June 2009 arXiv papers — page 9
Showing 801–900 of 5,471 papers
Hiroyuki Ohtori, Hiroshi Imamura
We theoretically analyzed the Andreev reflection in ferromagnetic metal/nonmagnetic metal/superconductor double junctions with special attention to the electron interference effect in the nonmagnetic metal layer. We showed that the conductance oscillates as a function of the bias voltage due to the geometrical resonance. We found that the exchange field, and
Stan Alama, Lia Bronsard, Vincent Millot
We study the variational convergence of a family of two-dimensional Ginzburg-Landau functionals arising in the study of superfluidity or thin-film superconductivity, as the Ginzburg-Landau parameter epsilon tends to 0. In this regime and for large enough applied rotations (for superfluids) or magnetic fields (for superconductors), the minimizers acquire quan
J. E. Gough, M. R. James, H. I. Nurdin
The aim of this paper is to extend linear quantum dynamical network theory to include static Bogoliubov components (such as squeezers). Within this integrated quantum network theory we provide general methods for cascade or series connections, as well as feedback interconnections using linear fractional transformations. In addition, we define input-output ma
Massimiliano Mella, Elena Polastri
Let $X$ be a projective variety of dimension $r$ over an algebraically closed field. It is proven that two birational embeddings of $X$ in $¶^n$, with $n\geq r+2$ are equivalent up to Cremona transformations of $¶^n$.
Masayuki Tanimoto, Yasusada Nambu, Kazuhiro Iwata
Void models provide a possible explanation of the "accelerated expansion" of the Universe without dark energy. To make the conventional void models more realistic, we allow the void, an underdense region around us, to be anisotropic and consider an average of the distance-redshift relations over the solid angle subtended at the observer. We first sho
High-field magnetization of a two dimensional spin frustration system Ni$_{5}$(TeO$_{3}$)$_{4}$X$_{2}$ (X = Br and Cl)
cond-mat.str-elJ. L. Her, Y. H. Matsuda, K. Suga, K. Kindo
High-field magnetization, M($H$), on Ni$_{5}$(TeO$_{3}$)$_{4}$X$_{2}$ (X = Br and Cl) were measured by using a pulse magnet. These compounds have a two dimensional crystal structure and a distorted kagome spin frustrated system which is builded by the Ni$^{2+}$ ions ($\textbf{S}$ = 1). The Néel transition temperatures are $T_{N} \sim$ 28 and 23 K for X = Br
Jacco Th. van Loon
Massive stars becoming red supergiants lose a significant amount of their mass during that brief evolutionary phase. They then either explode as a hydrogen-rich supernova (SN Type II), or continue to evolve as a hotter supergiant (before exploding). The slow, dusty ejecta of the red supergiant will be over-run by the hot star wind and/or SN ejecta. I will pr
D. V. Khomitsky, E. Ya. Sherman
The coupled nonlinear coordinate and spin dynamics of an electron in a double quantum dot with spin-orbit interaction is studied semiclassically. The system is driven by an electric field with the frequency matching the orbital or the Zeeman resonance in magnetic field. Calculated evolution of the spin state is crucially sensitive to the irregularities in th
A study of the Correlation of Arrival Directions of UHECRs with the Large Scale Structure of the Universe
astro-ph.HEDongsu Ryu, Hyesung Kang, Santabrata Das
Ultrahigh energy cosmic rays (UHECRs) are believed to originate from astrophysical sources, which should trace the large scale structure (LSS) of the universe. On the other hand, the magnetic field in the intergalactic space (IGMF), which also traces the LSS of the universe, deflects the trajectories of the charged UHECRs and spoils the positional correlatio
Pete Martin
The heuristic principle that constructive dynamics may arise wherever there exists a difference, or gradient, is discussed. Consideration of black-hole entropy appears to provide a clue for setting a lower bound on any extensive measure of such collective system difference, or potential to give rise to constructive dynamics. It is seen that the second-power
Kourosh Nozari, Siamak Akhshabi
We construct an inflation model on the Randall-Sundrum I (RSI) brane where a bulk scalar field stabilizes the inter-brane separation. We study impact of the bulk scalar field on the inflationary dynamics on the brane. We proceed in two different approaches: in the first approach, the stabilizing field potential is directly appeared in the Friedmann equation
Lorentz Jantschi
The design and the implementation of a genetic algorithm are described. The applicability domain is on structure-activity relationships expressed as multiple linear regressions and predictor variables are from families of structure-based molecular descriptors. An experiment to compare different selection and survival strategies was designed and realized. The
J. Theodore Cox, Rinaldo B. Schinazi
We study the ergodic theory of a multitype contact process with equal death rates and unequal birth rates on the $d$-dimensional integer lattice and regular trees. We prove that for birth rates in a certain interval there is coexistence on the tree, which by a result of Neuhauser is not possible on the lattice. We also prove a complete convergence result whe
Raymond Vozzo
We consider various generalisations of the string class of a loop group bundle. The string class is the obstruction to lifting a bundle whose structure group is the loop group $LG$ to one whose structure group is the Kac-Moody central extension of the loop group. We develop a notion of higher string classes for bundles whose structure group is the group of b
Pawel Danielewicz, Arnau Rios, Brent Barker
Nonequilibrium Green's functions represent a promising tool for describing central nuclear reactions. Even at the single-particle level, though, the Green's functions contain more information that computers may handle in the foreseeable future. In this study, we investigate whether all the information contained in the Green's functions is necessa
O. Titov
Some models of the expanding Universe predict that the astrometric proper motion of distant radio sources embedded in space-time are non-zero as radial distance from observer to the source grows. Systematic effects due to this proper motion can even increase with distance making possible to measure them with high precision astrometric techniques like VLBI. W
Forecasting Model for Crude Oil Price Using Artificial Neural Networks and Commodity Futures Prices
cs.NESiddhivinayak Kulkarni, Imad Haidar
This paper presents a model based on multilayer feedforward neural network to forecast crude oil spot price direction in the short-term, up to three days ahead. A great deal of attention was paid on finding the optimal ANN model structure. In addition, several methods of data pre-processing were tested. Our approach is to create a benchmark based on lagged v
Advances in the Design and Implementation of a Multi-Tier Architecture in the GIPSY Environment
cs.SEBin Han, Serguei A. Mokhov, Joey Paquet
We present advances in the software engineering design and implementation of the multi-tier run-time system for the General Intensional Programming System (GIPSY) by further unifying the distributed technologies used to implement the Demand Migration Framework (DMF) in order to streamline distributed execution of hybrid intensional-imperative programs using
Dragoş-Victor Anghel
I discuss the concept of fractional exclusion statistics (FES) and I show that in order to preserve the thermodynamic consistency of the formalism, the exclusion statistics parameters should change if the species of particles in the system are divided into subspecies. Using a simple and intuitive model I deduce the general equations that have to be obeyed by
Ken Kreutz-Delgado
A thorough discussion and development of the calculus of real-valued functions of complex-valued vectors is given using the framework of the Wirtinger Calculus. The presented material is suitable for exposition in an introductory Electrical Engineering graduate level course on the use of complex gradients and complex Hessian matrices, and has been successful
Global Stability Analysis for an Internet Congestion Control Model with a Time-Varying Link Capacity
cs.NIB. Rezaie, MR. Jahed Motlagh, M. Analoui, S. Khorsandi
In this paper, a global stability analysis is given for a rate-based congestion control system modeled by a nonlinear delayed differential equation. The model determines the dynamics of a single-source single-link network, with a time-varying capacity of link and a fixed communication delay. We obtain a sufficient delay-independent conditions on system param
John C. Howell, David J. Starling, P. Ben Dixon, Praveen K. Vudyasetu
We derive the weak value deflection given in a paper by Dixon et al. (Phys. Rev. Lett. 102, 173601 (2009)) both quantum mechanically and classically. This paper is meant to cover some of the mathematical details omitted in that paper owing to space constraints.
Fluctuation properties of strength function associated with the giant quadrupole resonance in 208Pb
nucl-thHirokazu Aiba, Masayuki Matsuo, Shigeru Nishizaki, Toru Suzuki
We performed fluctuation analysis by means of the local scaling dimension for the strength function of the isoscalar (IS) giant quadrupole resonance (GQR) in 208Pb where the strength function is obtained by the shell model calculation including 1p1h and 2p2h configurations. It is found that at almost all energy scales, fluctuation of the strength function ob
K. A. Ispirian, M. K. Ispiryan
Without developing a correct theory, the rate of the production of entangled photon pairs in the X-ray region by high energy electrons is estimated for experimental parameters used in a few experiments on X-ray parametric down conversion. Taking into account the need for X-ray entangled X-ray photons, it is proposed to begin the experimental study of such me
Hiroyuki Kamano
We present an overview of a research program for the excited nucleon states in Excited Baryon Analysis Center (EBAC) at Jefferson Lab. Current status of our analysis of the meson production reactions based on the unitary dynamical coupled-channels model is summarized, and the N* pole positions extracted from the constructed scattering amplitudes are presente
P. Ben Dixon, David J. Starling, Andrew N. Jordan, John C. Howell
We report on the use of an interferometric weak value technique to amplify very small transverse deflections of an optical beam. By entangling the beam's transverse degrees of freedom with the which-path states of a Sagnac interferometer, it is possible to realize an optical amplifier for polarization independent deflections. The theory for the interfero
Walid Saad, Zhu Han, Tamer Basar, Merouane Debbah
Cooperation between wireless network nodes is a promising technique for improving the physical layer security of wireless transmission, in terms of secrecy capacity, in the presence of multiple eavesdroppers. While existing physical layer security literature answered the question "what are the link-level secrecy capacity gains from cooperation?", thi
Won-Min Song, T. Di Matteo, Tomaso Aste
We construct a partial order relation which acts on the set of 3-cliques of a maximal planar graph G and defines a unique hierarchy. We demonstrate that G is the union of a set of special subgraphs, named `bubbles', that are themselves maximal planar graphs. The graph G is retrieved by connecting these bubbles in a tree structure where neighboring bubble
A consistent description of the iron dimer spectrum with a correlated single-determinant wave function
cond-mat.otherMichele Casula, Mariapia Marchi, Sam Azadi, Sandro Sorella
We study the iron dimer by using an accurate ansatz for quantum chemical calculations based on a simple variational wave function, defined by a single geminal expanded in molecular orbitals and combined with a real space correlation factor. By means of this approach we predict that, contrary to previous expectations, the neutral ground state is $^7 Δ$ while
J. Yin, J. L. Hou, N. Prantzos, S. Boissier
We study the chemical evolution of the disks of the Milky Way (MW) and of Andromeda (M31), in order to reveal common points and differences between the two major galaxies of the Local group. We use a large set of observational data for M31, including recent observations of the Star Formation Rate (SFR) and gas profiles, as well as stellar metallicity distrib
Christopher P. Herzog, Amos Yarom
Superfluids support many different types of sound waves. We investigate the relation between the sound waves in a relativistic and a non-relativistic superfluid by using hydrodynamics to calculate the various sound speeds. Then, using a particular holographic scalar gravity realization of a strongly interacting superfluid, we compute first, second and fourth
R. J. Allison, S. P. Goodwin, R. J. Parker, R. de Grijs
We discuss the observations and theory of star cluster formation to argue that clusters form dynamically cool (subvirial) and with substructure. We then perform an ensemble of simulations of cool, clumpy (fractal) clusters and show that they often dynamically mass segregate on timescales far shorter than expected from simple models. The mass segregation come
L. M. Green, B. Kliem
We analyse the evolution of a sigmoidal (S shaped) active region toward eruption, which includes a coronal mass ejection (CME) but leaves part of the filament in place. The X-ray sigmoid is found to trace out three different magnetic topologies in succession: a highly sheared arcade of coronal loops in its long-lived phase, a bald-patch separatrix surface (B
Y. -H. Chu, R. A. Gruendl, M. A. Guerrero, K. Y. L. Su
Spitzer MIPS 24 um images were obtained for 36 Galactic planetary nebulae (PNe) whose central stars are hot white dwarfs (WDs) or pre-WDs with effective temperatures of ~100,000 K or higher. Diffuse 24 um emission is detected in 28 of these PNe. The eight non-detections are angularly large PNe with very low H-alpha surface brightnesses. We find three types o
Measurement of dijet angular distributions at sqrt{s}=1.96TeV and searches for quark compositeness and extra spatial dimensions
hep-exD0 Collaboration, V. M. Abazov
We present the first measurement of dijet angular distributions in ppbar collisions at sqrt{s}=1.96TeV at the Fermilab Tevatron Collider. The measurement is based on a dataset corresponding to an integrated luminosity of up to 0.7fb-1 collected with the D0 detector. Dijet angular distributions have been measured over a range of dijet masses, from 0.25TeV to
D. Cherney, E. Latini, A. Waldron
We present the BRST cohomologies of a class of constraint (super) Lie algebras as detour complexes. By giving physical interpretations to the components of detour complexes as gauge invariances, Bianchi identities and equations of motion we obtain a large class of new gauge theories. The pivotal new machinery is a treatment of the ghost Hilbert space designe
Mordehai Milgrom
I pinpoint a previously unrecognized MOND effect that may act in the inner solar system, and is due to the galactic acceleration, g_g=eta*a0: a byproduct of the MOND external-field effect. Predictions of the effect are not generic to the MOND paradigm, but depend on the particular MOND formulation at hand. However, the modified-Poisson formulation, on which
Ramandeep Gill, Jeremy S. Heyl
A fully relativistic treatment of Bernstein waves in an electron-positron pair plasma has remained too formidable a task owing to the very complex nature of the problem. In this article, we perform contour integration of the dielectric response function and numerically compute the dispersion curves for a uniform, magnetized, relativistic electron-positron pa
Helge Ruddat
We give a spectral sequence to compute the logarithmic Hodge groups on a hypersurface type toric log Calabi-Yau space, compute its E_1 term explicitly in terms of tropical degeneration data and Jacobian rings and prove its degeneration at E_2 under mild assumptions. We prove the basechange of the affine Hodge groups and deduce it for the logarithmic Hodge gr
M. I. Wanas, Samah A. Ammar
The present work represents a step to deal with stellar structure using a pure geometric approach. A geometric field theory is used to construct a model for a spherically symmetric configuration. The model obtained can be considered as a pure geometric one in the sense that the tensor describing the material distributions is not a phenomenological object, bu
Alejandro Adem, Zinovy Reichstein
The cohomology of the classifying space BU(n) of the unitary groups can be identified with the ring of symmetric polynomials on n variables by restricting to the cohomology of BT, where T is a maximal torus in U(n). In this paper we explore the situation where BT = (CP^{infinity})^n is replaced by a product of finite dimensional projective spaces (CP^d)^n, f
Theodore F. Argo, Matthew D. Guild, Preston S. Wilson, Matthias Schröter
Sound propagation in water-saturated granular sediments is known to depend on the sediment porosity, but few data in the literature address both the frequency and porosity dependency. To begin to address this deficiency, a fluidized bed technique was used to control the porosity of an artificial sediment composed of glass spheres of 265 μm diameter. Time-of-
M. Valluri, V. P. Debattista, T. Quinn, B. Moore
Using spectral methods, we analyse the orbital structure of prolate/triaxial dark matter (DM) halos in N-body simulations to understand the processes that drive the evolution of shapes of DM halos and elliptical galaxies in which central masses are grown. A longstanding issue is whether the change in the shapes of DM halos is the result of chaotic scattering
Detailed Cluster Mass and Light profiles of A1703, A370 and RXJ1347-11 from Deep Subaru Imaging
astro-ph.COElinor Medezinski, Tom Broadhurst, Keiichi Umetsu, Masamune Oguri
Weak lensing work can be badly compromised by unlensed foreground and cluster members which dilute the true lensing signal. We show how the lensing amplitude in multi-colour space can be harnessed to securely separate cluster members from the foreground and background populations for three massive clusters, A1703 (z=0.258), A370 (z=0.375) and RXJ1347-11 (z=0
The Discovery of a Large Lyman-alpha+HeII Nebula at z~1.67: A Candidate Low Metallicity Region?
astro-ph.COM. K. M. Prescott, A. Dey, B. T. Jannuzi
We have discovered a ~45 kpc Lya nebula (or Lya ``blob'') at z~1.67 which exhibits strong, spatially-extended HeII emission and very weak CIV and CIII] emission. This is the first spatially-extended Lya+HeII emitter observed and the lowest redshift Lya blob yet found. Strong Lya and HeII-1640 emission in the absence of metal lines has been proposed a
Gleb Arutyunov, Marius de Leeuw, Ryo Suzuki, Alessandro Torrielli
We apply the algebraic Bethe ansatz technique to compute the eigenvalues of the transfer matrix constructed from the general bound state S-matrix of the light-cone AdS5 x S5 superstring. This allows us to verify certain conjectures on the quantum characteristic function, and to extend them to the general case.
Yu Jia, Wen-Long Sang
Two types of pseudoscalar quarkonium electromagnetic decay processes, i.e. decay to a lepton pair, and to a lepton pair plus a photon (Dalitz decay), are analyzed at the leading order in NRQCD expansion. The former type of processes, highly suppressed in the Standard Model, have been hoped to act as the sensitive probes of the possible new physics. The latte
Gia-Wei Chern, Paula Mellado, O. Tchernyshyov
Spin ice, a peculiar thermal state of a frustrated ferromagnet on the pyrochlore lattice, has a finite entropy density and excitations carrying magnetic charge. By combining analytical arguments and Monte Carlo simulations, we show that spin ice on the two-dimensional kagome lattice orders in two stages. The intermediate phase has ordered magnetic charges an
Jascha Sohl-Dickstein, Peter Battaglino, Michael R. DeWeese
Fitting probabilistic models to data is often difficult, due to the general intractability of the partition function and its derivatives. Here we propose a new parameter estimation technique that does not require computing an intractable normalization factor or sampling from the equilibrium distribution of the model. This is achieved by establishing dynamics
Andrew Berget
Let Δbe a finite sequence of n vectors from a vector space over any field. We consider the subspace of \operatorname{Sym}(V) spanned by \prod_{v \in S} v, where S is a subsequence of Δ. A result of Orlik and Terao provides a doubly indexed direct sum of this space. The main theorem is that the resulting Hilbert series is the Tutte polynomial evaluation T(Δ;1
Ruth Durrer, Giovanni Marozzi, Massimiliano Rinaldi
We discuss the impact of adiabatic renormalization on the power spectrum of scalar and tensor perturbations from inflation. We show that adiabatic regularization is ambiguous as it leads to very different results, for different adiabatic subtraction schemes, both in the range $v\equiv k/(aH) \gsim 0.1$ and in the infrared regime. All these schemes agree in t
Gordon Kane, Ran Lu, Scott Watson
Satellite data is accumulating that suggests and constrains dark matter physics. We argue there is a very well motivated theoretical preexisting framework consistent with dark matter annihilation being observed by the PAMELA satellite detector. The dark matter is (mainly) the neutral W boson superpartner, the wino with mass below 200 GeV. Using the program G
Victor Reiner, Yuval Roichman
For finite reflection groups of types A and B, we determine the diameter of the graph whose vertices are reduced words for the longest element and whose edges are braid relations. This is deduced from a more general theorem that applies to supersolvable hyperplane arrangements.
Sriram Somanchi, Chaitanya Nittala, Narahari Yadati
In this paper, we propose a bid optimizer for sponsored keyword search auctions which leads to better retention of advertisers by yielding attractive utilities to the advertisers without decreasing the revenue to the search engine. The bid optimizer is positioned as a key value added tool the search engine provides to the advertisers. The proposed bid optimi
Ben Elias, Daniel Krasner
Using the diagrammatic calculus for Soergel bimodules developed by B. Elias and M. Khovanov, we show that Rouquier complexes are functorial over braid cobordisms. We explicitly describe the chain maps which correspond to movie move generators.
Esther Hänggi, Renato Renner, Stefan Wolf
Barrett, Hardy, and Kent have shown in 2005 that protocols for quantum key agreement exist the security of which can be proven under the assumption that quantum or relativity theory is correct. More precisely, this is based on the non-local behavior of certain quantum systems, combined with the non-signaling postulate from relativity. An advantage is that th
Ravi Sankrit, W. Van Dyke Dixon
We present observations of O VI 1032 emission around the helium white dwarf KPD 0005+5106 obtained with the Far Ultraviolet Spectroscopic Explorer. Previously published data, reprocessed with an updated version of the calibration pipeline, are included along with new observations. The recent upward revision of the white dwarf's effective temperature to 2
Rosalind J. Allen, Chantal Valeriani, Pieter Rein ten Wolde
Rare events are ubiquitous in many different fields, yet they are notoriously difficult to simulate because few, if any, events are observed in a conventiona l simulation run. Over the past several decades, specialised simulation methods have been developed to overcome this problem. We review one recently-developed class of such methods, known as Forward Flu
O. Bertolami, J. Paramos
In this study one resorts to the phenomenology of models endowed with a non-minimal coupling between matter and geometry, in order to develop a mechanism through which dynamics similar to that due to the presence of dark matter is generated. As a first attempt, one tries to account for the flattening of the galaxy rotation curves as an effect of the non-(cov
Naresh Sharma
We study the fundamental properties of the quantum f-relative entropy, where f(.) is an operator convex function. We give the equality conditions under monotonicity and joint convexity, and these conditions are more general than, since they hold for a class of operator convex functions, and different for f(t) = -ln(t) from, the previously known conditions. T
Thomas Feierl
We consider lattice walks in $\R^k$ confined to the region $0<x_1<x_2...<x_k$ with fixed (but arbitrary) starting and end points. The walks are required to be "reflectable", that is, we assume that the number of paths can be counted using the reflection principle. The main results are asymptotic formulas for the total number of walks of length $n$ wi
Nicolas Dobigeon, Said Moussaoui, Jean-Yves Tourneret, Cedric Carteret
This paper addresses the problem of separating spectral sources which are linearly mixed with unknown proportions. The main difficulty of the problem is to ensure the full additivity (sum-to-one) of the mixing coefficients and non-negativity of sources and mixing coefficients. A Bayesian estimation approach based on Gamma priors was recently proposed to hand
V. Lubicz, F. Mescia, S. Simula, C. Tarantino
We present new lattice results of the K -> pion semileptonic form factors obtained from simulations with two flavors of dynamical twisted-mass fermions, using pion masses as light as 260 MeV. Our main result is f+(0) = 0.9560 (84), which, combined with the latest experimental data for Kl3 decays, leads to |V_{us}| = 0.2267 (5)_exp (20)_f+(0). Using the PDG(2
Frank W. Bentrem
A computational method is presented which efficiently segments digital grayscale images by directly applying the Q-state Ising (or Potts) model. Since the Potts model was first proposed in 1952, physicists have studied lattice models to gain deep insights into magnetism and other disordered systems. For some time, researchers have realized that digital image
Seok Kim, Kallingalthodi Madhu
We study local operators of U(N)xU(N) N=6 Chern-Simons-matter theory including a class of magnetic monopole operators. To take into account the interaction of monopoles and basic fields for large Chern-Simons level k, we consider the appropriate perturbation theory in 1/k which reliably describes small excitations around protected chiral operators. We also c
Tim Clunan, David Seery
We study signatures in the Cosmic Microwave Background (CMB) induced by the presence of strong spatial curvature prior to the epoch of inflation which generated our present universe. If inflation does not last sufficiently long to drive the large-scale spatial curvature to zero, then presently observable scales may have left the horizon while spatial slices
Paul J Cote, Mark A Johnson
In an earlier paper we provided an alternative to the standard gauge concept for deriving the classical electromagnetic wave equations. This alternative involves recognition of two previously overlooked basic equations and represents a simplification of the formalism and a clarification of some basic physics that is obscured in the standard method. It also r
Ivan Gatica Araus
In this article, we prove that if there exists a $σ$-antiset $X^{*}$, of a $σ$-set $X$, then it is unique and therefore we can present a characterization of the $σ$-antiset.
Betseygail Rand, Lorenzo Sadun
We show that every continuous map from one translationally finite tiling space to another can be approximated by a local map. If two local maps are homotopic, then the homotopy can be chosen so that every interpolating map is also local.
Spontaneous formation of a superconducting and antiferromagnetic hybrid state in SrFe2As2 under high pressure
cond-mat.supr-conK. Kitagawa, N. Katayama, H. Gotou, T. Yagi
We report a novel superconducting (SC) and antiferromagnetic (AF) hybrid state in SrFe2As2 revealed by 75As nuclear magnetic resonance (NMR) experiments on a single crystal under highly hydrostatic pressure up to 7 GPa. The NMR spectra at 5.4 GPa indicate simultaneous development of the SC and AF orders below 30 K. The nuclear spin-lattice relaxation rate in
Sergei P. Maydanyuk, Sergei V. Belchikov
We develop a new fully quantum method for determination of widths for nuclear decay by proton emission where multiple internal reflections of wave packet describing tunneling process inside proton--nucleus radial barrier are taken into account. Exact solutions for amplitudes of wave function, penetrability $T$ and reflection $R$ are found for $n$-step barrie
Gonzalo A. Palma, Subodh P. Patil
It is well understood that spatial non-commutativity, if indeed realized in nature, is a phenomenon whose effects are not just felt at energy scales comparable to the non-commutativity scale. Loop effects can transmit signatures of any underlying non-commutativity to macroscopic scales (a manifestation of a phenomenon that has come to be known as UV/IR mode
Mixtures of correlated bosons and fermions: Dynamical mean-field theory for normal and condensed phases
cond-mat.quant-gasKrzysztof Byczuk, Dieter Vollhardt
We derive a dynamical mean-field theory for mixtures of interacting bosons and fermions on a lattice (BF-DMFT). The BF-DMFT is a comprehensive, thermodynamically consistent framework for the theoretical investigation of Bose-Fermi mixtures and is applicable for arbitrary values of the coupling parameters and temperatures. It becomes exact in the limit of hig
Noam Gross, Zav Shotan, Servaas Kokkelmans, Lev Khaykovich
We report on experimental evidence of universality in ultracold 7Li atoms' three-body recombination loss in the vicinity of a Feshbach resonance. We observe a recombination minimum and an Efimov resonance in regions of positive and negative scattering lengths, respectively, which are connected through the pole of the Feshbach resonance. Both observed fea
Jean-Louis Loday
We study the operad of associative algebras equipped with a derivation. We show that it is determined by polynomials in several variables and substitution. Replacing polynomials by rational functions gives an operad which is isomorphic to the operad of "moulds". It provides an efficient environment for doing integro-differential calculus. Interesting
Dong Lai, Wynn C. G. Ho, Matthew van Adelsberg, Chen Wang
We review the polarization properties of X-ray emission from highly magnetized neutron stars, focusing on emission from the stellar surfaces. We discuss how x-ray polarization can be used to constrain neutron star magnetic field and emission geometry, and to probe strong-field quantum electrodynamics and possibly constrain the properties of axions.
Kurt Jacobs
Wave-function Monte Carlo methods are an important tool for simulating quantum systems, but the standard method cannot be used to simulate decoherence in continuously measured systems. Here we present a new Monte Carlo method for such systems. This was used to perform the simulations of a continuously measured nano-resonator in [Phys. Rev. Lett. 102, 057208
Bob Coecke, Ross Duncan
This paper has two tightly intertwined aims: (i) To introduce an intuitive and universal graphical calculus for multi-qubit systems, the ZX-calculus, which greatly simplifies derivations in the area of quantum computation and information. (ii) To axiomatise complementarity of quantum observables within a general framework for physical theories in terms of da
Sergei V. Zhukovsky, Dmitry N. Chigrin
We propose an optical memory cell based on ultrafast wavelength switching in coupled-cavity microlasers, featuring bistability between modes separated by several nanometers. A numerical implementation is demonstrated by simulating a two-dimensional photonic crystal microlaser. Switching times of less than 10 ps, switching energy around 15--30 fJ and on-off c
K. Jansen, C. McNeile, C. Michael, C. Urbach
We report results for the masses of the flavour non-singlet light 0++, 1--, and 1+- mesons from unquenched lattice QCD at two lattice spacings. The twisted mass formalism was used with two flavours of sea quarks. For the 0++ and 1+- mesons we look for the effect of decays on the mass dependence. For the light vector mesons we study the chiral extrapolations
Vadim E. Levit, Eugen Mandrescu
Let alpha(G) be the cardinality of a independence set of maximum size in the graph G, while mu(G) is the size of a maximum matching. G is a Konig--Egervary graph if its order equals alpha(G) + mu(G). The set core(G) is the intersection of all maximum independent sets of G (Levit & Mandrescu, 2002). The number def(G)=|V(G)|-2*mu(G) is the deficiency of G (Lov
Carlo A. Furia, Paola Spoletini
Metric LTL formulas rely on the next operator to encode time distances, whereas qualitative LTL formulas use only the until operator. This paper shows how to transform any metric LTL formula M into a qualitative formula Q, such that Q is satisfiable if and only if M is satisfiable over words with variability bounded with respect to the largest distances used
Yves Brise, Bernd Gärtner
Clarksons algorithm is a two-staged randomized algorithm for solving linear programs. This algorithm has been simplified and adapted to fit the framework of LP-type problems. In this framework we can tackle a number of non-linear problems such as computing the smallest enclosing ball of a set of points in R^d . In 2006, it has been shown that the algorithm i
Nicolas Bernal, Kfir Blum, Marta Losada, Yosef Nir
The addition of non-renormalizable terms involving the Higgs fields to the MSSM (BMSSM) ameliorates the little hierarchy problem of the MSSM. We analyze in detail the two main cosmological issues affected by the BMSSM: dark matter and baryogenesis. The regions for which the relic abundance of the LSP is consistent with WMAP and collider constraints are ident
D. V. Uvarov
The Type IIA superstring action on the AdS_4 x CP^3 background, obtainable by the double dimensional reduction of the AdS_4 x S^7 supermembrane, is considered in the kappa-symmetry light-cone gauge, in which the light-like directions are chosen on the D=3 Minkowski boundary of AdS_4. Such choice of the gauge condition relies on representing the AdS_4 x S^7 b
Modeling self-organization in pedestrians and animal groups from macroscopic and microscopic viewpoints
math-phEmiliano Cristiani, Benedetto Piccoli, Andrea Tosin
This paper is concerned with mathematical modeling of intelligent systems, such as human crowds and animal groups. In particular, the focus is on the emergence of different self-organized patterns from non-locality and anisotropy of the interactions among individuals. A mathematical technique by time-evolving measures is introduced to deal with both macrosco
Teodor Banica
We present a compact formulation of the orthogonal Weingarten formula, with the traditional quantity $I(i_1,...,i_{2k}:j_1,...,j_{2k}) = \int_{O_n}u_{i_1j_1} ... u_{i_{2k}j_{2k}} du$ replaced by the more advanced quantity $I(a)=\int_{O_n}Πu_{ij}^{a_{ij}} du$, depending on a matrix of exponents $a\in M_n(\mathbb N)$. Among consequences, we establish a number
Investigation of Hadronic Interactions at Ultra-High Energies with the Pierre Auger Observatory
astro-ph.HERalf Ulrich
The aim of the Pierre Auger Observatory is the investigation of the nature of cosmic ray particles at ultra-high energies. It can simultaneously observe the longitudinal air shower development in the atmosphere as well as particle densities on the ground. While there are no dedicated muon detectors, techniques have been developed to estimate the number of mu
Guihui Tian, Shuquan Zhong
The perturbation method in supersymmetric quantum mechanics (SUSYQM) is used to study the spheroidal wave functions' recurrence relations, which are revealed by the shape-invariance property of the super-potential. The super-potential is expanded by the parameter alpha and could be gotten by approximation method. Up to the first order, it has the shape-i
Guihui Tian, Shuquan Zhong
The perturbation method in supersymmetric quantum mechanics (SUSYQM) is used to study the spheroidal wave functions' eigenvalue problem. Expanding the super-potential in series of the parameter alpha, the first order term of ground eigen-value and the eigen-function are gotten. In the paper, the very excellent results are that all the first two terms app
Mariano Beguerisse-Diaz, Mason A. Porter, Jukka-Pekka Onnela
We present a dynamical model for rewiring and attachment in bipartite networks in which edges are added between nodes that belong to catalogs that can either be fixed in size or growing in size. The model is motivated by an empirical study of data from the video rental service Netflix, which invites its users to give ratings to the videos available in its ca
Stellar Kinematic Constraints on Galactic Structure Models Revisited: Bar and Spiral Arm Resonances
astro-ph.GAT. Antoja, O. Valenzuela, B. Pichardo, E. Moreno
We study the phase space available to the local stellar distribution using a Galactic potential consistent with several recent observational constraints. We find that the induced phase space structure has several observable consequences. The spiral arm contribution to the kinematic structure in the solar neighborhood may be as important as the one produced b
Manuel Blickle, Karl Schwede, Shunsuke Takagi, Wenliang Zhang
We prove that the $F$-jumping numbers of the test ideal $τ(X; Δ, \ba^t)$ are discrete and rational under the assumptions that $X$ is a normal and $F$-finite variety over a field of positive characteristic $p$, $K_X+Δ$ is $\bQ$-Cartier of index not divisible $p$, and either $X$ is essentially of finite type over a field or the sheaf of ideals $\ba$ is locally
Kowar Richard, Scherzer Otmar, Bonnefond Xavier
The work is inspired by thermo-and photoacoustic imaging, where recent efforts are devoted to take into account attenuation and varying wave speed parameters. In this paper we derive and analyze causal equations describing propagation of attenuated pressure waves. We also review standard models, like frequency power laws, and the thermo-viscous equation and
Joseph Marsano, Natalia Saulina, Sakura Schafer-Nameki
We analyze constraints for embedding local SU(5) F-theory GUTs into consistent compactifications and construct explicit three-generation models based on the geometry of arXiv:0904.3932. The key tool for studying constraints in this problem when there is an underlying E_8 structure is the spectral cover, which encodes all of the symmetries that fix the allowe
C. Giardina, F. Redig, K. Vafayi
We prove a comparison inequality between a system of independent random walkers and a system of random walkers which either interact by attracting each other -- a process which we call here the symmetric inclusion process (SIP) -- or repel each other -- a generalized version of the well-known symmetric exclusion process. As an application, new correlation in
Mehmet Önder, H. Huseyin Uğurlu
In this paper, using the classifications of timelike and spacelike ruled surfaces, we define and study the Mannheim offsets of spacelike ruled surfaces in Minkowski 3-space. We give the conditions for spacelike offset surfaces to be developable.
On subnormal solutions of periodic non-homogeneous linear differential equations, special functions and special polynomials
math.CVY. M. Chiang, K. W. Yu
This paper offers a new and complete description of subnormal solutions of certain non-homogeneous second order periodic linear differential equations first studied by Gundersen and Steinbart in 1994. We have established a previously unknown relation that the general solutions (\textit{i.e.}, whether subnormal or not) of the DEs can be solved explicitly in t
Peter W. Graham, Surjeet Rajendran
We argue that the fermion masses and mixings are organized in a specific pattern. The approximately equal hierarchies between successive generations, the sizes of the mixing angles, the heaviness of just the top quark, and the approximate down-lepton equality can all be accommodated by many flavor models but can appear ad hoc. We present a simple, predictive
J. M. Aldaz, J. Pérez Lázaro
We show that the lowest constant appearing in the weak type (1,1) inequality satisfied by the centered Hardy-Littlewood maximal operator on radial integrable functions is 1.