February 2009 arXiv papers — page 8
Showing 701–800 of 4,929 papers
Helmut Alt, Ludmila Scharf, Daria Schymura
We analyze a probabilistic algorithm for matching shapes modeled by planar regions under translations and rigid motions (rotation and translation). Given shapes $A$ and $B$, the algorithm computes a transformation $t$ such that with high probability the area of overlap of $t(A)$ and $B$ is close to maximal. In the case of polygons, we give a time bound that
P. S. Burada, G. Schmid, D. Reguera, J. M. Rubi
We demonstrate the existence of stochastic resonance (SR) in confined systems arising from entropy variations associated to the presence of irregular boundaries. When the motion of a Brownian particle is constrained to a region with uneven boundaries, the presence of a periodic input may give rise to a peak in the spectral amplification factor and therefore
Martin R. Galpin, David E. Logan
We consider an Anderson impurity model in which the locally correlated orbital is coupled to a host with a gapped density of states. Single-particle dynamics are studied, within a perturbative framework that includes both explicit second-order perturbation theory and self-consistent perturbation theory to all orders in the interaction. Away from particle-hol
G. R. Gupta, E. O'Shea, D. Banerjee, M. Popescu
Waves are important for the heating of the solar corona and the acceleration of the solar wind. We have examined a long spectral time series of a southern coronal hole observed on the 25th February 1997, with the SUMER spectrometer on-board SoHO. The observations were obtained in a transition region N IV 765 A line and in a low coronal Ne VIII 770 A line. Ou
P. Manshour, S. Saberi, Muhammad Sahimi, J. Peinke
We report on a novel stochastic analysis of seismic time series for the Earth's vertical velocity, by using methods originally developed for complex hierarchical systems, and in particular for turbulent flows. Analysis of the fluctuations of the detrended increments of the series reveals a pronounced change of the shapes of the probability density functi
Constraining the Sommerfeld enhancement with Cherenkov telescope observations of dwarf galaxies
astro-ph.HELidia Pieri, Massimiliano Lattanzi, Joseph Silk
The presence of dark matter in the halo of our galaxy could be revealed through indirect detection of annihilation products. Dark matter annihilation is one of the possible interpretations of the recent measured excesses in positron and electron fluxes, once boost factors of the order of 10^3 or more are taken into account. Such boost factors are actually ac
The Dynamical Architecture and Habitable Zones of the Quintuplet Planetary System 55 Cancri
astro-ph.EPJi Jianghui, H. Kinoshita, Liu Lin, Li Guangyu
We perform numerical simulations to study the secular orbital evolution and dynamical structure in the quintuplet planetary system 55 Cancri with the self-consistent orbital solutions by Fischer and coworkers (2008). In the simulations, we show that this system can be stable at least for $10^{8}$ yr. In addition, we extensively investigate the planetary conf
L. E. Labuschagne, W. A. Majewski
Let $\A$ ($\cM$) be a $C^*$-algebra (a von Neumann algebra respectively). By a quantum dynamical system we shall understand the pair $({\A}, T)$ ($({\cM}, T)$) where $T : {\A} \to {\A}$ ($T : {\cM} \to {\cM}$) is a linear, positive (normal respectively), and identity preserving map. In our lecture, we discuss how the techniques of quantum Orlicz spaces may b
Stability analysis of confined V-flames. I. Analytical treatment of the high-velocity limit
physics.flu-dynHazem El-Rabii, Guy Joulin, Kirill A. Kazakov
The problem of linear stability of confined V-flames with arbitrary gas expansion is addressed. Using the on-shell description of flame dynamics, a general equation governing propagation of disturbances of an anchored flame is obtained. This equation is solved analytically for V-flames in high-velocity channel streams. It is demonstrated that dynamics of fla
P. Riviere, O. Uhden, U. Saalmann, J. M. Rost
We investigate theoretically electron dynamics under a VUV attosecond pulse train which has a controlled phase delay with respect to an additional strong infrared laser field. Using the strong field approximation and the fact that the attosecond pulse is short compared to the excited electron dynamics, we arrive at a minimal analytical model for the kinetic
Accretion torques and motion of the hot spot on the accreting millisecond pulsar XTE J1807-294
astro-ph.HEAlessandro Patruno, Jacob M. Hartman, R. Wijnands, Deepto Chakrabarty
We present a coherent timing analysis of the 2003 outburst of the accreting millisecond pulsar XTE J1807-294. We find an upper limit for the spin frequency derivative of 5E-14 Hz/s. The sinusoidal fractional amplitudes of the pulsations are the highest observed among the accreting millisecond pulsars and can reach values of up to 27% (2.5-30 keV). The pulse
E. Poem, S. Khatsevich, Y. Benny, I. Marderfeld
We measured the polarization memory of excitonic and biexcitonic optical transitions from single quantum dots at either positive, negative or neutral charge states. Positive, negative and no circular or linear polarization memory was observed for various spectral lines, under the same quasi-resonant excitation below the wetting layer band-gap. We developed a
Y. Nakagawa, A. Voigt, E. -M. Ilgenfritz, M. Müller-Preussker
We study the momentum dependence of the ghost propagator and of the space and time components of the gluon propagator at equal time in pure SU(3) lattice Coulomb gauge theory carrying out a joint analysis of data collected independently at RCNP Osaka and Humboldt University Berlin. We focus on the scaling behavior of these propagators at beta=5.8,...,6.2 and
Tobias Ekholm
We relate the version of rational Symplectic Field Theory for exact Lagrangian cobordisms introduced in [5] with linearized Legendrian contact homology. More precisely, if $L\subset X$ is an exact Lagrangian submanifold of an exact symplectic manifold with convex end $Λ\subset Y$, where $Y$ is a contact manifold and $Λ$ is a Legendrian submanifold, and if $L
David Jewitt, Bin Yang, Nader Haghighipour
We present a study of the newly-discovered main-belt comet P/2008 R1 (Garradd), an object with the dynamical characteristics of an asteroid and the physical characteristics of a comet. Photometry sets a limit to the effective radius of the nucleus at r_e < 0.7 km (red geometric albedo 0.05 assumed). The coma shows a secular fading in our data caused by the e
Microscopic gauge-invariant theory of the c-axis infrared response of bilayer cuprate superconductors and the origin of the superconductivity induced absorption bands
cond-mat.supr-conJ. Chaloupka, C. Bernhard, D. Munzar
We report on results of our theoretical study of the c-axis infrared conductivity of bilayer high-Tc cuprate superconductors using a microscopic model involving the bilayer-split (bonding and antibonding) bands. An emphasis is on the gauge-invariance of the theory, which turns out to be essential for the physical understanding of the electrodynamics of these
Long-Fei Gan, Ming-Qiu Huang
We use QCD sum rules to estimate the leading-order universal form factors describing the semileptonic B decay into orbital excited $D$-wave charmed doublets, including the ($1^{-}$, $2^{-}$) states ($D_{1}^{*}$, $D'_{2}$) and the ($2^{-}$, $3^{-}$) states ($D_{2}$, $D_{3}^{*}$). The decay rates we predict are $Γ_{B\to D^{*}_{1}\ell\overlineν}=Γ_{B\to D&#
Crossover from First to Second-Order Transition in Frustrated Ising Antiferromagnetic Films
cond-mat.mtrl-sciX. T. Pham Phu, V. Thanh Ngo, Hung the Diep
In the bulk state, the Ising FCC antiferromagnet is fully frustrated and is known to have a very strong first-order transition. In this paper, we study the nature of this phase transition in the case of a thin film, as a function of the film thickness. Using Monte Carlo (MC) simulations, we show that the transition remains first order down to a thickness of
Production of $^{93,94,95,96}$Tc through $^{7}$Li+$^{nat}$Zr and $^{9}$Be+$^{nat}$Y reactions: Measurement of excitation functions
nucl-exMoumita Maiti, Susanta Lahiri
For the first time two separate production routes of Tc radionuclides have been studied bombarding $^{7}$Li on $^{nat}$Zr and $^{9}$Be on $^{89}$Y. Excitation functions of the evaporation residues produced in those reactions have been measured using stacked-foil technique followed by the $γ$-spectrometric studies in the energy range 37-45 MeV and 30-48 MeV r
Jérémie Ortalo, Jean Cviklinski, Pietro Lombardi, Julien Laurat
Interaction of a control and a signal field with an ensemble of three-level atoms allows direct mapping of the quantum state of the signal field into long lived coherences of an atomic ground state. For a vapor of cesium atoms, using Electromagnetically Induced Transparency (EIT) and Zeeman coherences, we compare the case where a tunable single-sideband is s
Jean-François Pommaret
The purpose of this paper is to revisit the infinite Lie group theoretical framework of hydrodynamics developped by V. Arnold in 1966. First of all, we extend this approach from the Lie pseudogroup of volume preserving transformations to an arbitrary Lie pseudogroup. Then we prove that, contrary to what could be believed from the work of Arnold which is of a
Fakhreddine Ouni, Ahmed Khacef, Jean Marie Cormier
Propane steam reforming using a sliding discharge reactor was investigated under atmospheric pressure and low temperature (420 K). Non-thermal plasma steam reforming proceeded efficiently and hydrogen was formed as a main product (H2 concentration up to 50%). By-products (C2-hydrocarbons, methane, carbon dioxide) were measured with concentrations lower than
Guillaume Carlier, Rabah Tahraoui
This article is devoted to the optimal control of state equations with memory of the form: ?[x(t) = F(x(t),u(t), \int_0^{+\infty} A(s) x(t-s) ds), t>0, with initial conditions x(0)=x, x(-s)=z(s), s>0.]Denoting by $y_{x,z,u}$ the solution of the previous Cauchy problem and: \[v(x,z):=\inf_{u\in V} \{\int_0^{+\infty} e^{-λs} L(y_{x,z,u}(s), u(s))ds \}\] where
Laurent Meersseman, Marcel Nicolau, Alberto Verjovsky
In this article, we focus on a very special class of foliations with complex leaves whose diffeomorphism type is fixed. They have a unique compact leaf and the noncompact leaves all accumulate onto it. We show that the complex structure along the non-compact leaves is fixed by the complex structure of the compact leaf. Reciprocally, we prove that the complex
François Germinet, Abel Klein, Benoît Mandy
In this note we prove the existence of a localization/delocalization transition for Landau Hamiltonians randomly perturbed by an electric potential with unbounded amplitude. In particular, with probability one, no Landau gaps survive as the random potential is turned on, the gaps close, filling up partly with localized states. A minimal rate of transport is
Ionel Sorin Ciuperca, José Ignacio Tello
We consider the problem of a rigid surface moving over a flat plane. The surfaces are separated by a small gap filled by a lubricant fluid. The relative position of the surfaces is unknown except for the initial time $t=0$. The total load applied over the upper surface is a know constant for $t>0$. The mathematical model consists in a coupled system formed b
The steady state configurational distribution diffusion equation of the standard FENE dumbbell polymer model: existence and uniqueness of solutions for arbitrary velocity gradients
math.APIonel Sorin Ciuperca, Liviu Iulian Palade
The configurational distribution function, solution of an evolution (diffusion) equation of the Fokker-Planck-Smoluchowski type, is (at least part of) the corner stone of polymer dynamics: it is the key to calculating the stress tensor components. This can be reckoned from \cite{bird2}, where a wealth of calculation details is presented regarding various pol
Statistical effects of dose deposition in track-structure modelling of radiobiology efficiency
physics.bio-phM. Beuve, A. Colliaux, D. Dabli, D. Dauvergne
Ion-induced cell killing has been reported to depend on the irradiation dose but also on the projectile parameters. In this paper we focus on two approaches developed and extensively used to predict cell survival in response to ion irradiation: the Local Effect Model and the Katz Model. These models are based on a track-structure description summarized in th
James M. Chappell, Azhar Iqbal, M. A. Lohe, Lorenz von Smekal
We analyze the quantum penny flip game using geometric algebra and so determine all possible unitary transformations which enable the player Q to implement a winning strategy. Geometric algebra provides a clear visual picture of the quantum game and its strategies, as well as providing a simple and direct derivation of the winning transformation, which we de
Stabilization with finite dimensional controllers for a periodic parabolic system under perturbations in the system conductivity
math.OCLing Lei
This work studies the stabilization for a periodic parabolic system under perturbations in the system conductivity. A perturbed system does not have any periodic solution in general. However, we will prove that the perturbed system can always be pulled back to a periodic system after imposing a control from a fixed finite dimensional subspace.
Shinji Koide
We derived one-fluid equations based on a relativistic two-fluid approximation of e$^\pm$ pair plasma and electron-ion plasma to reveal the specific relativistic nature of their behavior. Assuming simple condition on the relativistic one-fluid equations, we propose generalized relativistic magnetohydrodynamic (RMHD) equations which satisfy causality. We show
Weishi Liu, Bixiang Wang
We study global dynamics of the Poisson-Nernst-Planck (PNP) system for flows of two types of ions through a narrow tubular-like membrane channel. As the radius of the cross-section of the three-dimensional tubular-like membrane channel approaches zero, a one-dimensional limiting PNP system is derived. This one-dimensional limiting system differs from previou
Fu Liu
Eisenbud and Harris introduced the theory of limit linear series, and constructed a space parametrizing their limit linear series. Recently, Osserman introduced a new space which compactifies the Eisenbud-Harris construction. In the Eisenbud-Harris space, the set of refined limit linear series is always dense on a general reducible curve. Osserman asks when
V. N. Krishnachandran
This is the story of the rediscovery of classical three-dimensional geometry, especially the geometry of quadric surfaces, while studying the semigroup $M_2(\mathbb R)$ of linear endomorphisms of a real plane. One of the surfaces that appears prominently in this context is the hyperboloid of one sheet, referred to as {\em spaghetti bundle} in \cite{Samu:88}.
Burkhard Militzer
Hot dense helium is studied with first-principles computer simulations. By combining path integral Monte Carlo and density functional molecular dynamics, a large temperature and density interval ranging from 1000 to 1000000 K and 0.4 to 5.4 g/cc becomes accessible to first-principles simulations and the changes in the structure of dense hot fluids can be inv
Differences in the high-energy kink between hole- and electron-doped high-$T_{\rm c}$ superconductors
cond-mat.supr-conM. Ikeda, T. Yoshida, A. Fujimori, M. Kubota
We have performed an angle-resolved photoemission spectroscopy (ARPES) study of Nd$_{1.85}$Ce$_{0.15}$CuO$_{4}$ (NCCO) in order to elucidate the origin of the high-energy kink (HEK) observed in the high-$T_{\rm c}$ superconductors (HTSCs). The energy scale of the HEK in NCCO is large compared with that in hole-doped HTSCs, consistent with previous ARPES stud
R. E. Mennickent, B. Sabogal, A. Granada, L. Cidale
We present new L-band spectra of 13 outbursting Be stars obtained with ISAAC at the ESO Paranal observatory. These stars can be classified in three groups depending on the presence/absence of emission lines and the strength of Br$α$ and Pf$γ$ emission lines relative to those of Humphreys lines from transitions 6--14 to the end of the series. These groups are
Seiichi Kamada, Kanako Oshiro
We introduce the notion of a quandle with a good involution and its homology groups. Carter et al. defined quandle cocycle invariants for oriented links and oriented surface-links. By use of good involutions, quandle cocyle invariants can be defined for links and surface-links which are not necessarily oriented or orientable. The invariants can be used in or
Liang He, Su Yi
We study the ground state properties of a spin-3 Cr condensate subject to an external magnetic field by numerically solving the Gross-Piteavskii equations. We show that the widely adopted single-mode approximation is invalid under a finite magnetic field. In particular, a phase separation like behavior may be induced by the magnetic field. We also point out
Yukihiro Mimura, S. Nandi
In orbifold models, gauge, Higgs and the matter fields can be unified in one multiplet from the compactification of higher dimensional supersymmetric gauge theory. We study how three families of chiral fermions can be unified in the gauge multiplet. The bulk gauge interaction includes the Yukawa interactions to generate masses for quarks and leptons after th
Lee Smolin
These notes discuss several topics in neoclassical economics and alternatives, with an aim of reviewing fundamental issues in modeling economic markets. I start with a brief, non-rigorous summary of the basic Arrow-Debreu model of general equilibrium, as well as its extensions to include time and contingency. I then argue that symmetries due to similarly end
Alicia Miralles, Lichao Chen, Zhongzhi Zhang, Francesc Comellas
Many real life networks present an average path length logarithmic with the number of nodes and a degree distribution which follows a power law. Often these networks have also a modular and self-similar structure and, in some cases - usually associated with topological restrictions- their clustering is low and they are almost planar. In this paper we introdu
Ground states of Heisenberg evolution operator in discrete three-dimensional space-time and quantum discrete BKP equations
nlin.SISergey M. Sergeev
In this paper we consider three-dimensional quantum q-oscillator field theory without spectral parameters. We construct an essentially big set of eigenstates of evolution with unity eigenvalue of discrete time evolution operator. All these eigenstates belong to a subspace of total Hilbert space where an action of evolution operator can be identified with qua
Sergey M. Sergeev
We study "circular net" (discrete orthogonal net) equations for angular data generalized by external spectral parameters. A criterion defining physical regimes of these Hamiltonian equations is the reality of Lagrangian density. There are four distinct regimes for fields and spectral parameters classified by four types of spherical or hyperbolic tria
Improved estimate of the detectability of gravitational radiation from a magnetically confined mountain on an accreting neutron star
astro-ph.HEM. Vigelius, A. Melatos
We give an improved estimate of the detectability of gravitational waves from magnetically confined mountains on accreting neutron stars. The improved estimate includes the following effects for the first time: three-dimensional hydromagnetic ("fast") relaxation, three-dimensional resistive ("slow") relaxation, realistic accreted masses $M_a
Fundamental limit of sample generalized eigenvalue based detection of signals in noise using relatively few signal-bearing and noise-only samples
cs.ITN. Raj Rao, Jack W. Silverstein
The detection problem in statistical signal processing can be succinctly formulated: Given m (possibly) signal bearing, n-dimensional signal-plus-noise snapshot vectors (samples) and N statistically independent n-dimensional noise-only snapshot vectors, can one reliably infer the presence of a signal? This problem arises in the context of applications as div
Measuring the galaxy-mass and galaxy-dust correlations through magnification and reddening
astro-ph.COBrice Ménard, Ryan Scranton, Masataka Fukugita, Gordon Richards
We present a simultaneous detection of gravitational magnification and dust reddening effects due to galactic halos and large-scale structure. The measurement is based on correlating the brightness of ~85,000 quasars at z>1 with the position of 20 million galaxies at z~0.3 derived from the Sloan Digital Sky Survey and is used to constrain the galaxy-mass and
Duy Cuong Nguyen, Alexander Scholz, Marten H. van Kerkwijk, Ray Jayawardhana
We analyze the variability in accretion-related emission lines for 40 Classical T Tauri stars to probe the extent of accretion variations in young stellar objects. Our analysis is based on multi-epoch high-resolution spectra for young stars in Tau-Aur and Cha I. For all stars, we obtain typically four spectra, covering timescales from hours to months. As pro
Jaewoo Joo, Terry Rudolph, Barry C. Sanders
We propose a scheme for building a heralded two-qutrit entangled state from polarized photons. An optical circuit is presented to build the maximally entangled two-qutrit state from two heralded Bell pairs and ideal threshold detectors. Several schemes are discussed for constructing the two Bell pairs. We also show how one can produce an unbalanced two-qutri
Sonia Sharma
We generalize an important class of Banach spaces, namely the $M$-embedded Banach spaces, to the non-commutative setting of operator spaces. The one-sided $M$-embedded operator spaces are the operator spaces which are one-sided $M$-ideals in their second dual. We show that several properties from the classical setting, like the stability under taking subspac
F. E. Close, W. Melnitchouk
We explore quark-hadron duality in semi-inclusive pion electroproduction on proton and neutron targets. Using the spin-flavor symmetric quark model, we compute ratios of pi+ and pi- cross sections for both unpolarized and polarized scattering, and discuss realizations of duality in several symmetry breaking scenarios. The model calculations allow one to unde
Juliana Kwan, Matthew J. Francis, Geraint F. Lewis
The Fractal Bubble model has been proposed as a viable cosmology that does not require dark energy to account for cosmic acceleration, but rather attributes its observational signature to the formation of structure. In this paper it is demonstrated that, in contrast to previous findings, this model is not a good fit to cosmological supernovae data; there is
G. L. Klimchitskaya
We calculate the Casimir force between a Ge plate and a Ge spherical lens with neglected and included free charge carriers. Computations with included carriers are performed using the Drude, plasma, and diffusion models. It is shown that the plasma and the Drude models lead to almost identical computational results, while the results obtained using the diffu
Elena Aprile, Laura Baudis
The XENON experimental program aims to detect cold dark matter particles via their elastic collisions with xenon nuclei in two-phase time projection chambers (TPCs). We are currently testing a new TPC at the 100 kg scale, XENON100. This new, ultra-low background detector, has a total of 170 kg of xenon (65 kg in the target region and 105 kg in the active shi
Donu Arapura
In this paper, we explore a notion of nonabelian Hodge structure on the fundamental group of an algebraic variety. This is approach is compared to some alternative approaches due to Morgan, Hain and others. We also give criteria for a variety to be a Hodge theoretic K(pi,1), which roughly means that the cohomology of variations of mixed Hodge structure can b
On the rate of convergence of the two-dimensional $α$-models of turbulence to the Navier-Stokes equations
math-phY. Cao, E. S. Titi
Rates of convergence of solutions of various two-dimensional $α-$regularization models, subject to periodic boundary conditions, toward solutions of the exact Navier-Stokes equations are given in the $L^\infty$-$L^2$ time-space norm, in terms of the regularization parameter $ α$, when $α$ approaches zero. Furthermore, as a paradigm, error estimates for the G
Oleg Kurmaev
Constant-weight and constant-charge binary sequences with constrained run length of zeros are introduced. For these sequences, the weight and the charge distribution are found. Then, recurrent and direct formulas for calculating the number of these sequences are obtained. With considering these numbers of constant-weight and constant-charge RLL sequences as
Modeling Spectral Variability of Prompt GRB Emission within the Jitter Radiation Paradigm
astro-ph.HEMikhail V. Medvedev, Sriharsha S. Pothapragada, Sarah J. Reynolds
The origin of rapid spectral variability and certain spectral correlations of the prompt gamma-ray burst emission remains an intriguing question. The recently proposed theoretical model of the prompt emission is build upon unique spectral properties of jitter radiation -- the radiation from small-scale magnetic fields generated at a site of strong energy rel
Olivier Cyr-Choiniere, R. Daou, Francis Laliberte, David LeBoeuf
The Nernst effect in metals is highly sensitive to two kinds of phase transition: superconductivity and density-wave order. The large positive Nernst signal observed in hole-doped high-Tc superconductors above their transition temperature Tc has so far been attributed to fluctuating superconductivity. Here we show that in some of these materials the large Ne
R. J. Assef, B. S. Gaudi, K. Z. Stanek
Of the approximately 350 extrasolar planets currently known, of order 10% orbit evolved stars with radii R >~ 2.5 R_sun. These planets are of particular interest because they tend to orbit more massive hosts, and have been subjected to variable stellar insolation over their recent histories as their primaries evolved off the main sequence. Unfortunately, we
Temporal evolution of product shock measures in TASEP with sublattice-parallel update
cond-mat.stat-mechF. H. Jafarpour, S. R. Masharian
It is known that when the steady state of a one-dimensional multispecies system, which evolves via a random-sequential updating mechanism, is written in terms of a linear combination of Bernoulli shock measures with random-walk dynamics, it can be equivalently expressed as a matrix-product state. In this case the quadratic algebra of the system always has a
Vladimir Dragovic, Milena Radnovic
A detailed description of topology of integrable billiard systems is given. For elliptical billiards and geodesic billiards on ellipsoid, the corresponding Fomenko graphs are constructed.
L. Vostrikova
We study the differentiability of Bessel flow $\rho : x \to \rho ^x_t$, where $(\rho ^x_t)_{t\geq 0}$ is BES $^x(\delta $) process of dimension $\delta >1$ starting from $x$. For $\delta \geq 2$ we prove the existence of bicontinuous derivatives in P-a.s. sense at $x\geq 0$ and we study the asymptotic behaviour of the derivatives at $x=0$. For $1< \delta <2$
Richard T Hammond
The problem of self forces and radiation reaction is solved by conservation of energy methods. The longstanding problem of constant acceleration is solved, and it is shown that the self force does indeed affect the particle's motion, as expected on physical grounds. The relativistic generalization is also presented.
Magnetic field-induced phase transitions in a weakly coupled s = 1/2 quantum spin dimer system Ba$_{3}$Cr$_{2}$O$_{8}$
cond-mat.str-elM. Kofu, H. Ueda, H. Nojiri, Y. Oshima
By using bulk magnetization, electron spin resonance (ESR), heat capacity, and neutron scattering techniques, we characterize the thermodynamic and quantum phase diagrams of Ba$_3$Cr$_2$O$_8$. Our ESR measurements indicate that the low field paramagnetic ground state is a mixed state of the singlet and the S$_z$ = 0 triplet for $H \perp c$. This suggests the
A model-independent technique to determine one-dimensional radio source structure from interplanetary scintillation (IPS) observations
astro-ph.EPV R Venugopal, P K Manoharan, D G Banhatti, S Edwin Jayaraj
We outline a method of deriving one-dimensional phaseless visibility along solar wind direction from interplanetary scintillation power spectrum, together with the known visibility of a calibration source. The method is illustrated briefly. Details may be found in Edwin Jayaraj (1990).
Selective excitations of trasverse vibrational modes of a carbon nanotube through a "shuttle-like" electromechanical instability
cond-mat.mes-hallFabio Santandrea
We study the dynamics of transverse oscillations of a suspended carbon nanotube into which current is injected from the tip of a scanning tunneling microscope (STM). In this case the correlations between the displacement of the nanotube and its charge state, determined by the position-dependent electron tunneling rate, can lead to a "shuttle-like" in
Nicolas Templier
Let $\CmZ_{Y_0(N)}$ be the constant term of the logarithmic derivative at $s=1$ of the Selberg zeta function of the modular curve $Y_0(N)$. Jorgenson and Kramer established the bound $\CmZ_{Y_0(N)}=O_ε(N^ε)$, $ε>0$ by relating it to geometric invariants. In this article we give, for $N$ prime, another proof via $L$-functions and exponential sums improving on
K. J. Eskola, H. Paukkunen, C. A. Salgado
We present a next-to-leading order (NLO) global DGLAP analysis of nuclear parton distribution functions (nPDFs) and their uncertainties. Carrying out an NLO nPDF analysis for the first time with three different types of experimental input -- deep inelastic $\ell$+A scattering, Drell-Yan dilepton production in p+$A$ collisions, and inclusive pion production i
Markus Ahlers, Luis A. Anchordoqui, Subir Sarkar
The energy at which cosmic rays from extra-galactic sources begin to dominate over those from galactic sources is an important open question in astroparticle physics. A natural candidate is the energy at the 'ankle' in the approximately power-law energy spectrum which is indicative of a cross-over from a falling galactic component to a flatter extra-
Gautam Bharali
Let S be a smooth real surface in C^2 and let p\in S be a point at which the tangent plane is a complex line. How does one determine whether or not S is locally polynomially convex at such a p --- i.e. at a CR singularity ? Even when the order of contact of T_p(S) with S at p equals 2, no clean characterisation exists; difficulties are posed by parabolic poi
Iosif Pinelis
Integral expressions for positive-part moments E X_+^p (p>0) of random variables X are presented, in terms of the Fourier-Laplace or Fourier transforms of the distribution of X. A necessary and sufficient condition for the validity of such an expression is given. This study was motivated by extremal problems in probability and statistics, where one needs to
G. Ramalho, M. T. Pena, Franz Gross
Using a covariant spectator constituent quark model we predict an electric quadrupole moment -0.043 efm^2 and a magnetic octupole moment -0.0035 efm^3 for the Delta+ excited state of the nucleon.
R. N. Ganikhodzhaev, U. A. Rozikov
The history of the quadratic stochastic operators can be traced back to work of S.Bernshtein (1924). During more than 80 years this theory developed and many papers were published. In recent years it has again become of interest in connection with numerous applications to many branches of mathematics, biology and physics. But most results of the theory were
Stefano Camera, Daniele Bertacca, Antonaldo Diaferio, Nicola Bartolo
Weak gravitational lensing is a powerful tool for studying both the geometry and the dynamics of the Universe. Its power spectrum contains information on the sources emitting photons and on the large--scale structures that these hotons cross. We calculate the weak lensing cosmic convergence and shear power spectra, in linear theory and Limber's approxima
Wolfgang Lucha, Dmitri Melikhov, Silvano Simula
We study the accuracy of the bound-state parameters obtained with the method of dispersive sum rules, one of the most popular theoretical approaches in nonperturbative QCD and hadron physics. We make use of a quantum-mechanical potential model since it provides the only possibility to probe the reliability and the accuracy of this method: one obtains the bou
Gabriella Böhm
We construct a `weak' version EM^w(K) of Lack & Street's 2-category of monads in a 2-category K, by replacing their compatibility constraint of 1-cells with the units of monads by an additional condition on the 2-cells. A relation between monads in EM^w(K) and composite pre-monads in K is discussed. If K admits Eilenberg-Moore constructions for monad
Gabriella Böhm
A weak entwining structure in a 2-category K consists of a monad t and a comonad c, together with a 2-cell relating both structures in a way that generalizes a mixed distributive law.A weak entwining structure can be characterized as a compatible pair of a monad and a comonad, in 2-categories generalizing the 2-category of comonads and the 2-category of mona
Maksim Tomchenko
We analyze the microstructure of He-II in the framework of the method of collective variables (CV), which was proposed by Bogolyubov and Zubarev and was developed later by Yukhnovskii and Vakarchuk. The logarithm of the ground-state wave function of He-II, ln(Psi_0), is calculated in the approximation of "two sums", i.e., as a Jastrow function and fi
The Quantum Capacitance Detector: A concept for a pair-breaking radiation detector based on the single Cooper-pair box
cond-mat.mes-hallM. D. Shaw, J. Bueno, P. Day, C. M. Bradford
We present a proposed design for a pair-breaking photodetector for far-infrared and sub-millimeter radiation. Antenna-coupled radiation generates quasiparticles in a superconducting absorber, the density of which are measured using a single Cooper-pair box. Readout is performed using an electromagnetic oscillator or a microwave resonator, which is well suite
Tommaso Caneva, Michael Murphy, Tommaso Calarco, Rosario Fazio
Optimal control theory is a promising candidate for a drastic improvement of the performance of quantum information tasks. We explore its ultimate limit in paradigmatic cases, and demonstrate that it coincides with the maximum speed limit allowed by quantum evolution (the quantum speed limit).
A. A. Semenov, W. Vogel
Nonclassical properties of light propagating through the turbulent atmosphere are studied. We demonstrate by numerical simulation that the probability distribution of the transmission coefficient, which characterizes the effects of the atmosphere on the quantum state of light, can be reconstructed by homodyne detection. Nonclassical photon-statistics and, mo
All null supersymmetric backgrounds of N=2, D=4 gauged supergravity coupled to abelian vector multiplets
hep-thDietmar Klemm, Emanuele Zorzan
The lightlike supersymmetric solutions of N=2, D=4 gauged supergravity coupled to an arbitrary number of abelian vector multiplets are classified using spinorial geometry techniques. The solutions fall into two classes, depending on whether the Killing spinor is constant or not. In both cases, we give explicit examples of supersymmetric backgrounds. Among th
Lenka Zdeborová, Florent Krzakala
We study the planted ensemble of locked constraint satisfaction problems. We describe the connection between the random and planted ensembles. The use of the cavity method is combined with arguments from reconstruction on trees and first and second moment considerations; in particular the connection with the reconstruction on trees appears to be crucial. Our
Matsuo Sato
We propose a supersymmetric model that defines M-theory. It possesses SO(1, 10) super Poincare symmetry and is constructed based on the Lorentzian 3-algebra associated with U(N) Lie algebra. This model is a supersymmetric generalization of the model in arXiv:0902.1333. From our model, we derive BFSS matrix theory and IIB matrix model in the naive large N lim
A. M. Fischer, A. B. Dzyubenko, R. A. Roemer
We consider collective excitations in graphene with filled Landau levels (LL's) in the presence of an external potential due to a single charged donor D+ or acceptor A- impurity. We show that localized collective modes split off the magnetoplasmon continuum and, in addition, quasibound states are formed within the continuum. A study of the evolution of t
Louis Salvail, Christian Schaffner, Miroslava Sotakova
We study quantum protocols among two distrustful parties. Under the sole assumption of correctness - guaranteeing that honest players obtain their correct outcomes - we show that every protocol implementing a non-trivial primitive necessarily leaks information to a dishonest player. This extends known impossibility results to all non-trivial primitives. We p
Giuseppe Pesce, Giorgio Volpe, Anna Chiara De Luca, Giulia Rusciano
The forces acting on an optically trapped particle are usually assumed to be conservative. However, the presence of a non-conservative component has recently been demonstrated. Here we propose a technique that permits one to quantify the contribution of such non-conservative component. This is an extension of a standard optical tweezers calibration technique
K. Prasad, B. Sundar Rajan
In this work, we introduce convolutional codes for network-error correction in the context of coherent network coding. We give a construction of convolutional codes that correct a given set of error patterns, as long as consecutive errors are separated by a certain interval. We also give some bounds on the field size and the number of errors that can get cor
Yosuke Imamura
Monopole operators in Abelian N=4 Chern-Simons theories described by circular quiver diagrams are investigated. The magnetic charges of non-diagonal U(1) gauge symmetries form the SU(p)xSU(q) root lattice where p and q are numbers of untwisted and twisted hypermultiplets, respectively. For monopole operators corresponding to the root vectors, we propose a co
Ilya Kapovich, Martin Lustig
We prove that if $ϕ,ψ\in Out(F_N)$ are hyperbolic iwips (irreducible with irreducible powers) such that $<ϕ,ψ>\le Out(F_N)$ is not virtually cyclic then some high powers of $ϕ$ and $ψ$ generate a free subgroup of rank two, all of whose nontrivial elements are again hyperbolic iwips. Being a hyperbolic iwip element of $Out(F_N)$ is strongly analogous to being
Conductance through a potential barrier embedded in a Luttinger liquid: nonuniversal scaling at strong coupling
cond-mat.str-elD. N. Aristov, P. Woelfle
We calculate the linear response conductance of electrons in a Luttinger liquid with arbitrary interaction g_2, and subject to a potential barrier of arbitrary strength, as a function of temperature. We map the Hamiltonian in the basis of scattering states into an effective low energy Hamiltonian in current algebra form. First the renormalization group (RG)
Arithmetic theory of q-difference equations (G_q-functions and q-difference modules of type G, global q-Gevrey series)
math.NTLucia Di Vizio
In the first part of the paper we give a definition of G_q-function and we establish a regularity result, obtained as a combination of a q-analogue of the Andre'-Chudnovsky Theorem [And89, VI] and Katz Theorem [Kat70, §13]. In the second part of the paper, we combine it with some formal q-analogous Fourier transformations, obtaining a statement on the ir
Thomas Stoll
R. L. Graham and H. O. Pollak observed that the sequence $$u_1=1,\qquad u_{n+1}=\lfloor \sqrt{2} (u_n+1/2)\rfloor, \quad n\geq 1,$$ has the curious property that the sequence of numbers $(u_{2n+1}-2u_{2n-1})_{n\geq 1}$ denotes the binary digits of $\sqrt{2}$. We present an extension of Graham--Pollak's sequence which allows to get -- in a fancy way -- th
K. Wilhelm, B. N. Dwivedi, W. Curdt
Polar coronal plumes seen during solar eclipses can now be studied with space-borne telescopes and spectrometers. We briefly discuss such observations from space with a view to understanding their plasma characteristics. Using these observations, especially from SUMER/SOHO, but also from EUVI/STEREO, we deduce densities, temperatures, and abundance anomalies
Intensity dependence of ionization mechanisms for infrared frequencies in the strong field double ionization of diatomic molecules
physics.atom-phAgapi Emmanouilidou
Using a three-dimensional quasiclassical technique we explore the double ionization pathways of a diatomic molecule driven by an intense infrared (800nm) ultrashort laser pulse. For intensities corresponding to the tunneling regime, we find that the three main ionization mechanisms have distinct traces when considering the sum of the momenta parallel to the
The flavor-changing bottom and anti-strange quark production in the littlest Higgs model with T parity at the ILC
hep-phXuelei Wang, Jinzhong Han, Wujun Li, Hao Wang
In the littlest Higgs model with T-parity (LHT) the mirror quarks induce the special flavor structures and some new flavor-changing (FC) couplings which could greatly enhance the production rates of the FC processes. We in this paper study some bottom and anti-strange production processes in the LHT model at the International Linear Collider (ILC), i.e., $e^
Nanoparticle characterization by using Tilted Laser Microscopy: back scattering measurement in near field
physics.opticsD. Brogioli, D. Salerno, V. Cassina, F. Mantegazza
By using scattering in near field techniques, a microscope can be easily turned into a device measuring static and dynamic light scattering, very useful for the characterization of nanoparticle dispersions. Up to now, microscopy based techniques have been limited to forward scattering, up to a maximum of 30 degrees. In this paper we present a novel optical s
Zheng Li, Tao Wu, Jianshe Liu
An optimal effective current operator for flux qubit has been investigated by taking account of the inductive effects of the circuit loop. The whole system is treated as two interacting subsystems: one is the inductance-free flux qubit consisting of three Josephson junctions and the other a high frequency LC-oscillator. As the composite system hardly affords
M. Cristelli, V. Alfi, L. Pietronero, A. Zaccaria
We introduce a microscopic model for the dynamics of the order book to study how the lack of liquidity influences price fluctuations. We use the average density of the stored orders (granularity $g$) as a proxy for liquidity. This leads to a Price Impact Surface which depends on both volume $ω$ and $g$. The dependence on the volume (averaged over the granula