July 2004 arXiv papers

Michael E. Tobar, Peter Wolf, Alison Fowler, John G. Hartnett

We investigate experiments that are sensitive to the scalar and parity-odd coefficients for Lorentz violation in the photon sector of the Standard Model Extension (SME). We show that of the classic tests of special relativity, Ives-Stilwell (IS) experiments are sensitive to the scalar coefficient, but at only parts in 10^5 for the state-of-the-art experiment

W. H. Weber, G. W. Ford

Dispersion relations for dipolar modes propagating along a chain of metal nanoparticles are calculated by solving the full Maxwell equations, including radiation damping. The nanoparticles are treated as point dipoles, which means the results are valid only for a/d <= 1/3, where a is the particle radius and d the spacing. The discrete modes for a finite chai

B. Mitrovic

We calculate the change in the superconducting transition temperature Tc of MgB2 caused by interband nonmagnetic impurity scattering using the Eliashberg theory for the two-band model of this compound. Much slower rate of Tc suppression is obtained compared to the prediction based on the BCS treatment of the two-band model which ignores renormalization and d

M. Fatuzzo, F. C. Adams, P. C. Myers

Motivated by recent observations that show starless molecular cloud cores exhibit subsonic inward velocities, we revisit the collapse problem for polytropic gaseous spheres. In particular, we provide a generalized treatment of protostellar collapse in the spherical limit and find semi-analytic (self-similar) solutions, corresponding numerical solutions, and

Joshua Feinberg

We formulate and study a class of U(N)-invariant quantum mechanical models of large normal matrices with arbitrary rotation-invariant matrix potentials. We concentrate on the U(N) singlet sector of these models. In the particular case of quadratic matrix potential, the singlet sector can be mapped by a similarity transformation onto the two-dimensional Calog

Zhuo Li, Li-Ming Song

The central engine of gamma-ray bursts (GRBs) is believed to eject double-sided ultra-relativistic jets. For an observed GRB, one of the twin jets should point toward us, and is responsible for the prompt gamma-ray and subsequent afterglow emission. We consider in this Letter the other receding jet, which will give rise to late-time radio re-brightening (RRB

H. Nagahiro, S. Hirenzaki, E. Oset, M. J. Vicente Vacas

We present results on the production of bound states of $Θ^+$ in nuclei using the $(K^+,π^+)$ reaction. By taking into account the states obtained within a wide range of strength of the $Θ^+$ nucleus optical potential, plus the possibility to replace different nucleons of the nucleus, we obtain an excitation spectra with clearly differentiated peaks. The mag

A. E. Dorokhov

The behavior of the vector Adler function at spacelike momenta is studied in the framework of a covariant chiral quark model with instanton-like quark-quark interaction. The model reproduces the Adler function and $V-A$ correlator extracted from the ALEPH and OPAL data on hadronic $τ$ lepton decays, transformed into the Euclidean domain via dispersion relati

M. Kupczynski

In this short paper we present the main features of a new quantum programming language proposed recently by Peter Selinger which gives a good idea about the difficulties of constructing a scalable quantum computer. We show how some of these difficulties are related to the contextuality of quantum observables and to the abstract and statistical character of q

B. A. Nikolov, D. A. Trifonov

The exact and stable evolutions of generalized coherent states (GCS) for quantum systems are considered by making use of the time-dependent integrals of motion method and of the Klauder approach to the relationship between quantum and classical mechanics. It is shown that one can construct for any quantum system overcomplete family of states (OFS), related t

Norio Inui, Koichiro Kasahara, Yoshinao Konishi, Norio Konno

This work deals with both instantaneous uniform mixing property and temporal standard deviation for continuous-time quantum random walks on circles in order to study their fluctuations comparing with discrete-time quantum random walks, and continuous- and discrete-time classical random walks.

Baburaj A. Puthenveettil, Jaywant H. Arakeri

Laminar natural convection at unity Schmidt number over a horizontal surface with a weak normal velocity at the wall is studied using an integral analysis. To characterise the strength of the blowing, we define a non-dimensional parameter called the blowing parameter. After benchmarking with the no blowing case, the effect of the blowing parameter on boundar

Marin Soljacic, Elefterios Lidorikis, Lene Vestergaard Hau, J. D. Joannopoulos

We show analytically, and numerically that highly-dispersive media can be used to drastically increase lifetimes of high-Q microresonators. In such a resonator, lifetime is limited either by undesired coupling to radiation, or by intrinsic absorption of the constituent materials. The presence of dispersion weakens coupling to the undesired radiation modes an

Jiunn-Wei Chen, Xiangdong Ji, Yingchuan Li

Deuteron Compton scattering is calculated to $\mathcal{O}(Q^2)$ in pionless effective field theory using a dibaryon approach. The vector amplitude, which was not included in the previous pionless calculations, contributes to the cross section at $\mathcal{O}(Q^2)$ and influences significantly the extracted values of nucleon electric polarizability at inciden

Elliott H. Lieb, Michael Loss

The proof of the existence of the thermodynamic limit for electrons and nuclei interacting via the Coulomb potential, in the framework of non-relativistic quantum mechanics, was accomplished decades ago. This result did not take account of interactions caused by magnetic fields, however, (the spin-spin interaction, in particular) or of the quantized nature o

CheeWhye Chin

Let X be a smooth curve over a finite field of characteristic p, let E be a number field, and consider an E-compatible system of lisse sheaves on the curve X. For each place lambda of E not lying over p, the lambda-component of the system is a lisse E_lambda-sheaf on X, whose associated arithmetic monodromy group is an algebraic group over the local field E_

A. D. Alhaidari

We define a superalgebra S2(N/2) as a Z2 graded algebra of dimension 2N+3, where N is a positive, odd integer. The even component is a three-dimensional abelian subalgebra, while the odd component is made up of two N-dimensional, mutually conjugate algebras. For N = 1, two of the three even elements become identical, resulting in a four-dimensional superalge

S. Gómez-Avila, Mauro Napsuciale, J. A. Nieto, M. Kirchbach

We explicitly construct in the (1/2,1/2)X(1/2,1/2) representation space the operator of the squared Pauli-Lubanski vector and derive from it that the -6m^{2}eigensubspace (spin 2 in the rest frame), with well defined parity, is pinned down by the one sole equation, [ε_{μαβσ} ε^μ_{νδρ}p^σp^ρ-m^{2}g_{αβ}g_{ν\del ta}]h^{βδ}=0$.

C. Royon

We use a Monte Carlo implementation of recently developped models of double diffractive Higgs production to assess the sensitivity of the LHC experiments.

Gavin P. Salam

This talk gives a brief discussion of the motivations and principles behind computer automated expert semi-analytical resummation (CAESAR) for QCD final states.

Richard A. Matzner

Solving the 4-d Einstein equations as evolution in time requires solving equations of two types: the four elliptic initial data (constraint) equations, followed by the six second order evolution equations. Analytically the constraint equations remain solved under the action of the evolution, and one approach is to simply monitor them ({\it unconstrained} evo

R. P. Woodard

I argue against the widespread notion that manifest de Sitter invariance on the full de Sitter manifold is either useful or even attainable in gauge theories. Green&#39;s functions and propagators computed in a de Sitter invariant gauge are generally more complicated than in some noninvariant gauges. What is worse, solving the gauge-fixed field equations in

Michael Engelhardt, Andreas Kárpáti, Torsten Rack, Ivette Schmidt

While eLearning systems become more and more popular in daily education, available applications lack opportunities to structure, annotate and manage their contents in a high-level fashion. General efforts to improve these deficits are taken by initiatives to define rich meta data sets and a semanticWeb layer. In the present paper we introduce Hylos, an onlin

Thomas C. Schmidt, Matthias Wählisch

Emerging mobility standards within the next generation Internet Protocol, IPv6, promise to continuously operate devices roaming between IP networks. Associated with the paradigm of ubiquitous computing and communication, network technology is on the spot to deliver voice and videoconferencing as a standard internet solution. However, current roaming procedur

Michael Engelhardt, Thomas C. Schmidt

The semantic Web initiates new, high level access schemes to online content and applications. One area of superior need for a redefined content exploration is given by on-line educational applications and their concepts of interactivity in the framework of open hypermedia systems. In the present paper we discuss aspects and opportunities of gaining interacti

Nathan W. Mueggenburg

The design and development of a parallel plate shear cell for the study of large scale shear flows in granular materials is presented. The parallel plate geometry allows for shear studies without the effects of curvature found in the more common Couette experiments. A system of independently movable slats creates a well with side walls that deform in respons

A. N. Rubtsov, A. I. Lichtenstein

Numerically exact continuous-time Quantum Monte Carlo algorithm for finite fermionic systems with non-local interactions is proposed. The scheme is particularly applicable for general multi-band time-dependent correlations since it does not invoke Hubbard-Stratonovich transformation. The present determinantal grand-canonical method is based on a stochastic s

Wu-Sheng Dai, Mi Xie

In this paper we calculate some exact solutions of the grand partition functions for quantum gases in confined space, such as ideal gases in two- and three-dimensional boxes, in tubes, in annular containers, on the lateral surface of cylinders, and photon gases in three-dimensional boxes. Based on these exact solutions, which, of course, contain the complete

N. Kumar

It is argued that the environment induced decoherence between spatially separated parts of the wavefunction for an open quantum system also classicalizes the quantum statistics which is based on indistinguishability. This may imply a suppression of the BEC upon dilution with, e.g., isotopic fermions, in that the usual phase-space density criterion $nΛ^3 >$ 2

G. -Q. Zheng, N. Yamaguchi, H. Kan, Y. Kitaoka

We present a systematic ^{115}In NQR study on the heavy fermion compounds CeRh_{1-x}Ir_xIn_5 (x=0.25, 0.35, 0.45, 0.5, 0.55 and 0.75). The results provide strong evidence for the microscopic coexistence of antiferromagnetic (AF) order and superconductivity (SC) in the range of 0.35 \leq x \leq 0.55. Specifically, for x=0.5, T_N is observed at 3 K with a subs

W. J. Frith, P. J. Outram, T. Shanks

We present new evidence for a large deficiency in the local galaxy distribution situated in the 4000 sq.deg. APM survey area. We use models guided by the 2dF Galaxy Redshift Survey (2dFGRS) n(z) as a probe of the underlying LSS. We first check the usefulness of this technique by comparing the 2dFGRS n(z) model prediction with the K-band and B-band number cou

J. A. Combi, M. Ribo, I. F. Mirabel

We present a multiwavelength study of the environment of the unidentified X-ray/gamma-ray sources IGR J18027-1455 and IGR J21247+5058, recently discovered by the IBIS/ISGRI instrument, onboard the INTEGRAL satellite. The main properties of the sources found inside their position error circles, give us clues about the nature of these high-energy sources.

A. D. Kuzmin, A. A. Ershov

We report on observations of the recently detected (Kuzmin et al. 2004) giant pulses (GPs) from the pulsar PSR B0031-07 at 40 and 111 MHz. At 40 MHz the peak flux density of the strongest pulse is 1100 Jy, which is 400 times as high as the peak flux density of the average pulse (AP). Peak flux density of the GPs compared to the AP peak flux density has rough

G. Angloher, C. Bucci, P. Christ, C. Cozzini

We present first significant limits on WIMP dark matter by the phonon-light technique, where combined phonon and light signals from a scintillating cryogenic detector are used. Data from early 2004 with two 300 g CRESST-II prototype detector modules are presented, with a net exposure of 20.5 kg days. The modules consist of a CaWO4 scintillating ``target&#39;

Alejandra Valencia, Giuliano Scarcelli, Milena D&#39;Angelo, Y. Shih

We report the first experimental demonstration of two-photon imaging with a pseudo-thermal source. Similarly to the case of entangled states, a two-photon Gaussian thin lens equation is observed, indicating EPR type correlation in position. We introduce the concepts of two-photon coherent and two-photon incoherent imaging. The differences between the entangl

Hae-Young Kee, Yong Baek Kim

It is shown that metamagnetic transition in metals can occur via the formation of electronic nematic order. We consider a simple model where the spin-dependent Fermi surface instability gives rise to the formation of an electronic nematic phase upon increasing the applied Zeeman magnetic field. This leads to two consecutive metamagnetic transitions that sepa

Ken Hicks

A critical look is taken at both positive and null evidence for the $Θ^+$ pentaquark. Potential problems with experiments will be discussed and the question of what conclusion can be drawn from both the positive and the null results is examined. First the question of existence of the $Θ^+$ pentaquark is considered, followed by a discussion of new experiments

Kevork Abazajian, Zheng Zheng, Idit Zehavi, David H. Weinberg

We use the projected correlation function w_p(r_p) of a volume-limited subsample of the Sloan Digital Sky Survey (SDSS) main galaxy redshift catalogue to measure the halo occupation distribution (HOD) of the galaxies of the sample. Simultaneously, we allow the cosmology to vary within cosmological constraints imposed by cosmic microwave background experiment

F. E. Bauer, D. M. Alexander, W. N. Brandt, D. P. Schneider

We investigate the X-ray number counts in the 1-2 Ms Chandra Deep Fields (CDFs) to determine the contributions of faint X-ray source populations to the extragalactic X-ray background (XRB). X-ray sources were separated into Active Galactic Nuclei (AGN), star-forming galaxies, and Galactic stars based on several criteria. We find that AGN continue to dominate

Jean-Michel Levy

Practical formulae are derived for the cross-section and polarization of the $τ$ lepton produced in deep-inelastic neutrino-nucleon scattering in the frame of the simple quark-parton model.

BaBar Collaboration, B. Aubert

We present a measurement of the direct CP violating asymmetry in the decay B0 -> K+pi- using 227 x 10^6 Y(4S) -> BBbar decays collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we observe a total signal yield of n(K-pi+) + n(K+pi-) = 1606 +- 51 decays and measure the asymmetry [n(K-pi+)-n(K+pi-)]/[n(K-p+-)+n(K+pi-)] = -0

Niklas Beisert

The dilatation generator measures the scaling dimensions of local operators in a conformal field theory. In this thesis we consider the example of maximally supersymmetric gauge theory in four dimensions and develop and extend techniques to derive, investigate and apply the dilatation operator. We construct the dilatation operator by purely algebraic means:

Bahram Mashhoon

The measurement of an electromagnetic radiation field by a linearly accelerated observer is discussed. The nonlocality of this process is emphasized. The nonlocal theory of accelerated observers is briefly described and the consequences of this theory are illustrated using a concrete example involving the measurement of an incident pulse of radiation by an o

J. Bartelski, S. Tatur

Using generalized Sehgal equations for magnetic moments of baryon octet and taking into account $Σ^{0}-Λ$ mixing and two particle corrections to independent quark contributions we obtain very good fit using experimental values for errors of such moments. We present sum rules for quark magnetic moments ratios and for integrated spin dendities ratios. Due to t

Corrado Appignani

We tackle the problem of the accelerating universe by reconsidering the most general form of the metric when the speed of light is allowed to evolve with time in a homogeneous and isotropic universe. A new varying speed of light (VSL) model naturally emerges. We find it unconvenient to perform a general coordinate transformation to obtain the usual constant

Thomas Nattermann

The thermodynamic properties of ideal quantum gases are derived solely from dimensional arguments, the Pauli principle and thermodynamic relations, without resorting to statistical mechanics.

A. Enciso, F. Finkel, A. Gonzalez-Lopez, M. A. Rodriguez

We construct new solvable rational and trigonometric spin models with near-neighbors interactions by an extension of the Dunkl operator formalism. In the trigonometric case we obtain a finite number of energy levels in the center of mass frame, while the rational models are shown to possess an equally spaced infinite algebraic spectrum. For the trigonometric

D. Zschiesche, G. Zeeb, S. Schramm, H. Stoecker

We study the phase diagram of a generalized chiral SU(3)-flavor model in mean-field approximation. In particular, the influence of the baryon resonances, and their couplings to the scalar and vector fields, on the characteristics of the chiral phase transition as a function of temperature and baryon-chemical potential is investigated. Present and future fini

R. Catena, M. Pietroni, L. Scarabello

A scalar field interacting differently with dark matter and baryons may explain why their ratio is of order unity today. We provide three working examples, checking them against the observations of CMB, Large Scale Structure, supernovae Ia, and post-newtonian tests of gravity. Such a scenario could make life much easier for supersymmetric dark matter candida

Dzo Mikulovic, Alexander Schmidt, Hartmut Wachter

Attention is focused on antisymmetrized versions of quantum spaces that are of particular importance in physics, i.e. two-dimensional quantum plane, q-deformed Euclidean space in three or four dimensions as well as q-deformed Minkowski space. For each case standard techniques for dealing with q-deformed Grassmann variables are developed. Formulae for multipl

Benjamin D. G. Chandran, Naoki Bessho

We study relativistic particles undergoing surfing acceleration at perpendicular shocks. We assume that particles undergo diffusion in the component of momentum perpendicular to the shock plane due to moderate fluctuations in the shock electric and magnetic fields. We show that dN/dE, the number of surfing-accelerated particles per unit energy, attains a pow

Johan Alwall, Gunnar Ingelman

The NuTeV anomaly of a non-universal value of the fundamental parameter sin^2θ_W in the electroweak theory has been interpreted as an indication for new physics beyond the Standard Model. However, the observed quantity depends on a possible asymmetry in the momentum distributions of strange quarks and antiquarks in the nucleon. This asymmetry occurs naturall

Yu-xi Liu, Sahin Kaya Ozdemir, Adam Miranowicz, Nobuyuki Imoto

By definition, the Kraus representation of a harmonic oscillator suffering from the environment effect, modeled as the amplitude damping or the phase damping, is directly given by a simple operator algebra solution. As examples and applications, we first give a Kraus representation of a single qubit whose computational basis states are defined as bosonic vac

Dimitrios Tsimpis

We compute certain spinorial cohomology groups controlling possible supersymmetric deformations of eleven-dimensional supergravity up to order $l^3$ in the Planck length. At ${\cal O}(l)$ and ${\cal O}(l^2)$ the spinorial cohomology groups are trivial and therefore the theory cannot be deformed supersymmetrically. At ${\cal O}(l^3)$ the corresponding spinori

C. Aramo, A. Insolia, A. Leonardi, G. Miele

Ultra high energy neutrinos are produced by the interaction of hadronic cosmic rays with the cosmic radiation background. More exotic scenarios like topological defects or new hadrons predict even larger fluxes. In particular, Earth-skimming tau neutrinos could be detected by the Fluorescence Detector (FD) of Pierre Auger Observatory. A detailed evaluation o

Pedro G. Lind, Jason A. C. Gallas, Hans J. Herrmann

We study fully synchronized states in scale-free networks of chaotic logistic maps as a function of both dynamical and topological parameters. Three different network topologies are considered: (i) random scale-free topology, (ii) deterministic pseudo-fractal scale-free network, and (iii) Apollonian network. For the random scale-free topology we find a coupl

Durga Paudyal, Tanusri Saha-Dasgupta, Abhijit Mookerjee

We have studied the problem of phase stability in Fe-Pt and Co-Pt alloy systems. We have used the orbital peeling technique in the conjunction of augmented space recursion based on the tight binding linear orbital method as the method for the calculation of pair interaction energies. In particular, we have generalized our earlier technique to take into accou

S. Ghosh, A. K. Sood, S. Ramaswamy, N. Kumar

New experimental results, and a plausible theoretical understanding thereof, are presented for the flow-induced currents and voltages observed in single-walled carbon nanotube samples. In our experiments, the electrical response was found to be strongly sublinear -- nearly logarithmic -- in the flow speed over a wide range, and its direction could be control

P. B. Jones

Lower limits are found for the disorder resistivity of solid neutron-star matter in the neutron-drip region which is amorphous and heterogeneous in nuclear charge. This temperature-independent resistivity, large compared with that produced by phonon scattering, has direct consequences for theories of neutron-star magnetic field generation and evolution.

O. F. Dayi, B. Yapiskan

Equivalence of partition functions for U(1) gauge theory and its dual in appropriate phase spaces is established in terms of constrained hamiltonian formalism of their parent action. Relations between the electric--magnetic duality transformation and the (S) duality transformation which inverts the strong coupling domains to the weak coupling domains of nonc

A. J. Moreno, S. V. Buldyrev, E. La Nave, I. Saika-Voivod

We calculate the statistical properties of the energy landscape of a minimal model for strong network-forming liquids. Dynamics and thermodynamic properties of this model can be computed with arbitrary precision even at low temperatures. A degenerate disordered ground state and logarithmic statistics for the energy distribution are the landscape signatures o

Michel Deza, Mathieu Dutour, Sergey Shpectorov

The Wythoff construction takes a $d$-dimensional polytope $P$, a subset $S$ of $\{0,..., d\}$ and returns another $d$-dimensional polytope $P(S)$. If $P$ is a regular polytope, then $P(S)$ is vertex-transitive. This construction builds a large part of the Archimedean polytopes and tilings in dimension 3 and 4. We want to determine, which of those Wythoffians

S. Goto, D. R. Osborne, J. C. Vassilicos, J. D. Haigh

We introduce the velocity (Vs) of stagnation points as a means to characterise and measure statistical persistence of streamlines. Using theoretical arguments, Direct Numerical Simulations (DNS) and Kinematic Simulations (KS) of three-dimensional isotropic turbulence for different ratios of inner to outer length scales L/eta of the self-similar range, we sho

A. N. Aleksandrovskii, A. S Bakai, D. Cassidy, A. V. Dolbin

The dilatometric investigation in the temperature range of 2-28K shows that a first-order polyamorphous transition occurs in the orientational glasses based on C60 doped with H2, D2 and Xe. A polyamorphous transition was also detected in C60 doped with Kr and He. It is observed that the hysteresis of thermal expansion caused by the polyamorphous transition (

N. Mukunda, G. Marmo, Alessandro Zampini, S. Chaturvedi

The Wigner-Weyl isomorphism for quantum mechanics on a compact simple Lie group $G$ is developed in detail. Several New features are shown to arise which have no counterparts in the familiar Cartesian case. Notable among these is the notion of a `semiquantised phase space&#39;, a structure on which the Weyl symbols of operators turn out to be naturally defin

Masahiro Kawasaki, Fuminobu Takahashi, Tomo Takahashi

We discuss cosmic microwave background anisotropies in models with an unconventional primordial power spectrum. In particular, we consider an initial power spectrum with some ``spiky&#39;&#39; corrections. Interestingly, such a primordial power spectrum generates ``wavy&#39;&#39; structure in the CMB angular power spectrum.

Rim Dib, Scott M. Ransom, Paul S. Ray, Victoria M. Kaspi

As part of a large-scale search for coherent pulsations from LMXBs in the RXTE archive, we have completed a detailed series of searches for coherent pulsations of 4U 1820-30 -- an ultracompact LMXB with a binary period of 11.4 min, located in the globular cluster NGC6624. The short binary period implies any coherent signal would be highly accelerated, so we

Yanqin Wu

The process of tidal dissipation inside Jupiter is not yet understood. Its tidal quality factor ($Q$) is inferred to lie between $10^5$ and $10^6$. We examine effects of inertial-modes on tidal dissipation in a neutrally bouyant, core-less, uniformly rotating planet. The rate of dissipation caused by resonantly excited inertial-modes depends on the following

Reiho Sakamoto, Jun&#39;ichi Shiraishi, Daniel Arnaudon, Luc Frappat

We use the Jack symmetric functions as a basis of the Fock space, and study the action of the Virasoro generators $L_n$. We calculate explicitly the matrix elements of $L_n$ with respect to the Jack-basis. A combinatorial procedure which produces these matrix elements is conjectured. As a limiting case of the formula, we obtain a Pieri-type formula which rep

Yanqin Wu

We study global inertial-modes with the purpose of unraveling the role they play in the tidal dissipation process of Jupiter. For spheres of uniformly rotating, neutrally buoyant fluid, we show that the partial differential equation governing inertial-modes can be separated into two ordinary differential equations when the density is constant, or when the de

Ki-Seok Kim

In the context of the U(1) slave boson theory we derive a critical field theory near the quantum critical point of the Kondo lattice model in two spatial dimensions. First we argue that strong gauge fluctuations in the U(1) slave boson theory give rise to confinement between spinons and holons, thus causing &#34;neutralized&#34; spinons in association with t

Adam J. Burgasser

Monte Carlo simulations of the field substellar mass function (MF) are presented. Starting from various representations of the MF below 0.1 M$_{\sun}$ and the stellar birth rate, luminosity functions (LFs) and T$_{eff}$ distributions are produced for comparison with observed samples. These distributions exhibit distinct minima in the mid-type L dwarf regime

J. W. Flanagan, K. Ohmi, H. Fukuma, S. Hiramatsu

The effects of electron clouds on positively-charged beams have been an active area of research in recent years at particle accelerators around the world. Transverse beam-size blow-up due to electron clouds has been observed in some machines, and is considered to be a major limiting factor in the development of higher-current, higher-luminosity electron-posi

A. A. Pomeransky, O. V. Zhirov, D. L. Shepelyansky

We study effects of static inter-qubit interactions and random errors in quantum gates on the stability of various quantum algorithms including the Grover quantum search algorithm and the quantum chaos maps. For the Grover algorithm our numerical and analytical results show existence of regular and chaotic phases depending on the static imperfection strength

O. Kern, G. Alber, D. L. Shepelyansky

A general error correction method is presented which is capable of correcting coherent errors originating from static residual inter-qubit couplings in a quantum computer. It is based on a randomization of static imperfections in a many-qubit system by the repeated application of Pauli operators which change the computational basis. This Pauli-Random-Error-C

B. A. Nikolov, D. A. Trifonov

Using the Klauder approach the stable evolution of generalized coherent states (GCS) for some groups (SU(2), SU(1,1) and SU(N)) is considered and it is shown that one and the same classical solution z(t) can correctly characterize the quantum evolution of many different (in general nonequivalent) systems. As examples some concrete systems are treated in grea

Aurelien Dantan, Nicolas Treps, Alberto Bramati, Michel Pinard

We propose a protocol to achieve high fidelity quantum state teleportation of a macroscopic atomic ensemble using a pair of quantum-correlated atomic ensembles. We show how to prepare this pair of ensembles using quasiperfect quantum state transfer processes between light and atoms. Our protocol relies on optical joint measurements of the atomic ensemble sta

Yu. Dabaghian

We introduce an analytical solution to the one of the most familiar problems from the elementary quantum mechanics textbooks. The following discussion provides simple illustrations to a number of general concepts of quantum chaology, along with some recent developments in the field and a historical perspective on the subject.

Min-Fong Yang

We show that, for an exactly solvable quantum spin model, a discontinuity in the first derivative of the ground state concurrence appears in the absence of quantum phase transition. It is opposed to the popular belief that the non-analyticity property of entanglement (ground state concurrence) can be used to determine quantum phase transitions. We further po

Hartmut Klauck, Robert Spalek, Ronald de Wolf

A strong direct product theorem says that if we want to compute k independent instances of a function, using less than k times the resources needed for one instance, then our overall success probability will be exponentially small in k. We establish such theorems for the classical as well as quantum query complexity of the OR function. This implies slightly

Horace P. Yuen

A new approach to quantum cryptography to be called KCQ, keyed communication in quantum noise, is developed on the basis of quantum detection and communication theory for classical information transmission. By the use of a shared secret key that determines the quantum states generated for different data bit sequences, the users may employ the corresponding o

Hui Li, Jiangfeng Du

The purity of a reduced state for spins that is pure in the rest frame will most likely appear to degrade because spin and momentum become mixed when viewed by a moving observer. We show that such a boost-induced decrease in spin purity observed in a moving reference frame is intrinsically related to the spatial localization properties of the wave package ob

Chaitanya Athale, Yuri Mansury, Thomas S. Deisboeck

Experimental evidence indicates that human brain cancer cells proliferate or migrate, yet do not display both phenotypes at the same time. Here, we present a novel computational model simulating this cellular decision-process leading up to either phenotype based on a molecular interaction network of genes and proteins. The model&#39;s regulatory network cons

F. Guinea, V. A. A. Jansen, N. Stollenwerk

The statistics of outbreaks in a model for the propagation of meningococcal diseases is analyzed, taking into account the possibility that the population is fragmented into weakly connected patches. It is shown that, depending on the size of of the sample studied, the ratio between the variance and the mean of infected cases can vary from one (Poisson statis

Aleksandra M. Walczak, Masaki Sasai, Peter G. Wolynes

We present a self-consistent field approximation to the problem of the genetic switch composed of two mutually repressing/activating genes. The protein and DNA state dynamics are treated stochastically and on equal footing. In this approach the mean influence of the proteomic cloud created by one gene on the action of another is self-consistently computed. W

Mohammad Ghorbanalilu, B. Shokri

The production of weakly relativistic plasma by microwave electric field with circular polarization has been studied. Electron distribution function obtained for this produced plasma and shown that it is non-equilibrium and anisotropic. It is shown that produced plasma accelerated on direction of propagation microwave electric field. The electron velocity on

Zinovy Malkin

Three most long and dense VLBI nutation series obtained at the Goddard Space Flight Center, Institute of Applied Astronomy, and U.S. Naval Observatory were used for investigation of the Free Core Nutation (FCN) contribution to the celestial pole offset. Some recent studies have showed that the FCN period or/and phase does not remain constant, but varies in a

Neil Broderick, Anna Peacock, Katia Gallo, Ruth Lewen

Second harmonic generation in a two dimensional nonlinear quasi-crystal is demonstrated for the first time. Temperature and wavelength tuning of the crystal reveal the uniformity of the pattern while angle tuning reveals the dense nature of the crystal&#39;s Fourier spectrum. These results compare well with theoretical predictions showing the excellent unifo

Antonio Alfonso-Faus

We find five fundamental reasons demanding that any gravitational mass m, and the speed of light c, vary with cosmological time such that mc remains constant. This is required by the universal condition of conservation of momentum in a Universe with spatial homogeneity. We prove that this is consistent with Einstein&#39;s Theory of General Relativity. We cal

V. A. Andreev, D. Yu. Tsipenyuk

New approach to the description of a gravitation using analogy between the optical and mechanical phenomenon is advanced. For this purpose in extended (1+4)-dimensional space G(1,4) the gravitational effects are considered: the speed of escape, red shift, radar echo, deviation light and perihelion precession of Mercury. It is shown, that methods of the Exten

Alejandro Rivero

It can be found that with the adequate measure, the beta stability line is equidistant from neutron and proton drip lines. We explore this fact and its predictive potentiality in the simplest case, the classic liquid drop formula.

N. Kaiser

We analyze the spin-orbit coupling term in the nuclear energy density functional in terms of a zero-range NN-contact interaction and finite-range contributions from two-pion exchange. We show that the strength of the spin-orbit contact interaction as extracted from high-precision nucleon-nucleon potentials is in perfect agreement with that of phenomenologica

Matthias F. M. Lutz, Madeleine Soyeur

The $γp \to K^+ π^0 Λ$ and $γp \to K^+ πΣ$ reactions are studied in the kinematic region where the $π^0 Λ$(1116) and $πΣ$(1192) pairs originate dominantly from the decay of the $Σ$(1385) and $Λ$(1405) resonances. We consider laboratory photon energies around 2 GeV, significantly above the threshold for producing the $K^+ Σ$(1385) and $K^+ Λ$(1405) final stat

M. Pavon Valderrama, E. Ruiz Arriola

The Variable S-matrix approach offers a unique way to extract low energy threshold parameters for a given NN potential. We extract those parameters for the np system from the NijmII and Reid93 potentials, to all partial waves with total angular momentum $j \le m5 $, using the generalized effective range expansion % $$ ({\bf f}^{sj})_{l,l&#39;} k^l k^{l&#39;}

Sergei P. Maydanyuk, Vladislav S. Olkhovsky, Alexander K. Zaichenko

A non-stationary method for tunneling description of non-relativistic particles and photons through a barrier on the basis of consideration of the multiple internal reflections of vawe packets in relation of barrier boundaries is presented. The method is described in details and proved in the case of the one-dimentional tunneling of the particle through the

Y. M. Zhao, A. Arima, N. Yoshinaga

The ground states of all even-even nuclei have angular momentum, $I$, equal to zero, I=0, and positive parity, $π=+$. This feature was believed to be a consequence of the attractive short-range interaction between nucleons. However, in the presence of two-body random interactions, the predominance of $I^π=0^+$ ground states (0 g.s.) was found to be robust bo

T. Rozek, P. Moskal, H. -H. Adam, A. Budzanowski

The Lambda, Sigma0 and Sigma+ hyperon production in NN collisions is studied at the COSY - 11 installation in order to investigate the production mechanism as well as to extract information about the Y-N interaction.

Pierluigi Contucci, Cristian Giardina&#39;, Claudio Giberti, Cecilia Vernia

We consider optimization problems for complex systems in which the cost function has a multivalleyed landscape. We introduce a new class of dynamical algorithms which, using a suitable annealing procedure coupled with a balanced greedy-reluctant strategy drive the systems towards the deepest minimum of the cost function. Results are presented for the Sherrin

Soon-Tae Hong, Jaedong Choi, Young-Jai Park

We study a multiply warped product manifold associated with the Reissner-Nordstrom-AdS metric to investigate the physical properties inside the black hole event horizons. Our results include various limiting geometries of the RN, Schwarzschild--AdS and Schwarzschild space-times, through the successive truncation procedure of parameters in the original curved

M. Feigin

A basis of quasi-invariant module over invariants is explicitly constructed for the two-dimensional Coxeter systems with arbitrary multiplicities. It is proved that this basis consists of $m$-harmonic polynomials, thus the earlier results of Veselov and the author for the case of constant multiplicity are generalized.