September 2009 arXiv papers — page 21
Showing 2,001–2,100 of 5,691 papers
Delocalization to self-trapping transition of a Bose fluid confined in a double well potential. An analysis via one- and two-body correlation properties
cond-mat.quant-gasS. F. Caballero Benitez, V. Romero-Rochin, R. Paredes
We revisit the coherent or delocalized to self-trapping transition in an interacting bosonic quantum fluid confined in a double well potential, in the context of full quantum calculations. We show that an $N$-particle Bose-Hubbard fluid reaches an stationary state through the two-body interactions. These stationary states are either delocalized or self-trapp
J. S. Clark, P. A. Crowther, V. J. Mikles
X-ray and near-IR surveys of the central 2x0.8 degrees of the Galactic Centre have revealed a population of X-ray bright massive stars. However, the nature of the emission, originating in a wind collision zone or via accretion onto a compact object, is uncertain. In order to address this we investigated the nature of the luminous X-ray source CXOGC J174536.1
Cosmic Infrared Background Fluctuations in Deep Spitzer IRAC Images: Data Processing and Analysis
astro-ph.COR. G. Arendt, A. Kashlinsky, S. H. Moseley, J. Mather
This paper provides a detailed description of the data reduction and analysis procedures that have been employed in our previous studies of spatial fluctuation of the cosmic infrared background (CIB) using deep Spitzer IRAC observations. The self-calibration we apply removes a strong instrumental signal from the fluctuations which would otherwise corrupt our
Effect of pseudogap formation on the penetration depth of underdoped high $T_c$ cuprates
cond-mat.supr-conJ. P. Carbotte, K. A. G. Fisher, J. P. F. LeBlanc, E. J. Nicol
The penetration depth is calculated over the entire doping range of the cuprate phase diagram with emphasis on the underdoped regime. Pseudogap formation on approaching the Mott transition, for doping below a quantum critical point, is described within a model based on the resonating valence bond spin liquid which provides an ansatz for the coherent piece of
Polarization properties in the transition from below to above lasing threshold in broad-area vertical-cavity surface-emitting lasers
nlin.PSM. Schulz-Ruhtenberg, I. V. Babushkin, N. A. Loiko, K. F. Huang
For highly divergent emission of broad-area vertical-cavity surface-emitting lasers (VCSELs) a rotation of the polarization direction by up to 90 degrees occurs when the pump rate approaches the lasing threshold. Well below threshold the polarization is parallel to the direction of the transverse wave vector and is determined by the transmissive properties o
H. Allmaier, L. Chioncel, E. Arrigoni, M. I. Katsnelson
Electron correlation effects in the half-metallic ferromagnet NiMnSb are investigated within a combined density functional and many-body approach. Starting from a realistic multi-orbital Hubbard-model including Mn and Ni-d orbitals, the many-body problem is addressed via the Variational Cluster Approach. The density of states obtained in the calculation show
F. Giazotto, J. T. Peltonen, M. Meschke, J. P. Pekola
We present the realization and characterization of a novel-concept interferometer, the superconducting quantum interference proximity transistor (SQUIPT). Its operation relies on the modulation with the magnetic field of the density of states of a proximized metallic wire embedded in a superconducting ring. Flux sensitivities down to $\sim 10^{-5} Φ_0$Hz$^{-
John R. Klein, Claude L. Schochet, Samuel B. Smith
Let $A$ be a unital $C^*$-algebra. Its unitary group, $UA$, contains a wealth of topological information about $A$. However, the homotopy type of $UA$ is out of reach even for $A = M_2(\CC)$. There are two simplifications which have been considered. The first, well-traveled road, is to pass to $π_*(U(A\otimes \KK ))$ which is isomorphic (with a degree shift)
Isabeau Birindelli, Francoise Demengel
In this article we prove that solutions of singular fully nonlinear partial differential equations are $C^{1,β}$. We also prove the simplicity of the principal eigenvalues for the Dirichlet Problem associated to these operators using that regularity, a strict comparison principle and Sard's theorem.
Mario Bessa, Celia Ferreira, Jorge Rocha
A Hamiltonian level, say a pair $(H,e)$ of a Hamiltonian $H$ and an energy $e \in \mathbb{R}$, is said to be Anosov if there exists a connected component $\mathcal{E}_{H,e}$ of $H^{-1}({e})$ which is uniformly hyperbolic for the Hamiltonian flow $X_H^t$. The pair $(H,e)$ is said to be a Hamiltonian star system if there exists a connected component $\mathcal{
M. Pizzi
I reply to the four points raised by S. A. Hayward, R. Di Criscienzo, M. Nadalini, L. Vanzo, S. Zerbini (arXiv:0909.2956v1) against my comment (arXiv:0907.2020v1) to their previous article. I maintain my position on the wrongness of their paper, reporting also another mistake.
A. Sapar, A. Aret, L. Sapar, R. Poolamäe
Formation of anomalous isotope abundances in the atmospheres of chemically peculiar (CP) stars can be explained by light-induced drift (LID). This effect is additional to the radiative acceleration and appears due to systematic asymmetry of radiative flux in partly overlapping isotopic spectral line profiles. LID causes levitation of an isotope with a red-sh
Peter J. Eccles, Hadi Zare
This note is about spherical classes in $H_*Q_0S^0$. A conjecture, due to Ed. Curtis, predicts that only Hopf invariant one and Kervaire invariant one elements will give rise to spherical classes in $H_*Q_0S^0$. Yet, there has been no proof of this conjecture around. Assuming that this conjecture fails, there must exist some other spherical classes in $H_*Q_
Roni Parshani, Lidia A. Braunstein, Shlomo Havlin
We present a unified scaling theory for the structural behavior of polymers embedded in a disordered energy substrate. An optimal polymer configuration is defined as the polymer configuration that minimizes the sum of interacting energies between the monomers and the substrate. The fractal dimension of the optimal polymer in the limit of strong disorder (SD)
J. Sabater, S. Leon, L. Verdes-Montenegro, U. Lisenfeld
The project AMIGA (Analysis of the interstellar Medium of Isolated GAlaxies) provides a statistically significant sample of the most isolated galaxies in the northern sky. Such a control sample is necessary to understand the role of the environment in evolution and galaxy properties like the interstellar medium (ISM), star formation and nuclear activity. The
Optimization of large homogeneous air Cherenkov arrays and application to the design of a 1TeV-100TeV gamma-ray observatory
astro-ph.IMPierre Colin, Stephan LeBohec
At the time large air Cherenkov arrays are being discussed for future gamma-ray observatories, we review the relationship between the targeted capabilities and the main design parameters taking into account construction costs. As an example application, we describe a telescope array optimized for observations between 1 TeV and a few 100 TeV and use detailed
The Hurewicz image of the $η_i$ family, a polynomial subalgebra of $H_*Ω_0^{2^{i+1}-8+k}S^{2^i-2}$
math.ATPeter J. Eccles, Hadi Zare
We consider the problem of calculating the Hurewicz image of Mahowald's family $η_i\in{_2π_{2^i}^S}$. This allows us to identify specific spherical classes in $H_*Ω_0^{2^{i+1}-8+k}S^{2^i-2}$ for $0\leqslant k\leqslant 6$. We then identify the type of the subalgebras that these classes give rise to, and calculate the $A$-module and $R$-module structure of
M. Kidszun, S. Haindl, E. Reich, J. Haenisch
Superconducting and epitaxially grown LaFeAsOF thin films were successfully prepared on (001)-oriented LaAlO3 substrates using pulsed laser deposition. The prepared thin films show exclusively a single in-plane orientation with epitaxial relation (001)[100] parallel to (001)[100] and a FWHM value of 1deg. Furthermore, resistive measurement of the superconduc
Anatoly Pashkevich, Damien Chablat, Philippe Wenger
The paper proposes a new calibration method for parallel manipulators that allows efficient identification of the joint offsets using observations of the manipulator leg parallelism with respect to the base surface. The method employs a simple and low-cost measuring system, which evaluates deviation of the leg location during motions that are assumed to pres
P B Jones
Protons produced in electromagnetic showers formed by the reverse-electron flux are usually the largest component of the time-averaged polar-cap open magnetic flux-line current in neutron stars with positive corotational charge density. Although the electric-field boundary conditions in the corotating frame are time-independent, instabilities on both medium
Sara Felloni, Giuliano Strini
In the framework of ion-trap quantum computing, we develop a characterization of experimentally realistic imperfections which may affect the Cirac-Zoller implementation of the CNOT gate. The CNOT operation is performed by applying a protocol of five laser pulses of appropriate frequency and polarization. The laser-pulse protocol exploits auxiliary levels, an
Tensor part of the Skyrme energy density functional. II: Deformation properties of magic and semi-magic nuclei
nucl-thM. Bender, K. Bennaceur, T. Duguet, P. -H. Heenen
We study systematically the impact of the time-even tensor terms of the Skyrme energy density functional, i.e. terms bilinear in the spin-current tensor density, on deformation properties of closed shell nuclei corresponding to 20, 28, 40, 50, 82, and 126 neutron or proton shell closures. We compare results obtained with three different families of Skyrme pa
Kenichi Konishi, Yutaka Ookouchi
The smallest integer t for which the Wilson loop W^{t} fails to exhibit area law is known as the confinement index of a given field theory. The confinement index provides us with subtle information on the vacuum properties of the system. We study the behavior of the Wilson and 't Hooft loops and compute the confinement index in a wide class of N=1 supersymme
Extensive optical and near-infrared observations of the nearby, narrow-lined type Ic SN 2007gr: days 5 to 415
astro-ph.SRDeborah J. Hunter, Stefano Valenti, Rubina Kotak, Peter Meikle
We present photometric and spectroscopic observations at optical and near-infrared wavelengths of the nearby type Ic SN 2007gr. These represent the most extensive data-set to date of any supernova of this sub-type, with frequent coverage from shortly after discovery to more than one year post-explosion. We deduce a rise time to B-band maximum of 11.5 \pm 2.7
Eddy Godelle
The attracting set and the inverse limit set are important objects associated to a self-map on a set. We call \emph{stable set} of the self-map the projection of the inverse limit set. It is included in the attracting set, but is not equal in the general case. Here we determine whether or not the equality holds in several particular cases, among which are th
C. Rodríguez-López, A. Moya, R. Garrido, J. MacDonald
We have explored the possibility of driving pulsation modes in models of sdO stars in which the effects of element diffusion, gravitational settling and radiative levitation have been neglected so that the distribution of iron-peak elements remains uniform throughout the evolution. The stability of these models was determined using a non-adiabatic oscillatio
Trigonometric Parallaxes of Massive Star-Forming Regions: VII. G9.62+0.20 and the Expanding 3 KPC-ARM
astro-ph.GAA. Sanna, M. J. Reid, L. Moscadelli, T. M. Dame
We report a trigonometric parallax of 12 GHz methanol masers associated with the massive star forming region G9.62+0.20, corresponding to a distance of 5.2+-0.6 kpc. With a local standard of rest velocity of about 2 km/s, the region's kinematic distances of 0.5 and 16 kpc differ greatly from the distance derived here. Our measurement of the peculiar moti
Werner Bernreuther, Patrick Gonzalez, Martin Wiebusch
We examine, in a number of Standard Model extensions, whether the decays $A \to WW/ZZ$ of a neutral pseudoscalar (Higgs) resonance can have branching ratios at the percent level and we determine the possible size of $B(A \to WW/ZZ)$ relative to the respective branching ratios of a scalar boson $H$. The branching ratios of the these decay modes and the total
Soo-hyeon Nam, Kang Young Lee, Yong-Yeon Keum
We discuss the aspects of the fermions and gauge bosons in $SU(4)_L \times U(1)_X$ models with little Higgs. We introduce a set of fermions which ensures the cancellation of gauge anomaly, and explicitly show the cancellation of one-loop quadratic divergence to the Higgs mass from all fermion multiplets and all gauge bosons. We present the interactions of th
Georgi Dimitroff, Michael Scheutzow
We show that a stochastic flow which is generated by a stochastic differential equation on $\R^d$ with bounded volatility has a random attractor provided that the drift component in the direction towards the origin is larger than a certain strictly positive constant $β$ outside a large ball. Using a similar approach, we provide a lower bound for the linear g
Claus Kiefer
Time is absolute in standard quantum theory and dynamical in general relativity. The combination of both theories into a theory of quantum gravity leads therefore to a "problem of time". In my essay I shall investigate those consequences for the concept of time that may be drawn without a detailed knowledge of quantum gravity. The only assumptions ar
Laurent Pizzagalli, Julien Godet, Sandrine Brochard
We report an unexpected characteristic of dislocation cores in silicon. Using first-principles calculations, we show that all the stable core configurations for a non-dissociated 60$^\circ$ dislocation are sessile. The only glissile configuration, previously obtained by nucleation from surfaces, surprinsingly corresponds to an unstable core. As a result, the
Alf Onshuus, Alex Usvyatsov
In the first part of the paper we study orthogonality, domination, weight, regular and minimal types in the contexts of rosy and super-rosy theories. Then we try to develop analogous theory for arbitrary dependent theories.
Wei Chen, Xifan Wu, Roberto Car
The x-ray absorption spectra of water and ice are calculated with a many-body approach for electron-hole excitations. The experimental features, including the small effects of temperature change in the liquid, are quantitatively reproduced from molecular configurations generated by ab-initio molecular dynamics. The spectral difference between the solid and t
Suppression of radiation loss by hybridization effect in two coupled split-ring resonators
physics.opticsT. Q. Li, H. Liu, T. Li, S. M. Wang
This paper investigates the radiation properties of two coupled split-ring resonators (SRRs). Due to electromagnetic coupling, two hybrid magnetic plasmon modes were induced in the structure. Our calculations show that the radiation loss of the structure was greatly suppressed by the hybridization effect. This led to a remarkable increase in the Q-factor of
Bart-Jan Pors, C. H. Monken, Eric R. Eliel, J. P. Woerdman
We demonstrate experimentally how orbital-angular-momentum entanglement of two photons evolves under influence of atmospheric turbulence. We find that the quantum channel capacity is surprisingly robust: Its typical horizontal decay distance is of the order of 2 kilometers, demonstrating the potential of photonic orbital angular momentum for free-space quant
Phase-charge duality in Josephson junction circuits: Role of inertia and effect of microwave irradiation
cond-mat.mes-hallW. Guichard, F. W. J. Hekking
We investigate the physics of coherent quantum phase slips in two distinct circuits containing small Josephson junctions: (i) a single junction embedded in an inductive environment and (ii) a long chain of junctions. Starting from the standard Josephson Hamiltonian, the single junction circuit can be analyzed using quasi-classical methods; we formulate the c
The physical origin and the diagnostic potential of the scattering polarization in the lithium resonance doublet at 6708 A
astro-ph.SRLuca Belluzzi, Egidio Landi Degl'Innocenti, Javier Trujillo Bueno
High-sensitivity measurements of the linearly-polarized solar limb spectrum produced by scattering processes in quiet regions of the solar atmosphere showed that the Q/I profile of the lithium doublet at 6708 A has an amplitude ~10^{-4} and a curious three-peak structure, qualitatively similar to that found and confirmed by many observers in the Na I D_2 lin
Kuldeep Dixit, E. C. G. Sudarshan
Quantum channels can be mathematically represented as completely positive trace-preserving maps that act on a density matrix. A general quantum channel can be written as a convex sum of `extremal' channels. We show that for an $N$-level system, the extremal channel can be characterized in terms of $N^2$-$N$ real parameters coupled with rotations. We give
Anton Alekseev, Charles Torossian
We show that the Kashiwara-Vergne (KV) problem for quadratic Lie algebras (that is, Lie algebras admitting an invariant scalar product) reduces to the problem of representing the Campbell-Hausdorff series in the form ln(e^xe^y)=x+y+[x,a(x,y)]+[y,b(x,y)], where a(x,y) and b(x,y) are Lie series in x and y. This observation explains the existence of explicit ra
Károly J. Böröczky, Keith M. Ball
Two consequences of the stability version of the one dimensional Prékopa-Leindler inequality are presented. One is the stability version of the Blaschke-Santaló inequality, and the other is a stability version of the Prékopa-Leindler inequality for even functions in higher dimensions, where a recent stability version of the Brunn-Minkowski inequality is also
${\mathcal O}$-operators of Loday algebras and analogues of the classical Yang-Baxter equation
math-phChengming Bai
We introduce notions of ${\mathcal O}$-operators of the Loday algebras including the dendriform algebras and quadri-algebras as a natural generalization of Rota-Baxter operators. The invertible $\mathcal O$-operators give a sufficient and necessary condition on the existence of the $2^{n+1}$ operations on an algebra with the $2^{n}$ operations in an associat
Ch. C. Moustakidis
We provide an equation of state for high density supernova matter by applying a momentum-dependent effective interaction. We focus on the study of the equation of state of high-density and high-temperature nuclear matter containing leptons (electrons and neutrinos) under the chemical equilibrium condition. Thermal effects on the properties and equation of st
Károly J. Böröczky, Keith M. Ball
We prove a stability version of the Prékopa-Leindler inequality.
Zhen-Yu Wu, Xu Zhou, Jun Ma, Cui-Hua Du
We present and analyze kinematics and orbits for a sample of 488 open clusters in the Galaxy. The velocity ellipsoid for our present sample is derived as ($σ_{U}$, $σ_{V}$, $σ_{W})$=$(28.7$, 15.8, 11.0) km s$^{-1}$ which represents a young thin disc population. We also confirm that the velocity dispersions increase with the age of cluster subsample. The orbi
Paolo Michetti, Giuseppe Iannaccone
Nanotransistors typically operate in far-from-equilibrium (FFE) conditions, that cannot be described neither by drift-diffusion, nor by purely ballistic models. In carbonbased nanotransistors, source and drain contacts are often characterized by the formation of Schottky Barriers (SBs), with strong influence on transport. Here we present a model for onedimen
Vadim Mogilevskii
The main objects of our considerations are differential operators generated by a formally selfadjoint differential expression of an even order on the interval $[0,b> (b\leq \infty)$ with operator valued coefficients. We complement and develop the known Shtraus' results on generalized resolvents and characteristic matrices of the minimal operator $L_0$. O
M. Rüger, F. Spanier, K. Mannheim
We employ a time-dependent synchrotron-self-Compton code for modeling contemporaneous multiwavelength data of the blazar 1 ES 1218+30.4 The input parameters of the model are used to infer physical parameters of the emitting region. An acceptable fit to the data is obtained by taking into account a stellar emission component in the optical regime due to the h
How many bits may fit in a single magnetic dot? XMCD-PEEM evidences the switching of Néel caps inside Bloch domain walls
cond-mat.mtrl-sciFabien Cheynis, Aurélien Masseboeuf, Olivier Fruchart, Nicolas Rougemaille
Data storage relies on the handling of two states, called bits. The market of mass storage is currently still dominated by magnetic technology, hard disk drives for the broad public and tapes for massive archiving. In these devices each bit is stored in the form of the direction of magnetization of nanosized magnetic domains, i.e. areas of ferromagnetic mate
Spatially-temporal dynamics of a passively Q-switched Raman-active solid-state oscillator
physics.opticsV. L. Kalashnikov, A. M. Malyarevich, K. V. Yumashev
The spatially-temporal model of an all-solid-state passively Q-switched oscillator with an active medium providing the stimulated Raman scattering is presented. The model does not presume a Gaussian shape of the cylindrically symmetric modes at both fundamental and Stokes wavelengths. It is found, that the highly-nontrivial spatially-temporal dynamics can be
Electron transfer through a multiterminal quantum ring: magnetic forces and elastic scattering effects
cond-mat.mes-hallB. Szafran, M. R. Poniedzialek
We study electron transport through a semiconductor quantum ring with one input and two output terminals for an elastic scatterer present within one of the arms of the ring. We demonstrate that the scatterer not only introduces asymmetry in the transport probability to the two output leads but also reduces the visibility of the Aharonov-Bohm conductance osci
Maria Bondani, Alessia Allevi, Alessandra Andreoni
We present the reconstruction of the Wigner function of a classical phase-sensitive state, a pulsed coherent state, by measurements of the distributions of detected-photons of the state displaced by a coherent probe field. By using a hybrid photodetector operated above its photon-resolving regime, we obtained both the statistics at different values of the pr
Carlo Marinelli, Giacomo Ziglio
We study the asymptotic behavior of solutions to stochastic evolution equations with monotone drift and multiplicative Poisson noise in the variational setting, thus covering a large class of (fully) nonlinear partial differential equations perturbed by jump noise. In particular, we provide sufficient conditions for the existence, ergodicity, and uniqueness
The spin-1/2 J1-J2 Heisenberg antiferromagnet on the square lattice: Exact diagonalization for N=40 spins
cond-mat.str-elJ. Richter, J. Schulenburg
We present numerical exact results for the ground state and the low-lying excitations for the spin-1/2 J1-J2 Heisenberg antiferromagnet on finite square lattices of up to N=40 sites. Using finite-size extrapolation we determine the ground-state energy, the magnetic order parameters, the spin gap, the uniform susceptibility, as well as the spin-wave velocity
N. J. Upadhyay, B. K. Jain, K. P. Khemchandani, N. G. Kelkar
A model for the p d --> p d eta reaction published earlier, including the final state interaction (FSI) of all particles, is revisited to investigate the low energy data on this reaction. The three body problem of p-d-eta scattering in the final state is approximated in terms of pairwise interactions between the three particles in the final state. Apart from
Riccardo Balzan, Fergal Dalton, Vittorio Loreto, Alberto Petri
In this work we experimentally study the behavior of a freely-rotating asymmetric probe immersed in a vibrated granular medium. For a wide variety of vibration conditions the probe exhibits a steady rotation whose direction is constant with respect to the asymmetry. By changing the vibration amplitude and by filtering the noise in different frequency bands w
T. Monz, K. Kim, A. S. Villar, P. Schindler
Any residual coupling of a quantum computer to the environment results in computational errors. Encoding quantum information in a so-called decoherence-free subspace provides means to avoid these errors. Despite tremendous progress in employing this technique to extend memory storage times by orders of magnitude, computation within such subspaces has been sc
M. Giordano, E. Meggiolaro
We discuss the analyticity properties of the Wilson--loop correlation functions relevant to the problem of soft high-energy scattering, directly at the level of the functional integral, in a genuinely nonperturbative way.
Santanu K. Maiti
Electron transport characteristics through molecular wires are studied by using the Green's function formalism. Parametric calculations are performed based on the tight-binding model to investigate the transport properties through the wires. The transport characteristics are significantly influenced by (a) the interference effects, (b) chemical substitue
Carlo Morosi, Livio Pizzocchero
We consider the incompressible Navier-Stokes (NS) equations on a torus, in the setting of the spaces L^2 and H^1; our approach is based on a general framework for semi- or quasi-linear parabolic equations proposed in the previous work [9]. We present some estimates on the linear semigroup generated by the Laplacian and on the quadratic NS nonlinearity; these
T. M. Potter, L. Staveley-Smith, C. -Y. Ng, Lewis Ball
The aftermath of supernova (SN) 1987A continues to provide spectacular insights into the interaction between a SN blastwave and its circumstellar en- vironment. We here present 36 GHz observations from the Australia Telescope Compact Array of the radio remnant of SN 1987A. These new images, taken in 2008 Apr and 2008 Oct, substantially extend the frequency r
Rui-Xue Xu, Bao-Ling Tian, Jian Xu, Qiang Shi
We propose a nonperturbative quantum dissipation theory, in term of hierarchical quantum master equation. It may be used with a great degree of confidence to various dynamics systems in condensed phases. The theoretical development is rooted in an improved semiclassical treatment of Drude bath, beyond the conventional high temperature approximations. It lead
Anharmonicity and quasi-localization of the excess low-frequency vibrations in jammed solids
cond-mat.softNing Xu, Vincenzo Vitelli, Andrea J. Liu, Sidney R. Nagel
We compare the harmonic and anharmonic properties of the vibrational modes in 3-dimensional jammed packings of frictionless spheres interacting via repulsive, finite range potentials. A crossover frequency is apparent in the density of states, the diffusivity and the participation ratio of the modes. At this frequency, which shifts to zero at the jamming thr
D. L. Zhou
We develop a numerical algorithm to calculate the degrees of irreducible multiparty correlations for an arbitrary multiparty quantum state, which is efficient for any quantum state of up to five qubits. We demonstrate the power of the algorithm by the explicit calculations of the degrees of irreducible multiparty correlations in the 4-qubit GHZ state, the Sm
Ingrid Bauer, Fabrizio Catanese
This is the first in a series of articles on the moduli spaces of Burniat surfaces. We prove that Burniat surfaces are Inoue surfaces and we calculate their fundamental groups. As a main result of this paper we prove that every smooth projective surface which is homotopically equivalent to a primary Burniat surface (i.e., a Burniat surface with K^2 = 6) is i
Quirin P. Unterreithmeier, Thomas Faust, Jorg P. Kotthaus
The oscillatory response of nonlinear systems exhibits characteristic phenomena such as multistability, discontinuous jumps and hysteresis. These can be utilized in applications leading, e.g., to precise frequency measurement, mixing, memory elements, reduced noise characteristics in an oscillator or signal amplification. Approaching the quantum regime, conc
Yunjian Wu
Let $γ(G)$ denote the domination number of a graph $G$. A {\it Roman domination function} of a graph $G$ is a function $f: V\to\{0,1,2\}$ such that every vertex with 0 has a neighbor with 2. The {\it Roman domination number} $γ_R(G)$ is the minimum of $f(V(G))=Σ_{v\in V}f(v)$ over all such functions. Let $G\square H$ denote the Cartesian product of graphs $G
Experimental probing of the interplay between ferromagnetism and localisation in (Ga,Mn)As
cond-mat.mtrl-sciMaciej Sawicki, Daichi Chiba, Anna Korbecka, Yu Nishitani
The question whether the Anderson-Mott localisation enhances or reduces magnetic correlations is central to the physics of magnetic alloys. Particularly intriguing is the case of (Ga,Mn)As and related magnetic semiconductors, for which diverging theoretical scenarios have been proposed. Here, by direct magnetisation measurements we demonstrate how magnetism
Yaniv Erlich, Assaf Gordon, Michael Brand, Gregory J. Hannon
Significant volumes of knowledge have been accumulated in recent years linking subtle genetic variations to a wide variety of medical disorders from Cystic Fibrosis to mental retardation. Nevertheless, there are still great challenges in applying this knowledge routinely in the clinic, largely due to the relatively tedious and expensive process of DNA sequen
Ievgen Karnaukh
In the article the distributions of overjump functionals for almost semi-continuous processes on a finite irreducible Markov chain are considered.
Testing the Accretion Flow with Plasma Wave Heating Mechanism for Sagittarius a* by the 1.3MM Vlbi Measurements
astro-ph.GALei Huang, Rohta Takahashi, Zhi-Qiang Shen
The vicinity of the supermassive black hole associated with the compact radio source Sagittarius (Sgr) A* is believed to dominate the observed emission at wavelengths near and shorter than $\sim$ 1 millimeter. We show that a general relativistic accretion flow, heated via the plasma wave heating mechanism, is consistent with the polarization and recent mm-VL
Christian Haase, Gregg Musiker, Josephine Yu
A tropical curve Γis a metric graph with possibly unbounded edges, and tropical rational functions are continuous piecewise linear functions with integer slopes. We define the complete linear system |D| of a divisor D on a tropical curve Γanalogously to the classical counterpart. We investigate the structure of |D| as a cell complex and show that linear syst
Kevin H. Knuth
Previous derivations of the sum and product rules of probability theory relied on the algebraic properties of Boolean logic. Here they are derived within a more general framework based on lattice theory. The result is a new foundation of probability theory that encompasses and generalizes both the Cox and Kolmogorov formulations. In this picture probability
The phase structure of QGP-Hadron in a statistical model using Cornell, Richardson and Peshier potentials
hep-phR. Ramanathan, Agam K. Jha, K. K. Gupta, S. S. Singh
We study the phase structure of the QGP-Hadron system under quasi-static equilibrium using the Ramanathan et al. statistical model for the QGP fireball formation in a hadronic medium. While in the earlier published studies we had used the Peshier effective potential which is appropriate for the deconfined QGP phase but could be extrapolated to the transition
Yaming Yu
An inequality concerning ratios of gamma functions is proved. This answers a question of Guo and Qi (2003).
Xinyi Yuan
For a hermitian line bundle over an arithmetic variety, we construct a convex continuous function on the Okounkov body associated to the generic fibre of the line bundle. The integration of the continuous function gives the growth of the Euler characteristic of the hermitian line bundle. It is the global version of the recent work of Nystrom.
V. K. Sangwan, V. W. Ballarotto, M. S. Fuhrer, E. D. Williams
A simple scalable scheme is reported for fabricating suspended carbon nanotube field effect transistors (CNT-FETs) without exposing pristine as-grown carbon nanotubes to subsequent chemical processing. Versatility and ease of the technique is demonstrated by controlling the density of suspended nanotubes and reproducing devices multiple times on the same ele
Yilun Shang
A random geometric graph $G_n$ is given by picking $n$ vertices in $\mathbb{R}^d$ independently under a common bounded probability distribution, with two vertices adjacent if and only if their $l^p$-distance is at most $r_n$. We investigate the distant-$l$ chromatic number $χ_l(G_n)$ of $G_n$ for $l\ge1$. Complete picture of the ratios of $χ_l(G_n)$ to the c
Elizabeth K. Mahony, Scott M. Croom, Brian J. Boyle, Alastair C. Edge
We present a catalogue of 3405 X-ray sources from the ROSAT All Sky Survey (RASS) Bright Source Catalogue which fall within the area covered by the 6dF Galaxy Survey (6dFGS). The catalogue is count-rate limited at 0.05 cts\s in the X-ray and covers the area of sky with delta < 0 deg and |b|>10 deg. The RASS--6dFGS sample was one of the additional target cata
Co-evolution of AGN and Star-forming Galaxies in the Australia Telescope Large Area Survey
astro-ph.CORay P. Norris, the ATLAS team
ATLAS (Australia Telescope Large Area Survey) is a wide deep radio survey which is distinguished by its comprehensive multi-wavelength approach. ATLAS is creating a large dataset of radio-selected galaxies for studying the evolution and inter-relationship of star-forming and active galaxies. Although the project is far from complete, we are already starting
The capacitance of the circular parallel plate capacitor obtained by solving the Love integral equation using an analytic expansion of the kernel
math-phMartin Norgren, B. L. G. Jonsson
The capacitance of the circular parallel plate capacitor is calculated by expanding the solution to the Love integral equation into a Fourier cosine series. Previously, this kind of expansion has been carried out numerically, resulting in accuracy problems at small plate separations. We show that this bottleneck can be alleviated, by calculating all expansio
Yi-Kuo Yu
A rigorous derivation of the density functional via the effective action in the Hohenberg-Kohn theory is outlined. Using the auxiliary field method, in which the electric coupling constant $e^2$ need not be small, we show that the loop expansion of the exchange-correlation functional can be reorganized so as to be expressed entirely in terms of the Kohn-Sham
First-principles study of electron transport through the single-molecule magnet Mn12
cond-mat.mtrl-sciSalvador Barraza-Lopez, Kyungwha Park, Victor Garcia-Suarez, Jaime Ferrer
We examine electron transport through a single-molecule magnet Mn12 bridged between Au electrodes using the first-principles method. We find crucial features which were inaccessible in model Hamiltonian studies: spin filtering and a strong dependence of charge distribution on local environments. The spin filtering remains robust with different molecular geom
Kang Miao, Wang Xiao-Dong, Pan Na-Na
We study the cooling of hybrid stars coupling with spin-down. Due to the spin-down of hybrid stars, the interior density continuously increases, different neutrino reactions may be triggered(from the modified Urca process to the quark and nucleon direct Urca process) at different stages of evolution. We calculate the rate of neutrino emissivity of different
Spectral Classification of Galaxies using the Principal Component Analysis: a Web Based Tool
astro-ph.GAMauricio Ortiz, Gaspar Galaz
We have developed a web tool to perform Principal Component Analysis (PCA, Murtagh & Heck 1987; Kendall 1980) onto spectral data. The method is especially designed to perform spectral classification of galaxies from a sample of input spectra, giving the set of orthonormal vectors called Principal Components (PCs) and the corresponding projections. The first
Ray P. Norris, the EMU team
Next-generation continuum surveys will be strongly constrained by dynamic range and confusion. For example, the ASKAP-EMU (Evolutionary Map of the Universe) project will map 75% of the sky at 20cm to a sensitivity of 10 microJy - some 45 times deeper than NVSS, and is likely to be challenged by issues of confusion, cross-identification, and dynamic range. He
Going out with a bang: compact object collisions resulting from supernovae in binary systems
astro-ph.HEEleonora Troja, Graham A. Wynn, Paul T. O'Brien, Stephan Rosswog
Binary star systems containing a neutron star or a black hole with an evolved, massive star are dynamically perturbed when the latter undergoes a supernova explosion. It is possible that the natal kick received by the newly-formed neutron star in the supernova may place the stellar remnants into a bound, highly eccentric orbit. In this case, the two compact
Massimiliano Esposito, Ryoichi Kawai, Katja Lindenberg, Christian Van den Broeck
We investigate the finite time thermodynamics of a single-level fermion system interacting with a thermal reservoir through a tunneling junction. The optimal protocol to extract the maximum work from the system when moving the single energy level between an initial higher value and a final lower value in a finite time is calculated from a quantum master equa
HI Distribution and Tully-Fisher Distances of Gas-Poor Spiral Galaxies in the Virgo Cluster Region
astro-ph.COM. C. Toribio, J. M. Solanes
We present aperture synthesis observations in the 21 cm line of pointings centered on the Virgo Cluster region spirals NGC 4307, NGC 4356, NGC 4411B, and NGC 4492 using the Very Large Array (VLA) radiotelescope in its CS configuration. These galaxies were identified in a previous study of the three-dimensional distribution of HI emission in the Virgo region
Comment on: Superfluid density and specific heat within a self-consistent scheme for a two-band superconductor
cond-mat.supr-conAnnette Bussmann-Holder
Kogan et al. [Phys. Rev. B 80, 014507 (2009)] present a two-band model to investigate its effect on superconducting properties as, e.g., the superfluid density, the specific heat, the dependence of the superconducting transition temperature Tc on the model parameters. Due to a variety of simplifications and unphysical consequences of those, erroneous results
Eric Gaidos, Alexander N. Krot, Gary R. Huss
The 18O/17O ratio of the Solar System is 5.2 while that of the interstellar medium (ISM) and young stellar objects is ~4. This difference cannot be explained by pollution of the Sun's natal molecular cloud by 18O-rich supernova ejecta because (1) the necessary B-star progenitors live longer than the duration of star formation in molecular clouds; (2) the
Leo T. Butler
This paper numerically computes the topological and smooth invariants of Eschenburg spaces with small fourth cohomology group, following Kruggel's determination of the Kreck-Stolz invariants of Eschenburg spaces that satisfy condition C. The GNU GMP arbitrary-precision library is utilised.
Béla Szilágyi, Lee Lindblom, Mark A. Scheel
Several improvements in numerical methods and gauge choice are presented that make it possible now to perform simulations of the merger and ringdown phases of "generic" binary black-hole evolutions using the pseudo-spectral evolution code SpEC. These improvements include the use of a new damped-wave gauge condition, a new grid structure with appropri
D. Blas, O. Pujolas, S. Sibiryakov
We propose a natural extension of Horava's model for quantum gravity, which is free from the notorious pathologies of the original proposal. The new model endows the scalar graviton mode with a regular quadratic action and remains power-counting renormalizable. At low energies, it reduces to a Lorentz-violating scalar-tensor gravity theory. The deviation
Ghost instabilities of cosmological models with vector fields nonminimally coupled to the curvature
astro-ph.COBurak Himmetoglu, Carlo R. Contaldi, Marco Peloso
We prove that many cosmological models characterized by vectors nonminimally coupled to the curvature (such as the Turner-Widrow mechanism for the production of magnetic fields during inflation, and models of vector inflation or vector curvaton) contain ghosts. The ghosts are associated with the longitudinal vector polarization present in these models, and a
Mauro Patrão
In this paper, we prove, using only elementary geometric arguments and only assuming that the curves are continuous, that the geodesics on a sphere are the minor arcs of the great circles. Our result are valid for any sphere in any inner product space.
Four Momentum Transfer Discrepancy in the Charged Current $\pi^+$ Production in the MiniBooNE: Data vs. Theory
hep-phJaroslaw A. Nowak
The MiniBooNE experiment has collected what is currently the world's largest sample of neutrino muon charged current single charged pion interactions, roughly 46,000 events. The purity of the CC1pi+ sample is 87% making this the purest event sample observed in the MiniBooNE detector. The average energy of neutrinos producing CC1pi+ interactions in MiniBooNE
Hans Boden, Stefan Friedl
Given a knot K in an integral homology sphere with exterior N_K, there is a natural action of the cyclic group Z/n on the space of SL(n,C) representations of the knot group \pi_1(N_K), and this induces an action on the SL(n,C) character variety. We identify the fixed points of this action in terms of characters of metabelian representations, and we apply thi
Michael Morales
This paper shows the Fermi-Dirac Integrals expressed in terms of Riemann and Hurwitz Zeta functions. This is done by defining an auxiliar function that permits rewrite the Fermi-Dirac integral in terms of simpler and known integrals resulting in the Zeta functions mentioned. The approach used here evades the use of iterative methods for the integrals and pre
Ketan Savla, Emilio Frazzoli
In this paper, we introduce a model of dynamical queue, in which the service time depends on the server utilization history. The proposed queueing model is motivated by widely accepted empirical laws describing human performance as a function of mental arousal. The objective of this paper is to design task release control policies that can stabilize the queu