March 2010 arXiv papers — page 2
Showing 101–200 of 5,984 papers
Robert Beaird, Anton B. Vorontsov, Ilya Vekhter
We examine the effect of classical magnetic fluctuations on the phase diagram of paramagneticallylimited two-dimensional superconductors under a Zeeman magnetic field. We derive the free energy expansion in powers of the superconducting order parameter and analyze the character of the normalsuperconducting transition. While the transition is of the second or
Mark Agranovsky
Let $B^n$ be the unit ball in $\mathbb C^n$ and let the points $a_1,...,a_{n+1} \in B^n $ are affinely independent. If $f \in C(\partial B^n)$ and for any complex line $L$, containing at least one of the points $a_j$, the restriction $f|_{L \cap \partial B^n}$ extends holomorphically in the disc $L \cap B^n$, then $f$ is the boundary value of a holomorphic f
Vyacheslav Shatokhin, Tobias Geiger, Thomas Wellens, Andreas Buchleitner
This paper analyzes coherent backscattering of intense laser light by two randomly placed distant atoms. Starting from the general two-atom master equation, we analytically derive the elastic and inelastic background and interference components of the double scattering spectrum. By expressing the final results in terms of single-atom observables, the two-ato
T. Kriecherbauer, M. Shcherbina
We study the expectation of linear eigenvalue statistics of matrix models with any $β>0$, assuming that the potential $V$ is a real analytic function and that the corresponding equilibrium measure has a one-interval support. We obtain the first order (with respect to $n^{-1}$) correction terms for the expectation and apply this result to prove bulk universal
Fang Fang, Ward Manchester, William P. Abbett, Bart van der Holst
Here, we present numerical simulations of magnetic flux buoyantly rising from a granular convection zone into the low corona. We study the complex interaction of the magnetic field with the turbulent plasma. The model includes the radiative loss terms, non-ideal equations of state, and empirical corona heating. We find that the convection plays a crucial rol
S. Chatterjee, S. Giri, S. Majumdar, S. K. De
We report the observation of giant magneto-caloric effect (MCE) in ferromagnetic shape memory alloys (FSMAs) of nominal compositions Ni$_2$Mn$_{1.36}$Sn$_{0.64-x}$Ga$_{x}$ ($x$ =0.24, 0.28 and 0.32). Irrespective of the Ga doping, all the samples undergo long range ferromagnetic ordering below around 330 K. However, the martensitic transition temperature ($T
Moncy V. John
Marginal likelihoods for the cosmic expansion rates are evaluated using the `Constitution' data of 397 supernovas, thereby updating the results in some previous works. Even when beginning with a very strong prior probability that favors an accelerated expansion, we obtain a marginal likelihood for the deceleration parameter $q_0$ peaked around zero in th
Nianbei Li, Baowen Li, Sergej Flach
We investigate anomalous energy transport processes in the Fermi-Pasta-Ulam $β$ lattice. They are determined by the maximum sound velocity of the relevant weakly damped energy carriers. That velocity can be numerically resolved by measuring the propagating fronts of the correlation functions of energy/momentum fluctuations at different times. The numerical r
Jung Hun Lee, Sunchang Kim, Jongwook Kim, Nakwoo Kim
Recently Martelli and Sparks presented the first non-toric AdS_4/CFT_3 duality relation between M-theory on AdS_4 x V_{5,2}/Z_k and a class of three-dimensional N=2 quiver Chern-Simons-matter theories. V_{5,2} is a seven-dimensional homogeneneous Sasaki-Einstein manifold with isometry group SO(5)xU(1)_R, which is in general broken to SU(2)xU(1)xU(1)_R by the
Ratindranath Akhoury, Alexander D. Dolgov
We argue that superluminal propagation in a gravitational field discovered by Drummond and Hathrell in the lowest order of perturbation theory remains intact in higher orders. The criticism of this result based on an exact calculation of the one loop correction to the photon polarization operator in the Penrose plane wave approximation is not tenable. The st
V. Ferrer, I. Vainsencher
We give formulas for the degrees of the spaces of foliations in P2 with a dicritical singularity of prescribed order. Blowing up such singularity induces, generically, a foliation with all but finitely many leaves transversal to the exceptional line; we also find the degree of the locus defined by imposing a leaf of total contact with the exceptional line.
N. M. Chtchelkatchev, V. M. Vinokur, T. I. Baturina
A theory of far-from-equilibrium transport in arrays of tunnel junctions is developed. We show that at low temperatures the energy relaxation ensuring tunneling current can become a cascade two-stage process. First, charge carriers lose their energy to a bosonic environment via non-phonon energy exchange. The role of such an environment can be taken by elect
Partha Mukhopadhyay
We analyze exact conformal invariance of string worldsheet theory in non-trivial backgrounds using hamiltonian framework. In the first part of this talk we consider the example of type IIB superstrings in Ramond-Ramond pp-wave background. In particular, we discuss the quantum definition of energy-momentum (EM) tensor and two methods of computing Virasoro alg
P. S. Bhupal Dev, R. N. Mohapatra
In a recent paper, we proposed a new class of supersymmetric SO(10) models for neutrino masses where the TeV scale electroweak symmetry is SU(2)_L\times SU(2)_R\times U(1)_{B-L} making the associated gauge bosons W_R and Z' accessible at the Large Hadron Collider. We showed that there exists a domain of Yukawa coupling parameters and symmetry breaking pa
Stéphane Berciaud, Melinda Y. Han, Louis E. Brus, Philip Kim
We examine the intrinsic energy dissipation steps in electrically biased graphene channels. By combining in-situ measurements of the spontaneous optical emission with a Raman spectroscopy study of the graphene sample under conditions of current flow, we obtain independent information on the energy distribution of the electrons and phonons. The electrons and
P. Hall, T. J. Millar
Context: Complex molecules such as ethanol and dimethyl ether have been observed in a number of hot molecular cores and hot corinos. Attempts to model the molecular formation process using gas phase only models have so far been unsuccessful. Aims : To demonstrate that grain surface processing is a viable mechanism for complex molecule formation in these envi
Mahendra Panthee
We prove that the initial value problem (IVP) for the BBM equation is ill-posed for data in $H^s(\R)$, $s<0$ in the sense that the flow-map $u_0\mapsto u(t)$ that associates to initial data $u_0$ the solution $u$ cannot be continuous at the origin from $H^s(\R)$ to even $\mathcal{D}'(\R)$ at any fixed $t>0$ small enough. This result is sharp.
Jan Jakubuv, J. B. Wells
Shape types are a general concept of process types which work for many process calculi. We extend the previously published Poly* system of shape types to support name restriction. We evaluate the expressiveness of the extended system by showing that shape types are more expressive than an implicitly typed pi-calculus and an explicitly typed Mobile Ambients.
Oleg Semyonov, Arsen Subashiev, Zhichao Chen, Serge Luryi
Recombination of minority carriers in heavily doped n-InP wafers has been investigated using spectral and time-resolved photoluminescence at different temperatures. Studies of the transmitted luminescence were enabled by the partial transparency of the samples due to the Moss-Burstein effect. Temporal evolution of the transmitted luminescence shows virtually
C. Schuster, M. Kraus, A. Opitz, W. Brütting
Ambipolar charge carrier transport in Copper phthalocyanine (CuPc) is studied experimentally in field-effect transistors and metal-insulator-semiconductor diodes at various temperatures. The electronic structure and the transport properties of CuPc attached to leads are calculated using density functional theory and scattering theory at the non-equilibrium G
Rakesh P. Tiwari, D. Stroud
We describe a simple method of including dissipation in the spin wave band structure of a periodic ferromagnetic composite, by solving the Landau-Lifshitz equation for the magnetization with the Gilbert damping term. We use this approach to calculate the band structure of square and triangular arrays of Ni nanocylinders embedded in an Fe host. The results sh
Matthias Hammerl, Petr Somberg, Vladimir Soucek, Josef Silhan
A regular normal parabolic geometry of type $G/P$ on a manifold $M$ gives rise to sequences $D_i$ of invariant differential operators, known as the curved version of the BGG resolution. These sequences are constructed from the normal covariant derivative $\na^\om$ on the corresponding tractor bundle $V,$ where $\om$ is the normal Cartan connection. The first
"How many zombies do you know?" Using indirect survey methods to measure alien attacks and outbreaks of the undead
physics.soc-phAndrew Gelman
The zombie menace has so far been studied only qualitatively or through the use of mathematical models without empirical content. We propose to use a new tool in survey research to allow zombies to be studied indirectly without risk to the interviewers.
Mirko D'Ovidio, Enzo Orsingher
Iterated Bessel processes R^γ(t), t>0, γ>0 and their counterparts on hyperbolic spaces, i.e. hyperbolic Brownian motions B^{hp}(t), t>0 are examined and their probability laws derived. The higher-order partial differential equations governing the distributions of I_R(t)=_1R^γ(_2R^γ(t)), t>0 and J_R(t) =_1R^γ(|_2R^γ(t)|^2), t>0 are obtained and discussed. Pro
Ruth Lazkoz, Vincenzo Salzano, Irene Sendra
We study the possibility of detecting oscillating patterns in the equation of state (EoS) of the dark energy using different cosmological datasets. We follow a phenomenological approach and study three different oscillating models for the EoS, one of them periodic and the other two damped (proposed here for the first time). All the models are characterised b
C. Müller, A. B. Voitkiv, J. R. Crespo López-Urrutia, Z. Harman
In the presence of a neighboring atom, electron-ion recombination can proceed resonantly via excitation of an electron in the atom, with subsequent relaxation through radiative decay. It is shown that this two-center dielectronic process can largely dominate over single-center radiative recombination at internuclear distances as large as several nanometers.
Christof Walz, Matthias Fuchs
In this work a periodic crystal with point defects is described in the framework of linear response theory for broken symmetry states using correlation functions and Zwanzig-Mori equations. The main results are microscopic expressions for the elastic constants and for the coarse-grained density, point-defect density, and displacement field, which are valid i
S. Lottini, M. A. Rajabpour
We find the critical surface of the Ashkin-Teller model on the generic iso-radial graphs by using the results for the anisotropic Ashkin-teller model on the square lattice. Different geometrical aspects of this critical surface are discussed, especially their connection to the anisotropy angle. The free energy of the model on the generic iso-radial graph is
P. Castorina, R. V. Gavai, H. Satz
We consider the possibility that color deconfinement and chiral symmetry restoration do not coincide in dense baryonic matter at low temperature. As a consequence, a state of massive "constituent" quarks would exist as an intermediate phase between confined nuclear matter and the plasma of deconfined massless quarks and gluons. We discuss the propert
David R. Soderblom
The age of an individual star cannot be measured, only estimated through mostly model-dependent or empirical methods, and no single method works well for a broad range of stellar types or for a full range in age. This review presents a summary of the available techniques for age-dating stars and ensembles of stars, their realms of applicability, and their st
LUNA collaboration, T. Szucs, D. Bemmerer, C. Broggini
An escape-suppressed, composite high-purity germanium detector of the Clover type has been installed at the Laboratory for Underground Nuclear Astrophysics (LUNA) facility, deep underground in the Gran Sasso Laboratory, Italy. The laboratory gamma-ray background of the Clover detector has been studied underground at LUNA and, for comparison, also in an overg
T. Theivasanthi, M. Alagar
Copper nanopowder preparation and its X-Ray diffraction studies are reported in this paper. Electrolytic cathode deposition method is simple and cheapest process for its preparation. Copper nanopowder has been prepared from aqueous copper sulphate solution. Wide range of experimental conditions has been adopted in this process and its X-Ray diffraction chara
Alexandru I. Cabuz, André Nicolet, Frédéric Zolla, Didier Felbacq
It is well known that defining a local refractive index for a metamaterial requires that the wavelength be large with respect to the scale of its microscopic structure (generally the period). However, the converse does not hold. There are simple structures, such as the infinite, perfectly conducting wire medium, which remain non-local for arbitrarily large w
Curtis J. Saxton, Kinwah Wu, Svetlana Korunoska, Khee-Gan Lee
We investigated the time-dependent radiative and dynamical properties of light supersonic jets launched into an external medium, using hydrodynamic simulations and numerical radiative transfer calculations. These involved various structural models for the ambient media, with density profiles appropriate for galactic and extragalactic systems. The radiative t
The Invisible Tension of the Universe from Astrophysical Black Holes: a Solution to the Coincidence Problem of the Accelerated Expansion
astro-ph.COJordi Miralda-Escudé
Astronomical observations have shown that the expansion of the universe is at present accelerating, consistently with a constant negative pressure or tension. This is a major puzzle because we do not understand why this tension is so small compared to the Planck density; why, being so small, it is not exactly zero; and why it has precisely the required value
Joe Zuntz, Thomas G. Zlosnik, Caroline Zunckel, Jonathan T. L. Zwart
We analyze correlations between the first letter of the name of an author and the number of citations their papers receive. We look at simple mean counts, numbers of highly-cited papers, and normalized h-indices, by letter. To our surprise, we conclude that orthographically senior authors produce a better body of work than their colleagues, despite some evid
Star formation history of KDG 61 and KDG 64 from spectroscopy and colour-magnitude diagrams
astro-ph.COLidia Makarova, Mina Koleva, Dmitry Makarov, Philippe Prugniel
A study of two dE/dSph members of the nearby M 81 group of galaxies, KDG 61 and UGC 5442 = KDG 64, has been made. Direct Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) images and integrated-light spectra of 6 m telescope of Special Astrophysical Observatory of Russian Academy of Sciences have been used for quantitative star formation history
Clément Laurent
Let $(X_t,t\geq 0)$ be a random walk on $\mathbb{Z}^d$. Let $ l_T(x)= \int_0^T δ_x(X_s)ds$ the local time at the state $x$ and $ I_T= \sum\limits_{x\in\mathbb{Z}^d} l_T(x)^q $ the q-fold self-intersection local time (SILT). In \cite{Castell} Castell proves a large deviations principle for the SILT of the simple random walk in the critical case $q(d-2)=d$. In
Paolo Lipparini
We introduce a covering notion depending on two cardinals, which we call $\mathcal O $-$ [ μ, λ]$-compactness, and which encompasses both pseudocompactness and many other generalizations of pseudocompactness. For Tychonoff spaces, pseudocompactness turns out to be equivalent to $\mathcal O $-$ [ ω, ω ]$-compactness. We provide several characterizations of $\
Hui Wang, Shensheng Han
A special algorithm for the Fourier-transform Ghost Imaging (GI) scheme is discussed based on the Compressive Sampling (CS) theory. The CS algorithm could also be used for the Fourier spectrum reconstruction of pure phase object by setting a proper sensing matrix. This could find its application in diffraction imaging of X-ray, neutron and electron with high
Irreducible Modules over Finite Simple Lie Pseudoalgebras II. Primitive Pseudoalgebras of Type K
math.QABojko Bakalov, Alessandro D'Andrea, Victor G. Kac
One of the algebraic structures that has emerged recently in the study of the operator product expansions of chiral fields in conformal field theory is that of a Lie conformal algebra. A Lie pseudoalgebra is a generalization of the notion of a Lie conformal algebra for which C[\partial] is replaced by the universal enveloping algebra H of a finite-dimensiona
Rob C. Wagner, Mark S. Everitt, Viv M. Kendon, Martin L. Jones
We present universal continuous variable quantum computation (CVQC) in the micromaser. With a brief history as motivation we present the background theory and define universal CVQC. We then show how to generate a set of operations in the micromaser which can be used to achieve universal CVQC. It then follows that the micromaser is a potential architecture fo
Jon Gonzalez-Sanchez, Benjamin Klopsch
Let $w = w(x_1,..., x_n)$ be a word, i.e. an element of the free group $F =<x_1,...,x_n>$ on $n$ generators $x_1,..., x_n$. The verbal subgroup $w(G)$ of a group $G$ is the subgroup generated by the set $\{w (g_1,...,g_n)^{\pm 1} | g_i \in G, 1\leq i\leq n \}$ of all $w$-values in $G$. We say that a (finite) group $G$ is $w$-maximal if $|G:w(G)|> |H:w(H)|$ f
Localization of a Bose-Einstein condensate vortex in a bichromatic optical lattice
cond-mat.quant-gasS. K. Adhikari
By numerical simulation of the time-dependent Gross-Pitaevskii equation we show that a weakly interacting or noninteracting Bose-Einstein condensate (BEC) vortex can be localized in a three-dimensional bichromatic quasi-periodic optical-lattice (OL) potential generated by the superposition of two standing-wave polarized laser beams with incommensurate wavele
Julia Berashevich, Tapash Chakraborty
Discoveries of graphene and graphane possessing unique electronic and magnetic properties offer a bright future for carbon based electronics, with future prospects of superseding silicon in the semiconductor industry.
C. Karoff, H. Svensmark
Using kappa Ceti as a proxy for the young Sun we show that not only was the young Sun much more effective in protecting the Earth environment from galactic cosmic rays than the present day Sun; it also had flare and corona mass ejection rates up to three orders of magnitude larger than the present day Sun. The reduction in the galactic cosmic ray influx caus
Bijan Sahamie
This paper provides an introduction to the basics of Heegaard Floer homology with some emphasis on the hat theory and to the contact geometric invariants in the theory. The exposition is designed to be comprehensible to people without any prior knowledge of the subject.
Łukasz Kłopotowski, Mateusz Goryca, Tomasz Kazimierczuk, Piotr Kossacki
We study the leakage dynamics of charge stored in an ensemble of CdTe quantum dots embedded in a field-effect structure. Optically excited electrons are stored and read out by a proper time sequence of bias pulses. We monitor the dynamics of electron loss and find that the rate of the leakage is strongly dependent on time, which we attribute to an optically
Mikko Juhani Leskinen, Olli Heikki Tapio Nummi, Francesco Massel, Paivi Torma
We study a highly imbalanced Fermi gas in a one-dimensional optical lattice from the polaronic point of view. The time-evolving block decimationg algorithm is used to calculate the ground state and dynamics of the system. We find qualitatively similar polaronic behaviour as in the recent experiment by Schirotzek et al. \cite{Schirotzek2009a} where radio-freq
Michael J. Barber, Margarida Faria, Ludwig Streit, Oleg Strogan
We investigate research and development collaborations under the EU Framework Programs (FPs) for Research and Technological Development. The collaborations in the FPs give rise to bipartite networks, with edges existing between projects and the organizations taking part in them. A version of the modularity measure, adapted to bipartite networks, is presented
M. Obergaulinger, M. A. Aloy, E. Müller
Context. Global MHD simulations show Kelvin-Helmholtz (KH) instabilities at the contact surface of two merging neutron stars. That region has been identified as the site of efficient amplification of magnetic fields. However, these global simulations, due to numerical limitations, were unable to determine the saturation level of the field strength, and thus
Variable Threshold MOSFET Approach (Through Dynamic Threshold MOSFET) For Universal Logic Gates
cs.OHK. Ragini, M. Satyam, B. C. Jinaga
In this article, we proposed a Variable threshold MOSFET(VTMOS)approach which is realized from Dynamic Threshold MOSFET(DTMOS), suitable for sub-threshold digital circuit operation. Basically the principle of sub- threshold logics is operating MOSFET in sub-threshold region and using the leakage current in that region for switching action, there by drastical
Alan Huckleberry
This article was written on the occasion of Hans Grauert receiving the Cantor Medallion of the Deutsche Mathematische Vereinigung. It is a brief overview of his mathematical contributions and attempts to convey the author's great respect for the man and his science.
R. Fares, J. -F. Donati, C. Moutou, M. M. Jardine
HD 189733 is a K2 dwarf, orbited by a giant planet at 8.8 stellar radii. In order to study magnetospheric interactions between the star and the planet, we explore the large-scale magnetic field and activity of the host star. We collected spectra using the ESPaDOnS and the NARVAL spectropolarimeters, installed at the 3.6-m Canada-France-Hawaii telescope and t
B. Ekta, Jayaram N. Chengalur
Extremely metal-deficient (XMD) galaxies, by definition, have oxygen abundances \le 1/10 solar, and form a very small fraction of the local gas-rich, star-forming dwarf galaxy population. We examine their positions in the luminousity-metallicity (L-Z) and mass-metallicity (M-Z) planes, with respect to the L-Z and M-Z relations of other gas-rich, star-forming
Alan Huckleberry
Karl Stein was one of the pillars of the German school of several complex variables. In this article his scientific contributions are outlined in historical perspective.
Janne Kauttonen, Juha Merikoski
Molecules with complex internal structure in time-dependent periodic potentials are studied by using short Rubinstein-Duke model polymers as an example. We extend our earlier work on transport in stochastically varying potentials to cover also deterministic potential switching mechanisms, energetic efficiency and non-uniform charge distributions. We also use
Yutaka Hosotani
The Higgs boson is in the backbone of the standard model of electroweak interactions. It must exist in some form for achieving unification of interactions. In the gauge-Higgs unification scenario the Higgs boson becomes a part of the extra-dimensional component of gauge fields. The Higgs boson becomes absolutely stable in a class of the gauge-Higgs unificati
A distributional approach to the geometry of 2D dislocations at the mesoscale Part A: General theory and Volterra dislocations Part B: The case of a countable family of dislocations
math-phNicolas Van Goethem, Francois Dupret
This paper develops a geometrical model of dislocations and disclinations in single crystals at the mesoscopic scale. In the continuation of previous work the distribution theory is used to represent concentrated effects in the defect lines which in turn form the branching lines of the multiple-valued elastic displacement and rotation fields. Fundamental ide
Karim Noui
We tackle the question of motion in Quantum Gravity: what does motion mean at the Planck scale? Although we are still far from a complete answer we consider here a toy model in which the problem can be formulated and resolved precisely. The setting of the toy model is three dimensional Euclidean gravity. Before studying the model in detail, we argue that Loo
Inverse Spin Hall Effect and Anomalous Hall Effect in a Two-Dimensional Electron Gas
cond-mat.mes-hallP. Schwab, R. Raimondi, C. Gorini
We study the coupled dynamics of spin and charge currents in a two-dimensional electron gas in the transport diffusive regime. For systems with inversion symmetry there are established relations between the spin Hall effect, the anomalous Hall effect and the inverse spin Hall effect. However, in two-dimensional electron gases of semiconductors like GaAs, inv
Jean-Marc Bouclet
For Laplace-Beltrami operators associated to metrics which are long range perturbations of the flat one, we prove estimates for powers of the resolvent as the spectral parameter goes to zero. We also discuss applications to the local energy decay for the Schroedinger, Wave and Klein Gordon equations.
Rehana Ashraf, Barbu Berceanu
We study a subset of square free positive braids and we give a few algebraic characterizations of them and one geometric characterization: the set of positive braids whose closures are unlinks. We describe canonical forms of these braids and of their conjugacy classes.
Self-Energy and Excitonic Effects in the Electronic and Optical Properties of TiO2 Crystalline Phases
cond-mat.mtrl-sciLetizia Chiodo, Juan Maria Garcia-Lastra, Amilcare Iacomino, Stefano Ossicini
We present a unified ab-initio study of electronic and optical properties of TiO2 rutile and anatase phases, with a combination of Density Functional Theory and Many Body Perturbation Theory techniques. The consistent treatment of exchange-correlation, with the inclusion of many body one-particle and two-particles effects in self-energy and electron-hole int
Spectral and polarimetric characterization of the Gas Pixel Detector filled with dimethyl ether
astro-ph.IMF. Muleri, P. Soffitta, L. Baldini, R. Bellazzini
The Gas Pixel Detector belongs to the very limited class of gas detectors optimized for the measurement of X-ray polarization in the emission of astrophysical sources. The choice of the mixture in which X-ray photons are absorbed and photoelectrons propagate, deeply affects both the energy range of the instrument and its performance in terms of gain, track d
Lei Xu, Alexis Bergés, Peter J. Lu, André R. Studart
We investigate the 3D structure and drying dynamics of complex mixtures of emulsion droplets and colloidal particles, using confocal microscopy. Air invades and rapidly collapses large emulsion droplets, forcing their contents into the surrounding porous particle pack at a rate proportional to the square of the droplet radius. By contrast, small droplets do
Derek F Holt, Sarah Rees
We prove that any Artin group of large type is shortlex automatic with respect to its standard generating set, and that the set of all geodesic words over the same generating set satisfies the Falsification by Fellow-Traveller Property (FFTP) and hence is regular.
Alano Ancona
We first consider a question raised by Alexander Eremenko and show that if $Ω$ is an arbitrary connected open cone in ${\mathbb R}^d$, then any two positive harmonic functions in $Ω$ that vanish on $\partial Ω$ must be proportional -an already known fact when $Ω$ has a Lipschitz basis or more generally a John basis. It is also shown however that when $d \geq
S. Braccini, A. Ereditato, I. Kreslo, U. Moser
We propose an innovative method for proton radiography based on nuclear emulsion film detectors, a technique in which images are obtained by measuring the position and the residual range of protons passing through the patient's body. For this purpose, nuclear emulsion films interleaved with tissue equivalent absorbers can be used to reconstruct proton tr
Juan-Carlos Álvarez Paiva, Florent Balacheff
We study the infinitesimal aspects of the following problem. Let H be a Hamiltonian of \R^{2n} whose energy surface {H=1} encloses a compact starshaped domain of volume equal to that of the unit ball in \R^{2n}. Does the energy surface {H=1} carry a periodic orbit of the Hamiltonian system associated to H with action less than or equal to π?
Jean-Paul Marcerou
We demonstrate that the sequence of distorted commensurate phases observed in tilted chiral smectics is explained by the gain in electrostatic energy due to the lock-in of the unit cell to a number of layers which is the integer closest to the ratio pitch over thickness of the subjacent Sm-C$^*_α$ phase. We also explain the sign change of the helicity in the
Sobolev space estimates for a class of bilinear pseudodifferential operators lacking symbolic calculus
math.CAFrederic Bernicot, Rodolfo Torres
The reappearance of a sometimes called exotic behavior for linear and multilinear pseudodifferential operators is investigated. The phenomenon is shown to be present in a recently introduced class of bilinear pseudodifferential operators which can be seen as more general variable coefficient counterparts of the bilinear Hilbert transform and other singular b
Fadwa Joud, Frédéric Verpillat, Franck Laloë, Atlan Michael
In the measurement of the amplitude of vibration of objects, holographic imaging techniques usually involve fringe counting; due to the limited resolution of images, measurements of large amplitudes are not accessible. We demonstrate a technique that suppresses the necessity of fringe counting: frequency sideband imaging, where the order of the sideband is c
Jaroslav Hájek, András Szöllös, Jakub Šístek
The article introduces a new mechanism for selecting individuals to a Pareto archive. It was combined with a micro-genetic algorithm and tested on several problems. The ability of this approach to produce individuals uniformly distributed along the Pareto set without negative impact on convergence is demonstrated on presented results. The new concept was con
Reference antenna techniques for canceling radio frequency interference due to moving sources
astro-ph.IMD. A. Mitchell, J. G. Robertson
We investigate characteristics of radio frequency interference (RFI) signals that can affect the excision potential of some interference mitigation algorithms. The techniques considered are those that modify signals from auxiliary reference antennas to model and cancel interference from an astronomical observation. These techniques can be applied in the time
Asymptotics of Selberg-like integrals: The unitary case and Newton's interpolation formula
math-phChristophe Carré, Matthieu Deneufchatel, Jean-Gabriel Luque, Pierpaolo Vivo
We investigate the asymptotic behavior of the Selberg-like integral $$ \frac1{N!}\int_{[0,1]^N}x_1^p\prod_{i<j}(x_i-x_j)^2\prod_ix_i^{a-1}(1-x_i)^{b-1}dx_i$$, as $N\to\infty$ for different scalings of the parameters $a$ and $b$ with $N$. Integrals of this type arise in the random matrix theory of electronic scattering in chaotic cavities supporting $N$ chann
Marina Ghisi, Massimo Gobbino
In a celebrated paper (Tokyo J. Math. 1984) K. Nishihara proved global existence for Kirchhoff equations in a special class of initial data which lies in between analytic functions and Gevrey spaces. This class was defined in terms of Fourier components with weights satisfying suitable convexity and integrability conditions. In this paper we extend this resu
Subhashish Banerjee, R. Parthasarathy
A new q-deformed logistic map is proposed and it is found to have concavity in parts of the x-space. Its one-cycle and two-cycle non-trivial fixed points are obtained which are found to be qualitatively and quantitatively different from those of the usual logistic map. The stability of the proposed q-logistic map is studied using Lyapunov exponent and with a
Xiangyong Zeng, Jinyong Shan, Lei Hu
Based on a sufficient condition proposed by Hollmann and Xiang for constructing triple-error-correcting codes, the minimum distance of a binary cyclic code $\mathcal{C}_{1,3,13}$ with three zeros $α$, $α^3$, and $α^{13}$ of length $2^m-1$ and the weight divisibility of its dual code are studied, where $m\geq 5$ is odd and $α$ is a primitive element of the fi
Margarida Mendes Lopes, Rita Pardini, Gian Pietro Pirola
We prove that a complex surface S with irregularity q(S)=5 that has no irrational pencil of genus >1 has geometric genus p_g(S)>7. As a consequence, one is able to classify minimal surfaces S of general type with q(S)=5 and p_g(S)<8. This result is a negative answer, for q=5, to the question asked in arXiv:0811.0390 of the existence of surfaces of general ty
R. G. Gatiyatov, V. N. Lisin, A. A. Bukharaev
The transition from the ballistic electron transport to the diffuse one is experimentally observed in the study of the magnetic phase transition in Ni nanocontacts with different sizes. It is shown that the voltage $U_C$ needed for Joule heating of the near-contact region to the critical temperature does not depend on the contact size only in the diffuse mod
Jipeng Cheng, Jingsong He, Sen Hu
In this paper, we systematically develop the "ghost" symmetry of the BKP hierarchy through its actions on the Lax operator $L$, the eigenfunctions and the $τ$ function. In this process, the spectral representation of the eigenfunctions and a new potential are introduced by using squared eigenfunction potential(SEP) of the BKP hierarchy. Moreover, the
L. P. Teo
Eigenmodes of electromagnetic field with perfectly conducting or infinitely permeable conditions on the boundary of a D-dimensional spherically symmetric cavity is derived explicitly. It is shown that there are (D-2) polarizations for TE modes and one polarization for TM modes, giving rise to a total of (D-1) polarizations. In case of a D-dimensional ball, t
Taichiro Kugo, Tsutomu T. Yanagida
It is known that supersymmetric nonlinear sigma models for the compact Kahler manifolds G/H cannot be consistently coupled to supergravity, since the Kahler potentials are not invariant under the G transformation. We show that the supersymmetric nonlinear sigma models can be deformed such that the Kahler potential be exactly G-invariant if and only if one en
Guo-Hua Mu, Wei-Xing Zhou
There is convincing evidence showing that the probability distributions of stock returns in mature markets exhibit power-law tails and both the positive and negative tails conform to the inverse cubic law. It supports the possibility that the tail exponents are universal at least for mature markets in the sense that they do not depend on stock market, indust
Marcin Sabok
We show that the set of codes for Ramsey positive analytic sets is $\mathbfΣ^1_2$-complete. This is a one projective-step higher analogue of the Hurewicz theorem saying that the set of codes for uncountable analytic sets is $\mathbfΣ^1_1$-complete. This shows a close resemblance between the Sacks forcing and the Mathias forcing. In particular, we get that th
Joakim Arnlind, Jens Hoppe, Gerhard Huisken
We prove that many aspects of the differential geometry of embedded Riemannian manifolds can be formulated in terms of a multi-linear algebraic structure on the space of smooth functions. In particular, we find algebraic expressions for Weingarten's formula, the Ricci curvature and the Codazzi-Mainardi equations.
Devavrat Shah, John N. Tsitsiklis, Yuan Zhong
We consider a switched network, a fairly general constrained queueing network model that has been used successfully to model the detailed packet-level dynamics in communication networks, such as input-queued switches and wireless networks. The main operational issue in this model is that of deciding which queues to serve, subject to certain constraints. In t
Sigmund Selberg
We study bilinear $L^2$ Fourier restriction estimates which are related to the 2d wave equation in the sense that we restrict to subsets of thickened null cones. In an earlier paper we studied the corresponding 3d problem, obtaining several refinements of the Klainerman-Machedon type estimates. The latter are bilinear generalizations of the $L^4$ estimate of
Shengli Zhang, Ning Ma, Erhu Zhang
This paper is to explore the de Haas-van Alphen effect $(dHvA)$ of graphene in the presence of an in-plane uniform electric field. Three major findings are yielded. First of all, the electric field is found to modulate the de Haas-van Alphen magnetization and magnetic susceptibility through the dimensionless parameter $(β=\frac{E}{\upsilon_{F}B})$. As the pa
Paola Zizzi
The main aim of this thesis is to look for a logical deductive calculus (we will adopt sequent calculus, originally introduced in Gentzen, 1935), which could describe quantum information and its properties. More precisely, we intended to describe in logical terms the formation of the qubit (the unit of quantum information) which is a particular linear superp
Kwong Wa Chang, C. K. Law
We derive an exact non-Markovian master equation that generalizes the previous work [Hu, Paz and Zhang, Phys. Rev. D {\bf 45}, 2843 (1992)] to damped harmonic oscillators with time-varying parameters. This is achieved by exploiting the linearity of the system and operator solution in Heisenberg picture. Our equation governs the non-Markovian quantum dynamics
Alan Huckleberry
If G_0 is a real form of a complex semisimple Lie group G and Z is compact G-homogeneous projective algebraic manifold, then G_0 has only finitely many orbits on Z. Complex analytic properties of open G_0-orbits D (flag domains) are studied. Schubert incidence-geometry is used to prove the Kobayashi hyperbolicity of certain cycle space components C_q(D). Usi
Hiroki Kondo, Shingo Saito, Tatsushi Tanaka
The Bowman-Bradley theorem asserts that the multiple zeta values at the sequences obtained by inserting a fixed number of twos between 3,1,...,3,1 add up to a rational multiple of a power of pi. We establish its counterpart for multiple zeta-star values by showing an identity in a non-commutative polynomial algebra introduced by Hoffman.
Quantum transport in a curved one-dimensional quantum wire with spin-orbit interactions
cond-mat.mes-hallErhu Zhang, Shengli Zhang, Qi Wang
The one-dimensional effective Hamiltonian for a planar curvilinear quantum wire with arbitrary shape is proposed in the presence of the Rashba spin-orbit interaction. Single electron propagation through a device of two straight lines conjugated with an arc has been investigated and the analytic expressions of the reflection and transmission probabilities hav
Alan Huckleberry
Homogeneous complex manifolds satisfying various types of Levi conditions are considered. Classical results which were of particular interest to Andreotti are recalled. Convexity and concavity properties of flag domains are discussed in some detail. A precise classification of pseudoconvex flag domains is given. It is shown that flag domains which are in a c
Igor Goncharenko, Ajay Gopinathan
The asymptotic behaviour of the survival or reunion probability of vicious walks with short-range interactions is generally well studied. In many realistic processes, however, walks interact with a long ranged potential that decays in $d$ dimensions with distance $r$ as $r^{-d-σ}$. We employ methods of renormalized field theory to study the effect of such lo
Jung-Jung Su, Matthias J. Graf, Alexander V. Balatsky
The shear modulus of solid $^4$He exhibits an anomalous change of order 10%[1, 2] at low temperatures that is qualitatively similar to the much smaller frequency change in torsional oscillator experiments. We propose that in solid $^4$He the stiffening of the shear modulus with decreasing temperature can be described with a glass susceptibility assuming a te
Saurav Samanta
Following Mach's definition of mass and force in terms of space time measurement we build the conceptual structure of classical mechanics and show that it is remarkably similar to the results of Carnot and Clausius in thermodynamics. The analogy is extended to equality to derive the laws of gravity from the laws of thermodynamics.
D. Eksi, O. Kilicoglu, O. Goektas, A. Siddiki
In this work, we calculate the electron and the current density distributions both at the edges and the bulk of a two dimensional electron system, focusing on ideal and non-ideal contacts. A three dimensional Poisson equation is solved self-consistently to obtain the potential profile in the absence of an external magnetic field considering a Hall bar define