tasks of target detection, direction-finding, and phase change estimation with squeezed light. The SNR for heterodyne detection of coherent light using a squeezed local oscillator is lower than that obtained using a coherent local oscillator. This is tr

Matthew Daws

A theorem of Davis, Figiel, Johnson and Pełczyński tells us that weakly-compact operators between Banach spaces factor through reflexive Banach spaces. The machinery underlying this result is that of the real interpolation method, which has been adapted to the category of operator spaces by Xu, showing the this factorisation result also holds for completely

Luisa Arlotti, Bertrand Lods

We investigate the properties of the collision operator associated to the linear Boltzmann equation for dissipative hard-spheres arising in granular gas dynamics. We establish that, as in the case of non-dissipative interactions, the gain collision operator is an integral operator whose kernel is made explicit. One deduces from this result a complete picture

Ryan O&#39;Leary, Richard O&#39;Shaughnessy, Frederic Rasio

Binary black holes can form efficiently in dense young stellar clusters, such as the progenitors of globular clusters, via a combination of gravitational segregation and cluster evaporation. We use simple analytic arguments supported by detailed N-body simulations to determine how frequently black holes born in a single stellar cluster should form binaries,

Rodolfo Russo, Stefano Sciuto

We use the operator formalism to derive the bosonic contribution to the twisted open string partition function in toroidal compactifications. This amplitude describes, for instance, the planar interaction between g+1 magnetized or intersecting D-branes. We write the result both in the closed and in the open string channel in terms of Prym differentials on th

J. Nix

The first search for the rare kaon decay $\kppnn$ has been performed by the E391a collaboration at the KEK 12-GeV proton synchrotron. An upper limit of $4.7\times10^{-5}$ at the 90 % confidence level was set for the branching ratio of the decay $\kppnn$ using about 10 % of the data collected during the first period of data taking. First limits for the decay

H. Garcilazo, T. Fernandez-Carames, A. Valcarce

We calculate the hypertriton binding energy and the $Λd$ and $Σd$ scattering lengths using baryon-baryon interactions obtained from a chiral constituent quark model. We study consistently the $ΛNN$ and $ΣNN$ systems analyzing the effect of the $Σ\leftrightarrow Λ$ conversion. Our interactions correctly predict the hypertriton binding energy. The $(I,J)=(0,3/

Yu. S. Surovtsev, P. Bydzovsky

In the approach, based on analyticity and unitarity and assuming an influence of coupled channels, experimental data on the isovector P-wave of pion-pion scattering have been analyzed to study rho-like mesons below 1.9 GeV.

Stephane Norte, Fernando G. Lobo

In our society, people with motor impairments are oftentimes socially excluded from their environment. This is unfortunate because every human being should have the possibility to obtain the necessary conditions to live a normal life. Although there is technology to assist people with motor impairments, few systems are targeted for programming environments.

Bernard Kujawski, Bosiljka Tadic, Geoff J. Rodgers

We study the fluctuation properties and return-time statistics on inhomogeneous scale-free networks using packets moving with two different dynamical rules; random diffusion and locally navigated diffusive motion with preferred edges. Scaling in the fluctuations occurs when the dispersion of a quantity at each node or edge increases like the its mean to the

Shunsuke Takagi, Ken-ichi Yoshida

Hochster and Huneke proved in \cite{HH5} fine behaviors of symbolic powers of ideals in regular rings, using the theory of tight closure. In this paper, we use generalized test ideals, which are a characteristic $p$ analogue of multiplier ideals, to give a slight generalization of Hochster-Huneke&#39;s results.

Sune Lehmann, Lars Kai Hansen

We study community structure of networks. We have developed a scheme for maximizing the modularity Q based on mean field methods. Further, we have defined a simple family of random networks with community structure; we understand the behavior of these networks analytically. Using these networks, we show how the mean field methods display better performance t

Branko Saric

Based on the kinetic energy theorem, as one of the fundamental theorems from the classical mechanics, throughout the first part of the article an attempt has been made to derive the mathematical model of a material point motion in the three-dimensional spatial subspace of the integral four-dimensional space-time continuum and in the field of action of an act

D. Andrew Howell, Mark Sullivan, Alex Conley, Ray Carlberg

Recent studies indicate that Type Ia supernovae (SNe Ia) consist of two groups - a &#34;prompt&#34; component whose rates are proportional to the host galaxy star formation rate, whose members have broader lightcurves and are intrinsically more luminous, and a &#34;delayed&#34; component whose members take several Gyr to explode, have narrower lightcurves, a

Alessandro Sergi

A novel method is introduced in order to treat the dissipative dynamics of quantum systems interacting with a bath of classical degrees of freedom. The method is based upon an extension of the Nosè-Hoover chain (constant temperature) dynamics to quantum-classical systems. Both adiabatic and nonadiabatic numerical calculations on the relaxation dynamics of th

T. M. Mishonov, M. V. Stoev, Y. G. Maneva

Absorbtion of Alfven waves is considered to be the main mechanism of heating in the solar corona. It is concluded that the sharp increase of the plasma temperature by two orders of magnitude is related to a self-induced opacity with respect to Alfven waves. The maximal frequency for propagation of Alfven waves is determined by the strongly temperature depend

Miklos Abert, Andrei Jaikin-Zapirain, Nikolay Nikolov

This paper investigates the asymptotic behaviour of the minimal number of generators of finite index subgroups in residually finite groups. We analyze three natural classes of groups: amenable groups, groups possessing an infinite soluble normal subgroup and virtually free groups. As a tool for the amenable case we generalize Lackenby&#39;s trichotomy theore

Lu Guo, J. A. Maruhn, P. -G. Reinhard

The ground-state deformations of the Ge isotopes are investigated in the framework of Gogny-Hartree-Fock-Bogoliubov (HFB) and Skyrme Hartree-Fock plus pairing in the BCS approximation. Five different Skyrme parametrizations are used to explore the influence of different effective masses and spin-orbit models. There is generally good agreement for binding ene

Malcolm Fairbairn, Sara Rydbeck

We attempt to fit cosmological data using $f(R)$ modified Lagrangians containing inverse powers of the Ricci scalar varied with respect to the metric. While we can fit the supernova data well, we confirm the $a\propto t^{1/2}$ behaviour at medium to high redshifts reported elsewhere and argue that the easiest way to show that this class of models are inconsi

Djordje Baljozovic, Milan Merkle

For any given partial order in a $d$-dimensional euclidean space, under mild regularity assumptions, we show that the intersection of closed (generalized) intervals containing more than 1/2 of the probability mass, is a non-empty compact interval. This property is shared with common intervals on real line, where the intersection is the median set of the unde

Mohd Abubakr

There has been always an ambiguity in division when zero is present in the denominator. So far this ambiguity has been neglected by assuming that division by zero as a non-allowed operation. In this paper, I have derived the new set of numbers by considering that a number divided by zero gives rise to &#34;a beyond complex number&#34;. This is very similar t

G. Vaitheeswaran, V. Kanchana, S. Heathman, M. Idiri

The high-pressure structural behavior of lanthanum monochalcogenides is investigated by theory and experiment. Theory comprises density functional calculations of LaS, LaSe and LaTe with the general gradient approximation for exchange and correlation effects, as implemented within the full-potential linear muffin-tin orbital method. The experimental studies

Michail Stoilov

Anomalous quantization of the Electromagnetic field allows non-trivial (anti) self-dual configurations to exist in four-dimensional Euclidian space-time. These instanton-like objects are described as massless spinor particles.

Denis Denisov, Sergey Foss, Dmitry Korshunov

For a distribution $F^{*τ}$ of a random sum $S_τ=ξ_1+...+ξ_τ$ of i.i.d. random variables with a common distribution $F$ on the half-line $[0,\infty)$, we study the limits of the ratios of tails $\bar{F^{*τ}}(x)/\bar{F}(x)$ as $x\to\infty$ (here, $τ$ is a counting random variable which does not depend on $\{ξ_n\}_{n\ge1}$). We also consider applications of th

R. Rezaei, R. Schlichenmaier, C. A. R. Beck, J. H. M. J. Bruls

We simultaneously observed the Stokes parameters of the photospheric iron line pair at 630.2 nm and the intensity profile of the chromospheric Ca II H line at 396.8 nm in a quiet Sun region at a heliocentric angle of 53 deg. We perform a statistical analysis of network and inter-network properties.The H-index is the integrated emission in a 0.1 nm band aroun

Herbert K. Dreiner

We describe an initiative at the University of Bonn, where the students develop and perform a 2 hour physics show for school classes and the general public. The show is entertaining and educational and is aimed at children aged 10 and older. For the physics students this is a unique experience to apply their knowledge at an early stage and gives them the cha

Elena Kartashova

The structure of discrete resonances in water-wave turbulence is studied. It is shown that the number of exact 4-wave resonances is huge (hundreds million) even in comparatively small spectral domain when both scale and angle energy transport is taken into account. It is also shown that angle transport can contribute inexplicitly to scale transport. Restrict

Christoph Simon, Hugues de Riedmatten, Mikael Afzelius, Nicolas Sangouard

We propose a quantum repeater protocol which builds on the well-known DLCZ protocol [L.M. Duan, M.D. Lukin, J.I. Cirac, and P. Zoller, Nature 414, 413 (2001)], but which uses photon pair sources in combination with memories that allow to store a large number of temporal modes. We suggest to realize such multi-mode memories based on the principle of photon ec

Roni Waldman, Zalman Barkat

Exploring stellar models which ignite carbon off-center (in the mass range of about 1.05 - 1.25 Msun, depending on the carbon mass fraction) we find that they may present an interesting SN I progenitor scenario, since whereas in the standard scenario runaway always takes place at the same density of about 2 X 10^9 gr/cm^3, in our case, due to the small amoun

Marie-Francoise Ouedraogo, Sylvie Paycha

Observing that the logarithm of a product of two elliptic operators differs from the sum of the logarithms by a finite sum of operator brackets, we infer that regularised traces of this difference are local as finite sums of noncommutative residues. From an explicit local formula for such regularised traces, we derive an explicit local formula for the multip

Jonathan Plumridge, Edmund Clarke, Ray Murray, Chris Phillips

We study a semiconductor based quantum metamaterial which has the optical characteristics of a metal in two directions, but behaves like a collection of artificial atoms, whose properties can be designed in using quantum theory, in the third. We find that it supports a new type of guided collective plasma resonance (CPR) mode which exhibits efficient optical

Veronique Page

We argue that the superpartner of the Dirac right-handed neutrino is a prime candidate for dark matter created from a &#39;mattergenesis&#39; mechanism. We show that due to the smallness of the Yukawa couplings, a right-handed sneutrino density created in the early Universe would not be erased by annihilations, which remain out of thermal equilibrium. It wou

Cristiano Germani, William Nelson, Mairi Sakellariadou

Using a Liouville measure, similar to the one proposed recently by Gibbons and Turok, we investigate the probability that single-field inflation with a polynomial potential can last long enough to solve the shortcomings of the standard hot big bang model, within the semiclassical regime of loop quantum cosmology. We conclude that, for such a class of inflati

Vincent Bansaye

We consider a branching model introduced by Kimmel for cell division with parasite infection. Cells contain proliferating parasites which are shared randomly between the two daughter cells when they divide. We determine the probability that the organism recovers, meaning that the asymptotic proportion of contaminated cells vanishes. We study the tree of cont

Cai-Dian Lu, Wei Wang, Zheng-Tao Wei

The light cone method provides a convenient non-perturbative tool to study the heavy-to-light form factors. We construct a light cone quark model utilizing the soft collinear effective theory. In the leading order of effective theory, the ten $B$ to light physical form factors are reduced to three universal form factors which can be calculated as overlaps of

S. Creek, O. Efthimiou, P. Kanti, K. Tamvakis

We study the evaporation of (4+n)-dimensional rotating black holes into scalar degrees of freedom on the brane. We calculate the corresponding absorption probabilities and cross-sections obtaining analytic solutions in the low-energy regime, and compare the derived analytic expressions to numerical results, with very good agreement. We then consider the high

Dimitrios Tsimpis

Using recent results on eleven-dimensional superspace, we compute the contribution of fivebrane instantons with four fermionic zeromodes in M-theory compactifications on Calabi-Yau fourfolds with flux. We find that no superpotential is generated in this case. This result is compatible with a certain flux-dependent modification of the arithmetic genus criteri

Bruce Solomon

We produce skew loops -- loops having no pair of parallel tangent lines -- homotopic to any loop in a flat torus or other quotient of R^n. The interesting case here is n=3. More subtly for any n, we characterize the homotopy classes that will contain a skew loop having a specified loop in the unit sphere as tangent indicatrix.

Philippe Ribière, Patrick Richard, Pierre Philippe, Daniel Bideau

When submitted to gentle mechanical taps a granular packing slowly compacts until it reaches a stationary state that depends on the tap characteristics. The properties of such stationary states are experimentally investigated. The influence of the initial state, taps properties and tapping protocol are studied. The compactivity of the packings is determinate

W. Qi, C. F. Qiao, J. X. Wang

We analyze the uncertainties induced by different definitions of the momentum fraction $z$ in the application of gluon to heavy quarkonium fragmentation function. We numerically calculate the initial $g \to J / ψ$ fragmentation functions by using the non-covariant definitions of $z$ with finite gluon momentum and find that these fragmentation functions have

Daeseong Park, Jounghun Lee

We investigate alignments between the spin axes of cosmic voids and the principal axes of nearby superclusters using the Millennium Run simulation of a LCDM cosmology. The concept of void spin was first introduced by Lee and Park in 2006 to quantify the tidal effect on voids from the surrounding matter distribution. Our numerical analysis reveals that the vo

The Belle Collaboration, C. H. Wang

We report measurements of branching fractions and CP asymmetries for $B \to ηK^*$ and $B \to ηρ$ decays. These results are obtained from a $414 {\rm fb}^{-1}$ data sample collected at the $Υ(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We measure the following branching fractions: ${\mathcal B}(B^0 \to ηK^{*0}) = (

Lev B. Levitin, Tommaso Toffoli

Since reversible computing requires preservation of all information throughout the entire computational process, this implies that all errors that appear as a result of the interaction of the information-carrying system with uncontrolled degrees of freedom must be corrected. But this can only be done at the expense of an increase in the entropy of the enviro

X. H. Cui, H. G. Wang, R. X. Xu, G. J. Qiao

The consistence of the distributions of pulsar&#39;s kick velocities from the model of GRB and from the pulsar observations is tested based on the supernova-GRB ($γ$-ray burst) association and under the assumption that the GRB asymmetric explosions produce pulsars. The deduced distribution of kick velocity from the model of GRB and the observed kick distribu

Ho-Meoyng Choi

We investigate the magnetic dipole decays $V\to Pγ$ of various heavy-flavored mesons such as $(D,D^*,D_s,D^{*}_s,η_c, J/ψ)$ and $(B,B^*,B_s,B^*_s,η_b,Υ)$ using the light-front quark model constrained by the variational principle for the QCD-motivated effective Hamiltonian. The momentum dependent form factors $F_{VP}(q^2)$ for $V\to Pγ^*$ decays are obtained

Lukasz Cincio, Jacek Dziarmaga, Marek M. Rams, Wojciech H. Zurek

Quantum Ising model in one dimension is an exactly solvable example of a quantum phase transition. We investigate its behavior during a quench from a paramagnetic to ferromagnetic phase caused by a gradual turning off of the transverse field at a fixed rate characterized by the quench time $τ_Q$. In agreement with Kibble-Zurek mechanism, quantum state of the

Walter J. Freeman, Giuseppe Vitiello

We compare the predictions of the dissipative quantum model of brain with neurophysiological data collected from electroencephalograms resulting from high-density arrays fixed on the surfaces of primary sensory and limbic areas of trained rabbits and cats. Functional brain imaging in relation to behavior reveals the formation of coherent domains of synchroni

Jongbae Hong, Wonmyung Woo

We develop a nonperturbative dynamical theory (NDT) that is useful for treating nonequilibrium transport in a system with strong correlation. We apply our NDT to the single-impurity Anderson model in equilibrium to check its reliability by comparing with the results of numerical renormalization group method (NRG). We finally suggest a self-consistent loop to

Thomas Hofmann, Bernhard Schölkopf, Alexander J. Smola

We review machine learning methods employing positive definite kernels. These methods formulate learning and estimation problems in a reproducing kernel Hilbert space (RKHS) of functions defined on the data domain, expanded in terms of a kernel. Working in linear spaces of function has the benefit of facilitating the construction and analysis of learning alg

Loretta Bartolini, J. Hyam Rubinstein

This paper has been withdrawn by the author, as the proof of Theorem 3.2 contains a flaw; subsequently, both it and Theorem 3.3 are not known to hold. The content of Section 5 has been improved and expanded upon in two separate papers. The structural properties in 5.1 and 5.2 appear in arXiv:1101.2603; the classification in 5.3 in arxiv:1101.2890. Please ref

Florent Schaffhauser

We show that the quotient associated to a quasi-Hamiltonian space has a symplectic structure even when 1 is not a regular value of the momentum map: it is a disjoint union of symplectic manifolds of possibly different dimensions, which generalizes a result of Alekseev, Malkin and Meinrenken. We illustrate this theorem with the example of representation space

A. Muñoz Mateo, V. Delgado

We derive general approximate formulas that provide with remarkable accuracy the ground-state properties of any mean-field scalar Bose-Einstein condensate with short-range repulsive interatomic interactions, confined in arbitrary cylindrically symmetric harmonic traps. Our formulation is even applicable for condensates containing a multiply quantized axisymm

Oksana Bihun, Carmen Chicone

The problem of minimal distortion bending of smooth compact embedded connected Riemannian $n$-manifolds $M$ and $N$ without boundary is made precise by defining a deformation energy functional $Φ$ on the set of diffeomorphisms $\diff(M,N)$. We derive the Euler-Lagrange equation for $Φ$ and determine smooth minimizers of $Φ$ in case $M$ and $N$ are simple clo

A. I. Molev, E. Ragoucy

We construct an action of the braid group B_N on the twisted quantized enveloping algebra U&#39;_q(o_N) where the elements of B_N act as automorphisms. In the classical limit q -> 1 we recover the action of B_N on the polynomial functions on the space of upper triangular matrices with ones on the diagonal. The action preserves the Poisson bracket on the spac

Joss Bland-Hawthorn

The study of stellar populations is a discipline that is highly dependent on both imaging and spectroscopy. I discuss techniques in different regimes of resolving power: broadband imaging (R~4), intermediate band imaging (R~16, 64), narrowband spectral imaging (R~256, 1024, 4096). In recent years, we have seen major advances in broadband all-sky surveys that

David Gross

According to a classical result due to Hudson, the Wigner function of a pure, continuous variable quantum state is non-negative if and only if the state is Gaussian. We have proven an analogous statement for finite-dimensional quantum systems. In this context, the role of Gaussian states is taken on by stabilizer states. The general results have been publish

Fernando G. S. L. Brandao, Michael J. Hartmann, Martin B. Plenio

We show that a system of polaritons - combined atom and photon excitations - in an array of coupled cavities, under an experimental set-up usually considered in electromagnetically induced transparency, is described by the Bose-Hubbard model. This opens up the possibility of using this system as a quantum simulator, allowing for the observation of quantum ph

Martin Oberst, Frank Vewinger, A. I. Lvovsky

We demonstrate the preparation and probing of the coherence between the hyperfine ground states |5S_{1/2}, F=1> and |5S_{1/2}, F=2> of the Rubidium 87 isotope. The effect of various coherence control techniques, i.e. fractional Stimulated Raman Adiabatic Passage and Coherent Population Return on the coherence are investigated. These techniques are implemente

T. Vértesi

We study genuine tripartite entanglement shared among the spins of three localized fermions in the non-interacting Fermi gas at zero temperature. Firstly, we prove analytically with the aid of entanglement witnesses that in a particular configuration the three fermions are genuinely tripartite entangled. Then various three-fermion configurations are investig

Yong Zhang, Mo-Lin Ge

Recent study suggests that there are natural connections between quantum information theory and the Yang--Baxter equation. In this paper, in terms of the generalized almost-complex structure and with the help of its algebra, we define the generalized Bell matrix to yield all the GHZ states from the product base, prove it to form a unitary braid representatio

Thomas B. Bahder, Paul A. Lopata

We investigate the dependence of the fidelity of a Mach-Zehnder quantum interferometer on the prior information about the phase, for Fock state input and for maximally entangled (N00N) state input. For no prior information, the fidelity for Fock state input is greater than for N00N state input. In the limit of a narrow distribution describing the prior infor

Vladan Pankovic, Milan Predojevic

In this work spontaneous (non-dynamical) breaking (effective hiding) of the unitary quantum mechanical dynamical symmetry (superposition) is considered. It represents an especial but very interesting case of the general formalism of the spontaneous symmetry breaking (effective hiding). Conceptual analogies with spontaneous breaking of the gauge symmetry in W

Ditte Moller, Lars Bojer Madsen, Klaus Molmer

We consider stimulated Raman adiabatic passage (STIRAP) processes in tripod systems and show how to generate purely geometric phase changes of the quantum states involved. The geometric phases are controlled by three laser fields where pulse shapes, relative field strength and phases can be controlled. We present a robust set of universal gates for quantum c

Jerome Lodewyck, Thierry Debuisschert, Raul Garcia-Patron, Rosa Tualle-Brouri

An intercept-resend attack on a continuous-variable quantum-key-distribution protocol is investigated experimentally. By varying the interception fraction, one can implement a family of attacks where the eavesdropper totally controls the channel parameters. In general, such attacks add excess noise in the channel, and may also result in non-Gaussian output d

Eyob Alebachew, K. Fesseha

Applying stochastic differential equations, we study the squeezing and statistical properties of the cavity and output modes of a degenerate three-level laser whose cavity contains a parametric amplifier and coupled to a squeezed vacuum reservoir. We consider the case in which the top and bottom levels of the three-level cascade atoms injected into the cavit

Gábor Ivanyos, Luc Sanselme, Miklos Santha

Extraspecial groups form a remarkable subclass of p-groups. They are also present in quantum information theory, in particular in quantum error correction. We give here a polynomial time quantum algorithm for finding hidden subgroups in extraspecial groups. Our approach is quite different from the recent algorithms presented in [17] and [2] for the Heisenber

Georgy P. Karev

In this paper we develop a theory of general selection systems with discrete time and explore the evolution of selection systems, in particular, inhomogeneous populations. We show that the knowledge of the initial distribution of the selection system allows us to determine explicitly the system distribution at the entire time interval. All statistical charac

Bernard Kujawski, Janusz A. Holyst, Geoff J. Rodgers

We present an empirical study of the networks created by users within internet news groups and forums and show that they organise themselves into scale-free trees. The structure of these trees depends on the topic under discussion; specialist topics have trees with a short shallow structure whereas more universal topics are discussed widely and have a deeper

Javier Bootello

General Relativity explains with precision the anomalous advance of the perihelion of Mercury, discovered by Le Verrier in 1859. Otherwise, diverse post-Newtonian proposals trying to solve this anomaly, introduce mathematical potentials focused on a finite propagation speed. This paper tries to set some properties that should have any hypothetical gravitatio

Omar Yepez

A non-moving electron hydrogen model is proposed, resolving a long standing contradiction (94 years) in the hydrogen atom. This, however, forces to not use the &#34;in an orbit point particle kinetic energy&#34; as the phenomenon responsible for the atom stability. The repulsion between the masses of the electron and proton is what is responsible of such sta

William M. Briggs

Bayesian statistical models were developed for the number of tropical cyclones and the rate at which these cyclones became hurricanes in the North Atlantic. We find that, controlling for the cold tongue index and the North Atlantic oscillation index, there is high probability that the number of cyclones has increased in the past thirty years; but the rate at

AW Thomas, PAM Guichon

At the present time there is a lively debate within the nuclear community concerning the relevance of quark degrees of freedom in understanding nuclear structure. We outline the key issues and review the impressive progress made recently within the framework of the quark-meson coupling model. In particular, we explain in quite general terms how the modificat

N. Costiris, E. Mavrommatis, K. A. Gernoth, J. W. Clark

Statistical modeling of nuclear data using artificial neural networks (ANNs) and, more recently, support vector machines (SVMs), is providing novel approaches to systematics that are complementary to phenomenological and semi-microscopic theories. We present a global model of $β^-$-decay halflives of the class of nuclei that decay 100% by $β^-$ mode in their

Ulf-G. Meißner

I discuss the concept of the pion cloud surrounding the nucleon and other hadrons - and its limitations.

P. Braun-Munzinger

After a brief review of the various scenarios for quarkonium production in ultra-relativistic nucleus-nucleus collisions we focus on the ingredients and assumptions underlying the statistical hadronization model. We then confront model predictions for J/$ψ$ phase space distributions with the most recent data from the RHIC accelerator. Analysis of the rapidit

I. Selyuzhenkov

We present the Anti-Lambda hyperon global polarization in Au+Au collisions at sqrt(s_NN) = 62 GeV and 200 GeV measured with the STAR detector at RHIC. The observed Anti-Lambda hyperon global polarization is consistent with zero, what is in agreement with recent measurements of Lambda global polarization, as well as phi(1020) and K*0(892) vector mesons spin a

J. T. Mitchell

The PHENIX Experiment at the Relativistic Heavy Ion Collider has conducted a survey of fluctuations in charged hadron multiplicity in Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22, 62, and 200 GeV. A universal power law scaling for multiplicity fluctuations expressed as $σ^2/μ^2$ is observed as a function of $N_{part}$ for all species studied that is in

J. T. Mitchell

With the measurement of several observables at SPS energies that demonstrate non-monotonic behavior as a function of centrality and $\sqrt{s_{NN}}$, there is growing interest in pursuing a scan of relativistic heavy ion collisions at low energies at the Relativistic Heavy Ion Collider. The capabilities of the PHENIX experiment to take quality measurements at

S. J. Sanders

Identified particle elliptic flow results are presented for the Au+Au reaction at sqrt[s_{NN}] = 200$ GeV as a function of transverse momentum and pseudorapidity. Data at pseudorapidities eta approximately equal to 0, 1, and 3.4 were obtained using the two BRAHMS spectrometers. Differential v2(eta, pt) values for a given particle type are found to be essenti

S. Timoshenko

Ultra-peripheral heavy ion collisions involve long range electromagnetic interactions at impact parameters larger than twice the nuclear radius, where the strong nucleon-nuecleon interactions are uneffective. We present recent results from the STAR collaboration on these ultra-peripheral interactions likes incoherent rho0 production in deuteron-gold collisio

S. J. Sanders

Elliptic flow has been measured by the BRAHMS experiment as a function of transverse momentum and pseudorapidity for the Au+Au reaction at sqrt[s_{NN}] = 200 GeV. Identified-particle v2 (eta, pt) values were obtained with the two BRAHMS spectrometers at pseudorapidities eta approximately equal to 0, 1, and 3.4. The results show that the differential v2(eta,

A V Tsiganov

We construct two different incompatible Poisson pencils for the Toda lattice by using known variables of separation proposed by Moser and by Sklyanin.

Victor Tapia

We exhibit explicit expressions, in terms of components, of discriminants, determinants, characteristic polynomials and polynomial identities for matrices of higher rank. We define permutation tensors and in term of them we construct discriminants and the determinant as the discriminant of order $d$, where $d$ is the dimension of the matrix. The characterist

Celso Melchiades Doria

The $2^{nd}$ variation formula of the Seiberg-Witten functional is obtained in order to estimate the Morse index of redutible solutions $(A,0)$. It is shown that their Morse index is given by the dimension of the largest negative eigenspace of the operator $\triangle_{A} +\frac{k_{g}}{4}$, hence it is finite.