April 2009 arXiv papers — page 12
Showing 1,101–1,200 of 4,924 papers
Andrew Berdahl, Amer Shreim, Vishal Sood, Maya Paczuski
We clarify the effect different sampling methods and weighting schemes have on the statistics of attractors in ensembles of random Boolean networks (RBNs). We directly measure cycle lengths of attractors and sizes of basins of attraction in RBNs using exact enumeration of the state space. In general, the distribution of attractor lengths differs markedly fro
Christopher O. Ward
When using images to locate objects, there is the problem of correcting for distortion and misalignment in the images. An elegant way of solving this problem is to generate an error correcting function that maps points in an image to their corrected locations. We generate such a function by fitting a polynomial to a set of sample points. The objective is to
Ralph V. Chamberlin, George H. Wolf
The entropy per particle in most Monte-Carlo simulations is size dependent due to correlated energy fluctuations. Guided by nanothermodynamics, we find a constraint for the Ising model that enhances the fluctuations and lowers the free energy, while making the entropy homogeneous, additive, and extensive. Although the average interaction energy becomes size
Sagarmoy Dutta, Piyush P Kurur
In this paper we formulate and study the problem of representing groups on graphs. We show that with respect to polynomial time turing reducibility, both abelian and solvable group representability are all equivalent to graph isomorphism, even when the group is presented as a permutation group via generators. On the other hand, the representability problem f
Young-June Kim, J. P. Hill, H. Yamaguchi, T. Gog
A resonant inelastic x-ray scattering study of the electronic structure of the semiconductor cuprous oxide, $\rm Cu_2O$, is reported. When the incident x-ray energy is tuned to the Cu K-absorption edge, large enhancements of the spectral features corresponding to the electronic transitions between the valence band and the conduction band are observed. A feat
Enrico Vesperini, Stephen L. W. McMillan, Simon Portegies Zwart
In this paper we use N-body simulations to study the effects of primordial mass segregation on the early and long-term evolution of star clusters. Our simulations show that in segregated clusters early mass loss due to stellar evolution triggers a stronger expansion than for unsegregated clusters. Tidally limited, strongly segregated clusters may dissolve ra
Max Tegmark
I use cosmology examples to illustrate that the second law of thermodynamics is not old and tired, but alive and kicking, continuing to stimulate interesting research on really big puzzles. The question "Why is the entropy so low?" (despite the second law) suggests that our observable universe is merely a small and rather uniform patch in a vastly la
J. E. Roa, D. C. Latimer, D. J. Ernst
A three-neutrino analysis of oscillation data is performed using the recent, more finely binned Super-K oscillation data, together with the CHOOZ, K2K, and MINOS data. The solar parameters, $Δ_{21}$ and $θ_{12}$, are fixed from a recent analysis, and $Δ_{32}$, $θ_{13}$, and $θ_{23}$ are varied. We utilize the full three-neutrino oscillation probability and a
Andrew Keenan Richardson, Cole Arthur Brown
Although whether P equals NP is an important, open problem in computer science, and although Jaeger's 2008 paper, "Solving the P/NP Problem Under Intrinsic Uncertainty" (arXiv:0811.0463) presents an attempt at tackling the problem by discussing the possibility that all computation is uncertain to some degree, there are a number of logical oversig
Variability Timescales in the M87 Jet: Signatures of E-Squared Losses, Discovery of a Quasi-period in HST-1, and the Site of TeV Flaring
astro-ph.COD. E. Harris, C. C. Cheung, Lukasz Stawarz, J. A. Biretta
We investigate the variability timescales in the jet of M87 with two goals. The first is to use the rise times and decay times in the radio, ultraviolet and X-ray lightcurves of HST-1 to constrain the source size and the energy loss mechanisms affecting the relativistic electron distributions. HST-1 is the first jet knot clearly resolved from the nuclear emi
Christian Morfonios, Daniel Buchholz, Peter Schmelcher
Employing oval shaped quantum billiards connected by quantum wires as the building blocks of a linear quantum dot array, we calculate the ballistic magnetoconductance in the linear response regime. Optimizing the geometry of the billiards, we aim at a maximal finite- over zero-field ratio of the magnetoconductance. This switching effect arises from a relativ
Control, measurement and propagation of entanglement in photon pairs generated through type-II parametric downconversion
quant-phYasser Jeronimo-Moreno, Alfred B. U'Ren
We present a study of the effects of dispersion on the properties of photon pairs generated by type-II, collinear spontaneous parametric downconversion. Specifically, we take into consideration the effects of a chirped pump, as well as of dispersive propagation of the photon pairs. We present expressions for the joint amplitude both in the spectral and tempo
Gavriel Segre
Recent theologies concerning God's death after Auschwitz are mathematically formalized through a suitable temporalization of Gödel's Ontological Proof.
I. Snyman
When smooth, zero-on-average, periodic magnetic and electric fields are applied to a carbon mono-layer (graphene), a gap between the valence and conduction band is introduced. Here this gapped state is studied analytically. It is found that it does not correspond to a band insulator: a constant electric field induces a quantized Hall current even though the
J. Fransson
The recent experimental conductance measurements taken on magnetic impurities on metallic surfaces, using scanning tunneling microscopy technique and suggesting occurrence of inelastic scattering processes, are theoretically addressed. We argue that the observed conductance signatures are caused by transitions between the spin states which have opened due to
Joern N. Kupferschmidt, Piet W. Brouwer
We find that the triplet Andreev reflection amplitude at the interface between a half-metal and an s-wave superconductor in the presence of a domain wall is significantly enhanced if the half metal is a thin film, rather than an extended magnet. The enhancement is by a factor $l_{\rm d}/d$, where $l_{\rm d}$ is the width of the domain wall and $d$ the film t
B. de B. Pereira, E. M. Nascimento, F. Felix, G. F. M. Rezende
Background and Objective: The survival-agreement plot was proposed and improved to assess the reliability of a quantitative measure. We propose the use of survival analysis as an alternative non-parametric approach for comparison of ordinal qualitative data. Study Design and Setting: Two case studies were presented. The first one is related to a randomized,
J. A. Sheikh, W. Nazarewicz, J. C. Pei
A systematic study of fission-barrier dependence on excitation energy has been performed using the self-consistent finite-temperature Hartree-Fock+BCS (FT-HF+BCS) formalism with the SkM* Skyrme energy density functional. The calculations have been carried out for even-even superheavy nuclei with Z ranging between 110 and 124. For an accurate description of f
Michael C. Kaczmarczik, Gordon T. Richards, Sajjan S. Mehta, David J. Schlegel
The wavelength dependence of atmospheric refraction causes differential chromatic refraction (DCR), whereby objects imaged at different optical/UV wavelengths are observed at slightly different positions in the plane of the detector. Strong spectral features induce changes in the effective wavelengths of broad-band filters that are capable of producing signi
Michael Natapov, Vladimir Turaev
Given commuting elements a, b of a group G and a group epimorphism q : G' \to G with finite kernel, the set of commuting lifts of a, b to G' is finite (possibly, empty). The second named author obtained a formula for the number of such lifts in terms of representations of Ker q. We apply this formula to several group epimorphisms q with the same kern
Harry I. Ringermacher, Lawrence R. Mead
Seigar, et al, have recently demonstrated a new, tight correlation between galactic central supermassive black hole (BH) mass and the pitch angle of the spiral arm in disc galaxies which they attribute to other indirect correlations. They fit a double power law, governed by five parameters, to the BH mass as a function of pitch. Noting the features of their
Galerkin Methods for Parabolic and SCHR{Ö}DINGER Equations with Dynamical Boundary Conditions and Applications to Underwater Acoustics
math.NAD. C. Antonopoulou, V. A. Dougalis, G. E. Zouraris
In this paper we consider Galerkin-finite element methods that approximate the solutions of initial-boundary-value problems in one space dimension for parabolic and Schrödinger evolution equations with dynamical boundary conditions. Error estimates of optimal rates of convergence in $L^2$ and $H^1$ are proved for the accociated semidiscrete and fully discret
Subhasish Mandal, Ranjit Pati
We report first principles density functional calculations of electronic structures and energy bandgaps ($ΔE_g$) in PbS nanowires (NW). The $ΔE_g$ is tuned by varying the diameter of the NW - {\it revealing the role of quantum confinement}. The compressive radial strain (CS) on the NW is shown to be responsible for semiconducting to metallic phase transition
O. Chaix-Pluchery, J. Kreisel
We report an investigation of DyScO3 and GdScO3 single crystals by Raman scattering in various scattering configurations and at various wavelengths. The Raman spectra are well-defined and the reported spectral signature together with the mode assignment sets the basis for the use of Raman scattering for the investigation of RE-scandates. The observed positio
O. Bienaymé, B. Famaey, X. Wu, H. S. Zhao
We look for observational signatures that could discriminate between Newtonian and modified Newtonian (MOND) dynamics in the Milky Way, in view of the advent of large astrometric and spectroscopic surveys. Indeed, a typical signature of MOND is an apparent disk of "phantom" dark matter, which is uniquely correlated with the visible disk-density distr
Yu. M. Bunkov, G. E. Volovik
Bose-Einstein condensation (BEC) is a quantum phenomenon of formation of the collective quantum state, in which the macroscopic number of particles occupies the lowest energy state and thus is governed by a single wave function. Here we highlight the BEC in a magnetic subsystem -- the BEC of magnons, elementary magnetic excitations. Magnon BEC is manifested
P. Jachym, J. Koppen, J. Palous, F. Combes
Ram pressure stripping of galaxies in clusters can yield gas deficient disks. Previous numerical simulations based on various approaches suggested that, except for near edge-on disk orientations, the amount of stripping depends very little on the inclination angle. Following our previous study of face-on stripping, we extend the set of parameters with the di
Christian Wahle
We study the functor of Weil restriction in the category of Huber's adic spaces and in the category of Berkovich spaces. We prove criteria for the representability of these functors in the respective categories. As an application of adic Weil restrictions, we prove that adic Néron models behave well with respect to tamely ramified base change.
Itinerant magnetic multipole moments of rank five, triakontadipoles, as the hidden order in URu$_{2}$Si$_{2}$
cond-mat.str-elFrancesco Crichhio, fredrik Bultmark, Oscar Granas, Lars Nordstrom
A broken symmetry ground state without any magnetic moments has been calculated by means of local-density-approximation to density functional theory plus a local exchange term, the so-called LDA+$U$ approach, for URu$_{2}$Si$_{2}$. The solution is analysed in terms of a multipole tensor expansion of the itinerant density matrix and is found to be a non-trivi
Steve Huntsman
Under the Ansatz that the occupation times of a system with finitely many states are given by the Gibbs distribution, an effective temperature is uniquely determined (up to a choice of scale), and may be computed de novo, without any reference to a Hamiltonian for empirically accessible systems. As an example, the calculation of the effective temperature for
Jaan Pelt
Notions and limits from standard time series analysis must be modified when treating series which are measured irregularly and contain long gaps. Classical Nyquist criterion to estimate frequency range which is potentially recoverable must be modified to handle this more complex situation. When basic exposition of the modified criterion is given in earlier p
P. Godon, E. M. Sion, P. E. Barrett, A. P. Linnell
We present a spectral analysis of the FUSE spectra of EM Cygni, a Z Cam DN system. The FUSE spectrum, obtained in quiescence, consists of 4 individual exposures (orbits): two exposures, at orbital phases phi ~ 0.65 and phi ~ 0.90, have a lower flux; and two exposures, at orbital phases phi =0.15 and 0.45, have a relatively higher flux. The change of flux lev
Steve Kraemer, Rogier Windhorst, Kenneth G. Carpenter, Mike Crenshaw
There are several key open questions as to the nature and origin of AGN including: 1) what initiates the active phase, 2) the duration of the active phase, and 3) the effect of the AGN on the host galaxy. Critical new insights to these can be achieved by probing the central regions of AGN with sub-mas angular resolution at UV/optical wavelengths. In particul
Low-energy pion-pion scattering in the $pp \to ppπ^{+}π^{-}$ and $p\bar p \to p\bar pπ^{+}π^{-}$ reactions
nucl-thPiotr Lebiedowicz, Antoni Szczurek, Robert Kaminski
We evaluate the contribution of pion-pion rescattering to the $p p \to p p π^+ π^-$ and $p \bar p \to p \bar p π^+ π^-$ reactions. We compare our results with the close-to-threshold experimental data. The pion-pion rescattering contribution is found there to be negligible. The predictions for future experiments with PANDA detector at High Energy Storage Ring
E. J. Baurdoux, A. E. Kyprianou, J. C. Pardo
In Gapeev and Kühn (2005), the stochastic game corresponding to perpetual convertible bonds was considered when driven by a Brownian motion and a compound Poisson process with exponential jumps. We consider the same stochastic game but driven by a spectrally positive Lévy process. We establish a complete solution to the game indicating four principle paramet
Yield criteria for quasibrittle and frictional materials: a generalization to surfaces with corners
math-phAndrea Piccolroaz, Davide Bigoni
Convexity of a yield function (or phase-transformation function) and its relations to convexity of the corresponding yield surface (or phase-transformation surface) is essential to the invention, definition and comparison with experiments of new yield (or phase-transformation) criteria. This issue was previously addressed only under the hypothesis of smoothn
B. E. Eichinger
A theory for the transitive action of a group on the configuration space of a system of fermions is shown to lead to the conclusion that bosons can be represented by the action of cosets of the group. By application of the principle to fundamental, indivisible fermions, the symplectic group $Sp(n)$ is shown to be the largest group of isometries of the space.
D. F. Roscoe
Within no inertial frame can stationary charge exist. All charge, wherever it exists, experiences perpetual interaction with charge elsewhere and so can only exist as non-trivial current. It follows that the notion of the electrostatic scalar potential is a pragmatic idealization - it is not fundamental and is useful simply because, in many practical circums
Precise Balancing of Viscous and Radiation Forces on a Particle in Liquid-Filled Photonic Bandgap Fiber
physics.opticsT. G. Euser, M. K. Garbos, J. S. Y. Chen, P. St. J. Russell
It is shown that, in the liquid-filled hollow core of a single-mode photonic crystal fiber, a micron-sized particle can be held stably against a fluidic counter-flow using radiation pressure, and moved to and fro (over 10s of cm) by ramping the laser power up and down. The results represent a major advance over previous work on particle transport in opticall
The normal field instability under side-wall effects: comparison of experiments and computations
nlin.PSC Gollwitzer, A N Spyropoulos, A G Papathanasiou, A G Boudouvis
We consider a single spike of ferrofluid, arising in a small cylindrical container, when a vertically oriented magnetic field is applied. The height of the spike as well as the surface topography is measured experimentally by two different technologies and calculated numerically using the finite element method. As a consequence of the finite size of the cont
Rajesh R Parwani
Nonlinear corrections are proposed to the discrete equispaced area spectrum of quantum black holes obtained previously in some quantisation schemes. It is speculated that such a modified spectrum might be related to the fine structure found using the loop quantum gravity approach.
Two-dimensional kinematics of SLACS lenses: II. Combined lensing and dynamics analysis of early-type galaxies at z = 0.08 - 0.33
astro-ph.COMatteo Barnabe, Oliver Czoske, Leon Koopmans, Tommaso Treu
We present the first detailed analysis of the mass and dynamical structure of a sample of six early-type lens galaxies, selected from the Sloan Lens ACS Survey, in the redshift range 0.08 < z < 0.33. Both Hubble Space Telescope (HST)/ACS high-resolution imaging and VLT VIMOS integral field spectroscopy are available for these systems. The galaxies are modell
M. D. Johannes, Igor Mazin
One year after their initial discovery, two schools of thought have crystallized regarding the electronic structure and magnetic properties of ferropnictide systems. One postulates that these are itinerant weakly correlated metallic systems that become magnetic by virtue of spin-Peierls type transition due to near-nesting between the hole and the electron Fe
Konstantine Zelator
The material of this work is aimed at mathematics educators, as well as math specialists with a keen interest in progressions. In this paper, we study the subject of arithmetic, geometric, mixed, and harmonic progressions or sequences. Some of the material found in Sections 2,3,4,and 5, can also be found in standard precalculus texts. For example, refer to t
R. Cluckers, G. Comte, F. Loeser
We prove that a (globally) subanalytic p-adic function which is locally Lipschitz continuous with some constant C is piecewise (globally on each piece) Lipschitz continuous with possibly some other constant, where the pieces can be taken subanalytic. We also prove the analogous result for a subanalytic family of functions depending on p-adic parameters. The
J. C. Gladstone, T. P. Roberts
We report the results of spectral and temporal variability studies of the ultraluminous X-ray sources (ULXs) contained within the interacting pair of galaxies NGC 4485/4490, combining Chandra and XMM-Newton observations. Each of the four separate observations provide at least modest quality spectra and light curves for each of the six previously identified U
Synthesis, characterization and low temperature studies of iron chalcogenide superconductors
cond-mat.supr-conJ. Janaki, T. Geetha Kumary, Awadhesh Mani, S. Kalavathi
We have synthesized tetragonal iron selenide and telluride superconductors through solid state reaction at 450deg.C and 550deg.C respectively. These synthesis temperatures have been established by optimization. Electrical resistivity and magnetic susceptibility measurements (4.2-300 K) confirm superconductivity with Tc of around 8.5 K in all selenide samples
S. I. Blinnikov, I. V. Panov, M. A. Rudzsky, K. Sumiyoshi
The equation of state and composition of matter are calculated for conditions typical for pre-collapse and early collapse stages in core collapse supernovae. The composition is evaluated under the assumption of nuclear statistical equilibrium, when the matter is considered as an `almost' ideal gas with corrections due to thermal excitations of nuclei, to
D. J. Foster
Previous results on multi-charged Baby Skyrmion solutions have pointed to a modular structure, comprised of charge two rings and single charge one Skyrmions, which combine to form higher charged structures. In this paper we present numerical evidence which shows an alternative finite chain, multi-charged global energy minimum Baby Skymion solution. We then p
Konstantinos Draziotis, Dimitrios Poulakis
We obtain a quantitative version of the classical Chevalley-Weil theorem for curves. Let $ϕ: \tilde{C} \to C$ be an unramified morphism of non-singular plane projective curves defined over a number field $K$. We calculate an effective upper bound for the norm of the relative discriminant of the number field $K(Q)$ over $K$ for any point $P\in C(K)$ and $Q\in
Matias G. dell'Erba, Guillermo R. Zemba
We study a simplified model of the RNA molecule proposed by G. Vernizzi, H. Orland and A. Zee in the regime of strong concentration of positive ions in solution. The model considers a flexible chain of equal bases that can pairwise interact with any other one along the chain, while preserving the property of saturation of the interactions. In the regime cons
Bing Li, Yuexiao Dong
Sufficient dimension reduction methods often require stringent conditions on the joint distribution of the predictor, or, when such conditions are not satisfied, rely on marginal transformation or reweighting to fulfill them approximately. For example, a typical dimension reduction method would require the predictor to have elliptical or even multivariate no
Contribution of single pion electroproduction to the generalized Gerasimov-Drell-Hearn sum rule for the deuteron
nucl-thAlexander Fix, Hartmuth Arenhövel, Mahmoud Tammam
The generalized Gerasimov-Drell-Hearn sum rule is evaluated for the contribution of single pion production on the deuteron by explicit integration up to an energy of 1.5 GeV for both coherent and incoherent production. As elementary $γ^* N\toπN$ amplitude the MAID2003 model has been used. For incoherent production final state interaction is included in the f
Dmitry A. Ryndyk, Pino D'Amico, Klaus Richter
The single-spin memory effect is considered within a minimal polaron model describing a single-level quantum dot interacting with a vibron and weakly coupled to ferromagnetic leads. We show that in the case of strong electron-vibron and Coulomb interactions the rate of spontaneous quantum switching between two spin states is suppressed at zero bias voltage,
P. K. Panda, D. P. Menezes, C. Providência
Quark meson coupling (QMC) models can be successfully applied to the description of compact star properties in nuclear astrophysics as well as to nuclear matter. In the regime of hot hadronic matter very few calculations exist using the QMC model, in particular when applied to particle yields in heavy ion collisions. In the present work, we identify the free
Alexander A. Davydov, Massimo Giulietti, Stefano Marcugini, Fernanda Pambianco
Let A_{R,q} denote a family of covering codes, in which the covering radius R and the size q of the underlying Galois field are fixed, while the code length tends to infinity. In this paper, infinite sets of families A_{R,q}, where R is fixed but q ranges over an infinite set of prime powers are considered, and the dependence on q of the asymptotic covering
Andrew Wynn
Counterexamples are presented to weighted forms of the Weiss conjecture in discrete and continuous time. In particular, for certain ranges of $α$, operators are constructed that satisfy a given resolvent estimate, but fail to be $α$-admissible. For $α\in (-1,0)$ the operators constructed are normal, while for $α\in (0,1)$ the operator is the unilateral shift
D. Jamet, G. Paquin, G. Richomme, L. Vuillon
First introduced in the study of the Sturmian words, the iterated palindromic closure was recently generalized to pseudopalindromes. This operator allows one to construct words with an infinity of pseudopalindromic prefixes, called pseudostandard words. We provide here several combinatorial properties of the fixed points under the iterated pseudopalindromic
Annick Valibouze
In this paper, the changes of representations of a group are used in order to describe its action as algebraic Galois group of an univariate polynomial on the roots of factors of any Lagrange resolvent. By this way, the Galois group of resolvent factors are pre-determinated. In follows, different applications are exposed; in particular, some classical result
A Deep XMM-Newton Serendipitous Survey of a middle-latitude area. II. New deeper X-ray and optical observations
astro-ph.HEG. Novara, N. La Palombara, R. P. Mignani, E. Hatziminaoglou
The radio-quiet neutron star 1E1207.4-5209 has been the target of several XMM-Newton observations, with a total exposure of ~350 ks. The source is located at intermediate galactic latitude (b~10 degrees), i.e. in a sky region with an extremely interesting mix of both galactic and extra-galactic X-ray sources. The aim of our work is to investigate the propert
Antiferromagnetic fluctuations in Fe(Se1-xTex)0.92 (x = 0.75, 1) observed by inelastic neutron scattering
cond-mat.str-elSatoshi Iikubo, Masaki Fujita, Seiji Niitaka, Hidenori Takagi
Motivated by the discovery of superconductivity in F-doped LaFeAsO, we investigated the magnetic fluctuations in a related compound Fe(Se1-xTex)0.92 (x = 0.75, 1) using neutron scattering techniques. Non-superconducting FeTe0.92 shows antiferromagnetic (AF) ordering with the ordering vector |Q| = 0.97 A-1 (Q = (0.5,0,0.5)) at TN ~ 70 K and a structural trans
Three Flavor Neutrino Oscillations in Matter: Flavor Diagonal Potentials, the Adiabatic Basis and the CP phase
hep-phJames P. Kneller, Gail C. McLaughlin
We discuss the three neutrino flavor evolution problem with general, flavor-diagonal, matter potentials and a fully parameterized mixing matrix that includes CP violation, and derive expressions for the eigenvalues, mixing angles and phases. We demonstrate that, in the limit that the mu and tau potentials are equal, the eigenvalues and matter mixing angles t
Yanan Luo, Yu Zhang, Xiangfei Meng, Feng Pan
Patterns of shape-phase transition in the proton-neutron coupled systems are studied within the $SD$-pair shell model. The results show that some transitional patterns in the $SD$-pair shell model are similar to the $U(5)-SU(3)$, $U(5)-SO(6)$ transitions with signatures of the critical point symmetry of the interacting boson model.
Xavier-François Roblot, Alfred Weiss
Recently Ritter and Weiss introduced an equivariant "main conjecture" than generalizes and refines the Main Conjecture of Iwasawa theory. In this paper, we show that, for the prime 2 and a dihedral extension of order 8 over Q, this conjecture is equivalent to a congruence condition on the coefficients of a power series with 2-adic integral coefficien
New Numerical Methods to Evaluate Homogeneous Solutions of the Teukolsky Equation II. Solutions of the Continued Fraction Equation
gr-qcRyuichi Fujita, Hideyuki Tagoshi
We investigate the solution of the continued fraction equation by which we determine "the renormalized angular momentum parameter", $ν$, in the formalism developed by Leaver and Mano, Suzuki, and Takasugi. In this formalism, we describe the homogeneous solutions of the radial Teukolsky equation, which is the basic equation of the black hole perturbat
Sona Pochybova
The ALICE experiment at LHC is dedicated to study matter formed in heavy-ion collisions, but also has a strong physics program for $pp$ collisions. In these collisions, protons will collide at energies never reached before under laboratory conditions. At the high energies, ALICE will enable us to study jet physics in detail, especially the production of mult
Fabio Bossi
The hypothesis of the existence of a secluded gauge sector with manifestations at low energies can be tested at low and medium energy e+e- colliders, such as DAFNE.Some signatures are very straightforward and can be relatively easily isolated against background. Therefore KLOE, with its 2.5 fb-1 of data, and KLOE-2 with its proposed detector's upgrades a
Thermal Vacuum Radiation in Spontaneously Broken Second-Quantized Theories on Curved Phase Spaces of Constant Curvature
hep-thM. Calixto, V. Aldaya
We construct second-quantized (field) theories on coset spaces of pseudo-unitary groups U(p,q)$. The existence of degenerated quantum vacua (coherent states of zero modes) leads to a breakdown of the original pseudo-unitary symmetry. The action of some spontaneously broken symmetry transformations destabilize the vacuum and make it to radiate. We study the s
Magnetic response of the J1-J2 spin Hamiltonian from classical Monte Carlo and Schwinger boson mean field theory
cond-mat.str-elZhihua Yang, Jung Hoon Kim, Jung Hoon Han
Magnetic susceptibilities at several potential ordering wave vectors (0,0), (π,0), and (π,π) are analyzed for the antiferromagnetic J1-J2 spin Hamiltonian by classical Monte Carlo and Schwinger boson mean field theories over the parameter range 0 \le 2J_2/J_1 \le 2. We find a nearly linear-T behavior of the uniform susceptibility that extends up to the tempe
Forrest Sheng Bao, Jue-Ming Gao, Jing Hu, Donald Y. -C. Lie
Approximately over 50 million people worldwide suffer from epilepsy. Traditional diagnosis of epilepsy relies on tedious visual screening by highly trained clinicians from lengthy EEG recording that contains the presence of seizure (ictal) activities. Nowadays, there are many automatic systems that can recognize seizure-related EEG signals to help the diagno
gamma-hadron correlations as a tool to trace the flow of energy lost from hard partons in heavy-ion collisions
hep-phThorsten Renk
High transverse momentum (P_T) gamma-hadron correlations are currently being regarded as the 'golden channel' for the study of the medium produced in ultrarelativistic heavy ion collisions by means of hard probes. This is due to several reasons, all linked to the fact that because of the smallness of the electromagnetic coupling alpha, the photon doe
B. A. Piot, Z. Jiang, C. R. Dean, L. W. Engel
When a strong magnetic field is applied perpendicularly (along z) to a sheet confining electrons to two dimensions (x-y), highly correlated states emerge as a result of the interplay between electron-electron interactions, confinement and disorder. These so-called fractional quantum Hall (FQH) liquids form a series of states which ultimately give way to a pe
Colin Guillarmou, Leo Tzou
On a fixed smooth compact Riemann surface with boundary $(M_0,g)$, we show that the Cauchy data space (or Dirichlet-to-Neumann map $\mc{N}$) of the Schrödinger operator $Δ+V$ with $V\in C^2(M_0)$ determines uniquely the potential $V$. We also discuss briefly the corresponding consequences for potential scattering at 0 frequency on Riemann surfaces with asymp
Francois Hamel, Yannick Sire
This paper is devoted to the study of some qualitative and quantitative aspects of nonlinear propagation phenomena in diffusive media. More precisely, we consider the case a reaction-diffusion equation in a periodic medium with ignition-type nonlinearity, the heterogeneity being on the nonlinearity, the operator and the domain. Contrary to previous works, we
Tomas Persson
We study non-invertible piecewise hyperbolic maps in the plane. The Hausdorff dimension of the attractor is calculated in terms of the Lyapunov exponents, provided that the map satisfies a transversality condition. Explicit examples of maps for which this condition holds are given.
On the Exact Eigenstates and the Ground States Based on the Boson Realization for Many-Quark Model with su(4) Algebraic Structure
hep-phY. Tsue, C. Providencia, J. da Providencia, M. Yamamura
Based on the boson realization, the ground state and phase structure are investigated in a many-quark model with algebraic structure developed in our previous paper, in which the two-body pairing and particle-hole type interactions are active. The physical interpretation of the exact eigenstates obtained in the boson realization in our previous paper is give
Y. Tsue, C. Providencia, J. da Providencia, M. Yamamura
In a many-quark model developed in our previous paper where two-body color pairing and particle-hole type interactions are active, the exact energy eigenstates are re-formed with physically clearer expressions than those derived in our previous paper. By using the re-formed energy eigenstates, two types of the eigenstates in which the pairing correlation and
Eric Gawiser
Spectral Energy Distribution (SED) fitting is a well-developed astrophysical tool that has recently been applied to high-redshift Lyman Alpha-emitting galaxies. If rest-frame ultraviolet through near-infrared photometry is available, it allows the simultaneous determination of the star formation history and dust extinction of a galaxy. Lyman Alpha-emitter SE
Longbo Huang, Michael J. Neely
In this paper, we consider the problem of reducing network delay in stochastic network utility optimization problems. We start by studying the recently proposed quadratic Lyapunov function based algorithms (QLA). We show that for every stochastic problem, there is a corresponding \emph{deterministic} problem, whose dual optimal solution "exponentially at
Marko V. Jankovic
It is well known that projective measurement will not decrease the von Neumann entropy of a quantum state. In this paper, it is shown that projective measurement will not decrease the quantum Tsallis entropy of a quantum state, either. Using a similar analysis, it can be shown that projective measurement will not decrease the quantum unified (r, s)-entropy i
R. Maiolino, P. Caselli, T. Nagao, M. Walmsley
We report the detection of the [CII]157.74um fine-structure line in the lensed galaxy BRI 0952-0115 at z=4.43, using the APEX telescope. This is the first detection of the [CII] line in a source with L_FIR < 10^13 L_sun at high redshift. The line is very strong compared to previous [CII] detections at high-z (a factor of 5-8 higher in flux), partly due to th
Christophe P. Haynes, Anthony P. Roberts
We derive a renormalization method to calculate the spectral dimension $\bar{d}$ of deterministic self-similar networks with arbitrary base units and branching constants. The generality of the method allows the affect of a multitude of microstructural details to be quantitatively investigated. In addition to providing new models for physical networks, the re
Serguei A. Mokhov, Joey Paquet
A Forensic Lucid intensional programming language has been proposed for intensional cyberforensic analysis. In large part, the language is based on various predecessor and codecessor Lucid dialects bound by the higher-order intensional logic (HOIL) that is behind them. This work formally specifies the operational aspects of the Forensic Lucid language and co
Calibration and Performance of the AKARI Far-Infrared Surveyor (FIS) -- Slow-Scan Observation Mode for Point Sources
astro-ph.IMMai Shirahata, Shuji Matsuura, Sunao Hasegawa, Takafumi Ootsubo
We present the characterization and calibration of the Slow-Scan observation mode of the Far-Infrared Surveyor (FIS) onboard the AKARI satellite. The FIS, one of the two focal-plane instruments on AKARI, has four photometric bands between 50--180 um with two types of Ge:Ga array detectors. In addition to the All-Sky Survey, FIS has also taken detailed far-in
A peak in density dependence of electron spin relaxation time in $n$-type bulk GaAs in metallic regime
cond-mat.mtrl-sciK. Shen
We demonstrate that the peak in the density dependence of electron spin relaxation time in $n$-type bulk GaAs in the metallic regime predicted by Jiang and Wu [Phys. Rev. B {\bf 79}, 125206 (2009)] has been realized experimentally in the latest work by Krauß{\em et al}. [arXiv:0902.0270].
Penetration depth, lower critical fields, and quasiparticle conductivity in Fe-arsenide superconductors
cond-mat.supr-conT. Shibauchi, K. Hashimoto, R. Okazaki, Y. Matsuda
In this article, we review our recent studies of microwave penetration depth, lower critical fields, and quasiparticle conductivity in the superconducting state of Fe-arsenide superconductors. High-sensitivity microwave surface impedance measurements of the in-plane penetration depth in single crystals of electron-doped PrFeAsO1-y (y~0.1) and hole-doped Ba1-
Agnes Nagy, K. D. Sen, H. E. Montgomery
Lower bound for the shape complexity measure of López-Ruiz-Mancini-Calbet (LMC), $C_{LMC}$, is derived. Analytical relations for simple examples of the harmonic oscillator, the hydrogen atom and two-electron 'entangled artificial' atom proposed by Moshinsky are derived. Several numerical examples of the spherically confined model systems are presente
Deanna Needell
Compressed sensing has shown that it is possible to reconstruct sparse high dimensional signals from few linear measurements. In many cases, the solution can be obtained by solving an L1-minimization problem, and this method is accurate even in the presence of noise. Recent a modified version of this method, reweighted L1-minimization, has been suggested. Al
Roy Timo, Kim Blackmore, Leif Hanlen
A word-valued source $\mathbf{Y} = Y_1,Y_2,...$ is discrete random process that is formed by sequentially encoding the symbols of a random process $\mathbf{X} = X_1,X_2,...$ with codewords from a codebook $\mathscr{C}$. These processes appear frequently in information theory (in particular, in the analysis of source-coding algorithms), so it is of interest t
Soon-Yi Kang, Chang Heon Kim
After Zagier proved that the traces of singular moduli $j(z)$ are Fourier coefficients of a weakly holomorphic modular form, various properties of the traces of the singular values of modular functions mostly on the full modular group $PSL_2(\mathbb{Z})$ have been investigated such as their exact formulas, limiting distribution, duality, and congruences. The
Effect of electron-doping on spin excitations of underdoped BaFe$_{1.96}$Ni$_{0.04}$As$_{2}$
cond-mat.supr-conLeland W. Harriger, Astrid Schneidewind, Shiliang Li, Jun Zhao
We use neutron scattering to study magnetic order and spin excitations in BaFe$_{1.96}$Ni$_{0.04}$As$_{2}$. On cooling, the system first changes the lattice symmetry from tetragonal to orthoromhbic near $\sim$97 K, and then orders antiferromagnetically at $T_N=91$ K before developing weak superconductivity below $\sim$15 K. Although superconductivity appears
Bhaskar Dutta, Louis Leblond, Kuver Sinha
Recent anomalies in cosmic rays could be due to dark matter annihilation in our galaxy. In order to get the required large cross-section to explain the data while still obtaining the right relic density, we rely on a non standard thermal history between dark matter freeze-out and Big-Bang Nucleosynthesis (BBN). We show that through a reheating phase from the
Dominika Pilarczyk
In this paper, we discuss the asymptotic stability of singular steady states of the nonlinear heat equation in the weighted Lebesgue norms.
Kurt Jacobs
The traditional approach to feedback control is to apply forces to a system by modifying the Hamiltonian. Here we show that quantum systems can be controlled without any Hamiltonian feedback, purely by exploiting the random quantum back-action of a continuous weak measurement. We demonstrate that, quite remarkably, the quantum back-action of such an adaptive
Nir Cohen, Lino Grama, Caio J. C. Negreiros
This paper provides a characterization of homogeneous curves on a geometric flag manifold which are geodesic with respect to any invariant metric. We call such curves homogeneous equigeodesics. We also characterize homogeneous equigeodesics whose associated Killing field is closed, hence, the corresponding geodesics is closed.
Pengtao Li, Zhichun Zhai
In this paper, we establish separate necessary and sufficient John-Nirenberg (JN) type inequalities for functions in $Q_α^β(\mathbb{R}^{n})$ which imply Gagliardo-Nirenberg (GN) type inequalities in $Q_α(\mathbb{R}^{n}).$ Consequently, we obtain Trudinger-Moser type inequalities and Brezis-Gallouet-Wainger type inequalities in $Q_α(\mathbb{R}^{n}).$
Bilipschitz equivalence is not equivalent to quasi-isometric equivalence for finitely generated groups
math.GRTullia Dymarz
We show that certain lamplighter groups that are quasi-isometric to each other are not bilipschitz equivalent. This gives a positive answer to a question in Topics in Geometric Group Theory by Pierre de la Harpe (page 107).
John M. Cornwall
Although gauge-boson propagators in asymptotically-free gauge theories satisfy a dispersion relation, they do not satisfy the Källen-Lehmann (KL) representation because the spectral function changes sign. We argue that this is a simple consequence of asymptotic freedom. On the basis of the QED-like Ward identities of the pinch technique (PT) we claim that th
On the Approximability of Geometric and Geographic Generalization and the Min-Max Bin Covering Problem
cs.DSWenliang Du, David Eppstein, Michael T. Goodrich, George S. Lueker
We study the problem of abstracting a table of data about individuals so that no selection query can identify fewer than k individuals. We show that it is impossible to achieve arbitrarily good polynomial-time approximations for a number of natural variations of the generalization technique, unless P = NP, even when the table has only a single quasi-identify
Marcos Rigol
We use quantum quenches to study the dynamics and thermalization of hardcore bosons in finite one-dimensional lattices. We perform exact diagonalizations and find that, far away from integrability, few-body observables thermalize. We then study the breakdown of thermalization as one approaches an integrable point. This is found to be a smooth process in whic