April 2009 arXiv papers — page 7

T. Merker, J. Vrabec, H. Hasse

A molecular model for carbon dioxide is assessed regarding vapor-liquid equilibrium properties. Large deviations, being above 15 %, are found for vapor pressure and saturated vapor density in the entire temperature range.

I. Kakeya, Y. Kubo, M. Kohri, M. Iwase

We report the systematic investigations of the oscillation of the Josephson vortex (JV) flow resistance in Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ micro-fabricated junctions with various geometries and superconducting anisotropy parameters. As the applied magnetic field parallel to the $ab$-plane is increased, oscillation with a period corresponding to a $ϕ_0/2$ par a

J. J. Halliwell

In the decoherent histories approach to quantum theory, attention focuses on the conditions under which probabilities may be assigned to sets of quantum histories. A variety of conditions have been proposed, but the most important one is decoherence, which means that the interference between every pair of histories in the set is zero. Weaker conditions have

Yanfang Li, Ping Zhang, Bo Sun, Yu Yang

We investigate the atomic hydrogen adsorption on Mg(0001) by using density-functional theory within the generalized gradient approximation and a supercell approach. The coverage dependence of the adsorption structures and energetics is systematically studied for a wide range of coverage and adsorption sites. In the coverage range $0<Θ<1.0, the most stable am

Kamil Kaleta, Tadeusz Kulczycki

We study the Feynman-Kac semigroup generated by the Schr{ö}dinger operator based on the fractional Laplacian $-(-Δ)^{α/2} - q$ in $\Rd$, for $q \ge 0$, $α\in (0,2)$. We obtain sharp estimates of the first eigenfunction $ϕ_1$ of the Schr{ö}dinger operator and conditions equivalent to intrinsic ultracontractivity of the Feynman-Kac semigroup. For potentials $q

O. Entin-Wohlman, Y. Imry, A. Aharony

The inelastic scattering of electrons which carry current through a single-molecule junction is modeled by a quantum dot, coupled to electron reservoirs via two leads. When the electron is on the dot, it is coupled to a single harmonic oscillator of frequency $ω_0$. At zero temperature, the resonance peak in the linear-response conductance always narrows dow

J. Vranjes, S. Poedts

In a recent paper [Y. Taroyan, Phys. Rev. Lett 101, 245001 (2008) it is claimed that a new MHD instability of the Alfven wave has been found: incompressible Alfven modes propagating in a compressible spatially varying flow were apparently exponentially amplified. We show that the results of the work follow from an impossible equilibrium and therefore should

Pavel Krejci, Elisabetta Rocca, Juergen Sprekels

We propose here a model for solidification of a liquid contents of an elastic bottle in a freezer. The main goal is to explain the occurrence of high stresses inside the bottle. As a by-product, we derive a formula for the undercooling coefficient in terms of the elasticity constants, latent heat, and the phase expansion coefficient. We investigate the well-

Jinsong Yang, You Ding, Yongge Ma

Since there are quantization ambiguities in constructing the Hamiltonian constraint operator in isotropic loop quantum cosmology, it is crucial to check whether the key features of loop quantum cosmology are robust against the ambiguities. In this paper, we quantize the Lorentz term of the gravitational Hamiltonian constraint in the spatially flat FRW model

A. Hill, S. A. Mikhailov, K. Ziegler

The electromagnetic response of graphene, expressed by the dielectric function, and the spectrum of collective excitations are studied as a function of wave vector and frequency. Our calculation is based on the full band structure, calculated within the tight-binding approximation. As a result, we find plasmons whose dispersion is similar to that obtained in

LAT Collaboration

We report the discovery of gamma-ray pulsations from the nearby isolated millisecond pulsar PSR J0030+0451 with the Large Area Telescope (LAT) on the \emph{Fermi} Gamma-ray Space Telescope (formerly GLAST). This discovery makes PSR J0030+0451 the second millisecond pulsar to be detected in gamma-rays after PSR J0218+4232, observed by the EGRET instrument on

L. Kuiper, W. Hermsen

PSR J1846-0258 is a radio-quiet rotation-powered pulsar at the center of Supernova remnant Kes 75. It is the youngest pulsar (~723 year) of all known pulsars and slows down very predictably since its discovery in 2000. Till June 7, 2006 very stable behavior has been displayed both in the temporal and spectral domains with pulsed emission detectable by INTEGR

Oleksii Ignatenko

In this work the single server model with counteraction is considered. We extend the classic fluid model using results from the theory of conflict controlled processes. Our new model describes conflict processes in neworks. For this model were defined two players - an attacker and a defender. Dynamic of the system depends on strategies of these players. Ther

David Färm

We consider expanding maps such that the unit interval can be represented as a full symbolic shift space with bounded distortion. There are already theorems about the Hausdorff dimension for sets defined by the set of accumulation points for the frequencies of words in one symbolic space at a time. It is shown in this text that the dimension is preserved whe

E. Iltan

We study the possible annihilation cross section of scalar dark matter and its coupling λ_D to the standard model Higgs in the case of the electroweak symmetry breaking driven by unparticle. Here the annihilation process occurs with the help of three intermediate scalars which appear after the mixing. By respecting the annihilation rate which is compatible w

Mahdi Godazgar, Harvey S. Reall

A d-dimensional spacetime is &#34;axisymmetric&#34; if it possesses an SO(d-2) isometry group whose orbits are (d-3)-spheres. In this paper, algebraically special, axisymmetric solutions of the higher dimensional vacuum Einstein equation (with cosmological constant) are investigated. Necessary and sufficient conditions for static axisymmetric solutions to be

Sameer Ikhdair

The analytic solutions of the spatially-dependent mass Schrodinger equation of diatomic molecules with the centrifugal term l(l+1)/r2 for the generalized q-deformed Morse potential are obtained approximately by means of a parametric generalization of the Nikiforov-Uvarov (NU) method combined with the Pekeris approximation scheme. The energy eigenvalues and t

David Färm

Given a point and an expanding map on the unit interval, we consider the set of points for which the forward orbit under this map is bounded away from the given point. For maps like multiplication by an integer modulo 1, such sets have full Hausdorff dimension. We prove that such sets have a large intersection property, i.e. that countable intersections of s

Nathan Linial, Tahl Nowik

To any generic curve in an oriented surface there corresponds an oriented chord diagram, and any oriented chord diagram may be realized by a curve in some oriented surface. The genus of an oriented chord diagram is the minimal genus of an oriented surface in which it may be realized. Let g_n denote the expected genus of a randomly chosen oriented chord diagr

Arnab Bhattacharyya, Bernhard Haeupler

One of the characteristic features of genetic networks is their inherent robustness, that is, their ability to retain functionality in spite of the introduction of random errors. In this paper, we seek to better understand how robustness is achieved and what functionalities can be maintained robustly. Our goal is to formalize some of the language used in bio

E. M. Shahverdiev, K. A. Shore

We present the first report of the synchronization regimes in both unidirectionally and bidirectionally-coupled multiple time delay chaotic laser diodes subject to incoherent optical feedbacks and incoherent optical injection. We derive the existence conditions and numerically study the stability for lag, complete, and anticipating synchronization regimes an

Eoin Ó Colgáin, Hossein Yavartanoo

Recently proposed Horava-Lifshitz gravity promises a UV completion of Einstein&#39;s theory by sacrificing general covariance at short distances and introducing anisotropic spacetime scaling. Here we present a dyonic solution by coupling this theory to a vector field and we discuss some properties of solution.

O. Dovgoshey, D. Dordovskyi

The paper deals with pretangent spaces to general metric spaces. An ltrametricity criterion for pretangent spaces is found and it is closely related to the metric betweenness in the pretangent spaces.

Ulrich Bunke

We show that the Adams operations in complex K-theory lift to operations in smooth K-theory. The main result is a Riemann-Roch type theorem about the compatibility of the Adams operations and the integration in smooth K-theory.

L. Petit, A. Svane, Z. Szotek, W. M. Temmerman

The self-interaction corrected (SIC) local spin-density approximation (LSD) is used to investigate the groundstate valency configuration of the actinide ions in the actinide mono-carbides, AC (A = U, Np, Pu, Am, Cm), and the actinide mono-nitrides, AN. The electronic structure is characterized by a gradually increasing degree of f-electron localization from

S. K. Tiwari, P. Venkatakrishnan, K. Sankarasubramanian

In the solar atmosphere the twist parameter $α$ has the same sign as magnetic helicity. It has been observed using photospheric vector magnetograms that negative/positive helicity is dominant in the northern/southern hemisphere of the Sun. Chromospheric features show dextral/sinistral dominance in the northern/southern hemisphere and sigmoids observed in X-r

Eef van Beveren, George Rupp

Data on e+ e- --> J/psi pi+ pi- and the X(4260) enhancement by the BABAR collaboration [ arXiv:hep-ex/0506081, arXiv:0808.1543 ] are analysed by modelling missing signals that should be present in the complete production amplitude with vector quantum numbers in the charmonium region. Thus, it is shown that the data contain evidence for the existence of the p

L. Serreau, M. Beauvais, C. Heitz, Etienne Barthel

In the context of glass fiber manufacturing the onset of lubrication by a C18 double-chained cationic surfactant has been investigated at high normal contact pressures. Comparison with adsorption kinetics demonstrates that lubrication is not directly connected to the surfactant surface excess but originates from the transition to a defect-free bilayer which

M. R. Cimberle, F. Canepa, M. Ferretti, A. Martinelli

In this paper the magnetic behaviour of undoped and 15% F doped SmFeAsO (Sm-1111) and LaFeAsO (La-1111) samples is presented and discussed. Magnetization measurements are not a simple tool to use for the characterisation of the new family of Fe-based superconductors because magnetic impurities can be easily formed during the preparation procedure and may aff

O. Dovgoshey

We investigate a tangent space at a point of a general metric space and metric space valued derivatives. The conditions under which two different subspace of a metric space have isometric tangent spaces in a common point of these subspaces are completely determinated.

M. Reza Bakhtiari, M. J. Leskinen, P. Törmä

This is a Reply to: Comment on &#34;Spectral Signatures of the Fulde-Ferrell-Larkin-Ovchinnikov Order Parameter in One-Dimensional Optical Lattices&#34; R. A. Molina J. Dukelksy, and P. Schmitteckert, Phys. Rev. Lett. 102, 168901 (2009)

J. Nieves, E. Ruiz Arriola

The chiral limit of the rho and sigma masses and widths is discussed. We work within the inverse amplitude method to one loop in SU(2) ChPT and analyze the consequences that all chiral logarithms cancel out in the rho-channel, while they do not cancel for the sigma case, and how they strongly influence the properties of this latter resonance. Our results con

Roland Tresch, Maxime Guillaud, Erwin Riegler

Interference alignment in the K-user MIMO interference channel with constant channel coefficients is considered. A novel constructive method for finding the interference alignment solution is proposed for the case where the number of transmit antennas equals the number of receive antennas (NT = NR = N), the number of transmitter-receiver pairs equals K = N +

Ole Steuernagel

Superpositions of paraxial Laguerre-Gauss laser beam modes to generate optical potentials based on the optical dipole force are investigated theoretically. Parabolic and other monomial potentials with even powers, in cylindrical and spherical symmetry, with large diameters, can be synthesized. This superposition approach promises to help with high quality at

M. D. Tomchenko

The method of collective variables (MCV) has been used to calculate the logarithm of the He-II ground-state wave function, ln(Psi_0), to an accuracy of a first correction to the Jastrow function and, in a second approximation, the wave function Psi_k of the first excited state and the He-II quasiparticle spectrum. The functions Psi_0 and Psi_k were found as

Carlos J. Zapata-Rodriguez

We present a theoretical analysis of open aperture $Z$-scan signatures for materials exhibiting an absorption admixture of different multiphoton processes. Based on a polynomial expansion, we suggest some procedures to separate the contribution to the trace of the recorded transmittance made by absorptions of distinct order. The signal processing from experi

R. A. Molina J. Dukelsky P. Schmitteckert

Comment on &#34;Spectral Signatures of the Fulde-Ferrell-Larkin-Ovchinnikov Order Parameter in One-Dimensional Optical lattices&#34; M. Reza Bakhtiari, M. J. Leskinen, and P. Törmä, Phys. Rev. lett. {\bf 101}, 120404 (2008).

Juergen Winterlik, Gerhard H. Fecher, Taras Palasyuk, Claudia Felser

Among the various alkali oxides the sesquioxides Rb4O6 and Cs4O6 are of special interest. Electronic structure calculations using the local spin-density approximation predicted that Rb4O6 should be a half-metallic ferromagnet, which was later contradicted when an experimental investigation of the temperature dependent magnetization of Rb4O6 showed a low-temp

V. B. Zabolotnyy, D. V. Evtushinsky, A. A. Kordyuk, D. S. Inosov

Here we apply high resolution angle-resolved photoemission spectroscopy (ARPES) using a wide excitation energy range to probe the electronic structure and the Fermi surface topology of the Ba1-xKxFe2As2 (Tc = 32 K) superconductor. We find significant deviations in the low energy band structure from that predicted in calculations. A set of Fermi surface sheet

Martin Hövel, Martin Alws, Bruno Gompf, Martin Dressel

We report on optical reflection measurements of thin Au films at and around the percolation threshold (film thickness 3 to 10 nm) in an extremely broad spectral range from 500 to 35000 cm-1 (0.3 - 20 *10-6 m). Combining spectroscopic ellipsometry and Fourier-transform infrared spectroscopy, the dielectric properties of the films can be described over the who

S Mani, A Sagari, B Chakrabarti, A Bhattacharya

The properties of the neutrino in the early universe have been investigated incorporating a small inhomogeneity in the mass density of the early universe. Dependence on this factor is found in studying mean free path and mass bound of neutrinos. The oscillations of neutrinos flavours have been studied by assuming a free wave packet to represent the time prog

Bennett Palmer

We study an area minimization problem for spacelike zero mean curvature surfaces in four dimensional Lorentz-Minkowski space. The areas of these surfaces are compared of with the areas of certain marginally trapped surfaces having the same boundary values.

Alexander Kuznetsov

We investigate Hochschild cohomology and homology of admissible subcategories of derived categories of coherent sheaves on smooth projective varieties. We show that the Hochschild cohomology of an admissible subcategory is isomorphic to the derived endomorphisms of the kernel giving the corresponding projection functor, and the Hochschild homology is isomorp

Chikun Ding, Mengjie Wang, Jiliang Jing

Some authors have recently found that the tunneling approach gives a different Hawking temperature for a Schwarzschild black hole in a different coordinate system. In this paper, we find that to work out the Hawking temperature in a different coordinate system by the tunneling approach, we must use the correct definition of the energy of the radiating partic

Yufeng Mao, Jing Wang, Jianyan Wei

We present our analysis of the three HII-buried-AGN: SDSS J091053+333008, SDSS J121837+091324, and SDSS J153002-020415, by studying their optical spectra extracted from SDSS. The location in the BPT diagnostic diagrams of the three galaxies indicates that the narrow emission lines are mainly exited from HII regions. However, after the removal of the host gal

Nicolás Lorente Jean-Pierre Gauyacq

The excitation of the spin degrees of freedom of an adsorbed atom by tunneling electrons is computed using a strong coupling theory. The excitation process is shown to be a sudden switch between the initial state determined by the environmental anisotropy to an intermediate state given by the coupling to the tunnelling electron. This explains the observed la

V. N. Dumachev

On the basis of Liouville theorem the generalization of the Nambu mechanics is considered. Is shown, that Poisson manifolds of n-dimensional multi-symplectic phase space have inducting by (n-1) Hamiltonian k-vector fields, each of which requires of (k)-hamiltonians.

Aikaterini Aretaki, John Maroulas

A presentation of numerical range for rectangular matrices is undertaken in this paper, introducing two different definitions and elaborating basic properties. Then we are extended to the treatment of rank-k numerical range.

Ming He, Kasper T. Therkildsen, Brian B. Jensen, Anders Brusch

We report measurements of the isotope shifts of the (3s3p)$^3$P$_{0,1,2}$ - (3s4s)$^3$S$_1$ Mg I transitions for the stable isotopes $^{24}$Mg (I=0), $^{25}$Mg (I=5/2) and $^{26}$Mg (I=0). Furthermore the $^{25}$Mg $^3$S$_1$ hyperfine coefficient A($^3$S$_1$) = (-321.6 $\pm$ 1.5) MHz is extracted and found to be in excellent agreement with state-of-the-art t

Andrew Wynn

It is shown that the right shift semigroup on $L^2(\mathbb{R}_+)$ does not satisfy the weighted Weiss conjecture for $α\in (0,1)$. In other words, $α$-admissibility of scalar valued observation operators cannot always be characterised by a simple resolvent growth condition. This result is in contrast to the unweighted case, where 0-admissibility can be chara

Marc Bouchez, Emeric Daniau, Nicolas Visez, Olivier Herbinet

The last years saw a renewal of interest for hypersonic research in general and regenerative cooling specifically, with a large increase of the number of dedicated facilities and technical studies. In order to quantify the heat transfer in the cooled structures and the composition of the cracked fuel entering the combustor, an accurate model of the thermal d

Clifford V. Johnson, Arnab Kundu

We continue our study of the dynamics of the flavour sector of the Sakai-Sugimoto model in the presence of an external magnetic field, uncovering several features of the meson spectrum at high and low temperatures. We employ both analytical and numerical methods to study the coupled non-linear equations that result from the gravity dual.

I. Bonalde, R. L. Ribeiro, W. Bramer-Escamilla, C. Rojas

We report a study in which the effect of defects/impurities, growth process, off-stoichiometry, and presence of impurity phases on the superconducting properties of noncentrosymmetric CePt3Si is analysed by means of the temperature dependence of the magnetic penetration depth. We found that the linear low-temperature response of the penetration depth -indica

A. Sherman, N. Voropajeva

A heterostructure of a semi-infinite metal and a Mott insulator is considered. It is supposed that both materials have an identical lattice spacing and hopping integrals and differ in the Hubbard repulsion which is negligible in the metal and exceeds the critical value for the Mott transition in the insulator. At half-filling and for low temperatures the ins

David Eppstein, Elena Mumford

We construct partitions of rectangles into smaller rectangles from an input consisting of a planar dual graph of the layout together with restrictions on the orientations of edges and junctions of the layout. Such an orientation-constrained layout, if it exists, may be constructed in polynomial time, and all orientation-constrained layouts may be listed in p

A. Karmakar, S. Majumdar, A. K. Singh, S. Patnaik

Magnetization, magnetoresistance, and magnetodielectric measurements have been carried out on the half doped charge ordered manganite, Pr_0.5Ca_0.5MnO_3. The low temperature state is found to be strongly dependent on the oxygen stoichiometry whereas the high temperature state remains almost unaltered. A disorder driven phase separation in the low temperature

W. Aoki, N. Arimoto, K. Sadakane, E. Tolstoy

Chemical abundances of six extremely metal-poor ([Fe/H]<-2.5) stars in the Sextans dwarf spheroidal galaxy are determined based on high resolution spectroscopy (R=40,000) with the Subaru Telescope High Dispersion Spectrograph. (1) The Fe abundances derived from the high resolution spectra are in good agreement with the metallicity estimated from the Ca tripl

George Chapline, Jonathan L DuBois

A new approach to analyzing visual images is proposed, based on the idea of converting an optical image into a spatially varying pattern of polarized squeezed light, which is then used to produce a pattern of chiral edge currents in a thin film topological insulator. Thin films of Bi or Bi doped with Sb which are punctured with an array of sub-micron holes m

J. A. Green, N. M. McClure-Griffiths, J. L. Caswell, S. P. Ellingsen

We report on the presence of 6.7-GHz methanol masers, known tracers of high-mass star formation, in the 3-kpc arms of the inner Galaxy. We present 49 detections from the Methanol Multibeam Survey, the largest Galactic plane survey for 6.7-GHz methanol masers, which coincide in longitude, latitude and velocity with the recently discovered far-side 3-kpc arm a

Kei Kotake, Wakana Iwakami, Naofumi Ohnishi, Shoichi Yamada

We study properties of gravitational waves based on the three-dimensional simulations, which demonstrate the neutrino-driven explosions aided by the standing accretion shock instability (SASI). Pushed by evidence supporting slow rotation prior to core-collapse, we focus on the asphericities in neutrino emissions and matter motions outside the protoneutron st

Chen Shi, Fang Yuan

Game Theory has been frequently applied in biological research since 1970s. While the key idea of Game Theory is Nash Equilibrium, it is critical to understand and figure out the payoff matrix in order to calculate Nash Equilibrium. In this paper we present a dynamic programming implemented method to compute 2x2 non-cooperative finite resource allocation gam

Li-yun Hu, Hong-yi Fan

By virtue of the technique of integration within an ordered product (IWOP) of operators we present a new approach for deriving generalized thermo vacuum state which is simpler in form that the result by using the Umezawa-Takahashi approach, in this way the thermo field dynamics can be developed. Applications of the new state are discussed.

Katsunori Kawamura

Let ${\cal O}_{*}$ be the C$^{*}$-algebra defined as the direct sum of all Cuntz algebras. Then ${\cal O}_{*}$ has a non-cocommutative comultiplication $Δ_ϕ$ and a counit $ε$. Let ${\rm BI}({\cal O}_{*})$ denote the set of all closed biideals of the C$^{*}$-bialgebra $({\cal O}_{*},Δ_ϕ,ε)$ and let ${\cal P}({\bf P})$ denote the power set of the set of all pr

Clara Rojas, Victor M. Villalba

The phase-integral approximation devised by Fröman and Fröman, is used for computing cosmological perturbations in the quadratic chaotic inflationary model. The phase-integral formulas for the scalar and tensor power spectra are explicitly obtained up to fifth order of the phase-integral approximation. We show that, the phase integral gives a very good appro

Tian-Jun Li, Weiyi Zhang

In this paper we introduce the notion of relative Kodaira dimension for a symplectic 4-manifold M with a possibly disconnected embedded symplectic surface F. One notable feature is that the sphere components of F have to be discarded, which resembles the definition of Thurston norm of 3-manifolds. To define it we need to establish several homological propert

F. H. Busse, R. D. Simitev

For the understanding of planetary and stellar dynamos an overview of the major parameter dependences of convection driven dynamos in rotating spherical fluid shells is desirable. Although the computationally accessible parameter space is limited, earlier work is extended with emphasis on higher Prandtl numbers and uniform heat flux condition at the outer bo

Sooran Kang

In this paper, we discuss the Yang-Mills functional and a certain family of its critical points on quantum Heisenberg manifolds using noncommutative geometrical methods developed by A. Connes and M. Rieffel. In our main result, we construct a certain family of connections on a projective module over a quantum Heisenberg manifold that give rise to critical po

Ata Sarajedini, Conor L. Mancone, Tod R. Lauer, Alan Dressler

We present Hubble Space Telescope observations taken with the Advanced Camera for Surveys Wide Field Channel of two fields near M32 - between four and six kpc from the center of M31. The data cover a time baseline sufficient for the identification and characterization of 681 RR Lyrae variables of which 555 are ab-type and 126 are c-type. The mean magnitude o

Robert Delbourgo, David Elliott

By using the Fourier transforms of the general hydrogenic bound state wave functions (as ultraspherical polynomials) one may find expectation values of arbitrary functions of momentum p. In this manner the effect of a reciprocity perturbation 1/p can be evaluated for all hydrogenic states.

Izaskun San Roman, Ata Sarajedini, Donald R. Garnett, Jon A. Holtzman

We present integrated photometry and color-magnitude diagrams for 161 star clusters in M33, of which 115 were previously uncataloged, using the Advanced Camera For Surveys Wide Field Channel onboard the Hubble Space Telescope. The integrated V-band magnitudes of these clusters range from Mv~-9 to as faint as Mv~-4, extending the depth of the existing M33 clu

Michael F Moses

A block in a linear order is an equivalence class when factored by the block relation B(x,y), satisfied by elements that are finitely far apart. We show that every computable linear order with dense condensation-type (i.e. a dense collection of blocks) but no infinite, strongly η-like interval (i.e. with all blocks of size less than some fixed, finite k) has

Gang Chen, I. Miotkowski, A. K. Ramdas

The group IB impurities (Cu, Ag, and Au) incorporated into II-VI zinc blende hosts of ZnTe and CdTe exhibit well resolved excitation lines followed by a photoionization continuum in their infrared absorption spectra. They are associated with transitions from a &#34;1s-like&#34; ground state to various &#34;p-like&#34; excited state characteristic of a hole b

Cong Shen, Michael P. Fitz

Opportunistic Spatial Orthogonalization (OSO) is a cognitive radio scheme that allows the existence of secondary users and hence increases the system throughput, even if the primary user occupies all the frequency bands all the time. Notably, this throughput advantage is obtained without sacrificing the performance of the primary user, if the interference ma

Rajib Rahman, G. P. Lansbergen, Seung H. Park, J. Verduijn

Adiabatic shuttling of single impurity bound electrons to gate induced surface states in semiconductors has attracted much attention in recent times, mostly in the context of solid-state quantum computer architecture. A recent transport spectroscopy experiment for the first time was able to probe the Stark shifted spectrum of a single donor in silicon buried

M. H. Partovi, J. D. Griffiths

This work addresses the electrostatic problem of a thin, curved, cylindrical conductor, or a conducting filament, and shows that the corresponding linear charge density slowly tends to uniformity as the inverse of the logarithm of a characteristic parameter. An alternative derivation of this result directly based on energy minimization is developed. These re

Gregory Gabadadze, David Pirtskhalava

We develop further the proposal of arXiv:0806.3692 that a new state of matter -- charged condensate of spin-0 nuclei -- may exist in helium-core dwarf stars. The charged condensate and its fluctuations are described by an effective field theory Lagrangian. The spectrum of bosonic fluctuations is gapped, while electrons, at temperatures of interest, give rise

P. A. James, C. F. Bretherton, J. H. Knapen

We analyse the current build-up of stellar mass within the disks and bulges of nearby galaxies through a comparison of the spatial distributions of forming and old stellar populations. H alpha and R-band imaging are used to determine the distributions of young and old stellar populations in 313 S0a - Im field galaxies out to 40 Mpc. Concentration indices and

Sameer Murthy, Boris Pioline

We study exponentially suppressed contributions to the degeneracies of extremal black holes. Within Sen&#39;s quantum entropy function framework and focusing on extremal black holes with an intermediate AdS3 region, we identify an infinite family of semi-classical AdS2 geometries which can contribute effects of order exp(S_0/c), where S_0 is the Bekenstein-H

Massimo Fornasier, Rachel Ward

Free-discontinuity problems describe situations where the solution of interest is defined by a function and a lower dimensional set consisting of the discontinuities of the function. Hence, the derivative of the solution is assumed to be a `small&#39; function almost everywhere except on sets where it concentrates as a singular measure. This is the case, for

Robert G. Leigh, Nam Nguyen Hoang

We consider Lorentzian correlation functions in theories with non-relativistic Schrodinger symmetry. We employ the method developed by Skenderis and van Rees in which the contour in complex time defining a given correlation function is associated holographically with the gluing together of Euclidean and Lorentzian patches of spacetimes. This formalism extend

D. Milisavljevic, R. Fesen, C. Gerardy, R. Kirshner

We present optical spectra of SN 2007gr, SN 2007rz, SN 2007uy, SN 2008ax, and SN 2008bo obtained in the nebular phase when line profiles can lead to information about the velocity distribution of the exploded cores. We compare these to 13 other published spectra of stripped-envelope core-collapse supernovae (Type IIb, Ib, and Ic) to investigate properties of

Andreas A. Berlind, Glennys R. Farrar, Ingyin Zaw

We confirm the UHECR horizon established by the Pierre Auger Observatory using the heterogeneous Veron-Cetty Veron (VCV) catalog of AGNs, by performing a redshift-angle-IR luminosity scan using PSCz galaxies having infrared luminosity greater than 10^{10}L_sun. The strongest correlation -- for z < 0.016, psi = 2.1 deg, and L_ir > 10^{10.5}L_sun -- arises in

Rupert L. Frank, Elliott H. Lieb

We give a new proof of certain cases of the sharp HLS inequality. Instead of symmetric decreasing rearrangement it uses the reflection positivity of inversions in spheres. In doing this we extend a characterization of the minimizing functions due to Li and Zhu.

Alessandro Betti, Gianluca Fiori, Giuseppe Iannaccone

We present an expression for the shot noise power spectral density in quasi-one dimensional conductors electrostatically controlled by a gate electrode, that includes the effects of Coulomb interaction and of Pauli exclusion among charge carriers. In this sense, our expression extends the well known Landauer-Buttiker noise formula to include the effect of Co

Philippe Cara, Alice Devillers, Michael Giudici, Cheryl E. Praeger

We develop a theory for quotients of geometries and obtain sufficient conditions for the quotient of a geometry to be a geometry. These conditions are compared with earlier work on quotients, in particular by Pasini and Tits. We also explore geometric properties such as connectivity, firmness and transitivity conditions to determine when they are preserved u

Vladislav B. Tadić

This paper considers the asymptotic properties of the recursive maximum likelihood estimation in hidden Markov models. The paper is focused on the asymptotic behavior of the log-likelihood function and on the point-convergence and convergence rate of the recursive maximum likelihood estimator. Using the principle of analytical continuation, the analyticity o

Chao-Chin Yang, Kristen Menou

Sharp density features in protoplanetary discs, for instance at the edge of a magnetically dead zone, have recently been proposed as effective barriers to slow down or even stop the problematically fast migration of planetary cores into their central star. Density features on a radial scale approaching the disc vertical scale height might not exist, however,

Yuval Grossman, Zoltan Ligeti, Yosef Nir

In recent years, the CKM picture of flavor and CP violation has been confirmed, mainly due to B decay data. Yet, it is likely that there are small corrections to this picture. We expect to find new physics not much above the weak scale. This new physics could modify flavor changing processes compared to their SM expectations. Much larger B decay data sets, w

Yan Gong, Xin Wang, Zheng Zheng, Xuelei Chen

The primordial non-Gaussianity (PNG) in matter density perturbation is a very powerful probe of the physics of the very early Universe. The local PNG can induce a distinct scale-dependent bias on the large scale structure distribution of galaxies and quasars, which could be used for constraining it. We study the detection limits on PNG from the surveys of th

Yidong Xu, Xuelei Chen, Zuhui Fan, Hy Trac

Using high redshift radio sources as background, the 21cm forest observations probe the neutral hydrogen absorption signatures of early structures along the lines of sight. Directly sensitive to the spin temperature, it complements the 21cm tomography observations, and provides information on the temperature as well as the ionization state of the intergalact

Stefano Zibetti, Stephane Charlot, Hans-Walter Rix

(Abridged) We introduce a novel technique to construct spatially resolved maps of stellar mass surface density in galaxies based on optical and near IR imaging. We use optical/NIR colour(s) to infer effective stellar mass-to-light ratios (M/L) at each pixel, which are then multiplied by the surface brightness to obtain the local stellar surface mass density.

Sang-Jin Sin, Yang Zhou

We propose a Dirac-Born-Infeld (DBI) D5 vertex brane plus N_c fundamental strings configuration to describe a baryon probe in strongly coupled gauge theory with gluon condensation at finite temperature via AdS/CFT correspondence. We investigate properties of this configuration in a dilaton deformed AdS_5\times S^5 background, in which IIB string theroy is du

Mitchell Begelman, Isaac Shlosman

Rapid inflows associated with early galaxy formation lead to the accumulation of self-gravitating gas in the centers of proto-galaxies. Such gas accumulations are prone to non-axisymmetric instabilities, as in the well-known Maclaurin sequence of rotating ellipsoids, which are accompanied by a catastrophic loss of angular momentum (J). Self-gravitating gas i

Gianluca Calcagni, Giuseppe Nardelli

We find nonperturbative solutions of a nonlocal scalar field equation, with cubic or exponential potential on a cosmological background. The former case corresponds to the lowest level effective tachyon action of cubic string field theory. While the well known Minkowski solution is wildly oscillating, due to Hubble friction its cosmological counterpart descr

D. M. Liu, Q. Huang, M. Yue, J. W. Lynn

Neutron powder diffraction studies of the crystal and magnetic structures of the magnetocaloric compound Mn1.1Fe0.9(P0.8Ge0.2) have been carried out as a function of temperature, applied magnetic field, and pressure. The data reveal that there is only one transition observed over the entire range of variables explored, which is a combined magnetic and struct

Steen Ryom-Hansen

We study the seminormal basis ${f_t}$ for the Specht modules of the Iwahori-Hecke algebra ${\cal H}_n(q)$ of type $A_{n-1}$. We focus on the base change coefficients between the seminormal basis ${f_t}$ and Young's natural basis ${x_t}$ with emphasis on the denominators of these coefficients. In certain important cases we obtain simple formulas for these coe

Francis-Yan Cyr-Racine, Stefano Profumo, Kris Sigurdson

It has recently been argued that the PAMELA, ATIC and PPB-BETS data showing an anomalous excess of high-energy cosmic ray positrons and electrons might be explained by dark matter annihilating in the Galactic halo with a cross section resonantly enhanced compared to its value in the primeval plasma. We find that with a very large annihilation cross section t

Debasish Chatterjee, Eugenio Cinquemani, John Lygeros

We present a dynamic programming-based solution to the problem of maximizing the probability of attaining a target set before hitting a cemetery set for a discrete-time Markov control process. Under mild hypotheses we establish that there exists a deterministic stationary policy that achieves the maximum value of this probability. We demonstrate how the maxi

Bo-Sture Skagerstam, Per Kristian Rekdal, Asle Heide Vaskinn

We consider the energy shift for an atom close to a non-magnetic body with a magnetic moment coupled to a quantized magnetic field. The corresponding repulsive Casimir-Polder force is obtained for a perfect conductor, a metal, a dielectric medium, with dielectric properties modeled by a Drude formula, and a superconductor at zero temperature. The dielectric

P. Guillard, F. Boulanger, G. Pineau des Forets, P. N. Appleton

Context. The Spitzer Space Telescope has detected a powerful (L(H2)~10^41 erg s-1) mid-infrared H2 emission towards the galaxy-wide collision in the Stephan&#39;s Quintet (SQ) galaxy group. This discovery was followed by the detection of more distant H2-luminous extragalactic sources, with almost no spectroscopic signatures of star formation. These observati