July 2006 arXiv papers — page 26

Jozef Kosik, Vladimir Buzek, Mark Hillery

We investigate quantum walks in multiple dimensions with different quantum coins. We augment the model by assuming that at each step the amplitudes of the coin state are multiplied by random phases. This model enables us to study in detail the role of decoherence in quantum walks and to investigate the quantum-to-classical transition. We also provide classic

Nobuyuki Takei, Noriyuki Lee, Daiki Moriyama, J. S. Neergaard-Nielsen

We experimentally demonstrate creation and characterization of Einstein-Podolsky-Rosen (EPR) correlation between optical beams in the time domain. The correlated beams are created with two independent continuous-wave optical parametric oscillators and a half beam splitter. We define temporal modes using a square temporal filter with duration $T$ and make tim

X. L. Zhang, M. Feng, K. L. Gao

A potential scheme is proposed to generate complete sets of entangled photons in the context of cavity quantum electrodynamics (QED). The scheme includes twice interactions of atoms with cavities, in which the first interaction is made in two-mode optical cavities and the second one exists in a microwave cavity. In the optical cavities the atoms are resonant

G. A. Kells

The time-evolution operator for the kicked Harper model is reduced to block matrix form when the effective Planck's constant hbar = 2 pi M/N and M and N are integers. Each block matrix is spanned by an orthonormal set of N "kq" (quasi-position/quasi-momentum) functions. This implies that the system's eigenfunctions or stationary states are ne

Ivan Damgaard, Serge Fehr, Louis Salvail, Christian Schaffner

We initiate the study of two-party cryptographic primitives with unconditional security, assuming that the adversary's quantum memory is of bounded size. We show that oblivious transfer and bit commitment can be implemented in this model using protocols where honest parties need no quantum memory, whereas an adversarial player needs quantum memory of siz

Gerardo Adesso, Fabrizio Illuminati

It is a central trait of quantum information theory that there exist limitations to the free sharing of quantum correlations among multiple parties. Such 'monogamy constraints' have been introduced in a landmark paper by Coffman, Kundu and Wootters, who derived a quantitative inequality expressing a trade-off between the couplewise and the genuine tr

Andris Ambainis, Oded Regev

We provide an elementary proof of the quantum adiabatic theorem.

Debashis Gangopadhyay, Mahendra Nath Sinha Roy

We show that the quantum logic gates, {\it viz.} the single qubit Hadamard and Phase Shift gates, can also be realised using q-deformed angular momentum states constructed via the Jordan-Schwinger mechanism with two q-deformed oscillators. {\it Keywords :} quantum logic gates ; q-deformed oscillators ; quantum computation {\it PACS:} 03.67.Lx ; 02.20.Uw

Sudipta Samanta, J. Chakrabarti, Dhananjay Bhattacharyya

From the crystal structure data and using the concept of equilbrium statistical mechanics we show how to calculate the thermodynamics of protein/DNA complexes. We apply the method to the TATA-box binding protein (TBP)/TATA sequence complex. We have estimated the change in free energy and entropy for each of the base pair (bp). The local rigidity of the DNA i

C. Figueira de Morisson Faria, X. Liu

We investigate laser induced nonsequential multiple ionization using a simple statistical model in which an electron recollides inelastically with its parent ion. In this collision, it thermalizes with the remaining $N-1$ bound electrons within a time interval $Δt$. Subsequently, all the $N$ electrons leave. We address the question of how the above time dela

Hanno Essen

The idea here is to use large relative velocities of electrons and nuclei in accelerator beams to increase the probability of fusion. The function of the electrons is to both screen the positive charge and to produce an increased parallel pinching current. The increase in reaction probability is estimated using the Darwin magnetic interaction energy approach

V. G. Gurzadyan, D. A. Warburton

The recently shown two premises (Gurzadyan 2000), i.e. the absence of 56/64 year Venus cycle constraints, at the importance of the 8-year cycle in the Venus Tablet, stimulated new studies on the Chronology of the Ancient Near East (2nd millennium BC). The analysis by B.Banjevic using both premises, however, did not provide anchors of strenght similar to thos

Maurizio Michelini

In the present paradigm the space is filled with very high flux of very small quanta whose wavelength equals the Planck's length. The quantum energy is very small, so the relevant Planck constant ho is much smaller than the usual h. This physical paradigm imposes to the motion the conservation of energy and momentum, as well as the laws of the relativist

Olli Luukkonen, Pekka Ikonen, Sergei Tretyakov

In this paper we study microstrip antenna miniaturization using partial filling of the antenna volume with dielectric materials. An analytical expression is derived for the quality factor of an antenna loaded with a combination of two different materials. This expression can be used to optimize the filling pattern for the design that most efficiently retains

Alexandre F. da Fonseca, C. P. Malta

Real filaments are not perfectly homogeneous. Most of them have various materials composition and shapes making their stiffnesses not constant along the arclength. We investigate the existence of circular and helical equilibrium solutions of an intrinsically straight rod with varying bending and twisting stiffnesses, within the framework of the Kirchhoff mod

Atushi Ishikawa

We investigate the dynamical behavior in the large scale region of non-equilibrium systems, by employing data on the assessed value of land in 1983 -- 2006 Japan. In the system we find the detailed quasi-balance, which has the symmetry: x_1 -> a {x_2}^θ (x_1 and x_2 are two successive land prices). By using the detailed quasi-balance and Gibrat's law, we

S C Tiwari

Advances in gauge theories and unified theories have not thrown light on the meaning of electron. The problem of the origin of electronic charge is made precise, new insights gained from Weyl space are summarized, and the origin of charge in terms of fractional spin is suggested. New perspective on the abelian Chern-Simons theory is presented to explain char

Alex Kaivarainen

New concept of Bivacuum is introduced, as a dynamic matrix of the Universe, composed from sub-quantum particles and antiparticles, forming vortical structures. These structures are presented by continuum of dipoles, each dipole containing a pair of correlated torus and antitorus: V(+) and V(-) of the opposite energy/mass, spin, charge and magnetic moments, c

A. F. Krutov, V. E. Troitsky

The deuteron tensor polarization component T_20(Q^2) is calculated by relativistic Hamiltonian dynamics approach. It is shown that in the range of momentum transfers available in to-day experiments, relativistic effects, meson exchange currents and the choice of nucleon electromagnetic form factors almost do not influence the value of T_20(Q^2). At the same

A. V. Gorbach, D. V. Skryabin

We report families of discrete optical solitons in frequency space, or spectral-discrete solitons existing in a dispersive Raman medium, where individual side-bands are coupled by coherence. The associated time-domain patterns correspond to either trains of ultrashort pulses, or weakly modulated waves. We describe the physics behind the spectral localization

P. G. Grinevich, P. M. Santini

We study the complexification of the one-dimensional Newtonian particle in a monomial potential. We discuss two classes of motions on the associated Riemann surface: the rectilinear and the cyclic motions, corresponding to two different classes of real and autonomous Newtonian dynamics in the plane. The rectilinear motion has been studied in a number of pape

Eugene Smirnov, Christian E. Rueter, Milutin Stepic, Vladimir Shandarov

We report on the formation of dark discrete solitons in a nonlinear periodic system consisting of evanescently-coupled channel waveguides that are fabricated in defocusing lithium niobate. Localized nonlinear dark modes displaying a phase jump in the center that is located either on-channel (mode A) or in-between channels (mode B) are formed, which is to our

Dilip P. Ahalpara, Jitendra C. Parikh

Analytic models of two computer generated time series (Logistic map and Rossler system) and two real time series (ion saturation current in Aditya Tokamak plasma and NASDAQ composite index) are constructed using Genetic Programming (GP) framework. In each case, the optimal map that results from fitting part of the data set also provides a very good descripti

Yuri N. Fedorov, David Gomez-Ullate

This paper is part of a program that aims to understand the connection between the emergence of chaotic behaviour in dynamical systems in relation with the multi-valuedness of the solutions as functions of complex time $τ$. In this work we consider a family of systems whose solutions can be expressed as the inversion of a single hyperelliptic integral. The a

Dilip P. Ahalpara, Jitendra C. Parikh

Dynamics of complex systems is studied by first considering a chaotic time series generated by Lorenz equations and adding noise to it. The trend (smooth behavior) is separated from fluctuations at different scales using wavelet analysis and a prediction method proposed by Lorenz is applied to make out of sample predictions at different regions of the time s

Herintsitohaina Ratsimbarison

This paper gives a review of Connes-Kreimer formulation of perturbative renormalization in Quantum Field Theory. We begin with the derivation of the Feynman calculus, the Hopf algebra structure on Feynman diagrams and we show the natural occurence of Birkhoff decomposition in perturbative renormalization. Most of proofs is added in the present paper.

Frank Hansen

The operator function (A,B)\to\tr f(A,B)(K^*)K, defined on pairs of bounded self-adjoint operators in the domain of a function f of two real variables, is convex for every Hilbert Schmidt operator K, if and only if f is operator convex. As a special case we obtain a new proof of Lieb's concavity theorem for the function (A,B)\to\tr A^pK^*B^{q}K, where p

Al. A. Ivanov

We study non-nesting actions of groups on real trees. We prove some fixed point theorems for such actions under the assumption that groups are Polish and have comeagre conjugacy classes.

Dirk Blömker, Jinqiao Duan

Complex systems may be subject to various uncertainties. A great effort has been concentrated on predicting the dynamics under uncertainty in initial conditions. In the present work, we consider the well-known Burgers equation with random boundary forcing or with random body forcing. Our goal is to attempt to understand the stochastic Burgers dynamics by pre

Lei Ni, Baoqiang Wu

In this short note, as a simple application of the strong result proved recently by Böhm and Wilking, we give a classification on closed manifolds with 2-nonnegative curvature operator. Moreover, by the new invariant cone constructions of Böhm and Wilking, we show that any complete Riemannian manifold (with dimension $\ge 3$) whose curvature operator is boun

Valera Berestovskii, Conrad Plaut

We develop a generalized covering space theory for a class of uniform spaces called coverable spaces. Coverable spaces include all geodesic metric spaces, connected and locally pathwise connected compact topological spaces, in particular Peano continua, as well as more pathological spaces like the topologist's sine curve. Each coverable space has a gener

Samuel Cooper, Dominic Dotterrer, Stratos Prassidis

The operation of zig-zag products of graphs is the analogue of the semidirect product of groups. Using this observation, we present a categorical description of zig-zag products in order to generalize the construction for the category of simple graphs. Also, we examine the covering properties of zig-zag products and we utilize these results to estimate their

Clara Brasseur, Ryan E. Grady, Stratos Prassidis

D. A. Kahzdan first put forth property (T) in relation to the study of discrete subgroups of Lie groups of finite co-volume. Through a combinatorial approach, we define an analogue of property (T) for regular graphs. We then prove the basic combinatorial and metric properties of Kazhdan groups in this context. In particular, we use our methods to construct i

Jean-Camille Birget

We consider the subgroup lpG_{k,1} of length preserving elements of the Thompson-Higman group G_{k,1} and we show that all elements of G_{k,1} have a unique lpG_{k,1}.F_{k,1} factorization. This applies to the Thompson-Higman group T_{k,1} as well. We show that lpG_{k,1} is a ``diagonal'' direct limit of finite symmetric groups, and that lpT_{k,1} is

Krerley Oliveira

We construct equilibrium states, including measures of maximal entropy, for a large (open) class of non-uniformly expanding maps on compact manifolds. Moreover, we study uniqueness of these equilibrium states, as well as some of their ergodic properties.

Hendrik Hubrechts

Let E_G be a family of hyperelliptic curves over F2^(alg cl) with general Weierstrass equation given over a very small field F. We describe in this paper an algorithm to compute the zeta function of E_g for g in a degree n extension field of F, which has as time complexity O(n^3) and memory requirements O(n^2). With a slightly different algorithm we can get

Ben Hambly, Liza Jones

Some probabilistic aspects of the number variance statistic are investigated. Infinite systems of independent Brownian motions and symmetric alpha-stable processes are used to construct new examples of processes which exhibit both divergent and saturating number variance behaviour. We derive a general expression for the number variance for the spatial partic

Ravi Vakil, Aleksey Zinger

The space of smooth genus 0 curves in projective space has a natural smooth compactification: the moduli space of stable maps, which may be seen as the generalization of the classical space of complete conics. In arbitrary genus, no such natural smooth model is expected, as the space satisfies ``Murphy's Law''. In genus 1, however, the situation

Markus Reiß

We show that nonparametric regression is asymptotically equivalent in Le Cam's sense with a sequence of Gaussian white noise experiments as the number of observations tends to infinity. We propose a general constructive framework based on approximation spaces, which permits to achieve asymptotic equivalence even in the cases of multivariate and random de

A. Favaron

Let ${\cal A}(x;D_x)$ be a second-order linear differential operator in divergence form. We prove that the operator $łI- {\cal A}(x;D_x)$, where $ł\in\csp$ and $I$ stands for the identity operator, is closed and injective when ${\rm Re}ł$ is large enough and the domain of ${\cal A}(x;D_x)$ consists of a special class of weighted Sobolev function spaces relat

V. Gritsenko, K. Hulek, G. K. Sankaran

The moduli space of polarised K3 surfaces of degree 2d is a quasi-projective variety of dimension 19. For general d very little has been known about the Kodaira dimension of these varieties. In this paper we present an almost complete solution to this problem. Our main result says that this moduli space is of general type for d>61 and for d=46,50,54,58,60.

Georg Hein

We study base points of the generalized Theta-divisor on the moduli space of vector bundles on a smooth algebraic curve X of genus g defined over an algebraically closed field. To do so, we use the derived categories D(Pic(X)), D(Jac(X)), and the equivalence between them given by the Fourier-Mukai transform coming from the Poincaré bundle. The vector bundles

Yasuhide Numata

We consider certain modules of the symmetric groups whose basis elements are called tabloids. Some of these modules are isomorphic to subspaces of the cohomology rings of subvarieties of flag varieties as modules of the symmetric groups. We give a combinatorial description for some weighted sums of their characters, i.e., we introduce combinatorial objects c

Lee-Peng Teo

We study the Bers isomorphism between the Teichmüller space of the parabolic cyclic group and the universal Teichmüller curve. We prove that this is a group isomorphism and its derivative map gives a remarkable relation between Fourier coefficients of cusp forms and Fourier coefficients of vector fields on the unit circle. We generalize the Takhtajan-Zograf

E. I. Bunina, A. V. Mikhalev

In this paper we give a small review of some recent results of elementary equivalence of linear and algebraic groups and our last new results of elementary equivalence of categories of modules, endomorphism rings of modules, lattices of submodules of modules, and automorphism groups of modules.

Bhupinder Singh Anand

The only fault we can fairly lay at Lucas' and Penrose's doors, for continuing to believe in the essential soundness of the Goedelian argument, is their naive faith in, first, non-verifiable assertions in standard expositions of classical theory, and, second, in Goedel's unvalidated interpretation of his own formal reasoning. We show why their fa

Simona Paoli

Homotopy 3-types can be modelled algebraically by Tamsamani's weak 3-groupoids as well as, in the path-connected case, by cat^2-groups. This paper gives a comparison between the two models in the path-connected case. This leads to two different semistrict algebraic models of connected 3-types using the Tamsamani's model. Both are then related to Gray

Mariusz Ciesielski, Jacek Leszczynski

This paper deals with numerical solutions to a partial differential equation of fractional order. Generally this type of equation describes a transition from anomalous diffusion to transport processes. From a phenomenological point of view, the equation includes at least two fractional derivatives: spatial and temporal. In this paper we proposed a new numeri

Andreas Paffenholz, Axel Werner

We describe a construction for d-polytopes generalising the well known stacking operation. The construction is applied to produce 2-simplicial and 2-simple 4-polytopes with g_2=0 on any number of n >= 13 vertices. In particular, this implies that the ray l_1, described by Bayer (1987), is fully contained in the convex hull of all flag vectors of 4-polytopes.

Bin Zhu

We define Bernstein-Gelfand-Ponomarev reflection functors in the cluster categories of hereditary algebras. They are triangle equivalences which provide a natural quiver realization of the "truncated simple reflections" on the set of almost positive roots $Φ_{\ge -1}$ associated to a finite dimensional semisimple Lie algebra. Combining with the tilti

Jim Colliander, Markus Keel, Gigliola Staffilani, Hideo Takaoka

We prove an endpoint multilinear estimate for the $X^{s,b}$ spaces associated to the periodic Airy equation. As a consequence we obtain sharp local well-posedness results for periodic generalized KdV equations, as well as some global well-posedness results below the energy norm. In particular we prove a multilinear estimate which completes the proof of globa

J. Qiu

We calculate the one loop amplitudes for the two gluon scattering process in light cone gauge with fermions and scalars circulating in the loop. This extends the earlier works, in which only the gluon circulates the loop. By putting all fields in the adjoint representation with N_f=2, N_s=6, the scattering amplitude of gluon by gluon in the special case of N

Stefan Fredenhagen, Matthias R. Gaberdiel

Generalised permutation branes in products of N=2 minimal models play an important role in accounting for all RR charges of Gepner models. In this paper an explicit conformal field theory construction of these generalised permutation branes for one simple class of examples is given. We also comment on how this may be generalised to the other cases.

Gudrid Moortgat-Pick

Polarized e- and e+ at the International Linear Collider play an important role for discovering physics beyond the Standard Model and for precisely unravelling the structure of the underlying physics. The physics programme at the first energy stage at sqrt{s}=500 GeV benefits strongly from the polarization of both beams. But also at 1 TeV as well as at a pos

Guy D. Moore, Jean-Marie Robert

We re-examine soft dilepton emission from a weakly coupled Quark-Gluon Plasma. We show that Braaten, Pisarski, and Yuan&#39;s result that the dilepton rate rises as E^-4 (and the spectral weight scales as 1/E) at small energy E<<gT is correct, but that the coefficient they found for this behavior is not correct, because their analysis was incomplete. At stil

A. E. Dorokhov, W. Broniowski, E. Ruiz Arriola

The leading- and higher-twist distribution amplitudes and light-cone wave functions of real and virtual photons are analyzed in chiral quark models. The calculations are performed in the nonlocal quark model based on the instanton picture of QCD vacuum, as well as in the spectral quark model and the Nambu--Jona-Lasinio model with the Pauli-Villars regulator,

P. Marquard, J. H. Piclum, D. Seidel, M. Steinhauser

In this paper we consider the matching coefficient of the vector current between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) to three-loop order in perturbation theory. We evaluate the fermionic corrections containing a closed massless fermion loop. The results are building blocks both for the bottom and top quark system at threshold. We ex

S. Rai Choudhury, A. S. Cornell, Naveen Gaur, Ashok Goyal

Though the predictions of the Standard Model (SM) are in excellent agreement with experiments there are still several theoretical problems associated with the Higgs sector of the SM, where it is widely believed that some ``{\it new physics}&#39;&#39; will take over at the TeV scale. One beyond the SM theory which resolves these problems is the Little Higgs (

J. Cleymans, H. Oeschler, K. Redlich, S. Wheaton

The status of the energy dependence of the chemical freeze-out temperature and chemical potential obtained in heavy ion collisions is presented. Recent proposals for chemical freeze-out conditions are compared.

Hiroyuki Kawamura, Jiro Kodaira, Kazuhiro Tanaka

We discuss transverse double-spin asymmetries for dimuon production at small transverse-momentum $Q_T$ in $pp$ and $p\bar{p}$ collisions. All order resummation of large logarithms relevant in small $Q_T$ region is performed at next-to-leading logarithmic (NLL) accuracy, and asymmetries at RHIC, J-PARC and GSI are calculated.

Brian C. Tiburzi

We use vector flavor symmetry to relate form factors of isospin changing operators to isovector form factors. Flavor twisted boundary conditions in lattice QCD thus allow isovector form factors of twist-two operators, e.g, to be computed at continuous values of the momentum transfer. These twisted boundary conditions, moreover, are implemented only in the va

Yu. A. Troyan, E. B. Plekhanov, V. N. Pechenov, A. Yu. Troyan

Ten resonances were found in the mass spectrum of pi+pi- -system from the reaction np->nppi+pi- in np-interactions at Pn=5.20 GeV/c in the 1-m HBC of LHE JINR by using the criterion cos(teta)[c.m.c.] p>0. Such effects were not found in pi-pi0 - combinations from the reaction np->pppi-pi0. Therefore, it is necessary to attribute the value of isotopic spin I =

M. I. Wanas

The present work is a review of a series of papers, published in the last ten years, comprising an attempt to find a suitable avenue from geometry to quantum. It shows clearly that, any non-symmetric geometry admits some built-in quantum features. These features disappear completely once the geometry becomes symmetric (torsion-less). It is shown that, torsio

Oliver Kosut, Lang Tong

The problem of cooperative fusion in the presence of Byzantine sensors is considered. An information theoretic formulation is used to characterize the Shannon capacity of sensor fusion. It is shown that when less than half of the sensors are Byzantine, the effect of Byzantine attack can be entirely mitigated, and the fusion capacity is identical to that when

Xiao-Hong Peng, Paddy Farrell

Two product array codes are used to construct the (24, 12, 8) binary Golay code through the direct sum operation. This construction provides a systematic way to find proper (8, 4, 4) linear block component codes for generating the Golay code, and it generates and extends previously existing methods that use a similar construction framework. The code construc

Andrea Montanari, Devavrat Shah

We present a deterministic approximation algorithm to compute logarithm of the number of `good&#39; truth assignments for a random k-satisfiability (k-SAT) formula in polynomial time (by `good&#39; we mean that violate a small fraction of clauses). The relative error is bounded above by an arbitrarily small constant epsilon with high probability as long as t

Scott A. Turner, Manuel A. Perez-Quinones, Stephen H. Edwards

This paper presents our evaluation of using a Tablet-PC to provide peer-review comments in the first year Computer Science course. Our exploration consisted of an evaluation of how students write comments on other students&#39; assignments using three different methods: pen and paper, a Tablet-PC, and a desktop computer. Our ultimate goal is to explore the e

H. Fang, Y. Kilani, J. H. M. Lee, P. J. Stuckey

In this note we introduce the notion of islands for restricting local search. We show how we can construct islands for CNF SAT problems, and how much search space can be eliminated by restricting search to the island.

C. Deibel, D. Janssen, P. Heremans, V. de Cupere

Discotic liquid crystals can self-align to form one-dimensional semiconducting wires, many tens of microns long. In this letter, we describe the preparation of semiconducting films where the stacking direction of the disc-like molecules is perpendicular to the substrate surface. We present measurements of the charge carrier mobility, applying temperature-dep

Dallas R. Trinkle

Computing the atomic geometry of lattice defects--point defects, dislocations, crack tips, surfaces, or boundaries--requires an accurate coupling of the local strain field to the long-range elastic field. Periodic boundary conditions used by classical potentials or density-functional theory may not accurately reproduce the correct bulk response to an isolate

Qin Zhang, Abraham G. Kofman, John M. Martinis, Alexander N. Korotkov

We analyze several mechanisms leading to errors in a course of measurement of a superconducting flux-biased phase qubit. Insufficiently long measurement pulse may lead to nonadiabatic transitions between qubit states $|1>$ and $|0>$, before tunneling through a reduced barrier is supposed to distinguish the qubit states. Finite (though large) ratio of tunneli

S V Lishchuk, C M Care

A method is described for embedding a deformable, elastic, membrane within a lattice Boltzmann fluid. The membrane is represented by a set of massless points which advect with the fluid and which impose forces on the fluid which are derived from a free energy functional with a value which is dependent upon the geometric properties of the membrane. The method

V. Laukhin, V. Skumryev, X. Marti, D. Hrabovsky

The magnetic exchange bias between epitaxial thin films of the multiferroic (antiferromagnetic and ferroelectric) hexagonal YMnO3 oxide and a soft ferromagnetic (FM) layer is used to couple the magnetic response of the ferromagnetic layer to the magnetic state of the antiferromagnetic one. We will show that biasing the ferroelectric YMnO3 layer by an appropr

Olaf Wunnicke

Gate capacitances of back-gated nanowire field-effect transistors (NW-FETs) are calculated by means of finite element methods and the results are compared with analytical results of the ``metallic cylinder on an infinite metal plate model&#39;&#39;. Completely embedded and non-embedded NW-FETs are considered. It is shown that the use of the analytical expres

X. Marti, F. Sanchez, D. Hrabovsky, L. Fabrega

We report on the growth and functional characterization of epitaxial thin films of the multiferroic YMnO3. We show that using Pt as a seed layer on SrTiO3(111) substrates, epitaxial YMnO3 films (0001) textured are obtained. An atomic force microscope has been used to polarize electric domains revealing the ferroelectric nature of the film. When a Permalloy l

Stéphane Santucci, Joachim Mathiesen, Knut Jørgen Måløy, Alex Hansen

We analyse the statistical distribution function for the height fluctuations of brittle fracture surfaces using extensive experimental data sampled on widely different materials and geometries. We compare a direct measurement of the distribution to a new analysis based on the structure functions. For length scales $δ$ larger than a characteristic scale $δ^*$

G. Orso, C. Menotti, S. Stringari

We use Bogoliubov theory to calculate the beyond mean field correction to the equation of state of a weakly interacting Bose gas in the presence of a tight 2D optical lattice. We show that the lattice induces a characteristic 3D to 1D crossover in the behaviour of quantum fluctuations. Using the hydrodynamic theory of superfluids, we calculate the correspond

P. M. V. B. Barone, A. C. R. Mendes

We present a Lagrangian formalism to the dissipative system of a charge interacting with its own radiation field, which gives rise to the radiation damping \cite{Heitler}, by the indirect representation doubling the phase-space dimensions.

Ganapathy Baskaran

We analyze effective Hamiltonian of ferromagnetic half metal phase of doped manganites and find a latent d-wave spin triplet superconductivity. Spin triplet state for a d-wave pair is enabled by orbital degrees of freedom. This high Tc superconductivity is, however, kept dormant by some intrinsic strong cooper pair breaking processes. Low T anomalies such as

C. Michioka, Y. Itoh, H. Ohta, M. Kato

We report the $^{59}$Co NMR studies of the in-plane anisotropy of bilayer hydrated Na$_{x}\mathrm{CoO_{2}} \cdot$$y\mathrm{H_{2}O}$ using a oriented powder sample by a magnetic field in Fluorinert FC70. We found for the first time the $ab$-plane anisotropy of the $^{59}$Co NMR Knight shift $K$, the nuclear spin-lattice relaxation rate 1/$T_{1}$ and the nucle

O. Patsahan, I. Mryglod

We establish a link between the two functional approaches: a mesoscopic field theory developed recently by A.Ciach and G.Stell [A. Ciach and G. Stell, J. Mol. Liq. 87 (2000) 253] for the study of ionic models and an exact statistical field theory based on the method of collective variables.

Róbert Juhász, Ludger Santen, Ferenc Iglói

We study the stationary properties as well as the non-stationary dynamics of the one-dimensional partially asymmetric exclusion process with position dependent random hop rates. In a finite system of $L$ sites the stationary current, $J$, is determined by the largest barrier and the corresponding waiting time, $τ\sim J^{-1}$, is related to the waiting time o

Jyoti Dhar Sharma

Emphasizing the contribution of Professor Roger A Cowley, FRS to the Theory of Raman Scattering from crystals, the development of the Theory of Raman cattering since 1928 has been briefly discussed. Some experimental studies of Strontium Titanate using Inelastic Neutron Scattering, Raman Scattering, Electro- paramagnetic resonance measurement and X-ray & Gam

S. Krompiewski

Spin-dependent coherent quantum transport through carbon nanotubes (CNT) is studied theoretically within a tight-binding model and the Green&#39;s function partitioning technique. End-contacted metal/nanotube/metal systems are modelled and next studied in the magnetic context, i.e. either with ferromagnetic electrodes or at external magnetic fields. The form

Everaldo Arashiro, Tania Tome

We study a probabilistic cellular automaton to describe two population biology problems: the threshold of species coexistence in a predator-prey system and the spreading of an epidemic in a population. By carrying out time-dependent simulations we obtain the dynamic critical exponents and the phase boundaries (thresholds) related to the transition between an

Guan-Fang Wang, Di-Fa Ye, Li-Bin Fu, Xu-Zong Chen

We present a comprehensive analysis of the Landau-Zener tunnelling of a nonlinear three-level system in a linearly sweeping external field. We find the presence of nonzero tunnelling probability in the adiabatic limit (i.e., very slowly sweeping field) even for the situation that the nonlinear term is very small and the energy levels keep the same topologica

T. Gericke, C. Utfeld, N. Hommerstad, H. Ott

We propose a new technique for the detection of single atoms in ultracold quantum gases. The technique is based on scanning electron microscopy and employs the electron impact ionization of trapped atoms with a focussed electron probe. Subsequent detection of the resulting ions allows for the reconstruction of the atoms position. This technique is expected t

R. Danneau, O. Klochan, W. R. Clarke, L. H. Ho

We have studied the effect of an in-plane magnetic field B on a one-dimensional hole system in the ballistic regime created by surface gate confinement. We observed clearly the lifting of the spin degeneracy due to the Zeeman effect on the one dimensional subbands for B applied parallel to the channel. In contrast, no Zeeman splitting is detected for B appli

N. A. Buznikov, S. S. Yoon, C. G. Kim, C. O. Kim

A model describing the exchange-biased asymmetric giant magneto-impedance in Joule-heated amorphous wires is proposed. It is assumed that the Joule heating results in the formation of a surface hard magnetic crystalline layer, and the asymmetric giant magneto-impedance is related to the exchange coupling between the amorphous and crystalline phases. The coup

R. Danneau, O. Klochan, W. R. Clarke, L. H. Ho

We have studied the Zeeman splitting in ballistic hole quantum wires formed in a (311)A quantum well by surface gate confinement. Transport measurements clearly show lifting of the spin degeneracy and crossings of the subbands when an in-plane magnetic field B is applied parallel to the wire. When B is oriented perpendicular to the wire, no spin-splitting is

Yunong Qi, Michael E. Flatté

Spontaneous spin polarization of the electrical current flowing through nonmagnetic semiconductor junctions can be generated by carrier scattering processes that are independent of the carrier spin. The two required elements for current-induced spin polarization are (1) the presence of built-in spatially-varying electric fields in the junction and (2) energy

Tongye Shen, Peter G. Wolynes

It is believed that, much like a cat&#39;s cradle, the cytoskeleton can be thought of as a network of strings under tension. We show that both regular and random bond-disordered networks having bonds that buckle upon compression exhibit a variety of phase transitions as a function of temperature and extension. The results of self-consistent phonon calculatio

Xingang Wang, Ying-Cheng Lai, Chong Heng Lai

A complex network processing information or physical flows is usually characterized by a number of macroscopic quantities such as the diameter and the betweenness centrality. An issue of significant theoretical and practical interest is how such a network responds to sudden changes caused by attacks or disturbances. By introducing a model to address this iss

J. H. Kim, S. Zhou, M. S. A. Hossain, A. V. Pan

With the relatively high critical temperature (Tc) of 39 K1 and the high critical current density (Jc) of > 100000 A/cm2 in moderate fields, magnesium diboride (MgB2) superconductors could offer the promise of important large-scale and electronic device applications to be operated at 20 K. A significant enhancement in the electromagnetic properties of MgB2 h

Jiang-Ping Hu, Kangjun Seo

We show that the asymmetric tunneling spectrum observed in the cuprate superconductors stems from the existence of a competing order. The competition between the competing order and superconductivity can create a charge depletion region near the surface. The asymmetric response of the depletion region as the function of the external voltage causes the asymme

Jort Gemmeke, Simon Portegies Zwart, Chael Kruip

We present a qualitative diagnostic based on the continuous wavelet transform, for the detection of irregular behavior in time series of particle simulations. We apply the method to three qualitatively different gravitational 3-body encounters. The intrinsic irregular behavior of these encounters is well reproduced by the presented method, and we show that t

Shahram Abbassi, Jamshid Ghanbari, Fatemeh Salehi

We carry out the effect of $β$-prescription for viscosity which introduced by Duschel et al. 2000 & Hure, Richard & Zhan 2001, in a standard self-gravitating thin disks. We were predicted in a self-gravitating thin disk the $β$-model will have different dynamical behavior compare the well known $α$-prescriptions. We used self-similar methods for solving the

A. Prsa, T. Zwitter

With recent observational advancements, substantial amounts of photometric and spectroscopic eclipsing binary data have been acquired. As part of an ongoing effort to assemble a reliable pipeline for fully automatic data analysis, we put Powell&#39;s direction set method to the test. The method does not depend on numerical derivatives, only on function evalu

W. H. T. Vlemmings, P. J. Diamond

Water maser polarization observations in the precessing jet of W43A have revealed that it is magnetically collimated. Here we present a detailed description of the physical properties of the water maser environment in the jet. We discuss the maser saturation level and beaming angle as well as the intrinsic temperatures and densities. Additionally, we show th

The HESS Collaboration, F. Aharonian

The Crab nebula was observed with the H.E.S.S. stereoscopic Cherenkov-telescope array between October 2003 and January 2005 for a total of 22.9 hours (after data quality selection). Observations were made with three operational telescopes in late 2003 and with the complete 4 telescope array in January - February 2004 and October 2004 - January 2005. The obse