July 2003 arXiv papers — page 8
Showing 701–800 of 3,365 papers
Hector Martin, Eugenia D. Eugenieva, Zhigang Chen, Demetrios N. Christodoulides
We investigate the interaction between a light beam and a two-dimensional photonic lattice that is photo-induced in a photorefractive crystal using partially coherent light. We demonstrate that this interaction process is associated with a host of new phenomena including lattice dislocation, lattice deformation, and creation of structures akin to optical pol
G. Vidal, C. M. Dawson
We consider the implementation of two-qubit unitary transformations by means of CNOT gates and single-qubit unitary gates. We show, by means of an explicit quantum circuit, that together with local gates three CNOT gates are necessary and sufficient in order to implement an arbitrary unitary transformation of two qubits. We also identify the subset of two-qu
Jorge Alfaro, Maximo Banados
We argue that the quartic fermionic potential of five-dimensional Chern-Simons supergravity induces spontaneous symmetry breaking, in a phenomenon bearing a close connection with the Nambu and Jona-Lasinio model.
Photometry and Spectroscopy of GRB 030329 and Its Associated Supernova 2003dh: The First Two Months
astro-phT. Matheson, P. M. Garnavich, K. Z. Stanek, D. Bersier
We present extensive optical and infrared photometry of the afterglow of gamma-ray burst (GRB) 030329 and its associated supernova (SN) 2003dh over the first two months after detection (2003 March 30-May 29 UT). Optical spectroscopy from a variety of telescopes is shown and, when combined with the photometry, allows an unambiguous separation between the afte
Disk and Halo Wide Binaries from the Revised Luyten Catalog: Probes of Star Formation and MACHO Dark Matter
astro-phJulio Chaname, Andrew Gould
We present a catalog of 1147 candidate common proper motion binaries selected from the revised New Luyten Two-Tenths Catalog. Among these, we identify 999 genuine physical pairs using the measured proper-motion difference and the relative positions of each binary's components on a reduced proper-motion (RPM) diagram. The RPM positions also serve to class
Henning Moritz, Thilo Stöferle, Michael Köhl, Tilman Esslinger
We report on the realization of a trapped one dimensional Bose gas and its characterization by means of measuring its lowest lying collective excitations. The quantum degenerate Bose gas is prepared in a 2D optical lattice and we find the ratio of the frequencies of the lowest compressional (breathing) mode and the dipole mode to be $(ω_B/ω_D)^2\simeq3.1$, i
G. W. Gibbons, R. Guven, C. N. Pope
We prove the uniqueness of the supersymmetric Salam-Sezgin (Minkowski)_4\times S^2 ground state among all nonsingular solutions with a four-dimensional Poincare, de Sitter or anti-de Sitter symmetry. We construct the most general solutions with an axial symmetry in the two-dimensional internal space, and show that included amongst these is a family that is n
Effect of the Fast Nuclear Electromagnetic Pulse on the Electric Power Grid Nationwide: A Different View
physics.soc-phMario Rabinowitz
This paper primarily considers the potential effects of a single high-altitude nuclear burst on the U.S. power grid. A comparison is made between EMP and natural phenomena such as lightning. This paper concludes that EMP is no more harmful to the power grid than its counterparts in nature. An upper limit of the electric field of the very fast, high-amplitude
Frederic P Schuller, Hendryk Pfeiffer
We show that Dirac-Born-Infeld theory possesses a hidden invariance that enhances the local O(1,p) Lorentz symmetry on a Dirichlet p-brane to an O(1,p) x O(1,p) gauge group, encoding both an invariant velocity and acceleration (or length) scale. This enlarged gauge group predicts consequences for the kinematics of observers on Dirichlet branes, with admissib
P. P. Avelino, L. M. G. Beca, J. P. M. de Carvalho, C. J. A. P. Martins
We explicitly demonstrate that, contrary to recent claims, the dynamics of a generalized Chaplygin gas model with an equation of state $p=-C$ (where $C$ is a positive constant) is equivalent to that of a standard $Λ$CDM model to first order in the metric perturbations. We further argue that the analogy between the two models goes well beyond linear theory an
E. Sauvan, F. Carstoiu, N. A. Orr
A study of high energy (43--68 MeV/nucleon) one-neutron removal reactions on a range of neutron-rich psd-shell nuclei (Z = 5--9, A = 12--25) has been undertaken. The inclusive longitudinal and transverse momentum distributions for the core fragments, together with the cross sections have been measured for breakup on a carbon target. Momentum distributions fo
Giovanni Cennini, Gunnar Ritt, Carsten Geckeler, Martin Weitz
We demonstrate an atom laser using all-optical techniques. A Bose-Einstein condensate of rubidium atoms is created by direct evaporative cooling in a quasistatic dipole trap realized with a single, tightly focused CO$_{2}$-laser beam. An applied magnetic field gradient allows formation of the condensate in a field-insensitive $m_{F} = 0$ spin projection only
Quantum Stein's lemma revisited, inequalities for quantum entropies, and a concavity theorem of Lieb
quant-phIgor Bjelakovic, Rainer Siegmund-Schultze
We derive the monotonicity of the quantum relative entropy by an elementary operational argument based on Stein's lemma in quantum hypothesis testing. For the latter we present an elementary and short proof that requires the law of large numbers only. Joint convexity of the quantum relative entropy is proven too, resulting in a self-contained elementary
Doron Cohen
Quantum pumping in closed systems is considered. We explain that the Kubo formula contains all the physically relevant ingredients for the calculation of the pumped charge ($Q$) within the framework of linear response theory. The relation to the common formulations of adiabatic transport and ``geometric magnetism" is clarified. We distinguish between adi
József Cserti, Géza Tichy
The classical lattice dynamics of honeycomb lattices is studied in the harmonic approximation. Interactions between nearest neighbors are represented by springs connecting them. A short and necessary introduction of the lattice structure is presented. The dynamical matrix of the vibrational modes is then derived, and its eigenvalue problem is solved analytic
C. M. Harris, P. Richardson, B. R. Webber
CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte Carlo programs like HERWIG and PYTHIA which then perform the parton evolution and hadronization. The event generator i
Mario Rabinowitz
A method of using vacuum calorimetry as a means of determining directly the energy deposited in an electrically exploded wire is presented. This energy determination is compared with that given by the time integral of the product of voltage and current. A definite reproducible pattern of the explosion products is deposited on the walls of the calorimeter, wh
M. W. Kalinowski
In this paper we construct the Nonsymmetric Jordan-Thiry Theory unifying N.G.T., the Yang-Mills' field, the Higgs' fields and scalar forces in a geometric manner. In this way we get masses from higher dimensions. We discuss spontaneous symmetry breaking, the Higgs' mechanism and a mass generation in the theory. The scalar field (as in the classic
Vittorio Giovannetti
We derive a collection of separability conditions for bipartite systems of dimensions d X d which is based on the entropic version of the uncertainty relations. A detailed analysis of the two-qubit case is given by comparing the new separability conditions with existing criteria.
M. Ait Ben Haddou, A. Belhaj, E. H. Saidi
Using Katz, Klemm and Vafa geometric engineering method of $\mathcal{N}=2$ supersymmetric QFT$_{4}$s and results on the classification of generalized Cartan matrices of Kac-Moody (KM) algebras, we study the un-explored class of $\mathcal{N}=2$ CFT$_{4}$s based on \textit{indefinite} singularities. We show that the vanishing condition for the general expressi
A. Bottino, F. Donato, N. Fornengo, S. Scopel
The predictions of our previous analyses about possible low-mass (lower than 50 GeV) relic neutralinos are discussed in the light of the most recent results from WIMP direct detection experiments. It is proved that these light neutralinos are quite compatible with the new annual-modulation data of the DAMA Collaboration; our theoretical predictions are also
Andreas Hanke, Ralf Metzler, Paul G. Dommersnes, Yacov Kantor
We investigate the effects of topological constraints (entanglements) on two dimensional polymer loops in the dense phase, and at the collapse transition (Theta point). Previous studies have shown that in the dilute phase the entangled region becomes tight, and is thus localised on a small portion of the polymer. We find that the entropic force favouring tig
Yuuichirou Shibusa, Tsukasa Tada
We present a new fermionic solution of the supersymmetric matrix model. The solution satisfies the commutation and anticommutation relations for noncommutative superspace. Therefore the solution can be considered as an implementation of noncommutative superspace on the matrix model.
Florian Mintert, Karol Zyczkowski
We propose to quantify the entanglement of pure states of $N \times N$ bipartite quantum system by defining its Husimi distribution with respect to $SU(N)\times SU(N)$ coherent states. The Wehrl entropy is minimal if and only if the pure state analyzed is separable. The excess of the Wehrl entropy is shown to be equal to the subentropy of the mixed state obt
Tim Dokchitser
This note is an observation that the LLL algorithm applied to prime powers can be used to find "good" examples for the ABC and Szpiro conjectures.
V. Gayral, J. M. Gracia-Bondía, B. Iochum, T. Schücker
Axioms for nonunital spectral triples, extending those introduced in the unital case by Connes, are proposed. As a guide, and for the sake of their importance in noncommutative quantum field theory, the spaces $\R^{2N}$ endowed with Moyal products are intensively investigated. Some physical applications, such as the construction of noncommutative Wick monomi
Dao-jun Liu, Xin-zhou Li
We study the evolution of Born-Infeld-type phantom in the second Randall-Sundrum brane scenario, and find that there exists attractor solution for the potential with a maximum, which implies a cosmological constant at the late time. Especially, we discuss the BI model of constant potential without and with dust matter. In the weak tension limit of the brane,
Flavor decomposition of the sea quark helicity distributions in the nucleon from semi-inclusive deep-inelastic scattering
hep-exHERMES collaboration, A. Airapetian
Double-spin asymmetries of semi-inclusive cross sections for the production of identified pions and kaons have been measured in deep-inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with re-analyzed previous data for ide
J. M. P. Carmelo, K. Penc, P. D. Sacramento, M. Sing
In this paper we use the pseudofermion dynamical theory (PDT) in the study of the one-electron removal singular spectral features the one-dimensional Hubbard model. The PDT reveals that in the whole $(k, ω)$-plane such features are of power-law type and correspond to well defined lines of three types: the charge singular branch lines, the spin singular branc
Models of quintessence coupled to the electromagnetic field and the cosmological evolution of alpha
hep-phE. J. Copeland, N. J. Nunes, M. Pospelov
We study the change of the effective fine structure constant in the cosmological models of a scalar field with a non-vanishing coupling to the electromagnetic field. Combining cosmological data and terrestrial observations we place empirical constraints on the size of the possible coupling and explore a large class of models that exhibit tracking behavior. T
Henry Cohn, Christopher Umans
We develop a new, group-theoretic approach to bounding the exponent of matrix multiplication. There are two components to this approach: (1) identifying groups G that admit a certain type of embedding of matrix multiplication into the group algebra C[G], and (2) controlling the dimensions of the irreducible representations of such groups. We present machiner
Michael McGuigan
We apply the methods of lattice field theories to the quantization of cellular automata. We discuss the quantization of five main categories of cellular automata: bosonic, fermionic, supersymmetric, spin and quantum dot using path integral and operator formalisms of lattice field theories. We show that the quantization of supersymmetric cellular automata is
Zhuo-Liang Cao, Ming Yang
In this paper, we proposed a physical scheme to concentrate the non-maximally entangled atomic pure states via cavity QED by using atomic collision in a far-off-resonant cavity. The most distinctive advantage of our scheme is that there is no excitation of cavity mode during the distillation procedure. Therefore the requirement on the quality of cavity is gr
Zhuo-Liang Cao, Ming Yang
In this paper, we presented a physical scheme to generate the multi-cavity maximally entangled W state via cavity QED. All the operations needed in this scheme are to modulate the interaction time only once.
J. M. Isidro
The geometry of the classical phase space C of a finite number of degrees of freedom determines the possible duality symmetries of the corresponding quantum mechanics. Under duality we understand the relativity of the notion of a quantum with respect to an observer on C. We illustrate this property explicitly in the case when classical phase space is complex
Kazuyuki Fujii
In this paper we study the behavior of (laser--cooled) m--atoms trapped in a cavity interacting with a photon $...$ Cavity QED $...$ and attempt to solve the Schr{ö}dinger equation of this model in the strong coupling regime. In the case of m = 2 we construct Bell--Schr{\" o}dinger cat states (in our terminology) and obtain with such bases some unitary t
Bassano Vacchini
Different structures of master-equation used for the description of decoherence of a microsystem interacting through collisions with a surrounding environment are considered and compared. These results are connected to the general expression of the generator of a quantum dynamical semigroup in presence of translation invariance recently found by Holevo.
B G Sidharth
In this paper we discuss in detail the interface between Classical Electrodynamics and Quantum Theory, which shows up as well known unphysical phenomena at the Compton scale in both the theories and argue that the photon of the electromagnetic field can be considered to be a composite of a massless Dirac particle and its anti particle.
L. B. Okun
The life of Isaak Yakovlevich Pomeranchuk was short (20.05.1913 -- 14.12.1966). But the impact of his personality and his works on physics and physicists is remarkable. The talk describes the biography of I.Ya. Pomeranchuk, his major contibutions to condenced matter physics, nuclear and elementary particle physics. The talk is appended by a complete bibliogr
Josh E. Baker
Motor enzymes catalyze chemical reactions, like the hydrolysis of ATP, and in the process they also perform work. Recent studies indicate that motor enzymes perform work with specific intermediate steps in their catalyzed reactions, challenging the classic view (in Brownian motor models) that work can only be performed within biochemical states. An alternati
Scott Lacey, Hailin Wang, David H. Foster, Jens U. Noeckel
We report the surprising observation of directional tunneling escape from nearly spherical fused-silica optical resonators, in which most of the phase space is filled with nonchaotic regular trajectories. Experimental and theoretical studies of the dependence of the far-field emission pattern on both the degree of deformation and the excitation condition sho
Ulf-G. Meißner
I outline an ambitious program which aims to achieve a unified description of nucleon and nuclear properties based on one chiral effective field theory.
A. Lima-Santos, R. Malara
We investigate the possible regular solutions of the boundary Yang-Baxter equation for the vertex models associated with the $C_{n}^{(1)}$, $D_{n}^{(1)}$ and $A_{2n-1}^{(2)}$ affine Lie algebras. We find three types of solutions with $n$, $n-1$ and 1 free parameters,respectively. Special cases and all diagonal solutions are presented separately.
Darboux transformations for 5-point and 7-point self-adjoint schemes and an integrable discretization of the 2D Schrodinger operator
nlin.SIM. Nieszporski, P. M. Santini, A. Doliwa
With this paper we begin an investigation of difference schemes that possess Darboux transformations and can be regarded as natural discretizations of elliptic partial differential equations. We construct, in particular, the Darboux transformations for the general self adjoint schemes with five and seven neighbouring points. We also introduce a distinguished
M. Olshanetsky
We consider a large $N$ limit of the Hitchin type integrable systems. The first system is the elliptic rotator on $GL_N$ that corresponds to the Higgs bundle of degree one over an elliptic curve with a marked point. This system is gauge equivalent to the $N$-body elliptic Calogero-Moser system, that is derived from the Higgs bundle of degree zero over the sa
Tom Michoel, Bruno Nachtergaele
We present new results and give a concise review of recent previous results on the asymptotics for large spin of the low-lying spectrum of the ferromagnetic XXZ Heisenberg chain with kink boundary conditions. Our main interest is to gain detailed information on the interface ground states of this model and the low-lying excitations above them. The new and mo
Greg Friedman
We generalize the classical study of Alexander polynomials of smooth or PL locally-flat knots to PL knots that are not necessarily locally-flat. We introduce three families of generalized Alexander polynomials and study their properties. For knots with point singularities, we obtain a classification of these polynomials that is complete except for one specia
Philippe Gaucher
In this talk, I will explain the importance of the homotopy branching space functor (and of the homotopy merging space functor) in dihomotopy theory. The paper is a detailed abstract of math.AT/0304112 and math.AT/0305169.
S. V. Shadrin
In this note we prove that the enlarged Witten's conjecture is true in the case of the Boussinesq hierarchy for correlators in genus 3 with descendants only at one point.
Joaquim Bruna, Alexander Olevskii, Alexander Ulanovskii
We characterize, in terms of the Beurling-Malliavin density, the discrete spectra $Λ\subset\R$ for which a generator exists, that is a function $ϕ\in L^1(\R)$ such that its $Λ$-translates $ϕ(x-λ), λ\inΛ$, span $L^1(\R)$. It is shown that these spectra coincide with the uniqueness sets for certain analytic classes. We also present examples of discrete spectra
P. Ara, M. A. Gonzalez-Barroso, K. R. Goodearl, E. Pardo
Given an action of a monoid $T$ on a ring $A$ by ring endomorphisms, and an Ore subset $S$ of $T$, a general construction of a fractional skew monoid ring $S^{\rm op} * A * T$ is given, extending the usual constructions of skew group rings and of skew semigroup rings. In case $S$ is a subsemigroup of a group $G$ such that $G=S^{-1}S$, we obtain a $G$-graded
William Adkins, J. William Hoffman, Hao Hao Wang
Let $S$ be a parametric surface in $\proj{3}$ given as the image of $ϕ: \proj{1} \times \proj{1} \to \proj{3}$. This paper will show that the use of syzygies in the form of a combination of moving planes and moving quadrics provides a valid method for finding the implicit equation of $S$ when certain base points are present. This work extends the algorithm p
Simona Paoli
We define a cotriple (co)homology of crossed modules with coefficients in a $π_1$-module. We prove its general properties, including the connection with the existing cotriple theories on crossed modules. We establish the relationship with the (co)homology of the classifying space of a crossed module and with the cohomology of groups with operators. An exampl
J. William Hoffman, Hao Hao Wang
The paper is being withdrawn since the results are incorporated in paper arxiv.org/abs/math.AG/0306195.
Roger Bielawski
We give a simple interpretation of the adapted complex structure of Lempert-Szoke and Guillemin-Stenzel: it is given by a polar decomposition of the complexified manifold. We then give a twistorial construction of an SO(3)-invariant hypercomplex structure on a neighbourhood of $X$ in $TTX$, where $X$ is a real-analytic manifold equipped with a linear connect
H. Pierre Noyes
A calculation by E.D. Jones of the cosmological mass scale for the phase transition from pre-geometric to physical description as about 5 Tev could be interpreted as a prediction of an effective threshold for novel physical effects in particle-particle collisions.
Shiraz Minwalla, Tadashi Takayanagi
We study the evolution of stable D-branes of C/Z_n and twisted circle theories in the process of closed string tachyon condensation. We interpret the fractional branes in these backgrounds as type II branes wrapping (`blown up') cycles, and trace the evolution of the corresponding cycles under tachyon condensation. We also study RG flows of the correspon
N. S. Manton, A. F. Schunck
Solutions to the four-dimensional Euclidean Weyl equation in the background of a general JNR N-instanton are known to be normalisable and regular throughout four-space. We show that these solutions are asymptotically given by a linear combination of simple singular solutions to the free Weyl equation, which can be interpreted as localised spinors. The `spino
Masud Chaichian, Archil Kobakhidze
We consider a deformation of N=1 four dimensional Minkowski superspace where odd coordinates $θ^α$ do not anticommute. We define supersymmetric and associative star product and show how the remaining (anti)commutation relations among the superspace coordinates are modified. In particular, the even coordinates do not commute as well. We also study chiral and
Keiichi Akama
We develop a quantum theoretical formalism to derive the brane gravity from its origin -- brane-generating dynamics in higher dimensions. Based on it, we discuss characteristic properties of the brane induced gravity, as well as brane induced field theory.
Shiro Hirai
The effect of the initial conditions in inflation on scalar and tensor perturbations is investigated. Formulae for the power spectra of gravitational waves and curvature perturbations for any initial conditions in inflation are derived, and the ratio of scalar to tensor perturbations and spectral index are calculated. The formulation is applied to some simpl
Particle abundances and spectra in the hydrodynamical description of relativistic nuclear collisions with light projectiles
hep-phF. Grassi, Y. Hama, T. Kodama, O. Socolowski
We show that a hydrodynamical model with continuous particle emission instead of sudden freeze out may explain both the observed strange particle and pion abundances and transverse mass spectra for light projectile at SPS energy. We found that the observed enhancement of pion production corresponds, within the context of continuous emission, to the maximal e
Stephane Peigne
The quarkonium data suggest a qualitatively new production mechanism, enhancing the rate of the quarkonia produced in the fragmentation region of an incoming coloured particle.
P. J. A. Bicudo, A. V. Nefediev
In this paper we study the power-like confining potentials r^alpha. The region of allowed alphas is identified, the mass-gap equation is constructed for an arbitrary alpha and solved for several values of the latter, and the vacuum energy and the chiral condensate are calculated. The question of replica solutions to the mass-gap equation for such potentials
Keiichi Akama, Takashi Hattori, Kazuo Katsuura
We introduce a probabilistic measure of naturalness (naturalness level) to fix naturalness bounds quantitatively. It is applied to the anomalous magnetic moments and the electric dipole moments due to new physics.
The Constituent Quark Model Revisited - Quark Masses, New Predictions for Hadron Masses and KN Pentaquark
hep-phMarek Karliner, Harry J. Lipkin
Prompted by the recent surprising results in QCD spectroscopy, we extend to heavy flavors the hadron mass relations showing that the constituent quark mass differences and ratios have the same values when obtained from mesons and baryons. We obtain several new successful relations involving heavy quarks and provide some related predictions. We discuss in det
Dilip Kumar Ghosh, Xiao-Gang He, Yu-Kuo Hsiao, Jian-Qing Shi
We study contributions of quark-squark-gluino interactions in Minimal Supersymmetric Standard Model (MSSM) to B->PP (PP =Kpi, pipi, KK) decays using QCD improved factorization method for the evaluation of the hadronic matrix elements and taking into account renormalization group running of the Wilson coefficients from SUSY scale (~ m_{\tilde q}) to the low e
Lawrence Gibbons
I present a brief overview of the measurements of exclusive B -> X_u l nu transitions, with a focus on issues facing robust averaging of branching fractions and |Vub| from current and anticipated measurements.
Loop variables and gravitational Berry's quantum phase in the space-time of a rotating massive body
gr-qcJ. G. de Assis, V. B. Bezerra, C. Furtado
In this paper we compute the holonomies along curves in the gravitational field of a slowly rotating massive body. We use our results to study the gravitational analogue of Aharanov-Bohm effect in this space-time. We also investigate the behaviour of a scalar quantum particle in this space-time and determine Berry's quantum phase acquired by this particl
Dario Grasso
Thermal fluctuations in the early universe plasma and in very hot astrophysical objects are an unavoidable source of gravitational waves (GW). Differently from previous studies on the subject, we approach this problem using methods based on field theory at finite temperature. Such an approach allows to probe the infrared region of the spectrum where dissipat
V. N. Rudenko
Brief review of principal ideas, estimates and schemes proposed by Russian research groups in respect of the gravitational radiation generated and detected in the laboratory condition is presented. Analysis leads to conclusion that the more promising variant of the laboratory GW-Hertz experiment might be associated with power electromagnetic and acoustical i
Enrique Álvarez
Two popular attempts to understand the quantum physics of gravitation are critically assessed. The talk on which this paper is based was intended for a general particle-physics audience.
Fahiem Bacchus, Adam Grove, Joseph Y. Halpern, Daphne Koller
An intelligent agent will often be uncertain about various properties of its environment, and when acting in that environment it will frequently need to quantify its uncertainty. For example, if the agent wishes to employ the expected-utility paradigm of decision theory to guide its actions, it will need to assign degrees of belief (subjective probabilities)
Peter D. Turney, Michael L. Littman
We present an algorithm for learning from unlabeled text, based on the Vector Space Model (VSM) of information retrieval, that can solve verbal analogy questions of the kind found in the Scholastic Aptitude Test (SAT). A verbal analogy has the form A:B::C:D, meaning "A is to B as C is to D"; for example, mason:stone::carpenter:wood. SAT analogy quest
Contributions to the Development and Improvement of a Regulatory and Pre-Regulatory Digitally System for the Tools within Flexible Fabrication Systems
cs.CEViorel Putz, Mihai V. Putz
The paper reports the obtained results for the projection and realization of a digitally system aiming to assist the equipment for a regulatory and pre-regulatory tools and holding tools within the flexible fabrication systems (FFS). Moreover, based on the present results, the same methodology can be applied for assisting tools from the point of view of thei
Crystal Structure of the Sodium Cobaltate Deuterate Superconductor NaxCoO2o4xD2O (x=1/3)
cond-mat.supr-conJ. D. Jorgensen, M. Avdeev, D. G. Hinks, J. C. Burley
Neutron and x-ray powder diffraction have been used to investigate the crystal structures of a sample of the newly-discovered superconducting sodium cobaltate deuterate compound with composition Na0.31(3)CoO2o1.25(2)D2O and its anhydrous parent compound Na0.61(1)CoO2. The deuterate superconducting compound is formed by coordinating four D2O molecules (two ab
M. F. Laguna, Guillermo Abramson, Damian H. Zanette
We study a model for social influence in which the agents' opinion is a continuous variable [G. Weisbuch et al., Complexity \textbf{7}, 2, 55 (2002)]. The convergent opinion adjustment process takes place as a result of random binary encounters whenever the difference between agents' opinions is below a given threshold. The inhomogeneity in the dynam
Direct temporal measurement of hot-electron relaxation in a phonon-cooled metal island
cond-mat.mes-hallD. R. Schmidt, C. S. Yung, A. N. Cleland
We report temporal measurements of the electronic temperature and the electron-phonon thermal relaxation rate in a micron-scale metal island, with a heat capacity of order 1 fJ/K . We employed a superconductor-insulator-normal metal tunnel junction, embedded in a radio-frequency resonator, as a fast (~ 20 MHz) thermometer. A resistive heater coupled to the i
M. F. Laguna, Guillermo Abramson, Damian H. Zanette
We present numerical simulations of a model of social influence, where the opinion of each agent is represented by a binary vector. Agents adjust their opinions as a result of random encounters, whenever the difference between opinions is below a given threshold. Evolution leads to a steady state, which highly depends on the threshold and a convergence param
O. I. Vinogradova, D. Andrienko, V. V. Lulevich, S. Nordschild
We measure Young's modulus of a free polyelectrolyte multilayer film by studying osmotically induced swelling of polyelectrolyte multilayer microcapsules filled with the polyelectrolyte solution. Different filling techniques and core templates were used for the capsule preparation. Varying the concentration of the polyelectrolyte inside the capsule, its
Graeme J. Ackland, Xiangyang Huang, Karin M. Rabe
We apply the pseudopotential density functional perturbation theory approach along with the quasiharmonic approximation to calculate the thermal expansion of tungsten and two important metallic alloys, NiAl and PdTi. We derive the theory for anisotropic crystal structures and test the approximation that the anisotropic effects of thermal expansion are equiva
I. A. Fomin
Within a phenomenological approach possible forms of the order parameter of the superfluid phases of 3He in a vicinity of the transition temperature are discussed. Effect of aerogel is described by a random tensor field interacting with the orbital part of the order parameter. With respect to their interaction with the random tensor field a group of "rob
Bo Soderberg
We demonstrate how to generalize two of the most well-known random graph models, the classic random graph, and random graphs with a given degree distribution, by the introduction of hidden variables in the form of extra degrees of freedom, color, applied to vertices or stubs (half-edges). The color is assumed unobservable, but is allowed to affect edge proba
A non-equilibrium Monte Carlo approach to potential refinement in inverse problems
cond-mat.stat-mechN. B. Wilding
The inverse problem for a disordered system involves determining the interparticle interaction parameters consistent with a given set of experimental data. Recently, Rutledge has shown (Phys. Rev. E63, 021111 (2001)) that such problems can be generally expressed in terms of a grand canonical ensemble of polydisperse particles. Within this framework, one iden
G. A. Baramidze, G. A. Kharadze
The influence of spin-exchange scattering centers on the triplet Cooper pairing is considered to explore the behavior of superfluid 3He in high porosity aerogel containing 3He atoms localized at the surface of silica strands. The homogeneously located and isotropically scattering system of spin-polarized ``impurity'' centers is adopted as a simple mo
C. Clasen, J. Eggers, M. A. Fontelos, J. Li
By adding minute concentrations of a high molecular weight polymer, liquid jets or bridges collapsing under the action of surface tension develop a characteristic shape of uniform threads connecting spherical fluid drops. In this paper, high-precision measurements of this beads-on-string structure are combined with a theoretical analysis of the limiting case
Generalized Network Growth: from Microscopic Strategies to the Real Internet Properties
cond-mat.stat-mechGuido Caldarelli, Paolo De Los Rios, Luciano Pietronero
In this paper we present a generalized model for network growth that links the microscopical agent strategies with the large scale behavior. This model is intended to reproduce the largest number of features of the Internet network at the Autonomous System (AS) level. Our model of network grows by adding both new vertices and new edges between old vertices.
J-. B. Salmon, S. Manneville, A. Colin
We analyze the temporal fluctuations of the flow field associated to a shear-induced transition in a lyotropic lamellar phase: the layering transition of the onion texture. In the first part of this work [Salmon et al., submitted to Phys. Rev. E], we have evidenced banded flows at the onset of this shear-induced transition which are well accounted for by the
J-. B. Salmon, S. Manneville, A. Colin
Using velocity profile measurements based on dynamic light scattering and coupled to structural and rheological measurements in a Couette cell, we present evidences for a shear-banding scenario in the shear flow of the onion texture of a lyotropic lamellar phase. Time-averaged measurements clearly show the presence of structural shear-banding in the vicinity
J. Bouttier, P. Di Francesco, E. Guitter
We study the statistics of edges and vertices in the vicinity of a reference vertex (origin) within random planar quadrangulations and Eulerian triangulations. Exact generating functions are obtained for theses graphs with fixed numbers of edges and vertices at given geodesic distances from the origin. Our analysis relies on bijections with labeled trees, in
Wei Bao, Y. Chen, Y. Qiu, J. L. Sarrao
Only 3% hole doping by Li is sufficient to suppress the long-range 3-dimensional (3D) antiferromagnetic order in La2CuO4. The spin dynamics of such a 2D spin liquid state at T << J was investigated with measurements of the dynamic magnetic structure factor S(omega,q), using cold neutron spectroscopy, for single crystalline La2Cu0.94Li0.06O4. S(omega,q) peaks
Mean-field and fluctuation analyses of a forced turbulence simulated by the lattice Boltzmann method
cond-mat.stat-mechW. Sakikawa, O. Narikiyo
On the basis of the lattice Boltzmann method we have done a numerical experiment of a forced turbulence in real space and time. Our new findings are summarized into two points. First in the analysis of the mean-field behavior of the velocity field using the exit-time statistics we have verified Kolmogorov's scaling and Taylor's hypothesis for the fir
Michele Lazzeri, Francesco Mauri
We present a simple formalism for the calculation of the derivatives of the electronic density matrix at any order, within density functional theory. Our approach, contrary to previous ones, is not based on the perturbative expansion of the Kohn-Sham wavefunctions. It has the following advantages: (i) it allows a simple derivation for the expression for the
Lei Zhou, C. T. Chan, P. Sheng
We show that a class of negative index (n) materials has interesting anisotropic optical properties, manifest in the effective refraction index that can be positive, negative, or purely imaginary under different incidence conditions. With dispersion taken into account, reflection at a planar negative-index interface exhibits frequency selective total oblique
D. Natelson
This review article discusses and compares various techniques for fabricating metal nanowires. We begin by defining what we mean by a nanowire, and why such nanostructures are of scientific and technological interest. We then present different fabrication methodologies, describing in some detail the advantages of each. "Top-down" techniques discussed
S. R. Schofield, N. J. Curson, M. Y. Simmons, F. J. Ruess
We demonstrate the controlled incorporation of P dopant atoms in Si (001) presenting a new path toward the creation of atomic-scale electronic devices. We present a detailed study of the interaction of PH3 with Si (001) and show that it is possible to thermally incorporate P atoms into Si (001) below the H desorption temperature. Control over the precise spa
Sumiyoshi Abe
This paper has been withdrawn by the author.
Sean P. Gorman, Rajendra G. Kulkarni, Laurie A. Schintler, Roger R. Stough
Cybersecurity is an issue of increasing concern since the events of September 11th. Many questions have been raised concerning the security of the Internet and the rest of the US's information infrastructure. This paper begins to examine the issue by analyzing the Internet's autonomous system (AS) map. Using the AS map, malicious infections are simul
Ab initio Monte Carlo simulations for finite-temperature properties: Application to lithium clusters and bulk liquid lithium
cond-mat.mtrl-sciSanwu Wang, Steven J. Mitchell, Per Arne Rikvold
Ab initio Monte Carlo simulations have been performed to determine the equilibrium properties of liquid lithium and lithium clusters at different temperatures. First-principles density-functional methods were employed to calculate the potential-energy change for each proposed change of configuration, which was then accepted or rejected according to the Metro
The X-ray eclipse of OY Car resolved with XMM-Newton: X-ray emission from the polar regions of the white dwarf
astro-phPeter J. Wheatley, Richard G. West
We present the XMM-Newton X-ray eclipse lightcurve of the dwarf nova OY Car. The eclipse ingress and egress are well resolved for the first time in any dwarf nova placing strong constraints on the size and location of the X-ray emitting region. We find good fits to a simple linear eclipse model, giving ingress/egress durations of 30+/-3 sec. Remarkably this