April 2008 arXiv papers — page 42

C. K. Raju

Contrary to the informed consensus, time travel implies spontaneity (as distinct from chance) so that time travel can only be of the second kind.

Jozsi Jalics, Martin Krupa, Horacio G. Rotstein

We analyze a biophysical model of a neuron from the entorhinal cortex that includes persistent sodium and slow potassium as non-standard currents using reduction of dimension and dynamical systems techniques to determine the mechanisms for the generation of mixed-mode oscillations. We have found that the standard spiking currents (sodium and potassium) play

Robert H. Rubin, Janet P. Simpson, Sean W. J. Colgan, Reginald J. Dufour

We have observed emission lines of [S IV] 10.51, H(7-6) 12.37, [Ne II] 12.81, [Ne III] 15.56, and [S III] 18.71 um in a number of extragalactic H II regions with the Spitzer Space Telescope. A previous paper presented our data and analysis for the substantially face-on spiral galaxy M83. Here we report our results for the local group spiral galaxy M33. The n

X. L. Zhang, R. S. Fletcher, S. L. Rolston, P. N. Guzdar

We measure the expansion of an ultracold plasma across the field lines of a uniform magnetic field. We image the ion distribution by extracting the ions with a high voltage pulse onto a position-sensitive detector. Early in the lifetime of the plasma ($< 20$ $μ$s), the size of the image is dominated by the time-of-flight Coulomb explosion of the dense ion cl

R. H. Mendez, A. M. Teodorescu, D. Schoenberner, R. Jacob

We describe a procedure for the numerical simulation of the planetary nebulae luminosity function (PNLF), improving on previous work (Mendez & Soffner 1997). Earlier PNLF simulations were based on an imitation of the observed distribution of the intensities of [O III] 5007 relative to Hbeta, generated predominantly using random numbers. We are now able to re

Baopeng Cao, Colleen M. Neal, Anne K. Starace, Yurii N. Ovchinnikov

Heat capacities measured for Al45- and Al47- nanoclusters have reproducible jumps at ~ 200 K. These jumps are consistent with theoretical predictions that some clusters with highly degenerate electronic states near the Fermi level will undergo a transition into a high Tc superconducting state. An analysis based on a theoretical treatment of pairing in Al45-

Nikhil Padmanabhan, Martin White

We present an analysis of anisotropic baryon acoustic oscillations and elucidate how a mis-estimation of the cosmology, which leads to incorrect values of the angular diameter distance, d_A, and Hubble parameter, H, manifest themselves in changes to the monopole and quadrupole power spectrum of biased tracers of the density field. Previous work has focused o

Eric Keto, Paola Caselli

We describe a model for the thermal and dynamical equilibrium of starless cores that includes the radiative transfer of the gas and dust and simple CO chemistry. The model shows that the structure and behavior of the cores is significantly different depending on whether the central density is either above or below about 10^5 cm-3. This density is significant

E. M. Hankiewicz, G. Vignale, Y. Tserkovnyak

We present a unified theory of magnetic damping in itinerant electron ferromagnets at order $q^2$ including electron-electron interactions and disorder scattering. We show that the Gilbert damping coefficient can be expressed in terms of the spin conductivity, leading to a Matthiessen-type formula in which disorder and interaction contributions are additive.

Paul Stokes, Saiful I. Khondaker

Single electron transistors (SETs) are fabricated by placing single walled carbon nanotubes (SWNTs) on a 100 nm wide local Al/Al2O3 bottom gate and then contacting with Pd electrodes. Coulomb oscillations up to 125 K were observed and charging energies of 12-15 meV with level spacing of ~5 meV were measured from the Couloumb diamond, in agreement with a dot

Scott Aaronson, Salman Beigi, Andrew Drucker, Bill Fefferman

The class QMA(k), introduced by Kobayashi et al., consists of all languages that can be verified using k unentangled quantum proofs. Many of the simplest questions about this class have remained embarrassingly open: for example, can we give any evidence that k quantum proofs are more powerful than one? Does QMA(k)=QMA(2) for k>=2? Can QMA(k) protocols be amp

M. C. Fernández-Fernández, F. J. Castro-Jiménez

We describe the Gevrey solutions at singular points of irregular hypergeometric systems (GKZ systems) associated with affine monomial curves.

Gopal Sarma, Andrew Silberfarb, Hideo Mabuchi

We examine a proposal by Sherson and Moelmer to generate polarization-squeezed light in terms of the quantum stochastic calculus (QSC). We investigate the statistics of the output field and confirm their results using the QSC formalism. In addition, we study the atomic dynamics of the system and find that this setup can produce up to 3 dB of atomic spin sque

P. Kurlberg, Z. Rudnick

The number of points on a hyperelliptic curve over a field of $q$ elements may be expressed as $q+1+S$ where $S$ is a certain character sum. We study fluctuations of $S$ as the curve varies over a large family of hyperelliptic curves of genus $g$. For fixed genus and growing $q$, Katz and Sarnak showed that $S/\sqrt{q}$ is distributed as the trace of a rando

Luis G. Dias da Silva, Kevin Ingersent, Nancy Sandler, Sergio Ulloa

We study the linear conductance through a double-quantum-dot system consisting of an interacting dot in its Kondo regime and an effectively noninteracting dot, connected in parallel to metallic leads. Signatures in the zero-bias conductance at temperatures $T>0$ mark a pair of quantum (T=0) phase transitions between a Kondo-screened many-body ground state an

Meng-Chwan Tan

We generalise the analysis carried out in [arXiv:0710.5796], and find that our previous results can be extended beyond the case of SL(N,C). In particular, we show that an equivalence--at the level of the holomorphic chiral algebra--between a bosonic string on a smooth coset manifold G/B and a B-gauged version of itself on G, will imply an isomorphism of clas

L. Blackburn, L. Cadonati, S. Caride, S. Caudill

The LIGO Scientific Collaboration (LSC) glitch group is part of the LIGO detector characterization effort. It consists of data analysts and detector experts who, during and after science runs, collaborate for a better understanding of noise transients in the detectors. Goals of the glitch group during the fifth LIGO science run (S5) included (1) offline asse

M. A. McGuire, A. D. Christianson, A. S. Sefat, R. Jin

This paper has been withdrawn by the authors due to errors in the X-ray diffraction data. Other measured data are not affected; however, the errors significantly change the interpretation and conclusions, and thus warrant withdrawal and later resubmission.

Bohan Fang

In this paper, we apply the idea of T-duality to projective spaces. From a connection on a line bundle on $\mathbb P^n$, a Lagrangian in the mirror Landau-Ginzburg model is constructed. Under this correspondence, the full strong exceptional collection $\mathcal O_{\mathbb P^n}(-n-1),...,\mathcal O_{\mathbb P^n}(-1)$ is mapped to standard Lagrangians in the s

Csaba Csaki, Johannes Heinonen, Maxim Perelstein, Christian Spethmann

We construct a weakly coupled, renormalizable ultraviolet completion of the Littlest Higgs model with T-parity (LHT), based on an SU(5)xSU(2)xU(1) gauge theory with a discrete Z_2 symmetry. Our model reproduces the complete structure of the LHT below the 10 TeV scale, including the collective symmetry breaking mechanism which solves the little hierarchy prob

William D. Linch, Jock McOrist, Brenno Carlini Vallilo

We study type IIB string compactifications in the presence of RR and NSNS fluxes using worldsheet techniques. Vertex operators corresponding to internal RR and NSNS fluxes are constructed in the hybrid formalism with manifest target space supersymmetry. In a simple class of examples, we compute various known physical phenomena such as warping and the generat

Eyo Eyo Ita

In this paper we demonstrate closure of the quantum algebra of Hamiltonian constraints in a theory directly related to a certain sector of general relativity reduced to diagonal variables.

H. Aratyn, J. van de Leur

We present an explicit method to perform similarity reduction of a Riemann-Hilbert factorization problem for a homogeneous GL (N, C) loop group and use our results to find solutions to the Painleve VI equation for N=3. The tau function of the reduced hierarchy is shown to satisfy the sigma-form of the Painleve VI equation. A class of tau functions of the red

Marcelo Gleiser, David Sicilia

We develop an analytical procedure to compute all relevant physical properties of scalar field oscillons in models with quartic polynomial potentials: energy, radius, frequency, core-amplitude, and lifetime. We compare our predictions to numerical simulations of models with symmetric and asymmetric double well potentials in three spatial dimensions, obtainin

Guanghan Li, Isabel M. C. Salavessa

We prove the mean curvature flow of a spacelike graph in $(Σ_1\times Σ_2, g_1-g_2)$ of a map $f:Σ_1\to Σ_2$ from a closed Riemannian manifold $(Σ_1,g_1)$ with $Ricci_1> 0$ to a complete Riemannian manifold $(Σ_2,g_2)$ with bounded curvature tensor and derivatives, and with sectional curvatures satisfying $K_2\leq K_1$, remains a spacelike graph, exists for a

Jason Alicea

Algebraic spin liquids, which are exotic gapless spin states preserving all microscopic symmetries, have been widely studied due to potential realizations in frustrated quantum magnets and the cuprates. At low energies, such putative phases are described by quantum electrodynamics in 2+1 dimensions. While significant progress has been made in understanding t

Danil W. Boukhvalov, Mikhail I. Katsnelson

Based on density functional calculations, optimized structures of graphite oxide are found for various coverage by oxygen and hydroxyl groups, as well as their ratio corresponding to the minimum of total energy. The model proposed describes well known experimental results. In particular, it explains why it is so difficult to reduce the graphite oxide up to p

Elena Gubankova, Massimo Mannarelli, Rishi Sharma

We derive the low energy effective action for the collective modes in systems of fermions interacting via a short-range s-wave attraction, featuring unequal chemical potentials for the two fermionic species (asymmetric systems). As a consequence of the attractive interaction, fermions form a condensate that spontaneously breaks the U(1) symmetry associated w

D. Truzzolillo, F. Bordi, F. Sciortino, C. Cametti

Polymer chains adsorbed onto oppositely charged spherical colloidal particles can significantly modify the particle-particle interactions. For sufficient amounts of added polymers, the original electrostatic repulsion can even turn into an effective attraction and relatively large kinetically stable aggregates can form which display several unexpected and in

Paul Koerber, Dieter Lust, Dimitrios Tsimpis

We present a classification of a large class of type IIA N=1 supersymmetric compactifications to AdS4, based on left-invariant SU(3)-structures on coset spaces. In the absence of sources the parameter spaces of all cosets leading to a solution contain regions corresponding to nearly-Kaehler structure. I.e. all these cosets can be viewed as deformations of ne

Ashoke Sen

We give a manifestly U-duality invariant formula for the degeneracy of 1/8 BPS dyons in type II string theory on T^6 for a U-duality invariant subset of charge vectors. Besides depending on the Cremmer-Julia invariant the degeneracy also depends on other discrete invariants of E_{7(7)}(Z).

Marc S. Seigar, Daniel Kennefick, Julia Kennefick, Claud H. S. Lacy

We present a relationship between spiral arm pitch angle (a measure of the tightness of spiral structure) and the mass of supermassive black holes (BHs) in the nuclei of disk galaxies. We argue that this relationship is expected through a combination of other relationships, whose existence has already been demonstrated. The recent discovery of AGN in bulgele

Christophe Eloy, Romain Lagrange, Claire Souilliez, Lionel Schouveiler

We address the flutter instability of a flexible plate immersed in an axial flow. This instability is similar to flag flutter and results from the competition between destabilising pressure forces and stabilising bending stiffness. In previous experimental studies, the plates have always appeared much more stable than the predictions of two-dimensional model

Luca Girlanda

It is shown that the number of independent operators in the nucleon-nucleon parity-violating contact Lagrangian at the leading order in the low-momentum expansion, can be reduced to five, by using Fierz rearrangements of the nucleon fields.

J. Wabnig, B. W. Lovett, J. H. Jefferson, G. A. D. Briggs

We present a method of obtaining information about spin lifetimes in quantum dots from measurements of electrical transport. The dot is under resonant microwave irradiation and at temperatures comparable to or larger than the Zeeman energy. We find that the ratio of the spin coherence times T_{1}/T_{2} can be deduced from a measurement of current through the

Gia Dvali, Michele Redi, Sergey Sibiryakov, Arkady Vainshtein

We set an upper bound on the gravitational cutoff in theories with exact quantum numbers of large N periodicity, such as Z_N discrete symmetries. The bound stems from black hole physics. It is similar to the bound appearing in theories with N particle species, though a priori, a large discrete symmetry does not imply a large number of species. Thus, there em

D. S. Goldobin, M. Mishto, K. Textoris-Taube, P. M. Kloetzel

We address the problem of proteasomal protein translocation and introduce a new stochastic model of the proteasomal digestion (cleavage) of proteins. In this model we account for the protein translocation and the positioning of cleavage sites of a proteasome from first principles. We show by test examples and by processing experimental data that our model al

Vasili Perebeinos, Phaedon Avouris

We investigate theoretically the rates of non-radiative decay of excited semiconducting nanotubes by a variety of decay mechanisms and compare with experimental findings. We find that the multi-phonon decay (MPD) of free excitons is too slow to be responsible for the experimentally observed lifetimes. However, MPD lifetimes of localized excitons could be 2-3

N. Brahms, B. Newman, C. Johnson, T. Greytak

We have trapped large numbers of copper and silver atoms using buffer gas cooling. Up to 3x10^12 copper atoms and 4x10^13 silver atoms are trapped. Lifetimes are as long as 5 s, limited by collisions with the buffer gas. Ratios of elastic to inelastic collision rates with He are >~ 10^6, suggesting copper and silver are favorable for use in ultracold applica

M. F. Paulos

Superfield methods can be used to determine the precise way the self-dual five-form couples to the metric in the first non-trivial $α&#39;$ corrections to type IIB supergravity. We explicitly compute the exact tensor structure of these terms. This requires extensive use of computing algorithms to reduce the complicated expressions that appear to a surprising

Guo-Qiang Liu, V. N. Antonov, O. Jepsen, O. K. Andersen

The outstanding discrepancy between the measured and calculated (local-density approximation) Fermi surfaces in the well-characterized, paramagnetic Fermi liquid Sr2RhO4 is resolved by including the spin-orbit coupling and Coulomb repulsion. This results in an effective spin-orbit coupling constant enhanced 2.15 times over the bare value. A simple formalism

Natacha Callens, Christophe Minetti, Maud-Alix Mader, Gwennou Coupier

The dynamics of a vesicle suspension in a shear flow between parallel plates has been investigated under microgravity conditions, where vesicles are only submitted to hydrodynamic effects such as lift forces due to the presence of walls and drag forces. The temporal evolution of the spatial distribution of the vesicles has been recorded thanks to digital hol

W. Bednarek, R. M. Wagner

Recently, the MAGIC collaboration reported evidence for a delay in the arrival times of photons of different energies during a gamma-ray flare from the blazar Markarian 501 on 2005 July 9. We apply a homogeneous synchrotron self-Compton (SSC) model under the assumption that the blob containing relativistic electrons was observed in its acceleration phase. Th

Miguel Angel Escobedo, Joan Soto

We illustrate how to apply modern effective field theory techniques and dimensional regularization to factorize the various scales which appear in non-relativistic bound states at finite temperature. We focus here on the simplest case: the hydrogen atom. We discuss in detail the interplay of the hard, soft and ultrasoft scales of the non-relativistic system

Jarah Evslin, Ruben Minasian

We add to the mounting evidence that the topological B model&#39;s normalized holomorphic three-form has integral periods by demonstrating that otherwise the B2-brane partition function is ill-defined. The resulting Calabi-Yau manifolds are roughly fixed points of attractor flows. We propose here that any admissible background for topological strings require

J. Blawzdziewicz, E. Wajnryb

The leading-order far-field scattered flow produced by a particle in a parallel-wall channel under creeping flow conditions has a form of the parabolic velocity field driven by a 2D dipolar pressure distribution. We show that in a system of hydrodynamically interacting particles, the pressure dipoles contribute to the macroscopic suspension flow in a similar

Christophe Bernicot

We calculate all the four-photon helicity amplitudes at the one-loop level in a massive theory using multiple-cut methods. The amplitudes are derived in scalar QED, QED and $\textrm{QED}^{\caln =1}$ theories. We will see the origin of rational terms. We extend the calculation to the simplest six-photon helicity amplitude where all photons have the same helic

Fabrice Béthuel, Philippe Gravejat, Jean-Claude Saut, Didier Smets

We establish the orbital stability of the black soliton, or kink solution, $\v_0(x) = þ\big(\frac{x}{\sqrt{2}} \big)$, to the one-dimensional Gross-Pitaevskii equation, with respect to perturbations in the energy space.

Graham Smith

To each flat conformal structure (FCS) of hyperbolic type in the sense of Kulkarni-Pinkall, we associate, for all $θ\in[(n-1)π/2,nπ/2[$ and for all $r>\opTan(θ/n)$ a unique immersed hypersurface $Σ_{r,θ}=(M,i_{r,θ})$ in $\Bbb{H}^{n+1}$ of constant $θ$-special Lagrangian curvature equal to $r$. We show that these hypersurfaces smoothly approximate the boundar

Fiammetta Battaglia

We associate a geometric space to an arbitrary convex polytope. Our construction parallels the construction by D. Cox of a toric variety as a GIT quotient. The spaces that we obtain are endowed with a natural stratification and perfectly mimic the features of toric varieties associated to rational convex polytopes.

Laurent Viennot, Yacine Boufkhad, Fabien Mathieu, Fabien De Montgolfier

We analyze a distributed system where n nodes called boxes store a large set of videos and collaborate to serve simultaneously n videos or less. We explore under which conditions such a system can be scalable while serving any sequence of demands. We model this problem through a combination of two algorithms: a video allocation algorithm and a connection sch

Adam Lipowski, Krzysztof Gontarek, Marcel Ausloos

We introduce a two-player model of reinforcement learning with memory. Past actions of an iterated game are stored in a memory and used to determine player&#39;s next action. To examine the behaviour of the model some approximate methods are used and confronted against numerical simulations and exact master equation. When the length of memory of players incr

M. Avenhaus, H. B. Coldenstrodt-Ronge, K. Laiho, W. Mauerer

We experimentally analyze the complete photon number statistics of parametric downconversion and ascertain the influence of multimode effects. Our results clearly reveal a difference between single mode theoretical description and the measured distributions. Further investigations assure the applicability of loss-tolerant photon number reconstruction and pro

F. Pakovich

In 1922 Ritt described polynomial solutions of the functional equation P(f)=Q(g). In this paper we describe solutions of the equation above in the case when P,Q are polynomials while f,g are allowed to be arbitrary entire functions. In fact, we describe solutions of the more general functional equation s=P(f)=Q(g), where s,f,g are entire functions and P,Q ar

F. Pakovich

In this paper we give several conditions implying the irreducibility of the algebraic curve P(x)-Q(y)=0, where P,Q are rational functions. We also apply the results obtained to the functional equations P(f)=Q(g) and P(f)=cP(g), where c\in C. For example, we show that for a generic pair of rational functions P,Q the first equation has no non-constant solution

Keizo Hasegawa

The existence of some complex geometrical structures on a compact manifold such as complex structures, Kaehler (pseudo-Kaehler) structures often impose certain restrictions on its underling topological or differentiable manifold. In this article we survey recent developments in the study of the existence, classification and moduli problems of such structures

Gregory Gutin, Daniel Karapetyan

The generalized traveling salesman problem (GTSP) is an extension of the well-known traveling salesman problem. In GTSP, we are given a partition of cities into groups and we are required to find a minimum length tour that includes exactly one city from each group. The aim of this paper is to present a problem reduction algorithm that deletes redundant verti

C. W. Sandweg, S. J. Hermsdoerfer, H. Schultheiss, S. Schaefer

The thermal spin-wave distribution in a Ni81Fe19 stripe with an asymmetric transverse domain wall has been investigated using Brillouin light scattering microscopy. Clear evidence has been found that the existence of the domain wall influences the spin-wave distribution of the thermal modes. The thermal spin-wave modes are quantized due to the confinement in

Gregory Gutin, Daniel Karapetyan

The generalized traveling salesman problem (GTSP) is an extension of the well-known traveling salesman problem. In GTSP, we are given a partition of cities into groups and we are required to find a minimum length tour that includes exactly one city from each group. The recent studies on this subject consider different variations of a memetic algorithm approa

Hua Wei, Wan Li Yang, Zhi Jiao Deng, Mang Feng

We propose a many-qubit network with cavity QED by encoding qubits in decoherence-free subspace, based on which we can implement many-logic-qubit conditional gates by means of cavity assisted interaction with single-photon pulses. Our scheme could not only resist collective dephasing errors, but also much reduce the implementational steps compared to convent

Jean Bertoin, Vladas Sidoravicius, Maria Eulalia Vares

We consider a system of particles with arms that are activated randomly to grab other particles as a toy model for polymerization. We assume that the following two rules are fulfilled: Once a particle has been grabbed then it cannot be grabbed again, and an arm cannot grab a particle that belongs to its own cluster. We are interested in the shape of a typica

Stefan Antusch, Martin Spinrath

We investigate the effect of supersymmetric (SUSY) threshold corrections on the values of the running quark and charged lepton masses at the GUT scale within the large $\tanβ$ regime of the MSSM. In addition to the typically dominant SUSY QCD contributions for the quarks, we also include the electroweak contributions for quarks and leptons and show that they

Frederick H. Willeboordse

According to the Bell theorem, local hidden variable theories cannot reproduce all the predictions of quantum mechanics. An important consequence is that under physically reasonable assumptions quantum mechanics predicts correlations that seem impossible to obtain from a realistic system. In this paper, two simple binary apparatuses are discussed that can ac

Fang-Yu Hong, Shi-Jie Xiong

Dispersive interactions of matter qubits with bright squeezed light in a high-Q cavity is studied. Numerical simulation shows that higher fidelity of operations to obtain a certain phase shift of the pulse through the dispersive light-matter interaction may be reached using bright squeezed light than that using bright coherent light.

Anirban Mukhopadhyay, Kotyada Srinivas, Krishnan Rajkumar

It is proved that under some suitable conditions, the degree two functions in the Selberg class have infinitely many zeros on the critical line.

I. R. Shein, A. L. Ivanovskii

The full-potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) for the exchange-correlation potential has been applied to predict the elastic properties of quaternary oxyarsenide LaOFeAs - the basic phase for the newly discovered 26-52K superconductors. The optimized lattice parameters, independent elast

Zeynep Nilhan Gurkan, Oktay K. Pashaev

In the present paper an influence of the anisotropic antisymmetric exchange interaction, the Dzialoshinskii-Moriya (DM) interaction, on entanglement of two qubits in various magnetic spin models, including the pure DM model and the most general XYZ model are studied. We find that the time evolution generated by DM interaction can implement the SWAP gate and

Gennaro Amendola

We prove that the classical set of moves for standard spines of 3-manifolds (i.e. the MP-move and the V-move) does not suffice to relate to each other any two standard skeleta of a 3-manifold with marked boundary. We also describe a condition on the 3-manifold with marked boundary that tells whether the generalised set of moves, made up of the MP-move and th

Kentaro Saji, Masaaki Umehara, Kotaro Yamada

In this paper, we discuss the recognition problem for A_k-type singularities on wave fronts. We give computable and simple criteria of these singularities, which will play a fundamental role in generalizing the authors&#39; previous work &#34;the geometry of fronts&#34; for surfaces. The crucial point to prove our criteria for A_k-singularities is to introdu

Viatcheslav Grines, Francois Laudenbach, Olga Pochinka

The paper is devoted to finding conditions to the existence of a self-indexing energy function for Morse-Smale diffeomorphisms on a 3-manifold. These conditions involve how the stable and unstable manifolds of saddle points are embedded in the ambient manifold. We also show that the existence of a self-indexing energy function is equivalent to the existence

Nicolas Moeller

We find a codimension one lump solution of closed bosonic string field theory. We consider vertices up to quartic order and include in the string field the tachyon, the ghost dilaton, and a metric fluctuation. While the tachyon profile clearly is that of a lump, we observe that the ghost dilaton is roughly constant in the direction transverse to the lump, eq

Heng Lian

Statistical inference of genetic regulatory networks is essential for understanding temporal interactions of regulatory elements inside the cells. For inferences of large networks, identification of network structure is typical achieved under the assumption of sparsity of the networks. When the number of time points in the expression experiment is not too sm

Virginia L. Corless, Benjamin M. Dobke, Lindsay J. King

The Hubble constant can be constrained using the time delays between multiple images of gravitationally lensed sources. In some notable cases, typical lensing analyses assuming isothermal galaxy density profiles produce low values for the Hubble constant, inconsistent with the result of the HST Key Project (72 +- 8 km/s/Mpc). Possible systematics in the valu

A. Ganczarczyk, S. Rojek, A. Quindeau, M. Geller

We demonstrate tunable transverse rectification in a density-modulated two-dimensional electron gas (2DEG). The density modulation is induced by two surface gates, running in parallel along a narrow stripe of 2DEG. A transverse voltage in the direction of the density modulation is observed, i.e. perpendicular to the applied source-drain voltage. The polarity

A. S. Mel&#39;nikov, D. A. Ryzhov, M. A. Silaev

On the basis of the Bogoliubov--de Gennes theory we study the transformation of the quasiparticle spectrum in the mixed state of a mesoscopic superconductor, governed by an external magnetic field. We analyze the low energy part of the excitation spectrum and investigate the field--dependent behavior of anomalous spectral branches crossing the Fermi level. G

P. M. Dinh, J. Messud, P. -G. Reinhard, E. Suraud

We discuss various ways to handle self-interaction corrections (SIC) to Density Functional Theory (DFT) calculations. To that end, we use a simple model of few particles in a finite number of states together with a simple zero-range interaction for which full Hartree-Fock can easily be computed as a benchmark. The model allows to shed some light on the balan

J. Messud, P. M. Dinh, P. -G. Reinhard, E. Suraud

We propose a simplification of the Optimized Effective Potential (OEP) applied to the Self Interaction Correction (SIC) scheme of Density Functional Theory (DFT). The new scheme fulfills several key formal properties and turns out to be both simple and accurate. We show examples of applications on model molecules in terms of observables known to be especiall

Leslie V. Woodcock

Virial coefficients for the two-dimensional hard-disk fluid, when expressed in powers of density relative to maximum close packing, lead to an accurate closed equation-of-state for the equilibrium fluid, analogous to that recently found for hard spheres. The 2D series also converges for all densities up to a negative pole at close packing density. The virial

Leroux Philippe

We introduce the operad Moor, dual of the operad NAP and the notion of Moor-bialgebras. We warn the reader that the compatibility relation linking the Moor-operation with the Moor-cooperation is not distributive in the sense of Loday. Nevertheless, a rigidity theorem (à la Hopf-Borel) for the category of connected Moor-bialgebras is given. We show also that

Arnak Dalalyan, Nakahiro Yoshida

In this paper, we consider the problem of estimating the covariation of two diffusion processes when observations are subject to non-synchronicity. Building on recent papers \cite{Hay-Yos03, Hay-Yos04}, we derive second-order asymptotic expansions for the distribution of the Hayashi-Yoshida estimator in a fairly general setup including random sampling scheme

S. Cynk, D. van Straten

We use properties of small resolutions of the ordinary double point in dimension three to construct smooth non-liftable Calabi-Yau threefolds. In particular, we construct a smooth projective Calabi-Yau threefold over $\F_3$ that does not lift to characteristic zero and a smooth projective Calabi-Yau threefold over $\F_5$ having an obstructed deformation. We

Claus Kiefer, Barbara Sandhoefer

We give an introduction into quantum cosmology with emphasis on its conceptual parts. After a general motivation we review the formalism of canonical quantum gravity on which discussions of quantum cosmology are usually based. We then present the minisuperspace Wheeler--DeWitt equation and elaborate on the problem of time, the imposition of boundary conditio

A. Ya. Braginsky

The paper shows that inhomogeneity of translation properties of condensate leads to the interaction of local order parameter (OP) and its compensating field which is similar to gauge fields in the field theory. Dynamic models were considered in the theory of phase transitions to inhomogeneous state with local translational symmetry, generalizing analogous mo

Raimundas Vidunas

Univariate specializations of Appell&#39;s hypergeometric functions F1, F2, F3, F4 satisfy ordinary Fuchsian equations of order at most 4. In special cases, these differential equations are of order 2, and could be simple (pullback) transformations of Euler&#39;s differential equation for the Gauss hypergeometric function. The paper classifies these cases, a

Kristian L. McDonald

A recent work has investigated the possibility that the mass scale for the ultraviolet (UV) brane in the Randall-Sundrum (RS) model is of the order 10^3 TeV. In this so called ``Little Randall-Sundrum&#39;&#39; (LRS) model the bounds on the gauge sector are less severe, permitting a lower Kaluza-Klein scale and cleaner discovery channels. However employing a

Yu-ming Wang, Ying Li, Cai-Dian Lu

Within the Standard Model, we investigate the weak decays of $Λ_b \to Λ+ γ$ and $Λ_b \to Λ+ l^{+} l^{-}$ with the light-cone sum rules approach. The higher twist distribution amplitudes of $Λ$ baryon to the leading conformal spin are included in the sum rules for transition form factors. Our results indicate that the higher twist distribution amplitudes almo

Matthias Beck, Mary Halloran

We prove several old and new theorems about finite sums involving characters and trigonometric functions. These sums can be traced back to theta function identities from Ramanujan&#39;s notebooks and were systematically first studied by Berndt and Zaharescu; their proofs involved complex contour integration. We show how to prove most of Berndt-Zaharescu&#39;

Yuqun Chen, Chanyan Zhong

In this paper, we prove that two-generator one-relator groups with depth less than or equal to 3 can be effectively embedded into a tower of HNN-extensions in which each group has the effective standard normal form. We give an example to show how to deal with some general cases for one-relator groups. By using the Magnus method and Composition-Diamond Lemma,

L. A. Bokut, Yuqun Chen, Cihua Liu

In this paper, we define the Gröbner-Shirshov basis for a dialgebra. The Composition-Diamond lemma for dialgebras is given then. As results, we give Gröbner-Shirshov bases for the universal enveloping algebra of a Leibniz algebra, the bar extension of a dialgebra, the free product of two dialgebras, and Clifford dialgebra. We obtain some normal forms for alg

M. Ibe, Y. Nakayama, T. T. Yanagida

We discuss a class of gauge mediated supersymmetry breaking models with conformal invariance above the messenger mass scale (conformal gauge mediation). The spectrum of the supersymmetric particles including the gravitino is uniquely determined by the messenger mass. When the conformal fixed point is strongly interacting, it predicts a light gravitino of mas

Hao Sha, F. Ye, Pengcheng Dai, J. A. Fernandez-Baca

Neutron scattering has been used to investigate the evolution of the long- and short-range charge-ordered (CO), ferromagnetic (FM), and antiferromagnetic (AF) correlations in single crystals of Pr1-xCaxMnO3. The existence and population of spin clusters as refected by short-range correlations are found to drastically depend on the doping (x) and temperature

Namrata Vaswani

We consider the problem of reconstructing time sequences of spatially sparse signals (with unknown and time-varying sparsity patterns) from a limited number of linear &#34;incoherent&#34; measurements, in real-time. The signals are sparse in some transform domain referred to as the sparsity basis. For a single spatial signal, the solution is provided by Comp

Graziano Rossi, Ravi K. Sheth

Noisy distance estimates associated with photometric rather than spectroscopic redshifts lead to a mis-estimate of the luminosities, and produce a correlated mis-estimate of the sizes. We consider a sample of early-type galaxies from the SDSS DR6 and apply the generalization of the V_max method to correct for these biases. We show that our technique recovers

Iván Ezequiel Angiono

The class of standard braided vector spaces, introduced by Andruskiewitsch and the author in \texttt{arXiv:math/0703924v2} to understand the proof of a theorem of Heckenberger \cite{H2}, is slightly more general than the class of braided vector spaces of Cartan type. In the present paper, we classify standard braided vector spaces with finite-dimensional Nic

L. Angeleri Huegel, O. Kerner, J. Trlifaj

We study finiteness conditions on large tilting modules over arbitrary rings. We then turn to a hereditary artin algebra R and apply our results to the (infinite dimensional) tilting module L that generates all modules without preprojective direct summands. We show that the behaviour of L over its endomorphism ring determines the representation type of R. A

J. David zook, Norbert Schroeder

This chapter reviews the mechanisms by which sensors gather information from the physical world and transform it into the electronic signals that are used in today&#39;s information and control systems. It introduces a new methodology for describing sensing mechanisms based on the process of information flow and applies it to the broad spectrum of sensors, i

Kaibin Huang, Jeffrey G. Andrews, Robert W. Heath,, Dongning Guo

Interference between nodes directly limits the capacity of mobile ad hoc networks. This paper focuses on spatial interference cancelation with perfect channel state information (CSI), and analyzes the corresponding network capacity. Specifically, by using multiple antennas, zero-forcing beamforming is applied at each receiver for canceling the strongest inte

Eugene V. Sukhorukov, Jonathan Edwards

We propose to use the phenomenon of resonant tunneling for the detection of noise. The main idea of this method relies on the effect of homogeneous broadening of the resonant tunneling peak induced by the emission and absorption of collective charge excitations in the measurement circuit. In thermal equilibrium, the signal to noise ratio of the detector as a

A. Melandri, C. G. Mundell, S. Kobayashi, C. Guidorzi

We present a multiwavelength analysis of 63 Gamma-Ray Bursts observed with the world&#39;s three largest robotic optical telescopes, the Liverpool and Faulkes Telescopes (North and South). Optical emission was detected for 24 GRBs with brightnesses ranging from R = 10 to 22 mag in the first 10 minutes after the burst. By comparing optical and X-ray light cur

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

We study the hard-X-ray spectral properties of ten highly luminous radio-quiet (RQ) active galactic nuclei (AGNs) at z=1.3-3.2, including new XMM-Newton observations of four of these sources. We find a significant correlation between the normalized accretion rate (L/L_Edd) and the hard-X-ray photon index (Gamma) for 35 moderate-high luminosity RQ AGNs includ