June 2006 arXiv papers — page 24

J. Schnack, R. Klingeler, V. Kataev, B. Buechner

Magnetization measurements of Sr{14-x}Ca_xCu_{24}O_{41} with 0 <= x <=12 in magnetic fields up to 16 T show that the low-temperature magnetic response of the CuO_2 spin chains changes strongly upon Ca doping. For x=0 quantum statistical simulations yield that the temperature and field dependence of the magnetization can be well described by an effective Heis

Yasutaka Nishida, Atsushi Tsuruta, Kazumasa Miyake

The behavior of the resistivity of Ce-based heavy fermion systems is studied using a 1/$N$-expansion method a la Nagoya, where $N$ is the spin-orbital degeneracy of f-electrons. The 1/$N$-expansion is performed in terms of the auxiliary particles, and a strict requirement of the local constraints is fulfilled for each order of 1/N. The physical quantities ca

Paul von Allmen, Seungwon Lee

The electronic structure for a strained Si/SiGe quantum well grown on a tilted substrate with periodic steps is calculated using a parameterized tight-binding method. For a zero tilt angle the energy difference between the two lowest minima of the conduction band at the center of the Brillouin zone defines a non-zero valley splitting. At finite tilt angles,

R. Zillmer, R. Livi, A. Politi, A. Torcini

The dynamical behaviour of a weakly diluted fully-inhibitory network of pulse-coupled spiking neurons is investigated. Upon increasing the coupling strength, a transition from regular to stochastic-like regime is observed. In the weak-coupling phase, a periodic dynamics is rapidly approached, with all neurons firing with the same rate and mutually phase-lock

S. V. Kravchenko, A. A. Shashkin, S. Anissimova, A. Venkatesan

We measure thermodynamic magnetization of a low-disordered, strongly correlated two-dimensional electron system in silicon. Pauli spin susceptibility is observed to grow critically at low electron densities - behavior that is characteristic of the existence of a phase transition. A new, parameter-free method is used to directly determine the spectrum charact

Natalya A. Zimbovskaya

In this paper we present detailed theoretical analysis of the frequency and/or magnetic field dependence of the surface impedance of a metal at the anomalous skin effect. We calculate the surface impedance in the presence of a magnetic field directed along the normal to the metal surface. The effects of the Fermi-liquid interactions on the surface impedance

Andrew L. Goodwin, Martin T. Dove, Matthew G. Tucker, David A. Keen

A model-independent approach capable of extracting spin-wave frequencies and displacement vectors from ensembles of supercell spin configurations is presented. The method is appropriate for those systems whose spin-dynamical motion is well characterised by small-amplitude fluctuations that give harmonic spin waves. First, the the spin-dynamical matrix is des

W. Vincent Liu, Congjun Wu

The paradigm of Bose-Einstein condensation has been associated with zero momentum to which a macroscopic fraction of bosons condense. Here we propose a new quantum state where bosonic alkali-metal atoms condense at non-zero momenta, defying the paradigm. This becomes possible when the atoms are confined in the p-orbital Bloch band of an optical lattice rathe

R. J. Harris, A. Rákos, G. M. Schuetz

We consider the behaviour of current fluctuations in the one-dimensional partially asymmetric zero-range process with open boundaries. Significantly, we find that the distribution of large current fluctuations does not satisfy the Gallavotti-Cohen symmetry and that such a breakdown can generally occur in systems with unbounded state space. We also discuss th

Y. Yao, Z. Fang

First-principles calculations are applied to study spin Hall effect in semiconductors and simple metals. We found that intrinsic spin Hall conductivity (ISHC) in realistic materials shows rich sign changes, which may be used to distinguish the effect from the extrinsic one. The calculated ISHC in n-doped GaAs can be well compared with experiment, and it diff

Gyong Luck Khym, Sam Young Cho, Kicheon Kang

This paper has been withdrawn by the authors due to a crucial error.

Sebastien Ragot, Pietro Cortona

The Colle and Salvetti approach [Theoret. Chim. Acta, 37, 329 (1975)] to the calculation of the correlation energy of a system is modified in order to explicitly include into the theory the kinetic contribution to the correlation energy. This is achieved by deducing from a many electrons wave function, including the correlation effects via a Jastrow factor,

I. F. Mirabel

Compact astrophysical objects produce some of the highest energy light in the universe. The challenge is to determine what mechanism produces these photons.

Cuauhtemoc Campuzano, Sergio del Campo, Ramon Herrera

The curvaton reheating in a non-oscillatory inflationary universe model is studied in a Jordan-Brans-Dicke theory. For different scenarios, the temperature of reheating is computed. The result tells us that the reheating temperature becomes practically independent of the Jordan-Brans-Dicke parameter $w$. This reheating temperature results to be quite differe

M. Tafalla, M. S. N. Kumar, R. Bachiller

Aims. We present molecular line observations of the southwestern part of the IC 348 young cluster, and we use them together with NIR and mm continuum data to determine the distribution of dense gas, search for molecular outflows, and analyze the ongoing star formation activity in the region. Methods. Our molecular line data consists of C18O(1--0) and N2H+(1-

Ohad Shemmer, W. N. Brandt, Hagai Netzer, Roberto Maiolino

We present new XMM-Newton observations of two luminous and high accretion-rate radio-quiet active galactic nuclei (AGNs) at z~2. Together with archival X-ray and rest-frame optical spectra of three sources with similar properties as well as 25 moderate-luminosity radio-quiet AGNs at z<0.5, we investigate, for the first time, the dependence of the hard (>~2 k

A. Tokovinin, S. Heathcote

We propose a practical method to calculate Zernike aberrations from analysis of a single long-exposure defocused stellar image. It consists in fitting the aberration coefficients and seeing blur directly to a realistic image binned into detector pixels. This &#34;donut&#34; method is different from curvature sensing in that it does not make the usual approxi

Robert A. Fesen

Several commercial telecommunication ventures together with a well funded US military program make it a likely possibility that an autonomous, high-altitude, light-than-air (LTA) vehicle which could maneuver and station-keep for weeks to many months will be a reality in a few years. Here I outline how this technology could be used to develop a high-altitude

Phyllis M. Lugger, Haldan N. Cohn, Craig O. Heinke, Jonathan E. Grindlay

We report the detection of six discrete, low-luminosity (Lx < 10^33 erg/s) X-ray sources, located within 12 arcsec of the center of the collapsed-core globular cluster M30 (NGC 7099), and a total of 13 sources within the half-mass radius, from a 50 ksec Chandra ACIS-S exposure. Three sources lie within the very small upper limit of 1.9 arcsec on the core rad

Jean-Pierre Macquart, Geoffrey C. Bower, Melvyn C. H. Wright, Donald C. Backer

We report the detection of variable linear polarization from Sgr A* at a wavelength of 3.5mm, the longest wavelength yet at which a detection has been made. The mean polarization is 2.1 +/- 0.1% at a position angle of 16 +/- 2 deg with rms scatters of 0.4% and 9 deg over the five epochs. We also detect polarization variability on a timescale of days. Combine

M. De Becker, G. Rauw, J. Manfroid, P. Eenens

Aims: We address the issue of the multiplicity of the three brightest early-type stars of the young open cluster IC1805, namely HD15570, HD15629 and HD15558. Methods: For the three stars, we measured the radial velocity by fitting Gaussian curves to line profiles in the optical domain. In the case of the massive binary HD15558, we also used a spectral disent

B. Valat, F. X. Schmider, B. Lopez, R. Petrov

Recent site testing (see: http://www-luan.unice.fr/Concordiastro/indexantartic.html) has shown that Dome C in Antarctica might have a high potential for stellar interferometry if some solutions related to the surface atmospheric layer are found. A demonstrator interferometer could be envisioned in order to fully qualify the site and prepare the future develo

A. Meszaros, Z. Bagoly, L. G. Balazs, I. Horvath

The redshift distribution of gamma-ray bursts collected in the BATSE Catalog is compared with the star formation rate. We aim to clarify the accordance between them. We also study the case of comoving number density of bursts monotonously increasing up to redshift 6-20. A method independent of the models of the gamma-ray bursts is used. The short and the lon

A. J. Beasley, R. Murowinski, M. Tarenghi

The Atacama Large Millimeter/submillimeter Array (ALMA) is an international radio telescope under construction in the Atacama Desert of northern Chile. ALMA will be situated on a high-altitude site at 5000 m elevation which provides excellent atmospheric transmission over the instrument wavelength range of 0.3 to 3 mm. ALMA will be comprised of two key obser

S. Cristallo, R. Gallino, O. Straniero, L. Piersanti

We discuss the synthesis of some short-lived isotopes and of 23Na in thermally pulsing AGB stars with initial mass of 2 Msun and two different metallicities (Z=1.5e-2, corresponding to the metal amount in the Sun, and Z=1e-4), representative of disk and halo stars, respectively. The different nucleosynthesis channels are illustrated in some details. As previ

Mark Swinbank, ; Scott Chapman, Ian Smail, Chris Lindner

We present two-dimensional spectroscopy covering the rest-frame wavelengths of strong optical emission lines in six luminous submillimetre galaxies at z=1.3--2.5. Together with HST ACS and NICMOS imaging we map the dynamics and morphologies of these systems on scales from 4--11kpc. Four of the systems show multiple components in their spatially-resolved spec

Noam Soker, Romuald Tylenda

We discuss the main observational facts on the eruption of V838 Monocerotis in terms of possible outburst mechanisms. We conclude that the stellar merger scenario is the only one, which can consistently explain the observations.

Maurice A. Leutenegger, Frits B. S. Paerels, Steven M. Kahn, David H. Cohen

We discuss new methods of measuring and interpreting the forbidden-to-intercombination line ratios of helium-like triplets in the X-ray spectra of O-type stars, including accounting for the spatial distribution of the X-ray emitting plasma and using the detailed photospheric UV spectrum. Measurements are made for four O stars using archival Chandra HETGS dat

Charles B. Leffert

The new spatial condensation cosmological theory, based on the new universal constant of expansion, kappa = G Rho t^2 = 3/(32 Pi), is used to predict measurements of the supernova Ia data with no acceleration of the expansion rate of the universe. That goal was accomplished with the key assumption that radiation travels on great circles on the surface of the

Yujin Yang, Christy Tremonti, Ann Zabludoff, Dennis Zaritsky

HST ACS images reveal blue cores in four E+A, or post-starburst, galaxies. Follow-up spectroscopy shows that these cores have LINER spectra. The existence of LINERs, consistent with those in many elliptical galaxies, is yet one more piece of evidence that these post-merger, post-starburst, bulge-dominated galaxies will evolve into normal ellipticals. More in

Lucio Mayer, Graeme Lufkin, Thomas Quinn, James Wadsley

We report on the results of the first 3D SPH simulation of massive, gravitationally unstable protoplanetary disks with radiative transfer. We adopt a flux-limited diffusion scheme justified by the high opacity of most of the disk. The optically thin surface of the disk cools as a blackbody. The disks grow slowly in mass starting from a Toomre-stable initial

Ignacio Zaballa, Yeinzon Rodriguez, David H. Lyth

In this paper we calculate additional contributions to that part of the non-Gaussianity of the curvature perturbation, which come from the three-point correlator of the field perturbations. We estimate this contribution in the following models for its origin: single-component inflation, multi-component chaotic inflation, a two-component &#34;hybrid&#34; infl

Emory F. Bunn

Scattering of cosmic microwave background (CMB) radiation in galaxy clusters induces a polarization signal proportional to the CMB quadrupole anisotropy at the cluster&#39;s location and look-back time. A survey of such remote quadrupole measurements provides information about large-scale cosmological perturbations. This paper presents a formalism for calcul

Dorin Ervin Dutkay, Palle E. T. Jorgensen

We introduce a duality for Affine Iterated Function Systems (AIFS) which is naturally motivated by group duality in the context of traditional harmonic analysis. Our affine systems yield fractals defined by iteration of contractive affine mappings. We build a duality for such systems by scaling in two directions: fractals in the small by contractive iteratio

Cristian Martinez, Ricardo Troncoso

An electrically charged black hole solution with scalar hair in four dimensions is presented. The self-interacting scalar field is real and it is minimally coupled to gravity and electromagnetism. The event horizon is a surface of negative constant curvature and the asymptotic region is locally an AdS spacetime. The asymptotic fall-off of the fields is slowe

Jian-Xin Li, Chang-Qin Wu, Dung-Hai Lee

We consider the scenario where a 4-lattice constant, rotationally symmetric charge density wave (CDW) is present in the underdoped cuprates. We prove a theorem that puts strong constraint on the possible form factor of such a CDW. We demonstrate, within mean-field theory, that a particular form factor within the allowed class describes the angle-resolved pho

D. Rideout, S. Zohren

The various entropy bounds that exist in the literature suggest that spacetime is fundamentally discrete, and hint at an underlying relationship between geometry and &#34;information&#34;. The foundation of this relationship is yet to be uncovered, but should manifest itself in a theory of quantum gravity. We present a measure for the maximal entropy of sphe

Piotr T. Chrusciel, Daniel Maerten, Paul Tod

We prove upper bounds on angular momentum and centre of mass in terms of the Hamiltonian mass and cosmological constant for non-singular asymptotically anti-de Sitter initial data sets satisfying the dominant energy condition. We work in all space-dimensions larger than or equal to three, and allow a large class of asymptotic backgrounds, with spherical and

Miguel Angel Durán Roa, Mauro Copelli, Osame Kinouchi, Nestor Caticha

We study the transient regime of type-II biophysical neuron models and determine the scaling behavior of relaxation times $τ$ near but below the repetitive firing critical current, $τ\simeq C (I_c-I)^{-Δ}$. For both the Hodgkin-Huxley and Morris-Lecar models we find that the critical exponent is independent of the numerical integration time step and that bot

Jonathan L. Rosner

New results on hadron spectra have been appearing in abundance in the past few years as a result of improved experimental techniques. These include information on states made of both light quarks (u, d, and s) and with one or more heavy quarks (c, b). The present review, dedicated to the memory of R. H. Dalitz, treats light-quark states, glueballs, hybrids,

Héctor Blandín, Rafael Díaz

We give a combinatorial interpretation for the hypergeometric functions associated with tuples of rational numbers.

Zaira Nazario, David I. Santiago

The Neel magnetization of 2+1 D antiferromagnets is composed of quark-like spin 1/2 constituents, the spinons, as follows from the CP^1 mapping. These quark spinons are confined in both the Neel ordered phase and quantum paramagnetic phases. The confinement in the quantum paramagnetic phase is understood as arising from quantum tunneling events, instantons o

Erhan O. Iltan

We estimate the charged lepton electric dipole moments and the branching ratios of radiative lepton flavor violating decays in the framework of the two Higgs doublet model with the inclusion two extra dimensions. Here, we consider that the new Higgs doublet is accessible to one of the extra dimensions with a Gaussian profile and the fermions are accessible t

Alexei Kolezhuk, Subir Sachdev, Rudro R. Biswas, Peiqiu Chen

We describe spin correlations in the vicinity of a generalized impurity in a wide class of fractionalized spin liquid states. We argue that the primary characterization of the impurity is its electric charge under the gauge field describing singlet excitations in the spin liquid. We focus on two gapless U(1) spin liquids described by 2+1 dimensional conforma

David Poulin

We consider the problem of optimally decoding a quantum error correction code -- that is to find the optimal recovery procedure given the outcomes of partial &#34;check&#34; measurements on the system. In general, this problem is NP-hard. However, we demonstrate that for concatenated block codes, the optimal decoding can be efficiently computed using a messa

Stephen L. O&#39;Dell, Martin C. Weisskopf

The Chandra X-ray Observatory, one of NASA&#39;s Great Observatories, has an outstanding record of scientific and technical success. This success results from the efforts of a team comprising NASA, its contractors, the Smithsonian Astrophysical Observatory, the instrument groups, and other elements of the scientific community -- including the thousands of sc

Efstratios Manousakis

We use a quantum lattice gas model to describe essential aspects of the motion of 4He atoms and of 3He impurities in solid 4He. This study suggests that 3He impurities bind to defects and promote 4He atoms to interstitial sites which can turn the bosonic quantum disordered crystal into a metastable supersolid. It is suggested that defects and interstitial at

Ryan Quadri, Pieter van Dokkum, Eric Gawiser, Marijn Franx

We study the clustering properties of K-selected galaxies at 2<z<3.5 using deep multiwavelength imaging in three fields from the MUSYC survey. These are the first measurements to probe the spatial correlation function of K-selected galaxies in this redshift range on large scales, allowing for robust conclusions about the dark matter halos that host these gal

S. I. Kruglov

The scalar field theory with higher derivatives is considered in the first order formalism. The field equation of the forth order describes scalar particles possessing two mass states. The first order relativistic wave equation in the 10-dimensional matrix form is derived. We find the relativistically invariant bilinear form and corresponding Lagrangian. The

V. Smolcic, Z. Ivezic, M. Gacesa, K. Rakos

We synthesize the rest-frame Stroemgren colors using SDSS spectra for 99,088 galaxies selected from Data Release 1. This narrow-band ~200 AA photometric system (uz, vz, bz, yz), first designed for the determination of effective temperature, metallicity and gravity of stars, measures the continuum spectral slope of galaxies in the rest-frame 3200-5800 AA wave

L. A. Braunstein, Z. Wu, Y. Chen, S. V. Buldyrev

We review results on the scaling of the optimal path length in random networks with weighted links or nodes. In strong disorder we find that the length of the optimal path increases dramatically compared to the known small world result for the minimum distance. For Erdős-Rényi (ER) and scale free networks (SF), with parameter $λ$ ($λ>3$), we find that the sm

Raphael Bousso, Ben Freivogel, I-Sheng Yang

Motivated by the lessons of black hole complementarity, we develop a causal patch description of eternal inflation. We argue that an observer cannot ascribe a semiclassical geometry to regions outside his horizon, because the large-scale metric is governed by the fluctuations of quantum fields. In order to identify what is within the horizon, it is necessary

Sergei A. Voloshin

In this talk I concentrate on two topics closely related to the understanding of the energy and the system size dependence of the elliptic flow: determination of the elliptic flow ($v_2$) ``free&#39;&#39; from the effects of non-flow and flow fluctuations, and the role of fluctuations in the initial eccentricity of the overlap region. I introduce a new appro

Aiyalam P. Balachandran, Babar Ahmed Qureshi

In this talk, we review the basics concepts of fuzzy physics and quantum field theory on the Groenwald-Moyal Plane as examples of noncommutative spaces in physics. We introduce the basic ideas, and discuss some important results in these fields. In the end we outline some recent developments in the field.

Paolo C. Grigis, Arnold O. Benz

Context: Stochastic acceleration is thought to be a key mechanism in the energization of solar flare electrons. Aims: We study whether stochastic acceleration can reproduce the observed soft-hard-soft evolution of the spectral features of the hard X-ray emitted by suprathermal electron. We pay special attention to the effects of particle trapping and escape.

Vijay Balasubramanian, Eric G. Gimon, Thomas S. Levi

We propose that every supersymmetric four dimensional black hole of finite area can be split up into microstates made up of primitive half-BPS &#34;atoms&#39;&#39;. The mutual non-locality of the charges of these &#34;atoms&#39;&#39; binds the state together. In support of this proposal, we display a class of smooth, horizon-free, four dimensional supergravi

Diego Conti

We consider hypersurfaces in Einstein-Sasaki 5-manifolds which are tangent to the characteristic vector field. We introduce evolution equations that can be used to reconstruct the 5-dimensional metric from such a hypersurface, analogous to the (nearly) hypo and half-flat evolution equations in higher dimensions. We use these equations to classify Einstein-Sa

Ginestra Bianconi

In this paper we describe the emergence of scale-free degree distributions from statistical mechanics principles. We define an energy associated to a degree sequence as the logarithm of the number of indistinguishable simple networks it is possible to draw given the degree sequence. Keeping fixed the total number of nodes and links, we show that the energy o

V. S. Khrapai, S. Ludwig, J. P. Kotthaus, H. P. Tranitz

We study a double quantum dot (DQD) coupled to a strongly biased quantum point contact (QPC), each embedded in independent electric circuits. For weak interdot tunnelling we observe a finite current flowing through the unbiased Coulomb blockaded DQD in response to a strong bias on the QPC. The direction of the current through the DQD is determined by the rel

Eduard Masso, Javier Redondo

The PVLAS collaboration has results that may be interpreted in terms of a light axion-like particle, while the CAST collaboration has not found any signal of such particles. We propose a particle physics model with paraphotons and with a low energy scale in which this apparent inconsistency is circumvented.

Michael A. Bender, Raphael Clifford, Kostas Tsichlas

This paper presents scheduling algorithms for procrastinators, where the speed that a procrastinator executes a job increases as the due date approaches. We give optimal off-line scheduling policies for linearly increasing speed functions. We then explain the computational/numerical issues involved in implementing this policy. We next explore the online sett

Gleb Arutyunov, Sergey Frolov, Marija Zamaklar

In order to analyze finite-size effects for the gauge-fixed string sigma model on AdS_5 x S^5, we construct one-soliton solutions carrying finite angular momentum J. In the infinite J limit the solutions reduce to the recently constructed one-magnon configuration of Hofman and Maldacena. The solutions do not satisfy the level-matching condition and hence exh

Dario Poletti, Gabriel G. Carlo, Baowen Li

We investigate the ratchet current that appears in a kicked Hamiltonian system when the period of the kicks corresponds to the regime of quantum resonance. In the classical analogue, a spatial-temporal symmetry should be broken to obtain a net directed current. It was recently discovered that in quantum resonance the temporal symmetry can be kept, and we pro

Jose B. Almeida

The presentation makes use of geometric algebra, also known as Clifford algebra, in 5-dimensional spacetime. The choice of this space is given the character of first principle, justified solely by the consequences that can be derived from such choice and their consistency with experimental results. Given a metric space of any dimension, one can define monoge

Christopher J. Leininger, D. B. McReynolds, Walter D. Neumann, Alan W. Reid

Two Riemannian manifolds are called eigenvalue equivalent when their sets of eigenvalues of the Laplace-Beltrami operator are equal (ignoring multiplicities). They are (primitive) length equivalent when the sets of lengths of their (primitive) closed geodesics are equal. We give a general construction of eigenvalue equivalent and primitive length equivalent

Srdjan Ostojic, Debabrata Panja

Transmission of forces in static granular materials are studied within the framework of the force network ensemble, by numerically evaluating the mechanical response of hexagonal packings of frictionless grains and rectangular packings of frictional grains. In both cases, close to the point of application of the overload, the response is non-linear and displ

S. Duhot, R. Mélin

An Andreev pair from a s-wave superconductor (S) entering a conventional gapless charge density wave (CDW) below the Peierls gap dephases on the Fermi wavelength while one particle states are localized on the CDW coherence length. The paths following different sequences of impurities interfere destructively, due to the different electron and hole densities i

Guillaume Adenier, Andrei Yu. Khrennikov

We analyze optical EPR experimental data performed by Weihs et al in Innsbruck 1997-1998. We show that for some linear combinations of the raw coincidence rates, the experimental results display some anomalous behavior that a more general source state (like non-maximally entangled state) cannot straightforwardly account for. We attempt to explain these anoma

D Bozi

This thesis report deals with the 1D Hubbard model and the quantum objects that diagonalize the normal ordered Hubbard hamiltonian, among those the so called PseudoFermions (PFs). These PFs have no residual energy interactions, are eta-spin and spin zero objects, and are the scatterers and the scattering centers of the theory. The S-matrix of this representa

M. Ali-Akbari, M. M. Sheikh-Jabbari, M. Torabian

In this paper we continue analysis of the Matrix theory describing the DLCQ of type IIB string theory on AdS_5 x S^5 (and/or the plane-wave) background, i.e. the Tiny Graviton Matrix Theory (TGMT)[hep-th/0406214]. We study and classify 1/2, 1/4 and 1/8 BPS solutions of the TGMT which are generically of the form of rotating three brane giants. These are brane

A. N. W. Hone, V. S Novikov, C. Verhoeven

We consider an integrable scalar partial differential equation (PDE) that is second order in time. By rewriting it as a system and applying the Wahlquist-Estabrook prolongation algebra method, we obtain the zero curvature representation of the equation, which leads to a Lax representation in terms of an energy-dependent Schrödinger spectral problem of the ty

Marc Henneaux, Mauricio Leston, Daniel Persson, Philippe Spindel

We re-examine previously found cosmological solutions to eleven-dimensional supergravity in the light of the E_{10}-approach to M-theory. We focus on the solutions with non zero electric field determined by geometric configurations (n_m, g_3), n\leq 10. We show that these solutions are associated with rank $g$ regular subalgebras of E_{10}, the Dynkin diagra

T. Gilad, S. A. Gurvitz

We propose to monitor a qubit with a double-dot (DD) resonant-tunneling detector, which can operate at higher temperatures than a single-dot detector. In order to assess the effectiveness of this device, we derive rate equations for the density matrix of the entire system. We show that the signal-to-noise ratio can be greatly improved by a proper choice of t

Michael J. Schauber, Seth A. Newman, Lindsey R. Goodman, Itsuko S. Suzuki

We present a simple method to determine the mutual inductance $M$ between two coils in a coupled AC circuit by using a digital dual-phase lock-in amplifier. The frequency dependence of the real and imaginary parts is measured as the coupling constant is changed. The mutual inductance $M$ decreases as the distance $d$ between the centers of coils is increased

Alberto Blasi, Nicola Maggiore

We give the general solution of the Ward identity for the linear vector supersymmetry which characterizes all topological models. Such solution, whose expression is quite compact and simple, greatly simplifies the study of theories displaying a supersymmetric algebraic structure, reducing to a few lines the proof of their possible finiteness. In particular,

B. M. Connolly, S. Y. BenZvi, C. B. Finley, A. C. O&#39;Neill

The current measurements of the cosmic ray energy spectrum at ultra-high energies ($\text{E}>10^{19}$ eV) are characterized by large systematic errors and poor statistics. In addition, the experimental results of the two experiments with the largest published data sets, AGASA and HiRes, appear to be inconsistent with each other, with AGASA seeing an unabated

Atabey Kaygun

We define a version of Hochschild homology and cohomology suitable for a class of algebras admitting compatible actions of bialgebras, called module algebras. We show this (co)homology, called Hopf--Hochschild (co)homology, can also be defined as a derived functor on the category of representations of a crossed product algebra. We investigate the relationshi

H. I. Jørgensen, K. Grove-Rasmussen, J. R. Hauptmann, P. E. Lindelof

We report on two top-gate defined, coupled quantum dots in a semiconducting single wall carbon nanotube, constituting a tunable double quantum dot system. The single wall carbon nanotubes are contacted by titanium electrodes, and gated by three narrow top-gate electrodes as well as a back-gate. We show that a bias spectroscopy plot on just one of the two qua

Varun Sahni, Yuri Shtanov

A proposal is made to test Newton&#39;s inverse-square law using the perihelion shift of test masses (planets) in free fall within a spacecraft located at the Earth-Sun L2 point. Such an Artificial Planetary System In Space (APSIS) will operate in a drag-free environment with controlled experimental conditions and minimal interference from terrestrial source

Jingsong He, Yinghua Li, Yi Cheng

Using the determinant representation of gauge transformation operator, we have shown that the general form of $τ$ function of the $q$-KP hierarchy is a q-deformed generalized Wronskian, which includes the q-deformed Wronskian as a special case. On the basis of these, we study the q-deformed constrained KP ($q$-cKP) hierarchy, i.e. $l$-constraints of $q$-KP h

Nicola Caporaso, Luca Griguolo, Marcos Marino, Sara Pasquetti

Topological strings on Calabi--Yau manifolds are known to undergo phase transitions at small distances. We study this issue in the case of perturbative topological strings on local Calabi--Yau threefolds given by a bundle over a two-sphere. This theory can be regarded as a q--deformation of Hurwitz theory, and it has a conjectural nonperturbative description

T. Padmanabhan

A general paradigm for describing classical (and semiclassical) gravity is presented. This approach brings to the centre-stage a holographic relationship between the bulk and surface terms in a general class of action functionals and provides a deeper insight into several aspects of classical gravity which have no explanation in the conventional approach. Af

Rafael Sánchez, Ernesto Cota, Ramón Aguado, Gloria Platero

Recently it has been shown that ac-driven double quantum dots can act as spin pumps and spin filters. By calculating the current through the system for each spin polarization, by means of the time evolution of the reduced density matrix in the sequential tunneling regime (Born-Markov approximation), we demonstrate that the spin polarization of the current ca

A. Banerjee, K. Mukherjee, Kranti Kumar, P. Chaddah

We show that minimal disturbance to the robust charge ordered Pr(0.5)Ca(0.5)MnO(3) by 2.5% Al substitution on Mn-site drives the system towards ferromagnetic ground state. The history-dependent coexisting phases observed are explained as an outcome of a hindered first order transition with glass like arrest of kinetics resulting in irreversibility. Consisten

G. Barr, O. Chvala, H. G. Fischer, M. Kreps

The new data on pion production in p+C interactions from the NA49 experiment at the CERN SPS are used for a detailed study of hadronization in the collision of protons with light nuclei. The comparison to the extensive set of data from p+p collisions obtained with the same detector allows for the separation and extraction of the projectile and target contrib

Klaus Vollmann, Thomas Eversberg

Equivalent width measurements for rapid line variability in atomic spectral lines are degraded by increasing error bars with shorter exposure times. We derive an expression for the error of the line equivalent width $σ(W_λ)$ with respect to pure photon noise statistics and provide a correction value for previous calculations.

E. Joung, J. Mourad, R. Parentani

Using unitary irreducible representations of the de Sitter group, we construct the Fock space of a massive free scalar field. In this approach, the vacuum is the unique dS invariant state. The quantum field is a posteriori defined by an operator subject to covariant transformations under the dS isometry group. This insures that it obeys canonical commutation

Yuriy E. Kuzovlev

A very good as well as simple approximate solution is suggested to the problem which flat circular distribution of electric current in finite film produces a given axially symmetric distribution of normal-to-film magnetic field.

Bjoern Schenke, Michael Strickland

We determine the fermionic collective modes of a quark-gluon plasma which is anisotropic in momentum space. We calculate the fermion self-energy in both the imaginary- and real-time formalisms and find that numerically and analytically (for two special cases) there are no unstable fermionic modes. In addition we demonstrate that in the hard-loop limit the Ku

P. Kasprzak

We start from Rieffel data (A,f,X) where A is a C*-algebra, X is an action of an abelian group H on A and f is a 2-cocycle on the dual group. Using Landstad theory of crossed product we get a deformed C*-algebra A(f). In the case of H being the n-th Cartesian product of the real numbers we obtain a very simple proof of invariance of K-groups under the deform

A. V. Turbiner, N. L. Guevara

A trial function is presented for the $H_2$ molecule which provides the most accurate (the lowest) Bohr-Oppenheimer ground state energy among few-parametric trial functions (with $\leq 14$ parameters). It includes the electronic correlation term in the form $\sim \exp{(γr_{12})}$ where $γ$ is a variational parameter.

A. S. Alexandrov, A. M. Bratkovsky

Devices for nano- and molecular size electronics are currently a focus of research aimed at an efficient current rectification and switching. Current switching due to conformational changes in the molecules is slow, on the order of a few kHz. Fast switching on the order of 1 THz may be achieved, at least in principle, in a degenerate molecular quantum dot wi

Frank Neven, Thomas Schwentick

XPath is a simple language for navigating an XML-tree and returning a set of answer nodes. The focus in this paper is on the complexity of the containment problem for various fragments of XPath. We restrict attention to the most common XPath expressions which navigate along the child and/or descendant axis. In addition to basic expressions using only node te

V. Kurlin

The classical Baker-Campbell-Hausdorff formula gives a recursive way to compute the Hausdorff series H=ln(e^X e^Y) for non-commuting X,Y. Formally H lives in the graded completion of the free Lie algebra L generated by X,Y. We present a closed explicit formula for H=ln(e^X e^Y) in a linear basis of the graded completion of the free metabelian Lie algebra L/[

C. Matti

We revisit the issue of the quark masses and mixing angles in the framework of large extra dimension. We consider three identical standard model families resulting from higher-dimensional fields localized on different branes embedded in a large extra dimension. Furthermore we use a decaying profile in the bulk different form previous works. With the Higgs fi

Alexander A. Klyachko, Barış Öztop, Alexander S. Shumovsky

We show that entanglement of pure multi-party states can be quantified by means of quantum uncertainties of certain basic observables through the use of measure that has been initially proposed in [10] for bipartite systems.

Gerrit Coddens

It has recently been claimed that the dynamics of long-wavelength phason fluctuations has been observed in i-AlPdMn quasicrystals. We will show that the data reported call for a more detailed development of the elasticity theory of Jaric and Nelsson in order to determine the nature of small phonon-like atomic displacements with a symmetry that follows the ph

Gyong Luck Khym, Kicheon Kang

We report on a study of complementarity in a two-terminal &#34;closed-loop&#34; Aharonov-Bohm interferometer. In this interferometer, the simple picture of two-path interference cannot be applied. We introduce a nearby quantum point contact to detect the electron in a quantum dot inserted in the interferometer. We found that charge detection reduces but does

M T Batchelor, X W Guan

We show that below the degenerate temperature the distribution profiles of strongly interacting anyons in one dimension coincide with the most probable distributions of ideal particles obeying generalized exclusion statistics (GES). In the strongly interacting regime the thermodynamics and the local two-particle correlation function derived from the GES are

Yugui Yao, Fei Ye, Xiao-Liang Qi, Shou-Cheng Zhang

Even though graphene is a low energy system consisting of the two dimensional honeycomb lattice of carbon atoms, its quasi-particle excitations are fully described by the 2+1 dimensional relativistic Dirac equation. In this paper we show that while the spin-orbit interaction in graphene is of the order of $4 meV$, it opens up a gap of the order of $10^{-3} m