March 2008 arXiv papers — page 39
Showing 3,801–3,900 of 4,524 papers
Huidong Guo, Erick J. Weinberg
Attempts to construct chromodyons - objects with both magnetic charge and non-Abelian electric charge - in the context of spontaneously broken gauge theories have been thwarted in the past by topological obstructions to globally defining the unbroken non-Abelian "color'' subgroup. In this paper we consider the possibility of chromodyons in a theo
Gautam Chinta, Paul E. Gunnells
Let Phi be a reduced root system of rank r. A Weyl group multiple Dirichlet series for Phi is a Dirichlet series in r complex variables s_1,...,s_r, initially converging for Re(s_i) sufficiently large, that has meromorphic continuation to C^r and satisfies functional equations under the transformations of C^r corresponding to the Weyl group of Phi. A heurist
Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
astro-phG. Hinshaw, J. L. Weiland, R. S. Hill, N. Odegard
We present new full-sky temperature and polarization maps in five frequency bands from 23 to 94 GHz, based on data from the first five years of the WMAP sky survey. The five-year maps incorporate several improvements in data processing made possible by the additional years of data and by a more complete analysis of the instrument calibration and in-flight be
Marie-Pierre Béal, Dominique Perrin
The Road Coloring Theorem states that every aperiodic directed graph with constant out-degree has a synchronized coloring. This theorem had been conjectured during many years as the Road Coloring Problem before being settled by A. Trahtman. Trahtman's proof leads to an algorithm that finds a synchronized labeling with a cubic worst-case time complexity.
J. Chopin, D. Vella, A. Boudaoud
We consider a thin elastic sheet adhering to a stiff substrate by means of the surface tension of a thin liquid layer. Debonding is initiated by imposing a vertical displacement at the centre of the sheet and leads to the formation of a delaminated region, or `blister'. This experiment reveals that the perimeter of the blister takes one of three differen
Stefan Yoshi Buhmann, Stefan Scheel
We critically discuss the common belief that the thermal Casimir-Polder force can always be represented as a Matsubara sum, as it is true for the Casimir force. On the contrary, an exact treatment of the atom-field coupling reveals that for a ground-state atom, terms associated with virtual-photon absorption contribute to the force which are identified as a
Ning Chen, Zhiyuan Yan
For the majority of the applications of Reed-Solomon (RS) codes, hard decision decoding is based on syndromes. Recently, there has been renewed interest in decoding RS codes without using syndromes. In this paper, we investigate the complexity of syndromeless decoding for RS codes, and compare it to that of syndrome-based decoding. Aiming to provide guidelin
Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Likelihoods and Parameters from the WMAP data
astro-phJ. Dunkley, E. Komatsu, M. R. Nolta, D. N. Spergel
This paper focuses on cosmological constraints derived from analysis of WMAP data alone. A simple LCDM cosmological model fits the five-year WMAP temperature and polarization data. The basic parameters of the model are consistent with the three-year data and now better constrained: Omega_b h^2 = 0.02273+-0.00062, Omega_c h^2 = 0.1099+-0.0062, Omega_L = 0.742
Mark Veraar
In this note we obtain lower bounds for $¶(ξ\geq 0)$ and $¶(ξ>0)$ under assumptions on the moments of a centered random variable $ξ$. The obtained estimates are shown to be optimal and improve results from the literature. The results are applied to obtain probability lower bounds for second order Rademacher chaos.
The elliptic curve discrete logarithm problem and equivalent hard problems for elliptic divisibility sequences
math.NTKristin E. Lauter, Katherine E. Stange
We define three hard problems in the theory of elliptic divisibility sequences (EDS Association, EDS Residue and EDS Discrete Log), each of which is solvable in sub-exponential time if and only if the elliptic curve discrete logarithm problem is solvable in sub-exponential time. We also relate the problem of EDS Association to the Tate pairing and the MOV, F
Emil Prodan, Roberto Car
The tunneling transport theory developed in Phys. Rev. B {\bf 76}, 115102 (2007) is applied to molecular devices made of alkyl chains linked to gold electrodes via amine groups. Using the analytic expression of the tunneling conductance derived in our previous work, we identify the key physical quantities that characterize the conductance of these devices. B
Short-range magnetic ordering process for the triangular lattice compound NiGa2S4: a positive muon spin rotation and relaxation study
cond-mat.str-elA. Yaouanc, P. Dalmas de Reotier, Y. Chapuis, C. Marin
We report a study of the triangular lattice Heisenberg magnet NiGa2S4 by the positive muon spin rotation and relaxation technique. We unravel three temperature regimes: (i) below T_c = 9.2(2) K a spontaneous static magnetic field at the muon site is observed and the spin dynamics is appreciable: the time scale of the modes we probe is ~ 7 ns; (ii) an unconve
Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Galactic Foreground Emission
astro-phB. Gold, C. L. Bennett, R. S. Hill, G. Hinshaw
We present a new estimate of foreground emission in the WMAP data, using a Markov chain Monte Carlo (MCMC) method. The new technique delivers maps of each foreground component for a variety of foreground models, error estimates of the uncertainty of each foreground component, and provides an overall goodness-of-fit measurement. The resulting foreground maps
Michael Finkelberg, Victor Ginzburg
Let an algebraic group G act on X, a connected algebraic manifold, with finitely many orbits. For any Harish-Chandra pair (D,G) where D is a sheaf of twisted differential operators on X, we form a left ideal D.g in D generated by the Lie algebra g, of G. Then, D/D.g is a holonomic D-module and its restriction to a unique Zariski open dense G-orbit in X is a
Some remarks on varieties of pairs of commuting upper triangular matrices and an interpretation of commuting varieties
math.AGRoberta Basili
It is known that the variety of pairs of n x n commuting upper triangular matrices isn't a complete intersection for infinitely many values of n; we show that there exists m such that this happens if and only if n > m. We also show that m < 18 and that it could be found by determining the dimension of the variety of pairs of commuting strictly upper tria
Bernhard Keller, Daniel Murfet, Michel Van den Bergh
In the recent paper "Mutation in triangulated categories and rigid Cohen-Macaulay modules" Iyama and Yoshino consider two interesting examples of isolated singularities over which it is possible to classify the indecomposable maximal Cohen-Macaulay modules in terms of linear algebra data. In this paper we present two new approaches to these examples.
Five-Year Wilkinson Microwave Anisotropy Probe (WMAP)Observations: Beam Maps and Window Functions
astro-phR. S. Hill, J. L. Weiland, N. Odegard, E. Wollack
Cosmology and other scientific results from the WMAP mission require an accurate knowledge of the beam patterns in flight. While the degree of beam knowledge for the WMAP one-year and three-year results was unprecedented for a CMB experiment, we have significantly improved the beam determination as part of the five-year data release. Physical optics fits are
Spin-orbit coupling, edge states and quantum spin Hall criticality due to Dirac fermion confinement: The case study of graphene
cond-mat.mes-hallGrigory Tkachov, Martina Hentschel
We propose a generalized Dirac fermion description for the electronic state of graphene terminated by a zigzag edge. This description admits a spin-orbit coupling needed to preserve time-reversal invariance of the zigzag confinement, otherwise, for spinless particles, showing the parity anomaly typical of quantum electrodynamics in (2+1) dimensions. At a cer
D0 Collaboration
We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron ppbar collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top quark partner that is always produced from strong coupling processes.
E. Tomasi-Gustafsson, G. I. Gakh, C. Adamuščín
A model independent formalism for the electron positron annihilation reaction $e^++e^-\to a_1(1260)+π$ has been derived. The differential and total cross sections and the elements of the spin--density matrix of the $a_1$-meson were calculated in terms of the electromagnetic form factors of the corresponding $γ^*a_1π$ current. Simple models of $a_1$ form fact
HESS Collaboration, F Aharonian
The supernova remnant (SNR) complex CTB 37 is an interesting candidate for observations with Very High Energy (VHE) gamma-ray telescopes such as H.E.S.S. In this region, three SNRs are seen. One of them is potentially associated with several molecular clouds, a circumstance that can be used to probe the acceleration of hadronic cosmic rays. This region was o
Peng Gao, Boris Pioline
We revisit the holomorphic anomaly equations satisfied by the topological string amplitude from the perspective of the 4D-5D lift, in the context of ''magic'' N=2 supergravity theories. In particular, we interpret the Gopakumar-Vafa relation between 5D black hole degeneracies and the topological string amplitude as the result of a canonical t
M. Shifman, A. Yung
We continue explorations of non-Abelian strings, focusing on the solution of a heterotic deformation of the CP(N-1) model with an extra right-handed fermion field and N=(0,2) supersymmetry. This model emerges as a low-energy theory on the worldsheet of the BPS-saturated flux tubes (strings) in N=2 supersymmetric QCD deformed by a superpotential of a special
J. Layssac, S. Narison
C-odd asymmetry can be studied from an accurate measurement of the angular distribution due to the interference between the S- and P-waves in e+e- --> pi+ pi- at order alpha^3. The asymmetry is dominated by the pion rescattering diagram which is enhanced by the presence of the ln(s/m^2_e), and is quite large (10% at theta=30^0 and sqrt{s} < M_{f_2}) compared
J. A. R. Cembranos, A. de la Cruz-Dombriz, A. Dobado, A. L. Maroto
One of the most striking features found in the cosmic microwave background data is the presence of an anomalous Cold Spot (CS) in the temperature maps made by the Wilkinson Microwave Anisotropy Probe (WMAP). This CS has been interpreted as the result of the presence of a collapsing texture, perhaps coming from some early universe Grand Unified Theory (GUT) p
T. Gehrmann, G. Luisoni, H. Stenzel
We study the matching of the next-to-leading logarithmic approximation (NLLA) onto the fixed next-to-next-to-leading order (NNLO) calculation for event shape distributions in electron-positron annihilation. The resulting theoretical predictions combine all precision QCD knowledge on the distributions, and are theoretically reliable over an extended kinematic
Jun Otsuka, Tomoya Ono, Kikuji Hirose
A first-principles study of the electronic polarization of BN and AlN nanotubes and their graphitic sheets under an external electric field has been performed. We found that the polarization per atom of zigzag nanotubes increases with decreasing diameter while that of armchair nanotubes decreases. The variation of the polarization is related to the exterior
Jeong-Eun Lee, Edwin A. Bergin, James R. Lyons
We present results from a model of oxygen isotopic anomaly production through selective photodissociation of CO within the collapsing proto-Solar cloud. Our model produces a proto-Sun with a wide range of Delta_17O values depending on the intensity of the ultraviolet radiation field. Dramatically different results from two recent Solar wind oxygen isotope me
Charles Horowitz, Karin Usadi Katz, Mikhail G. Katz
We show that Bonnesen's isoperimetic defect has a systolic analog for Loewner's torus inequality. The isosystolic defect is expressed in terms of the probabilistic variance of the conformal factor of the metric g with respect to the flat metric of unit area in the conformal class of g.
Energy spectra of gamma-rays, electrons and neutrinos produced at interactions of relativistic protons with low energy radiation
astro-phS. R. Kelner, F. A. Aharonian
We derived simple analytical parametrizations for energy distributions of photons, electrons, and neutrinos produced in interactions of relativistic protons with an isotropic monochromatic radiation field. The results on photomeson processes are obtained using numerical simulations of proton-photon interactions based on the public available Monte-Carlo code
Jonas T. Hartwig
We define a notion of pseudo-unitarizability for weight modules over a generalized Weyl algebra (of rank one, with commutative coeffiecient ring $R$), which is assumed to carry an involution of the form $X^*=Y$, $R^*\subseteq R$. We prove that a weight module $V$ is pseudo-unitarizable iff it is isomorphic to its finitistic dual $V^\sharp$. Using the classif
HESS Collaboration, F. Aharonian
The >100 GeV gamma-ray source, HESS J1713-381, apparently associated with the shell-type supernova remnant (SNR) CTB 37B, was discovered using H.E.S.S. in 2006. X-ray follow-up observations with Chandra were performed in 2007 with the aim of identifying a synchrotron counterpart to the TeV source and/or thermal emission from the SNR shell. These new Chandra
Mohsen Alishahiha, Subir Mukhopadhyay
In this note we discuss a possible holographic dual of the two dimensional conformal field theory associated with the world-sheet of a macroscopic superstring in a compactification on four-torus. We assume the near horizon geometry of the black string has symmetries of $AdS_3\times S^3\times T^4$ and construct a sigma model in the bulk. Analyzing the symmetr
Theo Buehler
We modify the definition of l^1-homology and argue why our definition is more adequate than the classical one. While we cannot reconstruct the classical l^1-homology from the new definition for various reasons, we can reconstruct its Hausdorffification so that no information concerning semi-norms is lost. We obtain an axiomatic characterization of our l^1-ho
Guido Burkard
Within the lowest-order Born approximation, we calculate the exact dynamics of a single qubit in the presence of 1/f noise, without making any Markov approximation. We show that the non-Markovian qubit time-evolution exhibits asymmetries and beatings that cannot be explained within a Markovian theory. The present theory for 1/f noise is relevant for both spi
R. V. Harlander, P. Kant, L. Mihaila, M. Steinhauser
Within the minimal supersymmetric extension of the Standard Model, the mass of the light CP-even Higgs boson is computed to three-loop accuracy, taking into account the next-to-next-to-leading order effects from supersymmetric Quantum Chromodynamics. We consider two different scenarios for the mass hierarchies of the supersymmetric spectrum. Our numerical re
Sourish Dutta, D. A. Steer, Tanmay Vachaspati
We study the creation of solitons from particles, using the $λϕ^4$ model as a prototype. We consider the scattering of small, identical, wave pulses, that are equivalent to a sequence of particles, and find that kink-antikink pairs are created for a large region in parameter space. We also find that scattering at {\it low} velocities is favorable for creatin
C. Fedeli, M. Bartelmann, M. Meneghetti, L. Moscardini
We use semi-analytic modelling of the galaxy-cluster population and its strong lensing efficiency to explore how the expected abundance of large gravitational arcs on the sky depends on $σ_8$. Our models take all effects into account that have been shown to affect strong cluster lensing substantially, in particular cluster asymmetry, substructure, merging, a
Mohamed Hebiri
We consider the linear regression problem. We propose the S-Lasso procedure to estimate the unknown regression parameters. This estimator enjoys sparsity of the representation while taking into account correlation between successive covariates (or predictors). The study covers the case when $p\gg n$, i.e. the number of covariates is much larger than the numb
Examples of smooth maps with finitely many critical points in dimensions $(4,3)$, $(8,5)$ and $(16,9)$
math.GTLouis Funar, Cornel Pintea, Ping Zhang
We consider manifolds $M^{2n}$ which admit smooth maps into a connected sum of $S^1\times S^n$ with only finitely many critical points, for $n\in\{2,4,8\}$, and compute the minimal number of critical points.
Scaling and super-universality in the coarsening dynamics of the 3d random field Ising model
cond-mat.dis-nnCamille Aron, Claudio Chamon, Leticia F. Cugliandolo, Marco Picco
We study the coarsening dynamics of the three-dimensional random field Ising model using Monte Carlo numerical simulations. We test the dynamic scaling and super-scaling properties of global and local two-time observables. We treat in parallel the three-dimensional Edward-Anderson spin-glass and we recall results on Lennard-Jones mixtures and colloidal suspe
Qing-Guo Huang, S. -H. Henry Tye
An earlier paper points out that a quantum treatment of the string landscape is necessary. It suggests that the wavefunction of the universe is mobile in the landscape until the universe reaches a meta-stable site with its cosmological constant $Λ_0$ smaller than the critical value $Λ_c$, where $Λ_c$ is estimated to be exponentially small compared to the Pla
John D. Barrow, Christos G. Tsagas
We describe how magnetic fields in Friedmann universes can experience superadiabatic growth without departing from conventional electromagnetism. The reason is the relativistic coupling between vector fields and spacetime geometry, which slows down the decay of large-scale magnetic fields in open universes, compared to that seen in perfectly flat models. The
The UTfit Collaboration, M. Bona, M. Ciuchini, E. Franco
We combine all the available experimental information on Bs mixing, including the very recent tagged analyses of Bs to J/Psi phi by the CDF and D0 collaborations. We find that the phase of the Bs mixing amplitude deviates more than 3 sigma from the Standard Model prediction. While no single measurement has a 3 sigma significance yet, all the constraints show
Daniel Roggenkamp, Katrin Wendland
To certain geometries, string theory associates conformal field theories. We discuss techniques to perform the reverse procedure: To recover geometrical data from abstractly defined conformal field theories. This is done by introducing appropriate notions of limits of conformal field theories and their degenerations, and by applying techniques from noncommut
E. Nieppola, E. Valtaoja, M. Tornikoski, T. Hovatta
The blazar sequence is a scenario in which the bolometric luminosity of the blazar governs the appearance of its spectral energy distribution. The most prominent result is the significant negative correlation between the synchrotron peak frequencies and the synchrotron peak luminosities of the blazar population. Observational studies of the blazar sequence h
N. Bree, I. Stefanescu, P. A. Butler, J. Cederkäll
The $B(E2;0^+\to2^+)$ value in $^{68}$Ni has been measured using Coulomb excitation at safe energies. The $^{68}$Ni radioactive beam was post-accelerated at the ISOLDE facility (CERN) to 2.9 MeV/u. The emitted $γ$ rays were detected by the MINIBALL detector array. A kinematic particle reconstruction was performed in order to increase the measured c.m. angula
István Rácz
The global extendibility of smooth causal geodesically incomplete spacetimes is investigated. Denote by $γ$ one of the incomplete non-extendible causal geodesics of a causal geodesically incomplete spacetime $(M,g_{ab})$. First, it is shown that it is always possible to select a synchronised family of causal geodesics $Γ$ and an open neighbourhood $\mathcal{
Multiplicity, mean $p_T$, $p_T$-spectra and elliptic flow of identified particles in Pb+Pb collisions at LHC
nucl-thA. K. Chaudhuri
Israel-Stewart's causal theory of dissipative hydrodynamics, with the ADS/CFT lower limit of shear viscosity to entropy ratio ($η/s$=0.08), give consistent description of a number of experimental observables in Au+Au collisions at RHIC (c.m. energy $\sqrt{s}$=200 GeV) \cite{Chaudhuri:2008sj}. Assuming that in Pb+Pb collisions at LHC (c.m. energy $\sqrt{s
Amir Dzambic
The purpose of the present paper is to explain the fake projective plane constructed by J.H. Keum from the point of view of arithmetic ball quotients. Beside the ball quotient associated with the fake projective plane, we also analize two further naturally related ball quotients whose minimal desingularizations lead to two elliptic surfaces, one already cons
Stefano Francaviglia, Armando Martino
We define metrics on Culler-Vogtmann space, which are an analogue of the Teichmuller metric and are constructed using stretching factors. In fact the metrics we study are related, one being a symmetrised version of the other. We investigate the basic properties of these metrics, showing the advantages and pathologies of both choices. We show how to compute s
Toshifumi Jittoh, Masafumi Koike, Takaaki Nomura, Joe Sato
We investigate the gauge-Higgs unification models within the scheme of the coset space dimensional reduction, beginning with a gauge theory in a fourteen-dimensional spacetime where extra-dimensional space has the structure of a ten-dimensional compact coset space. We found seventeen phenomenologically acceptable models through an exhaustive search for the c
Reliable Identification of Compton-thick Quasars at z~2: Spitzer Mid-IR spectroscopy of HDF-oMD49
astro-phD. M. Alexander, R. R. Chary, A. Pope, F. E. Bauer
Many models that seek to explain the origin of the unresolved X-ray background predict that Compton-thick Active Galactic Nuclei (AGNs) are ubiquitious at high redshift. However, few distant Compton-thick AGNs have been reliably identified to date. Here we present Spitzer-IRS spectroscopy and 3.6-70um photometry of a z=2.2 optically identified AGN (HDF-oMD49
Joint effects of nutrients and contaminants on the dynamics of a food chain in marine ecosystems
q-bio.PEFlora S. Bacelar, Sibylle Dueri, Emilio Hernandez-Garcia, Jose-Manuel Zaldivar
We analyze the joint effect of contaminants and nutrient loading on population dynamics of marine food chains by means of bifurcation analysis. Contaminant toxicity is assumed to alter mortality of some species with a sigmoidal dose-response relationship. A generic effect of pollutants is to delay transitions to complex dynamical states towards higher nutrie
An Averaging Principle for Combined Interaction Graphs. Part I: Connectivity and Applications to Genetic Switches
q-bio.MNMarkus Kirkilionis, Luca Sbano
Time-continuous dynamical systems defined on graphs are often used to model complex systems with many interacting components in a non-spatial context. In the reverse sense attaching meaningful dynamics to given 'interaction diagrams' is a central bottleneck problem in many application areas, especially in cell biology where various such diagrams with
Marco Regis
We study the multi-wavelength signal induced by pairs annihilations at the Galactic center (GC) of a recently proposed dark matter (DM) candidate. The weakly interacting massive particle (WIMP) candidate, named A_, is the first Kaluza-Klein mode of a five dimensional Abelian gauge boson. Electroweak precision tests and the DM cosmological bound constrain its
A. Seifahrt, T. Roell, R. Neuhaeuser, A. Reiners
We present a refined orbital solution for the components A, B, and C of the nearby late-M type multiple system LHS 1070. By combining astrometric datapoints from NACO/VLT, CIAO/SUBARU, and PUEO/CFHT, as well as a radial velocity measurement from the newly commissioned near infrared high-resolution spectrograph CRIRES/VLT, we achieve a very precise orbital so
Maria Calle, Darren Lee
We show that there exists a metric with positive scalar curvature on S2xS1 and a sequence of embedded minimal cylinders that converges to a minimal lamination that, in a neighborhood of a strictly stable 2-sphere, is smooth except at two helicoid-like singularities on the 2-sphere. The construction is inspired by a recent example by D. Hoffman and B. White.
Iain MacPhee, Mikhail Menshikov, Dimitri Petritis, Serguei Popov
We consider a polling model with multiple stations, each with Poisson arrivals and a queue of infinite capacity. The service regime is exhaustive and there is Jacksonian feedback of served customers. What is new here is that when the server comes to a station it chooses the service rate and the feedback parameters at random; these remain valid during the who
Hall effect and magnetoresistance in the normal state of the superconductor LaO$_{0.9}$F$_{0.1-x}$FeAs
cond-mat.supr-conHuan Yang, Xiyu Zhu, Lei Fang, Gang Mu
By using a two-step method, we successfully synthesized the iron based new superconductor LaO$_{0.9}$F$_{0.1-x}$FeAs. The Hall effect and magnetoresistance were measured in wide temperature region. A negative Hall coefficient R_H has been found implying a dominant conduction by electron-like charge carriers in this material. The charge carrier density determ
Kelly Jabbusch
In this paper we prove a generalization of a theorem of Schneider, which gives a criterion for a projective surface over the complex numbers to have an ample cotangent bundle. After reviewing different notions of positivity, we introduce a slightly weaker notion of ampleness, which we call quasi-ample, and then are able to extend Schneider's result to higher
Andreas Heuer, Oliver Rubner
We analyze the time series of soccer matches in a model-free way using data for the German soccer league (Bundesliga). We argue that the goal difference is a better measure for the overall fitness of a team than the number of points. It is shown that the time evolution of the table during a season can be interpreted as a random walk with an underlying consta
Structural, vibrational and quasiparticle properties of the Peierls semiconductor $\rm BaBiO_3$: a hybrid functional and self-consistent GW+vertex-corrections study
cond-mat.str-elC. Franchini, A. Sanna, M. Marsman, G. Kresse
$\rm BaBiO_3$ is characterized by a charge disproportionation with half of the Bi atoms possessing a valence 3+ and half a valence 5+. Because of selfinteraction errors, local and semi-local density functionals fail to describe the charge disproportionation quantitatively, yielding a too small structural distortion and no band gap. Using hybrid functionals w
A. A. Ivanov
Possible extragalactic sources of cosmic rays at energies above 4*10^{19} eV detected with the Yakutsk array are sought. Correlation of the shower arrival directions with objects from Veron's catalog that are located closer than 100 Mpc from the Earth confirms the observations at the Pierre Auger observatory, as well as the Greisen-Zatsepin-Kuzmin effect on
Peter Jung
In this article we consider the approximate description of doubly--dispersive channels by its symbol. We focus on channel operators with compactly supported spreading, which are widely used to represent fast fading multipath communication channels. The concept of approximate eigenstructure is introduced, which measures the accuracy E_p of the approximation o
D. L. Looper, C. R. Gelino, A. J. Burgasser, J. D. Kirkpatrick
We present Keck laser guide star observations of two T2.5 dwarfs - 2MASS J11061197+2754225 & 2MASS J14044941-3159329 - using NIRC2 on Keck-II and find 2MASS J14044941-3159329 to be a 0.13" binary. This system has a secondary that is 0.45 mags brighter than the primary in J-band but 0.49 mags fainter in H-band and 1.13 mags fainter in Ks-band. We use this
Huanxia Fa, Junbo Li, Yongsheng Cheng
In this paper the q-deformed $W$ algebra $\WW_q$ is constructed, whose nontrivial quantum group structure is presented.
The Relationship Between a Function, a Functions Inverse, and their Antiderivatives with an Emphasis in Finding Exact Roots with the Technique of Integration
math.GMJudah Francis Unmuth-Yockey
Using a new technique involving integration it is possible to find the exact roots of simple functions. In this case, simple functions are defined as smooth functions having an inverse, and that inverse having an antiderivative. This technique now makes it possible to find the exact roots of certain functions without the use of numerical or iterative methods
M. R. Nolta, J. Dunkley, R. S. Hill, G. Hinshaw
We present the temperature and polarization angular power spectra of the cosmic microwave background (CMB) derived from the first 5 years of WMAP data. The 5-year temperature (TT) spectrum is cosmic variance limited up to multipole l=530, and individual l-modes have S/N>1 for l<920. The best fitting six-parameter LambdaCDM model has a reduced chi^2 for l=33-
Eugen Paal, Jyri Virkepu
It is explained how the time evolution of operadic variables may be introduced by using the operadic Lax equation. As an example, a 2-dimensional binary operadic Lax representation for the harmonic oscillator is constructed.
Takayuki Myo, Yuma Kikuchi, Kiyoshi Kato, Hiroshi Toki
We make a systematic study of Li isotopes (A=9,10,11) in the tensor optimized shell model for 9Li and treat the additional valence neutrons in the cluster model approach by taking into account the Pauli-blocking effect caused by the tensor and pairing correlations. We describe the tensor correlations in 9Li fully in the tensor-optimized shell model, where th
Rychard J. Bouwens, Garth D. Illingworth, Marijn Franx, Holland Ford
We use all available deep optical ACS and near-IR data over both the HUDF and the two GOODS fields to search for star-forming galaxies at z>~7 and constrain the UV LF within the first 700 Myrs. Our data set includes ~23 arcmin^2 of deep NICMOS J+H data and ~248 arcmin^2 of ground-based (ISAAC+MOIRCS) data, coincident with ACS optical data of greater or equal
T. R. Hunter, C. L. Brogan, R. Indebetouw, C. J. Cyganowski
We present the first subarcsecond submillimeter images of the enigmatic ultracompact HII region (UCHII) G5.89-0.39. Observed with the SMA, the 875 micron continuum emission exhibits a shell-like morphology similar to longer wavelengths. By using images with comparable angular resolution at five frequencies obtained from the VLA archive and CARMA, we have rem
Angular Momentum Transport in Accretion Disks and its Implications for Spin Estimates in Black Hole Binaries
astro-phChris Done, Shane W. Davis
The accretion flow in the disk dominated state of black hole binaries has peak temperature and luminosity which vary together in such a way as to indicate an approximately constant emitting area. The association of this with the last stable orbit gives one of the few ways to estimate spin when the mass of the black hole is known. However, deriving this radiu
Adrian P. Flitney, Maximilian Schlosshauer, Christian Schmid, Wieslaw Laskowski
We show that, for a continuous set of entangled four-partite states, the task of maximizing the payoff in the symmetric-strategy four-player quantum Minority game is equivalent to maximizing the violation of a four-particle Bell inequality with each observer choosing the same set of two dichotomic observables. We conclude the existence of direct corresponden
E. L. Wright, X. Chen, N. Odegard, C. L. Bennett
We present the list of point sources found in the WMAP 5-year maps. The technique used in the first-year and three-year analysis now finds 390 point sources, and the five-year source catalog is complete for regions of the sky away from the galactic plane to a 2 Jy limit, with SNR > 4.7 in all bands in the least covered parts of the sky. The noise at high fre
Jean-Claude Falmagne
Any subset Q' of the domain Q of a learning space defines a projection of that learning space on Q' which is itself a learning space consistent with the original one. Moreover, such a construction defines a partition of Q having each of its classes defining a learning space also consistent with the original learning space. We give a direct proof of t
Yong-Wan Kim, Hyung Won Lee, Yun Soo Myung, Mu-In Park
We investigate the new agegraphic dark energy models with generalized uncertainty principle (GUP). It turns out that although the GUP affects the early universe, it does not change the current and future dark energy-dominated universe significantly. Furthermore, this model could describe the matter-dominated universe in the past only when the parameter $n$ i
Nicolas Botbol
We develop in this paper some methods for studying the implicitization problem for a rational map $ϕ: \mathbb{P}^n \to (\mathbb{P}^1)^{n+1}$ defining a hypersurface in $(\mathbb{P}^1)^{n+1}$, based on computing the determinant of a graded strand of a Koszul complex. We show that the classical study of Macaulay Resultants and Koszul complexes coincides, in th
Arun Ram, Martha Yip
In this paper we use the combinatorics of alcove walks to give a uniform combinatorial formula for Macdonald polynomials for all Lie types. These formulas are generalizations of the formulas of Haglund-Haiman-Loehr for Macdonald polynoimals of type GL(n). At q=0 these formulas specialize to the formula of Schwer for the Macdonald spherical function in terms
G. Gotsbacher
The automorphic cohomology of a connected reductive algebraic group defined over Q decomposes as a direct algebraic sum of cuspidal and Eisenstein cohomology. In the present paper we construct regular Eisenstein cohomology classes for congruence subgroups of a rational form G of Q-rank 2 of SO(n,2).
Florian Mintert, Ana Maria Rey, Indubala I. Satija, Charles W. Clark
We show that entanglement monotones can characterize the pronounced enhancement of entanglement at a quantum phase transition if they are sensitive to long-range high order correlations. These monotones are found to develop a sharp peak at the critical point and to exhibit universal scaling. We demonstrate that similar features are shared by noise correlatio
Angel Paredes, Kasper Peeters, Marija Zamaklar
In holographic models of gauge theories with matter, there generically exists a first order phase transition in which mesons dissociate. We perform a careful analysis of the meson and quasi-particle spectra in the overheated resp. undercooled regimes close to the junction of the two phases. We show that all overheated finite meson masses eventually become in
Florian Sebert, Leslie Ying, Yi Ming Zou
Recent work in compressed sensing theory shows that $n\times N$ independent and identically distributed (IID) sensing matrices whose entries are drawn independently from certain probability distributions guarantee exact recovery of a sparse signal with high probability even if $n\ll N$. Motivated by signal processing applications, random filtering with Toepl
Aruna Mohan, Anatoly B. Kolomeisky, Matteo Pasquali
We propose a method for the theoretical investigation of polymer translocation through composite pore structures possessing arbitrarily specified geometries. Translocation through each constituent part of the composite is treated as being analogous to the diffusion of the translocation coordinate over the free energy landscape derived from the chain configur
L. de' Medici, A. Georges, G. Kotliar
We investigate sum-rules applying to the Raman intensity in a strongly correlated system close to the Mott transition. Quite generally, it can be shown that, provided the frequency integration is performed up to a cutoff smaller than the upper Hubbard band, a sum-rule applies to the non-resonant Raman signal of a doped Mott insulator, resulting in an integra
P. Barmby, J. -S. Huang, M. L. N. Ashby, P. R. M. Eisenhardt
The Extended Groth Strip (EGS) is one of the premier fields for extragalactic deep surveys. Deep observations of the EGS with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope cover an area of 0.38 square degrees to a 50% completeness limit of 1.5 uJy at 3.6 um. The catalog comprises 57434 objects detected at 3.6 um, with 84%, 28%, and 24% also
Compressible or incompressible blend of interacting monodisperse star and linear polymers near a surface
cond-mat.softRichard Batman, P. D. Gujrati
We consider a lattice model of a mixture of repulsive, attractive, or neutral monodisperse star (species A) and linear (species B) polymers with a third monomeric species C, which may represent free volume. The mixture is next to a hard, infinite plate whose interactions with A and C can be attractive, repulsive, or neutral. These two interactions are the on
A. Pal, G. A. Bakos, G. Torres, R. W. Noyes
We report on the latest discovery of the HATNet project; a very hot giant planet orbiting a bright (V = 10.5) star with a small semi-major axis of a = 0.0377 +/- 0.0005 AU. Ephemeris for the system is P = 2.2047299 +/- 0.0000040 days, mid-transit time E = 2,453,790.2593 +/- 0.0010 (BJD). Based on the available spectroscopic data on the host star and photomet
Jay Anderson, Ivan R. King, Harvey B. Richer, Gregory G. Fahlman
We describe here the reduction methods that we developed to study the faintest red dwarfs and white dwarfs in an outer field of NGC6397, which was observed by \hst for 126 orbits in 2005. The particular challenge of this data set is that the faintest stars are not readily visible in individual exposures, so special care must be taken to combine the informati
S. Adam, S. Das Sarma
Motivated by recent experiments on suspended graphene showing carrier mobilities as high as 200,000 cm^2/Vs, we theoretically calculate transport properties assuming Coulomb impurities as the dominant scattering mechanism. We argue that the substrate-free experiments done in the diffusive regime are consistent with our theory and verify many of our earlier p
A Single Charged Quantum Dot in a Strong Optical Field: Absorption, Gain, and the AC Stark Effect
cond-mat.mes-hallXiaodong Xu, Bo Sun, Erik D. Kim, Katherine Smirl
We investigate a singly-charged quantum dot under a strong optical driving field by probing the system with a weak optical field. When the driving field is detuned from the trion transition, the probe absorption spectrum is shifted from the trion resonance as a consequence of the dynamic Stark effect. Simultaneously, a gain sideband is created, resulting fro
Partha Goswami
The two-dimensional d-p model (or extended Hubbard model) on a square lattice is investigated for fermion pairing by a slave boson method. The inter-site d-fermion interaction is introduced additionally. The momentum space counterpart of this interaction is taken to be separable and expanded in terms of basis functions corresponding to mixed symmetry states.
Investigation of the Vertical Movement of an Isothermal Line at the Density Maximum in H2O and D2O
physics.chem-phWilliam R. Gorman, Gregory J. Parks, James D. Brownridge
We studied the cooling of a column of water, primarily in a freezer, and analyzed the development and movement of an isothermal line at ~4 degC in H2O and ~11 degC in D2O. Our experiments show that the vertical velocity of the symmetrical isothermal line moving up the column of water is inversely proportional to the diameter of the column of water. It has a
Hans Christianson
Following the work of Duistermaat-Singer \cite{DS} on isomorphisms of algebras of global pseudodifferential operators, we classify isomorphisms of algebras of microlocally defined semiclassical pseudodifferential operators. Specifically, we show that any such isomorphism is given by conjugation by $A = BF$, where $B$ is a microlocally elliptic semiclassical
Atsushi Ito, Hiroaki Nakamura
Energy density and energy flux was introduced along Takesue's method. Particle energies were localized at particle positions using Dirac delta function. The energy density was connected with the energy flux by continuity equation. New method was proposed to deal with multi--body interaction. Consequently, the energy current between particles could be cal
U. Haboeck
We show that the "twisted" planar random walk - which results by summing up stationary increments rotated by multiples of a fixed angle - is recurrent under diverse assumptions on the increment process. For example, if the increment process is alpha-mixing and of finite second moment, then the twisted random walk is recurrent for every angle fixed ch
Y. Kozuka, T. Susaki, H. Y. Hwang
We have investigated the extreme quantum limit of photogenerated electrons in quantum paraelectric SrTiO3. This regime is distinct from conventional semiconductors, due to the large electron effective mass and large lattice dielectric constant. At low temperature, the magnetoresistance and Hall resistivity saturate at high magnetic field, deviating from conv
J. M. Paredes, J. Marti, C. H. Ishwara-Chandra, D. F. Torres
Context. A considerable fraction of the gamma-ray sources discovered with the Energetic Gamma-Ray Experiment Telescope (EGRET) remain unidentified. The EGRET sources that have been properly identified are either pulsars or variable sources at both radio and gamma-ray wavelengths. Most of the variable sources are strong radio blazars.However, some low galacti
Umberto Marini Bettolo Marconi, Andrea Puglisi, Lamberto Rondoni, Angelo Vulpiani
General aspects of the Fluctuation-Dissipation Relation (FDR), and Response Theory are considered. After analyzing the conceptual and historical relevance of fluctuations in statistical mechanics, we illustrate the relation between the relaxation of spontaneous fluctuations, and the response to an external perturbation. These studies date back to Einstein