November 2008 arXiv papers — page 5
Showing 401–500 of 4,899 papers
Redamy Perez Ramos
The hadronic $\kt$-spectrum and the gluon to quark average multiplicity ratio $r=N_g/N_q$ inside a high energy sub-jet are determined from a precise definition of the jet axis, including corrections of relative magnitude ${\cal O}(\sqrt{α_s})$ with respect to the Modified Leading Logarithmic Approximation (MLLA), in the limiting spectrum approximation (assum
S. Ospelkaus, K. -K. Ni, M. H. G. de Miranda, B. Neyenhuis
We report the creation and characterization of a near quantum-degenerate gas of polar $^{40}$K-$^{87}$Rb molecules in their absolute rovibrational ground state. Starting from weakly bound heteronuclear KRb Feshbach molecules, we implement precise control of the molecular electronic, vibrational, and rotational degrees of freedom with phase-coherent laser fie
Paul Cresswell, Richard P. Nelson
We investigate the stability of those low-mass Trojan planets that form in a protoplanetary disc and subsequently accrete gas to become gas giants. We calculate their evolution before, during, and after gas disc dispersal. A two-dimensional hydrodynamics code combined with an N-body solver is used to evolve the system of disc and planets. Gas disc dispersal
I. D. Karachentsev, O. G. Kashibadze, D. I. Makarov, R. B. Tully
We use updated data on distances and velocities of galaxies in the proximity of the Local Group (LG) in order to establish properties of the local Hubble flow. For 30 neighbouring galaxies with distances 0.7 < D_LG < 3.0 Mpc, the Local flow is characterized by the Hubble parameter H_loc = (78+/-2) km/(s*Mpc), the mean-square peculiar velocity sigma_v = 25 km
M. C. B. Abdalla, M. E. X. Guimaraes, J. M. Hoff da Silva
We review some recent results obtained from the application of the Gauss-Codazzi formalism to brane-worlds models in the Brans-Dicke gravity. The cases of 4-branes embedded in a six-dimensional with and without $\mathbb{Z}_{2}$ symmetry are both analyzed.
Jean Alexandre, Anna Kostouki, Nick E. Mavromatos
Within the framework of a novel functional method on the world-sheet of the string, we discuss simple but re-summed (in the Regge slope) inflationary scenarios in the context of closed Bosonic strings, living in four target-space dimensions, in the presence of non-trivial tachyon, dilaton and graviton cosmological backgrounds. The inflationary solutions are
Kazunori Nishio, Kenji Kashima, Jun-ichi Imura
We investigate feedback control of linear quantum systems subject to feedback-loop time delays. In particular, we examine the relation between the potentially achievable control performance and the time delays, and provide theoretical guidelines for the future experimental setup in two physical systems, which are typical in this research field. The evaluatio
Lubomir Gavrilov, Iliya D. Iliev
We study the stratum in the set of all quadratic differential systems $\dot{x}=P_2(x,y), \dot{y}=Q_2(x,y)$ with a center, known as the codimension-four case $Q_4$. It has a center and a node and a rational first integral. The limit cycles under small quadratic perturbations in the system are determined by the zeros of the first Poincaré-Pontryagin-Melnikov i
Mohammad Reza Yaghouti, Fraydoun Rezakhanlou, Alan Hammond
The Smoluchowski equation is a system of partial differential equations modelling the diffusion and binary coagulation of a large collection of tiny particles. The mass parameter may be indexed either by positive integers, or by positive reals, these corresponding to the discrete or the continuous form of the equations. In dimension at least 3, we derive the
Arthur P. Smith
A review of some of the evidence for the IPCC's conclusion that doubling CO$_2$ levels will warm Earth significantly, in contrast to the claims of a recent article$^1$. Simply looking at raw temperature and CO$_2$ data over the past 150 years gives a transient response of roughly 2 K per doubling, in good agreement with IPCC conclusions based on far more
Two-dimensional magnetism in the pnictide superconductor parent material SrFeAsF probed by muon-spin relaxation
cond-mat.supr-conP. J. Baker, I. Franke, T. Lancaster, S. J. Blundell
We report muon-spin relaxation measurements on SrFeAsF, which is the parent compound of a newly discovered iron-arsenic-fluoride based series of superconducting materials. We find that this material has very similar magnetic properties to LaFeAsO, such as separated magnetic and structural transitions (TN = 120 K, Ts = 175 K), contrasting with SrFe2As2 where
N. C. Mamani, G. M. Gusev, O. E. Raichev, T. E. Lamas
We study the evolution of low-temperature magnetoresistance in double quantum wells in the region below 1 Tesla as the applied current density increases. A flip of the magneto-intersubband oscillation peaks, which occurs as a result of the current-induced inversion of the quantum component of resistivity, is observed. We also see splitting of these peaks as
Photophysical characterizations of 2-(4-Biphenylyl)-5 phenyl-1,3,4- oxadiazole in restricted geometry
cond-mat.mtrl-sciP. K. Paul, S. A. Hussain, D. Bhattacharjee
Langmuir and Langmuir-Blodgett (LB) films of nonamphiphilic 2-(4-Biphenylyl)-5 phenyl-1,3,4- oxadiazole (abbreviated as PBD) mixed with stearic acid (SA) as well as also with the inert polymer matrix poly(methyl methacrylate) (PMMA) have been studied. Surface pressure versus area per molecule (-A) isotherms studies suggest that PBD molecules very likely stan
Thorsten Feldmann
Soft-collinear effective theory (SCET) has become a standard tool to study the factorization of short- and long-distance effects in processes involving low-energetic (soft) particles and high-energetic/low-virtuality (collinear) modes. In this contribution I give a brief overview on recent results for inclusive and exclusive B decays and on applications in c
R. Collet, M. Asplund, P. E. Nissen
We derive the mixture of odd to even barium isotopes in the atmosphere of the metal-poor subgiant HD140283 from the analysis of the Ba II transition at 455.4 nm in a high-resolution high signal-to-noise spectrum of the star. The detailed shape of this spectral line depends on the relative contributions of odd and even isotopes via isotopic and hyperfine spli
Ion Garate, Jairo Sinova, T. Jungwirth, A. H. MacDonald
We study quantum interference corrections to the conductivity in (Ga,Mn)As ferromagnetic semiconductors using a model with disordered valence band holes coupled to localized Mn moments through a p-d kinetic-exchange interaction. We find that at Mn concentrations above 1% quantum interference corrections lead to negative magnetoresistance, i.e. to weak locali
S. Kurth, C. R. Proetto, K. Capelle
Explicitly orbital-dependent approximations to the exchange-correlation energy functional of density functional theory typically not only depend on the single-particle Kohn-Sham orbitals but also on their occupation numbers in the ground state Slater determinant. The variational calculation of the corresponding exchange-correlation potentials with the Optimi
M. Wojciechowski, Marek Cieplak
We perform molecular dynamics simulations for a simple coarse-grained model of crambin placed inside of a softly repulsive sphere of radius R. The confinement makes folding at the optimal temperature slower and affects the folding scenarios, but both effects are not dramatic. The influence of crowding on folding are studied by placing several identical prote
Fabio Leoni, Stefano Zapperi
We study the growth of slip line in a plastically deforming crystal by numerical simulation of a double-ended pile-up model with a dislocation source at one end, and an absorbing wall at the other end. In presence of defects, the pile-up undergoes a second order non-equilibrium phase transition as a function of stress, which can be characterized by finite si
Rene Messina
Recent progress in the understanding of the effect of electrostatics in soft matter is presented. A vast amount of materials contains ions ranging from the molecular scale (e.g., electrolyte) to the meso/macroscopic one (e.g., charged colloidal particles or polyelectrolytes). Their (micro)structure and physicochemical properties are especially dictated by th
Norbert Wermes
Pixel Detectors, as the current technology of choice for the innermost vertex detection, have reached a stage at which large detectors have been built for the LHC experiments and a new era of developments, both for hybrid and for monolithic or semi-monolithic pixel detectors is in full swing. This is largely driven by the requirements of the upgrade programm
Aline Bonami, Szilárd Gy. Révész
This is a companion paper of a recent one, entitled {\sl Integral concentration of idempotent trigonometric polynomials with gaps}. New results of the present work concern $L^1$ concentration, while the above mentioned paper deals with $L^p$-concentration. Our aim here is two-fold. At the first place we try to explain methods and results, and give further st
L. Keek, J. J. M. in 't Zand
Hydrogen and helium accreted onto a neutron star undergo thermonuclear burning. Explosive burning is observed as a type I X-ray burst. We describe the different burning regimes and focus on some of the current inconsistencies between theory and observations. Of special interest are the rare kinds of X-ray bursts such as carbon-fueled superbursts and helium-f
Possible creation of net circular polarization and not only depolarization of spectral lines by isotropic collisions
astro-phJiri Stepan, Sylvie Sahal-Brechot
We will show that isotropic collisions of electrons and protons with neutral hydrogen can lead to creation of net orientation of the atomic levels in the presence of a magnetic field. Consequently, the emitted Stokes-V profile of the spectral lines can be almost symmetric in contrast to the typical antisymmetric signature of the Zeeman effect. Moreover, the
Ronan Flatley
Let S be a symbol algebra. The trace form of S is computed and it is shown how this form can be used to determine whether S is a division algebra or not. In addition, the exterior powers of the trace form of S are computed.
S. Heinemeyer, V. A. Khoze, M. G. Ryskin, M. Tasevsky
The prospects for central exclusive diffractive (CED) production of MSSM Higgs bosons at the LHC are reviewed. These processes can provide important information on the $\cp$-even Higgs bosons, allowing to probe interesting regions of the $\MA$--$\tb$ parameter plane. The sensitivity of the searches in the forward proton mode for the Higgs bosons in the so-ca
Roberto Giambò
This paper investigates the evolution of collapsing FRW models with a scalar field having the potential which arises in the conformal frame of high order gravity theories, coupled to matter described by a perfect fluid with energy density $ρ$ and pressure $p$, obeying a barotropic equation of state. The solutions are shown to evolve generically to a singular
Michiel Wouters, Vincenzo Savona
We use the truncated Wigner approximation to derive stochastic classical field equations for the description of polariton condensates. Our equations are shown to reduce to the Boltzmann equation in the limit of low polariton density. Monte Carlo simulations are performed to analyze the momentum distribution and the first and second order coherence when the p
Dimitrije Stepanenko, Minchul Lee, Guido Burkard, Daniel Loss
We study the coherent transport of heavy holes through a one-dimensional ring in the presence of spin-orbit coupling. Spin-orbit interaction of holes, cubic in the in-plane components of momentum, gives rise to an angular momentum dependent spin texture of the eigenstates and influences transport. We analyze the dependence of the resulting differential condu
Shi Jin, Matthew R. McKay, Caijun Zhong, Kai-Kit Wong
This paper presents an analytical characterization of the ergodic capacity of amplify-and-forward (AF) MIMO dual-hop relay channels, assuming that the channel state information is available at the destination terminal only. In contrast to prior results, our expressions apply for arbitrary numbers of antennas and arbitrary relay configurations. We derive an e
R. Paškauskas, C. Chandre, T. Uzer
Finding the causes for the nonstatistical vibrational energy relaxation in the planar carbonyl sulfide (OCS) molecule is a longstanding problem in chemical physics: Not only is the relaxation incomplete long past the predicted statistical relaxation time, but it also consists of a sequence of abrupt transitions between long-lived regions of localized energy
A unified theory for the cuprates, iron-based and similar superconducting systems: non-Fermi-liquid to Fermi-liquid crossover, low-energy and waterfall anomalies
cond-mat.supr-conJ. Ashkenazi
A unified theory is outlined for the cuprates, Fe-based, and related superconductors. Their low-energy excitations are approached in terms of auxiliary particles representing combinations of atomic-like electron configurations, and the introduction of a Lagrange Bose field enables their treatment as bosons or fermions. This theory correctly describes the obs
M. Akhalkatsi, G. Gogoberidze
Acoustic wave generation by turbulence in the stratified, moist atmosphere is studied. It is shown that in the saturated moist air turbulence in addition to the Lighthill's quadrupole and the dipole sources of sound related to stratification and temperature fluctuations, there exist monopole sources related to heat and mass production during the condensa
Ultrafast electron dynamics following outer-valence ionization: The impact of low-lying relaxation satellite states
physics.chem-phSiegfried Lünnemann, Alexander I. Kuleff, Lorenz S. Cederbaum
Low-lying relaxation satellites give rise to ultrafast electron dynamics following outer-valence ionization of a molecular system is studied. To demonstrate the impact of such satellites, the evolution of the electronic cloud after sudden removal of an electron from the highest occupied molecular orbital (HOMO) of the organic unsaturated nitroso compound 2-N
D. Kotnik-Karuza, M. Friedjung, K. Exter
The aim of this work is to make available unpublished non-Fe+ emission line fluxes from optical spectra of the symbiotic nova RR Tel which were taken in 2000, and to compare them with fluxes of the same lines from spectra taken in 1996. After leaving out blends and misidentifications, as well as the unreliable far-red and violet lines, we present the log (F2
F. Li, G. Parteder, F. Allegretti, C. Franchini
Two-dimensional manganese oxide layers have been grown on Pd(100) and have been characterized by scanning tunnelling microscopy (STM), low-energy electron diffraction (LEED) and X-ray photoelectron spectroscopy (XPS). The complex surface phase diagram of MnOx on Pd(100) is reported, where nine different novel Mn oxide phases have been detected as a function
The inhomogeneous equation of state and the road towards the solution of the cosmological constant problem
gr-qcHrvoje Stefancic
We present a cosmological model containing a cosmological constant $Λ$ and a component with an inhomogeneous equation of state. We study the form of the inhomogeneous equation of state for which the model exhibits the relaxation of the cosmological constant, i.e. it asymptotically tends to the de Sitter regime characterized by a small positive effective cosm
U. Adem, M. Mostovoy, N. Bellido, A. A. Nugroho
We observe a seemingly complex magnetic field dependence of dielectric constant of hexagonal YbMnO3 near the spin ordering temperature. After rescaling, the data taken at different temperatures and magnetic fields collapse on a single curve describing the sharp anomaly in nonlinear magnetoelectric response at the magnetic transition. We show that this anomal
Eva Ziebarth
Gluino pair production in an EGRET motivated supersymmetry scenario has been studied. The analysis shows, that this special scenario could be proven with the first LHC data, and assuming a higher integrated luminosity the analysis would be able to cover a large region of the minimal supergravity (mSUGRA) parameter space.
Eike Lau
We propose a notion of frames and windows that allows an alternative proof of the Vasiu-Zink classification of p-divisible groups over ramified complete regular local rings by their Breuil windows.
Electrical resistance of Ni nanowires (diameter greater than or equal to 20 nm) near the Curie Temperatures
cond-mat.mtrl-sciM. Venkata Kamalakar, A. K. Raychaudhuri
In this letter we report electrical transport measurements on nickel nanowires of diameters down to 20 nm in the region close to its paramagnetic-ferromagnetic transition temperature T_C (reduced temperature|t| less than or equal to 0.001). The data analysis done in the frame work of critical behavior of resistance near TC shows that the critical behavior pe
M. Buballa, A. G. Grunfeld, A. E. Radzhabov, D. Scheffler
We discuss three applications of NJL- and PNJL-like models to assess aspects of the QCD phase diagram: First, we study the effect of mesonic correlations on the pressure below and above the finite temperature phase transition within a nonlocal PNJL model beyond the mean-field approximation. Second, we reconstruct the phase boundary of an NJL model from a Tay
Monolithic Pixel Sensors in Deep-Submicron SOI Technology with Analog and Digital Pixels
physics.ins-detMarco Battaglia, Dario Bisello, Devis Contarato, Peter Denes
This paper presents the design and test results of a prototype monolithic pixel sensor manufactured in deep-submicron fully-depleted Silicon-On-Insulator (SOI) CMOS technology. In the SOI technology, a thin layer of integrated electronics is insulated from a (high-resistivity) silicon substrate by a buried oxide. Vias etched through the oxide allow to contac
Birkhoff normal form and splitting methods for semi linear Hamiltonian PDEs. Part I: Finite dimensional discretization
math.NAErwan Faou, Benoit Grebert, Eric Paturel
We consider {\em discretized} Hamiltonian PDEs associated with a Hamiltonian function that can be split into a linear unbounded operator and a regular nonlinear part. We consider splitting methods associated with this decomposition. Using a finite dimensional Birkhoff normal form result, we show the almost preservation of the {\em actions} of the numerical s
Søren Fournais, Thomas Østergaard Sørensen
We consider a pseudorelativistic model of atoms and molecules, where the kinetic energy of the electrons is given by $\sqrt{p^2+m^2}-m$. In this model the eigenfunctions are generally not even bounded, however, we prove that the corresponding one-electron densities are smooth away from the nuclei.
Moti Fridman, Micha Nixon, Vardit Eckhouse, Nir Davidson
A new configuration for synchronizing two chaotic fiber lasers, which includes both coupling and losses, is presented. Experimental and calculated results reveal that the synchronization time can be significantly shorter than with configuration that have only coupling.
S. M. Dubiel, J. Zukrowski, J. Cieslak
Binding of 57Fe atoms in a metallic chromium was investigated in a Cr-Fe alloy, containing less than 0.1 at% Fe enriched to ~95 % in 57Fe isotope, using 57Fe-site Mossbauer spectroscopy. The binding force was derived from the Debye temperature, T_D, that, in turn, was calculated from the temperature dependence of the central shift of the Mossbauer spectra re
Interpolative approach for electron-electron and electron-phonon interactions: from the Kondo to the polaronic regime
cond-mat.str-elA. Martin-Rodero, A. Levy Yeyati, F Flores, R. C. Monreal
We present a theoretical approach to determine the electronic properties of nanoscale systems exhibiting strong electron-electron and electron-phonon interactions and coupled to metallic electrodes. This approach is based on an interpolative ansatz for the electronic self-energy which becomes exact both in the limit of weak and strong coupling to the electro
M. V. Chistyakov, D. A. Rumyantsev
The electromagnetic processes of Compton scattering and photon splitting/merging are investigated in the presence of strongly magnetized electron-positron plasma. The influence of these processes on the radiation transfer in the astrophysical environment is studied. In particular, the contribution of the processes under consideration in coefficients of the t
Hubert F M Goenner
The article is a tribute to Hermann Minkowski leading from his geometry of numbers to an attempt at using Finsler geometry for a break of Lorentz invariance.
M. V. Chistyakov, D. A. Rumyantsev
The photon-neutrino processes $γe^{\pm} \to e^{\pm} ν\bar ν$, $γ\to ν\bar ν$ and $γγ\to ν\bar ν$ are investigated in the presence of a strongly magnetized and dense electron-positron plasma. The amplitudes of the reactions $γe^{\pm} \to e^{\pm} ν\bar ν$ and $γγ\to ν\bar ν$ are obtained. In the case of a cold degenerate plasma contributions of the considering
Michael P. Tuite
We consider the application of permutation orbifold constructions towards a new possible understanding of the genus zero property in Monstrous and Generalized Moonshine. We describe a theory of twisted Hecke operators in this setting and conjecture on the form of Generalized Moonshine replication formulas.
Lorenzo Zaninetti
The absolute visual magnitude as function of the observed colour (B-V), also named Hertzsprung-Russell diagram can be described through five equations; that in presence of calibrated stars means eight constants. The developed framework allows to deduce the remaining physical parameters that are mass, radius and luminosity. This new technique is applied to th
Michael P. Tuite
We consider exceptional vertex operator algebras for which particular Casimir vectors constructed from the primary vectors of lowest conformal weight are Virasoro descendants of the vacuum. We discuss constraints on these theories that follow from an analysis of appropriate genus zero and genus one two point correlation functions. We find explicit differenti
Lenny Taelman
We propose a conjecture on special values of $ L $-functions in a function field context with positive characteristic coefficients. For $ M $ a uniformizable $ t $-motive with everywhere good reduction we conjecture a relation between the value of the Goss $ L $-function $ L(M^\vee, s) $ at $ s = 0 $ and the uniformization of the abelian $ t $-module associa
P. Tsoutsis, C. Kalapotharakos, C. Efthymiopoulos, G. Contopoulos
The unstable invariant manifolds of the short-period family of periodic orbits around the unstable Lagrangian points $L_1$ and $L_2$ of a barred galaxy define loci in the configuration space which take the form of a trailing spiral pattern. In the present paper we investigate this association in the case of the self-consistent models of Kaufmann & Contopoulo
R. Schwengner, G. Rusev, N. Tsoneva, N. Benouaret
The dipole response of the N=50 nucleus 90Zr was studied in photon-scattering experiments at the electron linear accelerator ELBE with bremsstrahlung produced at kinetic electron energies of 7.9, 9.0, and 13.2 MeV. We identified 189 levels up to an excitation energy of 12.9 MeV. Statistical methods were applied to estimate intensities of inelastic transition
G. Boffetta, F. De Lillo, A. Mazzino
Mixing of a passive scalar in the peripheral region close to a wall is investigated by means of accurate direct numerical simulations of both a three-dimensional Couette channel flow at low Reynolds numbers and a two-dimensional synthetic flow. In both cases, the resulting phenomenology can be understood in terms of the theory recently developed by Lebedev a
Helmar Bender, Philippe Courteille, Claus Zimmermann, Sebastian Slama
We present a surface trap which allows for studying the coherent interaction of ultracold atoms with evanescent waves. The trap combines a magnetic Joffe trap with a repulsive evanescent dipole potential. The position of the magnetic trap can be controlled with high precision which makes it possible to move ultracold atoms to the surface of a glass prism in
H. Nagahiro, D. Jido, S. Hirenzaki
We calculate formation spectra of eta-nucleus systems in (pi,N) reactions with nuclear targets, which can be performed at existing and/or forthcoming facilities, including J-PARC, in order to investigate eta-nucleus interactions. Based on the N^*(1535) dominance in the eta N system, eta-mesic nuclei are suitable systems for study of in-medium properties of t
Cristina Manuel
At asymptotic high density and low temperature quarks form Cooper pairs in a color-flavor locked (CFL) configuration. The diquark condensates break spontaneously the baryon symmetry, and this fact makes the CFL phase also superfluid. At low temperatures the transport properties are dominated by the contribution of the superfluid phonon, the Goldstone boson a
Raphael Cerf, Reda Messikh
We study the 2d-Ising model defined on finite boxes at temperatures that are below but very close from the critical point. When the temperature approaches the critical point and the size of the box grows fast enough, we establish large deviations estimates on FK-percolation events that concern the phenomenon of phase coexistence.
Michiel Wouters, Iacopo Carusotto
We propose a four wave mixing experiment to probe the elementary excitation spectrum of a non-equilibrium Bose-Einstein condensate of exciton-polaritons under non-resonant pumping. Analytical calculations based on mean-field theory show that this method is able to reveal the characteristic negative energy feature of the Bogoliubov dispersion. Numerical simul
Ben Gripaios, Hyung Do Kim, Riccardo Rattazzi, Michele Redi
We study supersymmetric QED in AdS4 with massless matter. At 1-loop the ultra-violet regulator of the theory generates a contribution to the gaugino mass that is naively inconsistent with unbroken supersymmetry. We show that this effect, known in flat space as anomaly mediated supersymmetry breaking, is required to cancel an infra-red contribution arising fr
C. Adam, P. Klimas, J. Sanchez-Guillen, A. Wereszczynski
We investigate a version of the abelian Higgs model with a non-standard kinetic term (K field theory) in 2+1 dimensions. The existence of vortex type solutions with compact support (topological compactons) is established by a combination of analytical and numerical methods. This result demonstrates that the concept of compact solitons in K field theories can
V. de Alfaro, A. T. Filippov
General properties of a class of two-dimensional dilaton gravity (DG) theories with multi-exponential potentials are studied and a subclass of these theories, in which the equations of motion reduce to Toda and Liouville equations, is treated in detail. A combination of parameters of the equations should satisfy a certain constraint that is identified and so
Martha Constantinou, Haralambos Panagopoulos, Fotos Stylianou
We present the corrections to the fermion propagator, to second order in the lattice spacing, O(a^2), in 1-loop perturbation theory. The fermions are described by the clover action and for the gluons we use a 3-parameter family of Symanzik improved actions. Our calculation has been carried out in a general covariant gauge. The results are provided as a polyn
P. D. García, R. Sapienza, Luis S. Froufe-Pérez, C. López
We describe a smooth transition from (fully ordered) photonic crystal to (fully disordered) photonic glass that enables us to make an accurate measurement of the scattering mean free path in nanostructured media and, in turn, establishes the dominant role of the density of states. We have found one order of magnitude chromatic variation in the scattering mea
Koji Ishiwata, Shigeki Matsumoto, Takeo Moroi
We discuss the synchrotron radiation flux from the Galactic center in unstable dark matter scenario. Motivated by the anomalous excess of the positron fraction recently reported by the PAMELA collaboration, we consider the case that the dark matter particle is unstable (and long-lived), and that energetic electron and positron are produced by the decay of da
M. Häfner, J. K. Viljas, J. C. Cuevas
Recent experiments in ferromagnetic atomic-sized contacts have shown that the anisotropic magnetoresistance (AMR) is greatly enhanced and has an asymmetric angular dependence as compared with that of bulk samples. The origin of these effects is still under debate. In this work we present a theoretical analysis of the AMR in atomic contacts of the 3d ferromag
Alexander Knebe, Chris Power
Using a set of high-resolution dark matter only cosmological simulations we found a correlation between the dark matter halo mass M and its spin parameter lambda for objects forming at redshifts z > 10: the spin parameter decreases with increasing mass. However, halos forming at later times do not exhibit such a strong correlation, in agreement with the find
Large Deviations estimates for some non-local equations I. Fast decaying kernels and explicit bounds
math.APCristina Brändle, Emmanuel Chasseigne
We study large deviations for some non-local parabolic type equations. We show that, under some assumptions on the non-local term, problems defined in a bounded domain converge with an exponential rate to the solution of the problem defined in the whole space. We compute this rate in different examples, with different kernels defining the non-local term, and
E. Agliari, R. Burioni, D. Cassi, F. M. Neri
We study the dynamics of a system made up of particles of two different species undergoing irreversible quadratic autocatalytic reactions: $A + B \to 2A$. We especially focus on the reaction velocity and on the average time at which the system achieves its inert state. By means of both analytical and numerical methods, we are also able to highlight the role
Ahmed Younes
Grover's quantum search algorithm is considered as one of the milestone in the field of quantum computing. The algorithm can search for a single match in a database with $N$ records in $O(\sqrt{N})$ assuming that the item must exist in the database with quadratic speedup over the best known classical algorithm. This review paper discusses the performance
C. Adami, R. Pello, M. P. Ulmer, J. C. Cuillandre
This project is the continuation of our study of faint Low Surface Brightness Galaxies (fLSBs) in one of the densest nearby galaxy regions known, the Coma cluster. Our goal is to improve our understanding of the nature of these objects by comparing the broad band spectral energy distribution with population synthesis models. The data were obtained with the M
Junpeng Cao, Peng He, Yuzhu Jiang, Yupeng Wang
A systematic method to construct the complete set of conserved quantities of the Haldane-Shastry type spin chains is proposed. The hidden relationship between the Yang-Baxter relation and the conservation laws of the long-range interacting integrable models is exposed explicitly. An integrable anisotropic Haldane-Shastry model is also constructed.
J. Leon, P. Anghel-Vasilescu, F. Ginovart, N. Allegra
The Maxwell-Bloch system describes a quantum two-level medium interacting with a classical electromagnetic field by mediation of the the population density. This population density variation is a purely quantum effect which is actually at the very origin of nonlinearity. The resulting nonlinear coupling possesses particularly interesting consequences at the
B. Braverman, K. B. Kuntz, M. Lobino, E. M. Pessina
We report on an interferometry-based measurement of the phase and group velocities of optical Bessel beams, providing confirmation of their superluminal character in the non-diffractive region. The measurements were performed in free space with a continuous wave laser and femtosecond pulses for phase and group velocities respectively. The Bessel beams were p
Jie Peng, Pei Wang, Nengfeng Zhou, Ji Zhu
In this paper, we propose a computationally efficient approach -- space(Sparse PArtial Correlation Estimation)-- for selecting non-zero partial correlations under the high-dimension-low-sample-size setting. This method assumes the overall sparsity of the partial correlation matrix and employs sparse regression techniques for model fitting. We illustrate the
Jonathan Sparling
In this note, we derive explicitly the local relative trace formula for the symmetric space F*\SL(2,F) at the level of Lie algebras, where F is a p-adic field of residue characteristic greater than two and F* is the set of invertible elements in F. This is perhaps one of the simplest non-trivial analogs of the trace formula, and also a motivating example for
Yong Wang
We compute the transgressed forms of some modularly invariant characteristic forms,which are related to the twisted elliptic genera. We study the modularity properties of these secondary characteristic forms and relations among them. We also get some twisted anomaly cancellation formulas on some odd dimensional manifolds.
N. Quang Hung, N. Dinh Dang
Nuclear pairing properties are studied within an approach that includes the quasiparticle-number fluctuation (QNF) and coupling to the quasiparticle-pair vibrations at finite temperature and angular momentum. The formalism is developed to describe non-collective rotations about the symmetry axis. The numerical calculations are performed within a doubly-folde
Johanna Garzón
We define weighted fractional Brownian sheets, which are a class of Gaussian random fields with four parameters that include fractional Brownian sheets as special cases, and we give some of their properties. We show that for certain values of the parameters the weighted fractional Brownian sheets are obtained as limits in law of occupation time fluctuations
Andrei Negut
This paper contains a proof of a conjecture of Braverman concerning Laumon quasiflag spaces. We consider the generating function Z(m), whose coefficients are the integrals of the equivariant Chern polynomial (with variable m) of the tangent bundles of the Laumon spaces. We prove Braverman's conjecture, which states that Z(m) coincides with the eigenfunction
Gennady P. Berman, Alexander I. Nesterov
We propose a novel non-Hermitian adiabatic quantum optimization algorithm. One of the new ideas is to use a non-Hermitian auxiliary "initial'' Hamiltonian that provides an effective level repulsion for the main Hamiltonian. This effect enables us to develop an adiabatic theory which determines ground state much more efficiently than Hermitian met
Alexander Gutfraind
Terrorist organizations change over time because of processes such as recruitment and training as well as counter-terrorism (CT) measures, but the effects of these processes are typically studied qualitatively and in separation from each other. Seeking a more quantitative and integrated understanding, we constructed a simple dynamic model where equations des
Zoltan Bajnok, Romuald A. Janik, Tomasz Lukowski
The anomalous dimensions of twist two operators have to satisfy certain consistency requirements derived from BFKL. For N=4 SYM it was shown that at four loops, the anomalous dimensions derived from the all-loop asymptotic Bethe ansatz do not pass this test. In this paper we obtain the remaining wrapping part of these anomalous dimensions from string theory
Michael Graesser, Jessie Shelton
The chiral structure of supersymmetric particle couplings involving third generation Standard Model fermions depends on left-right squark and slepton mixings as well as gaugino-higgsino mixings. The shapes and intercorrelations of invariant mass distributions of a first or second generation lepton with bottoms and taus arising from adjacent branches of SUSY
Lawrence Ein, Mircea Mustata
Building on results of Kollár, we prove Shokurov's ACC Conjecture for log canonical thresholds on smooth varieties, and more generally, on varieties with quotient singularities.
Dimitrie Culcer, R. Winkler
We formulate a theory of transport in graphene bilayers in the weak momentum scattering regime in such a way as to take into account contributions to the electrical conductivity to leading and next-to-leading order in the scattering potential. The response of bilayers to an electric field cannot be regarded as a sum of terms due to individual layers. Rather,
D. Agboola
We present the solutions of the Schr$\ddot{o}$dinger equation with the Hulth$\acute{e}$n potential plus ring-shape potential for $\ell\neq 0$ states within the framework of an exponential approximation of the centrifugal potential.Solutions to the corresponding angular and radial equations are obtained in terms of special functions using the conventional Nik
Agnieszka Kondrat, Jorge Enrique Hamann-Borrero, Norman Leps, Martin Kosmala
We have prepared the newly discovered Fe-based superconducting material $\rm LaO_{1-x}F_xFeAs$ ($0\leq x\leq 0.2$) in polycrystalline form and have investigated the samples by means of structural, thermodynamic and transport measurements. Our investigations reveal a non superconducting phase at $0\leq x\lesssim0.04$ which for $x=0$ is characterized by a stru
Ironing out primordial temperature fluctuations with polarisation: optimal detection of cosmic structure imprints
astro-phMona Frommert, Torsten A. Ensslin
Secondary anisotropies of the cosmic microwave background (CMB) can be detected by using the cross-correlation between the large-scale structure (LSS) and the CMB temperature fluctuations. In such studies, chance correlations of primordial CMB fluctuations with the LSS are the main source of uncertainty. We present a method for reducing this noise by exploit
Kathryn M. Zurek
We explore multi-component dark matter models where the dark sector consists of multiple stable states with different mass scales, and dark forces coupling these states further enrich the dynamics. The multi-component nature of the dark matter naturally arises in supersymmetric models, where both R parity and an additional symmetry, such as a $Z_2$, is prese
Shane P. O'Sullivan, Denise C. Gabuzda
The parsec-scale Faraday rotation measure (RM) distribution of six "blazars" is investigated using multi-frequency (4.6--43 GHz) polarization observations taken on 2006 July 2 with the VLBA. Analysis of the RM provides the direction of the line-of-sight (LoS) magnetic field component, as well as the intrinsic 2-D polarization distribution on the plan
Gregory Gabadadze, Rachel A. Rosen
A condensate of charged scalars in a neutralizing background of fermions (e.g., condensed helium-4 nuclei in an electron background in white dwarf cores) is investigated further. We discuss an effective Lagrangian approach to this system and show that the strong screening of an electric charge found previously in arXiv:0806.3692 in a mean-field approximation
Tatsuo Azeyanagi, Noriaki Ogawa, Seiji Terashima
We apply Brown-Henneaux's method to the 5D extremal rotating Kaluza-Klein black holes essentially following the calculation of the Kerr/CFT correspondence, which is not based on supersymmetry nor string theory. We find that there are two completely different Virasoro algebras that can be obtained as the asymptotic symmetry algebras according to appropria
S. Salur, O. Santillan
IAs is well known, when D6 branes wrap a special lagrangian cycle on a non compact CY 3-fold in such a way that the internal string frame metric is Kahler there exists a dual description, which is given in terms of a purely geometrical eleven dimensional background with an internal metric of $G_2$ holonomy. It is also known that when D6 branes wrap a coassoc
A. D. Supanitsky, G. Medina-Tanco, A. Etchegoyen
The transition between the Galactic and extragalactic cosmic ray components could take place either in the region of the spectrum known as the second knee or in the ankle. There are several models of the transition but it is not possible to confirm or even rule out any of them from the flux measurement alone. Therefore, the measurement of the composition as
Vladimir Kalitvianski
In this article I show why the fundamental constants obtain perturbative corrections in higher orders, why the renormalizations work and how to reformulate the theory in order to avoid these technical and conceptual complications. I demonstrate that the perturbative mass and charge corrections are caused exclusively with the kinetic nature of the interaction