December 2005 arXiv papers — page 30
Showing 2,901–3,000 of 4,155 papers
Zhenxin Liu
The well-known Conley's theorem states that the complement of chain recurrent set equals the union of all connecting orbits of the flow $ϕ$ on the compact metric space $X$, i.e. $X-\mathcal{CR}(ϕ)=\bigcup [B(A)-A]$, where $\mathcal{CR}(ϕ)$ denotes the chain recurrent set of $ϕ$, $A$ stands for an attractor and $B(A)$ is the basin determined by $A$. In th
Finite flat commutative group schemes over complete discrete valuation rings III: classification, tangent spaces, and semistable reduction of Abelian varieties
math.AGM. V. Bondarko
We classify group schemes in terms of their Cartier modules. We also prove the equivalence of different definitions of the tangent space and the dimension for these group schemes; in particular, the minimal dimension of a formal group law that contains $S$ as a closed subgroup is equal to the minimal number of generators for the affine algebra of $S$. As an
U. K. Anandavardhanan, Dipendra Prasad
Let E/F be a quadratic extension of number fields. For a cuspidal representation $π$ of SL(2,A_E), we study the non-vanishing of the period integral on SL(2,F)\SL(2,A_F). We characterise the non-vanishing of the period integral of $π$ in terms of $π$ being generic with respect to characters of E\A_E which are trivial on A_F. We show that the period integral
Gianmarco Capitanio
We give a global description of envelopes of geodesic tangents of regular curves in (not necessarily convex) Riemannian surfaces. We prove that such an envelope is the union of the curve itself, its inflectional geodesics and its tangential caustics (formed by the conjugate points to those of the initial curve along the tangent geodesics). Stable singulariti
E. Klimenko, N. Kopteva
We deal with two-generator subgroups of PSL(2,C) with real traces of both generators and their commutator. We give discreteness criteria for these groups when at least one of the generators is parabolic. We also present a list of the corresponding orbifolds.
Michael Carr, Satyan L. Devadoss
Given a graph G, we construct a simple, convex polytope whose face poset is based on the connected subgraphs of G. This provides a natural generalization of the Stasheff associahedron and the Bott-Taubes cyclohedron. Moreover, we show that for any simplicial Coxeter system, the minimal blow-ups of its associated Coxeter complex has a tiling by graph-associah
P. J. Arias, N. Bolívar, E. Fuenmayor, Lorenzo Leal
Non-relativistic charged open strings coupled with Abelian gauge fields are quantized in a geometric representation that generalizes the Loop Representation. The model comprises open-strings interacting through a Kalb-Ramond field in four dimensions. It is shown that a consistent geometric-representation can be built using a scheme of ``surfaces and lines of
F. Cannata, M. V. Ioffe, D. N. Nishnianidze
Supersymmetrical intertwining relations of second order in derivatives allow to construct a two-dimensional quantum model with complex potential, for which {\it all} energy levels and bound state wave functions are obtained analytically. This model {\it is not amenable} to separation of variables, and it can be considered as a specific complexified version o
M. Bertolini, F. Bigazzi, A. L. Cotrone
We report on some recent results within the string/gauge theory correspondence, both in the conformal and in the non conformal cases, for a recently found class of N=1 dual pairs. These results provide the first cross check of AdS/CFT and field theory techniques like a-maximization. Moreover, they furnish new examples of cascading gauge theories and the firs
Teiji Kunihiro, Kyosuke Tsumura
We first give a comprehensive review of the renormalization group method for global and asymptotic analysis, putting an emphasis on the relevance to the classical theory of envelopes and on the importance of the existence of invariant manifolds of the dynamics under consideration. We clarify that an essential point of the method is to convert the problem fro
L. Sh. Grigoryan, H. F. Khachatryan, S. R. Arzumanyan, M. L. Grigoryan
Some characteristic features in the radiation from a relativistic electron uniformly rotating along an equatorial orbit around a dielectric ball have been studied. It was shown that at some harmonics, in case of weak absorption of radiation in the ball material, the electron may generate radiation field quanta exceeding in several dozens of times those gener
Maxim Perelstein
This article reviews the Little Higgs models of electroweak symmetry breaking and their phenomenology. Little Higgs models incorporate a light composite Higgs boson and remain perturbative until a scale of order 10 TeV, as required by precision electroweak data. The collective symmetry breaking mechanism, which forms the basis of Little Higgs models, is intr
R. Decker, J. Pestieau
This paper has been presented at the DESY Workshop, October 22-24, 1979. Assuming cancellation of lepton self-mass ultraviolet divergences in the SU(2) x U(1) gauge theory, we predict heavy quark t and Higgs scalar masses. In Eq.(6), the mass sum rule necessary to the vanishing of quadratic divergences is formulated.
M. Anselmino, M. Boglione, U. D'Alesio, E. Leader
We present a generalized QCD factorization scheme for the high energy inclusive polarized process, (A, S_A) + (B, S_B) -> C + X, including all intrinsic partonic motions. This introduces many non-trivial azimuthal phases and several new spin and k_T dependent soft functions. The formal expressions for single and double spin asymmetries are discussed. Numeric
D. Kekez, D. Klabucar, M. D. Scadron
Many meson processes are related to the U_A(1) axial anomaly, present in the Feynman graphs where fermion loops connect axial vertices with vector vertices. However, the coupling of pseudoscalar mesons to quarks does not have to be formulated via axial vertices. The pseudoscalar coupling is also possible, and this approach is especially natural on the level
Gluon transverse momenta and charm quark-antiquark pair production in $p-\bar p$ collisions at Tevatron
hep-phM. Luszczak, A. Szczurek
We discuss and compare different approaches to include gluon transverse momenta for heavy quark-antiquark pair production. The correlations in azimuthal angle and in heavy quark, heavy antiquark transverse momenta are studied in detail. The results are illustrated with the help of different unintegrated gluon distribution functons (UGDF) from the literature.
Takehiko Asaka, Koji Ishiwata, Takeo Moroi
We consider supersymmetric models with right-handed neutrinos where neutrino masses are purely Dirac-type. In this model, right-handed sneutrino can be the lightest supersymmetric particle and can be a viable candidate of cold dark matter of the universe. Right-handed sneutrinos are never thermalized in the early universe because of weakness of Yukawa intera
M. Marklund, B. Eliasson, P. K. Shukla
Photon-photon scattering, due to photons interacting with virtual electron-positron pairs, is an intriguing deviation from classical electromagnetism predicted by quantum electrodynamics (QED). Apart from being of fundamental interest in itself, collisions between photons are believed to be of importance in the vicinity of magnetars, in the present generatio
Elliot Leader, Aleksander V. Sidorov, Dimiter B. Stamenov
We have re-analyzed the world data on inclusive polarized DIS, in both NLO and LO QCD, including the new HERMES and COMPASS data. The updated NLO polarized densities are given in both the $\rm \bar{MS}$ and JET schemes. The impact of the new data on the results is discussed.
G. X. Peng, X. J. Wen, Y. D. Chen
Recent publications rule out the negatively charged beta equilibrium strangelets in ordinary phase, and the color-flavor locked (CFL) strangelets are reported to be also positively charged. This letter presents new solutions to the system equations where CFL strangelets are slightly negatively charged. If the ratio of the square-root bag constant to the gap
Yong Zhou
We discuss the gauge dependence of fermion mass definition and physical result under the conventional on-shell mass renormalization scheme and the recently proposed pole mass renormalization scheme in standard model. By the two-loop calculations of top quark's mass counterterm and the cross section of physical process $W^{-}W^{+}\to b\bar{b}$ we strictly
M. Gockeler, Ph. Hagler, R. Horsley, D. Pleiter
This talk presents results from the QCDSF-UKQCD collaboration for moments of leading twist generalized parton distributions in two-flavor lattice QCD based on O(a) improved Wilson Fermions. We study helicity independent and helicity flip GPDs with a focus on densities of quarks in the transverse plane.
Diego Tonelli
I report the analysis of B-->h+h'- decays (where h and h' denote K or pi), in 180 pb-1 of proton-antiproton collisions at s**0.5= 1.96 TeV, with the CDF II detector at the Tevatron Collider. A B-->h+h'- signal was reconstructed at a hadron collider for the first time, in the sample collected by the dedicated trigger on long-lived decays. With abo
The BABAR Collaboration, B. Aubert
The e+e- -> p anti-p cross section is determined over a range of p anti-p masses, from threshold to 4.5 GeV/c^2, by studying the e+e- -> p anti-p gamma process. The data set corresponds to an integrated luminosity of 232 fb^-1, collected with the BABAR detector at the PEP-II storage ring, at an e+e- center-of-mass energy of 10.6 GeV. The mass dependence of t
PVLAS Collaboration, E. Zavattini
The PVLAS experiment operates an ellipsometer which embraces a superconducting dipole magnet and can measure ellipticity and rotation induced by the magnetic field onto linearly polarized light. The sensitivity of the instrument is about 10-7rad Hz-1/2. With a residual pressure less than 10-7mbar the apparatus gives both ellipticity and rotation signals at t
Numerical Simulation of Rotating Accretion Disk Around the Schwarzschild Black Hole Using GRH Code
gr-qcOrhan Donmez
The 2D time dependent solution of thin accretion disk in a close binary system have been presented on the equatorial plane around the Schwarzschild black hole. To do that, the special part of the General Relativistic Hydrodynamical(GRH) equations are solved using High Resolution Shock Capturing (HRSC) schemes. The spiral shock waves on the accretion disk are
Aubert Daigneault
Irving Ezra Segal (1918-1998) has proposed some axioms for mathematical cosmology. These are here re-examined and Segal's redshift formula and energy conservation in the Einstein universe are established in full on their basis. A detailed table of contents appears at the end.
Changing the Hilbert space structure as a consequence of gauge transformations in "extended phase space" version of quantum geometrodynamics
gr-qcT. P. Shestakova
In the earlier works on quantum geometrodynamics in extended phase space it has been argued that a wave function of the Universe should satisfy a Schrodinger equation. Its form, as well as a measure in Schrodinger scalar product, depends on a gauge condition (a chosen reference frame). It is known that the geometry of an appropriate Hilbert space is determin
Jose P. Mimoso, Ana Nunes, Diego Pavon
We analyze the dynamics of models of warm inflation with general dissipative effects. We consider phenomenological terms both for the inflaton decay rate and for viscous effects within matter. We provide a classification of the asymptotic behavior of these models and show that the existence of a late-time scaling regime depends not only on an asymptotic beha
Alfred Scharff Goldhaber
It is possible that the expansion of the universe began with an inflationary phase, in which the inflaton driving the process also was a Higgs field capable of stabilizing magnetic monopoles in a grand-unified gauge theory. If so, then the smallness of intensity fluctuations observed in the cosmic microwave background radiation implies that the self-coupling
Analytic expressions for gravitational inner multipole moments of elementary solids and for the force between two rectangular solids
gr-qcE. G. Adelberger, Nathan A. Collins, C. D. Hoyle
We give analytic expressions for the gravitational inner spherical multipole moments, q_{lm} with l <= 5, for 11 elementary solid shapes. These moments, in conjunction with their known rotational and translational properties, can be used to calculate precisely the moments of complex objects that may be assembled from the elementary shapes. We also give an an
Sergey P. Tarasov, Mikhail N. Vyalyi
A rational number can be naturally presented by an arithmetic computation (AC): a sequence of elementary arithmetic operations starting from a fixed constant, say 1. The asymptotic complexity issues of such a representation are studied e.g. in the framework of the algebraic complexity theory over arbitrary field. Here we study a related problem of the comple
A Conditionally Cubic-Gaussian Stochastic Lagrangian Model for Acceleration in Isotropic Turbulence
cond-mat.softA. G. Lamorgese, S. B. Pope, P. K. Yeung, B. L. Sawford
The modelling of fluid particle accelerations in homogeneous, isotropic turbulence in terms of second-order stochastic models for the Lagrangian velocity is considered. The basis for the Reynolds model (A. M. Reynolds, \textit{Phys. Rev. Lett.} $\mathbf{91}(8)$, 084503 (2003)) is reviewed and examined by reference to DNS data. In particular, we show DNS data
Hirokazu Tsunetsugu, Mitsuhiro Arikawa
Spin nematic order is investigated for a S=1 spin model on triangular lattice with bilinear-biquadratic interactions. We particularly studied an antiferro nematic order phase with three-sublattice structure, and magnetic properties are calculated at zero temperature by means of bosonization. Two types of bosonic excitations are found. One is a gapless excita
M. S. Reis, V. S. Amaral, R. S. Sarthour, I. S. Oliveira
We show how to extract the $q$ parameter from experimental data, considering an inhomogeneous magnetic system composed by many Maxwell-Boltzmann homogeneous parts, which after integration over the whole system recover the Tsallis non-extensivity. Analyzing the cluster distribution of La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ manganite, obtained through scanning tunnelli
A. V. Nikulov
It is argued that only a single spontaneous long-range order, namely the phase coherence exists in the Abrikosov state, and the prediction of the crystalline long-range order of vortex lattice does not correspond to the facts.
Quantum Oscillations of the Critical Current of Asymmetric Aluminum Loops in Magnetic Field
cond-mat.supr-conV. L. Gurtovoi, S. V Dubonos, A. V. Nikulov, N. N. Osipov
The periodical dependencies in magnetic field of the asymmetry of the current-voltage curves of asymmetric aluminum loop are investigated experimentally at different temperatures below the transition into the superconducting state T < Tc. The obtained periodical dependencies of the critical current on magnetic field allow to explain the quantum oscillations
Superconducting Junctions with Ferromagnetic, Antiferromagnetic or Charge-Density-Wave Interlayers
cond-mat.supr-conYuri Barash, I. V. Bobkova, Brian M. Andersen, T. Kopp
Spectra and spin structures of Andreev interface states and the Josephson current are investigated theoretically in junctions between clean superconductors (SC) with ordered interlayers. The Josephson current through the ferromagnet-insulator-ferromagnet interlayer can exhibit a nonmonotonic dependence on the misorientation angle. The characteristic behavior
Stacking of oligo and polythiophenes cations in solution: surface tension and dielectric saturation
cond-mat.mtrl-sciDamian A. Scherlis, Jean-Luc Fattebert, Nicola Marzari
The stacking of positively charged (or doped) terthiophene oligomers and quaterthiophene polymers in solution is investigated applying a recently developed unified electrostatic and cavitation model for first-principles calculations in a continuum solvent. The thermodynamic and structural patterns of the dimerization are explored in different solvents, and t
M. I. Katsnelson, A. Fasolino
We show that a spontaneous bending of single layer bolaamphiphiles results from the frustration due to the competition between core-core and tail-solvent interactions. We find that spherical vesicles are stable under rather general assumptions on these interactions described within the Flory-Huggins theory. We consider also the deformation of the vesicles in
Molecular orbital calculations of two-electron states for P donor solid-state spin qubits
cond-mat.mes-hallL. M. Kettle, Hsi-Sheng Goan, Sean C. Smith
We theoretically study the Hilbert space structure of two neighbouring P donor electrons in silicon-based quantum computer architectures. To use electron spins as qubits, a crucial condition is the isolation of the electron spins from their environment, including the electronic orbital degrees of freedom. We provide detailed electronic structure calculations
Characterizing the stepwise transformation from a low-density to a very-high-density form of supercooled liquid water
cond-mat.stat-mechDietmar Paschek, Alfons Geiger
We explore the phase diagram of TIP4P-Ew [J. Chem. Phys. {\bf 120}, 9665 (2004)] liquid model water from the boiling-point down to $150 {K}$ at densities ranging from $0.950 {g} {cm}^{-3}$ to $1.355 {g} {cm}^{-3}$. In addition to the low-density/high-density (LDL/HDL) liquid-liquid transition, we observe a high-density/very-high-density (HDL/VHDL) transforma
H(T) Phase Diagram in Nb3Sn: A Different Behavior in Single Crystals, Polycristalline Samples and Multifilamentary Wires
cond-mat.supr-conM. G. Adesso, D. Uglietti, R. Fluekiger, M. Polichetti
A comparative study of magnetic behavior in a DC magnetic field up to 19 Tesla has been undertaken on different Nb3Sn samples, i.e. single crystals, polycrystal samples and multifilamentary wires. From the 1st and 3rd harmonics of the AC magnetic susceptibility a peak effect was experimentally observed in the single crystal and in the polycrystal, whereas th
Bertrand Berche, Ricardo Paredes
Simulations of nematic-isotropic transition of liquid crystals in two dimensions are performed using an O(2) vector model characterised by non linear nearest neighbour spin interaction governed by the fourth Legendre polynomial $P\_4$. The system is studied through standard Finite-Size Scaling and conformal rescaling of density profiles or correlation functi
S. E. Sebastian, V. S. Zapf, N. Harrison, C. D. Batista
In a recent paper \cite{Radu}, Radu \textit{et al.} report experimental results they claim to support Bose-Einstein condensation (BEC) of magnons in Cs$_2$CuCl$_4$. It is true that an experimentally measured critical power law scaling exponent in agreement with the BEC universality class would support the realization of a BEC in magnetic systems that order a
Kristian Rabenstein
This work deals with two pressing issues in the design and operation of Josephson qubits -- loss of coherence and measurement. (Longer abstract follows in the work.)
O. Anatole von Lilienfeld, Denis Andrienko
Using Kohn-Sham density functional theory (KS-DFT), we have studied the interaction between various polyaromatic hydrocarbon molecules. The systems range from mono-cyclic benzene up to hexabenzocoronene (hbc). For several conventional exchange-correlation functionals potential energy curves of interaction of the $π$-$π$ stacking hbc dimer are reported. It is
Philip D. Mannheim
In a previous study of the dynamics of crystals with substitutional point defects we had obtained simple and exact expressions for the positions of the perturbed crystal modes and the intensities in them in the case in which both the host-host and the host-impurity force-constants were taken to be central and nearest neighbor. Such expressions required knowl
Daniel Proga
We present our recent results from numerical simulations of a magnetized flow in the vicinity of a black hole in the context of the collapsar model for GRBs. The simulations show that after an initial transient, the flow settles into a complex convolution of several distinct, time-dependent flow components including an accretion torus, its corona and outflow
Simple, Accurate, Approximate Orbits in the Logarithmic and a Range of Power-Law Galactic Potentials
astro-phCurtis Struck
Curves in a family derived from powers of the polar coordinate formula for ellipses are found to provide good fits to bound orbits in a range of power-law potentials. This range includes the well-known $1/r$ (Keplerian) and logarithmic potentials. These approximate orbits, called p-ellipses, retain some of the basic geometric properties of ellipses. They sat
Sergey Trudolyubov, William Priedhorsky, France Cordova
We present the results of X-ray observations of four bright transients sources detected in the July 2004 XMM-Newton observations of the central bulge of M31. Two X-ray sources, XMMU J004315.5+412440 and XMMU J004144.7+411110, were discovered for the first time. Two other sources, CXOM31 J004309.9+412332 and CXOM31 J004241.8+411635, were previously detected b
Piotr M. Kowalski
We investigate the dissociation equilibrium of $\rm H_2$ in very cool, helium-rich white dwarf atmospheres. We present the solution of the non-ideal chemical equilibrium for the dissociation of molecular hydrogen in a medium of dense helium. We find that at the photosphere of cool white dwarfs of $T_{\rm eff}\rm=4000 K$, the non-ideality results in an increa
Multiplicity of very low-mass objects in the Upper Scorpius OB association: a possible wide binary population
astro-phH. Bouy, E. L. Martin, W. Brandner, M. R. Zapatero-Osorio
We report the initial results of a VLT/NACO high spatial resolution imaging survey for multiple systems among 58 M-type members of the nearby Upper Scorpius OB association. Nine pairs with separations below 100 have been resolved. Their small angular separations and the similarity in the brightness of the components (DMagK <1 for all of them), indicate there
A. Golden, S. Bourke, G. Clyne, R. F. Butler
In an investigative 16 hour L band observation using the MERLIN radio interferometric array, we have resolved both the pulsar PSR B1951+32 and structure within the flat spectral radio continuum region, believed to be the synchrotron nebula associated with the interaction of the pulsar and its `host' supernova remnant CTB 80. The extended structure we see
Alessandro Morbidelli
This text was originally written to accompany a series of lectures that I gave at the `35th Saas-Fee advanced course' in Switzerland and at the Institute for Astronomy of the University of Hawaii. It reviews my current understanding of the dynamics of comets and of the origin and primordial sculpting of their reservoirs. It starts discussing the structur
Guillermo Torres
We report spectroscopic observations of HD 27638B, the secondary in a visual binary in which the physically associated primary (separation approximately 19 arcsec) is a B9V star. The secondary shows strong Li 6708 absorption suggesting youth, and has attracted attention in the past as a candidate post-T Tauri star although this has subsequently been ruled ou
Infrared Spectroscopy of Symbiotic Stars. IV. V2116 Ophiuchi/GX 1+4, The Neutron Star Symbiotic
astro-phKenneth H. Hinkle, Francis C. Fekel, Richard R. Joyce, Peter R. Wood
We have computed, based on 17 infrared radial velocities, the first set of orbital elements for the M giant in the symbiotic binary V2116 Ophiuchi. The giant's companion is a neutron star, the bright X-ray source GX 1+4. We find an orbital period of 1161 days by far the longest of any known X-ray binary. The orbit has a modest eccentricity of 0.10 with a
Naomi Hirano, Sheng-Yuan Liu, Hsien Shang, Paul T. P. Ho
We have mapped the SiO J=5-4 line at 217GHz from the HH211 molecular outflow with the Submillimeter Array (SMA). The high resolution map (1.6''x0.9'') shows that the SiO J=5-4 emission comes from the central narrow jet along the outflow axis with a width of ~0.8'' (~250 AU) FWHM. The SiO jet consists of a chain of knots separated by 3
The Effect of the Transit of Venus on ACRIM's Total Solar Irradiance Measurements: Implications for Transit Studies of Extrasolar Planets
astro-phG. Schneider, J. M. Pasachoff, R. C. Willson
We used the 8 June 2004 transit of Venus (ToV) as a surrogate to test observing methods, strategies and techniques that are being contemplated for future space missions to detect and characterize extrasolar terrestrial planets (ETPs) as they transit their host stars, notably NASA's Kepler mission planned for 2008. As an analog to "Kepler-like" ph
Pedro Augusto, Alastair C. Edge, Claire J. Chandler
We present multi-frequency, multi-epoch radio imaging of the complex radio source B2151+174 in the core of the cluster, Abell 2390 (z~0.23). From new and literature data we conclude that the FRII-powerful radio source is the combination of a compact, core-dominated `medium-symmetric object' (MSO) with a more extended, steeper spectrum mini-halo. B2151+17
G. Branduardi-Raymont, A. Bhardwaj, R. F. Elsner, G. R. Gladstone
We present the results of two XMM-Newton observations of Jupiter carried out in 2003 for 100 and 250 ks (or 3 and 7 planet rotations) respectively. X-ray images from the EPIC CCD cameras show prominent emission from the auroral regions in the 0.2 - 2.0 keV band: the spectra are well modelled by a combination of emission lines, including most prominently thos
A. Asensio Ramos, J. Trujillo Bueno
The development of fast numerical methods for multilevel radiative transfer (RT) applications often leads to important breakthroughs in astrophysics, because they allow the investigation of problems that could not be properly tackled using the methods previously available. Probably, the most familiar example is the so-called Multilevel Accelerated $Λ$-Iterat
D. A. Hubber, S. P. Goodwin, A. P. Whitworth
Jeans showed analytically that, in an infinite uniform-density isothermal gas, plane-wave perturbations collapse to dense sheets if their wavelength, $λ$, satisfies $λ> λ_{_{\rm JEANS}} = (πa^2 / G ρ_{_0})^{1/2}$ (where $a$ is the isothermal sound speed and $ρ_{_0}$ is the unperturbed density); in contrast, perturbations with smaller $λ$ oscillate about the
A New Multidimensional Relativistic Hydrodynamics code based on Semidiscrete Central and WENO schemes
astro-phTanvir Rahman, R. B. Moore
We have proposed a new High Resolution Shock Capturing (HRSC) scheme for Special Relativistic Hydrodynamics (SRHD) based on the semidiscrete central Godunov-type schemes and a modified Weighted Essentially Non-oscillatory (WENO) data reconstruction algorithm. This is the first application of the semidiscrete central schemes with high order WENO data reconstr
Florentin Millour, Martin Vannier, R. G. Petrov, Bruno Lopez
We present the current performances of the AMBER / VLTI instrument in terms of differential observables (differential phase and differential visibility) and show that we are already able to reach a sufficient precision for very low mass companions spectroscopy and mass characterization. We perform some extrapolations with the knowledge of the current limitat
Boxy/peanut "bulges": comparing the structure of galaxies with the underlying families of periodic orbits
astro-phP. A. Patsis, E. M. Xilouris
The vertical profiles of disc galaxies are built by the material trapped around stable periodic orbits, which form their "skeletons". According to this, the knowledge of the stability of the main families of periodic orbits in appropriate 3D models, can predict possible morphologies for edge-on disc galaxies. In a pilot survey we compare the orbital
Nestor Sanchez, Emilio J. Alfaro, Enrique Perez
We study the physical properties derived from interstellar cloud complexes having a fractal structure. We first generate fractal clouds with a given fractal dimension and associate each clump with a maximum in the resulting density field. Then, we discuss the effect that different criteria for clump selection has on the derived global properties. We calculat
P. Kaaret, S. Corbel, J. A. Tomsick, J. Lazendic
We report on new X-ray observations of the large-scale jets recently discovered in X-rays from the black hole candidate 4U 1755-33. Our observations in 2004 show that the jets found in 2001 are still present in X-rays. However, sensitive radio observations in 2004 failed to detect the jets. We suggest that synchrotron radiation is a viable emission mechanism
SDSS J0806+2006 and SDSS J1353+1138: Two New Gravitationally Lensed Quasars from the Sloan Digital Sky Survey
astro-phNaohisa Inada, Masamune Oguri, Robert H. Becker, Richard L. White
We report the discoveries of two, two-image gravitationally lensed quasars selected from the Sloan Digital Sky Survey: SDSS J0806+2006 at z_s=1.540 and SDSS J1353+1138 at z_s=1.629 with image separations of 1.40" and 1.41" respectively. Spectroscopic and optical/near-infrared imaging follow-up observations show that the quasar images have identical r
A. Pereyra, B. V. Castilho, A. M. Magalhaes
Protoplanetary nebulae typically present non-spherical envelopes. The origin of such geometry is still controversial. There are indications that it may be carried over from an earlier phase of stellar evolution, such as the AGB phase. But how early in the star's evolution does the non-spherical envelope appear? Li-rich giants show dusty circumstellar env
Takeshi Morita
It is known that Yang-Mills theories on non-commutative space can be derived from large-N reduced models. Gauge fields in non-commutative Yang-Mills theories can be described as fluctuations of matrices expanded about an appropriate classical solution of the reduced models. We investigate a generalization of this procedure in superfield formalism. We show th
D. Peressounko
We review recent results on hard observables in p+p, d+A and A+A collisions obtained by the PHENIX experiment. Emphasis is put on those measurements that provide insight into the properties of hot QCD media expected to be created in nucleus-nucleus collisions at RHIC energies. Direct photon spectra, jet properties and heavy quarks production measured in p+p
D. Peressounko
We consider recent developments in the theory of the two-photon interferometry in ultrarelativistic heavy ion collisions with emphasis on the difference between photon and hadron interferometry. We review the available experimental results and discuss possibilities of measurement of the photon Bose-Einstein correlations in ongoing and future experiments.
Richard Easther, Liam McAllister
N-flation is a promising embedding of inflation in string theory in which many string axions combine to drive inflation. We characterize the dynamics of a general N-flation model with non-degenerate axion masses. Although the precise mass of a single axion depends on compactification details in a complicated way, the distribution of masses can be computed wi
Thorsten Naab, Peter H. Johansson, Jeremiah P. Ostriker, George Efstathiou
We describe high resolution Smoothed Particle Hydrodynamics (SPH) simulations of three approximately $M_*$ field galaxies starting from \LCDM initial conditions. The simulations are made intentionally simple, and include photoionization, cooling of the intergalactic medium, and star formation but not feedback from AGN or supernovae. All of the galaxies under
Alison L. Coil, Jeffrey A. Newman, Michael C. Cooper, Marc Davis
We measure the clustering of DEEP2 galaxies at z=1 as a function of luminosity on scales 0.1 Mpc/h to 20 Mpc/h. Drawing from a parent catalog of 25,000 galaxies at 0.7<z<1.3 in the full DEEP2 survey, we create volume-limited samples having upper luminosity limits between M_B=-19 and M_B=-20.5, roughly 0.2-1 L^* at z=1. We find that brighter galaxies are more
Measurement of the Inclusive Jet Cross Section in ppbar Interactions at sqrt{s}=1.96 TeV Using a Cone-based Jet Algorithm
hep-exCDF Collaboration
We present a measurement of the inclusive jet cross section in ppbar interactions at sqrt{s}=1.96 TeV using 385 pb^{-1} of data collected with the CDF II detector at the Fermilab Tevatron. The results are obtained using an improved cone-based jet algorithm (Midpoint). The data cover the jet transverse momentum range from 61 to 620 GeV/c, extending the reach
Vahagn Nazaryan, Carl E. Carlson, Keith A. Griffioen
We present a state-of-the-art evaluation of the polarizability corrections--the inelastic nucleon corrections--to the hydrogen ground-state hyperfine splitting using analytic fits to the most recent data. We find a value $Δ_{\rm pol} = 1.3 \pm 0.3$ ppm. This is 1--2 ppm smaller than the value of $Δ_{\rm pol}$ deduced using hyperfine splitting data and elasti
Marco Cirelli, Nicolao Fornengo, Alessandro Strumia
A few multiplets that can be added to the SM contain a lightest neutral component which is automatically stable and provides allowed DM candidates with a non-standard phenomenology. Thanks to coannihilations, a successful thermal abundance is obtained for well defined DM masses. The best candidate seems to be a SU(2)_L fermion quintuplet with mass 4.4 TeV, a
Description of electric dipole excitations in the tin isotopes within the quasiparticle time blocking approximation
nucl-thE. V. Litvinova, V. I. Tselyaev
The quasiparticle time blocking approximation (QTBA) is applied to describe E1 excitations in the even-even tin isotopes. Within the model pairing correlations, two-quasiparticle (2q), and 2q*phonon configurations are included. Thus the QTBA is an extension of the quasiparticle random phase approximation to include quasiparticle-phonon coupling. Calculationa
V. Desai, L. Armus, B. T. Soifer, D. W. Weedman
We present low-resolution (64 < R < 124) mid-infrared (8--38 micron) Spitzer/IRS spectra of two z~1.3 ultraluminous infrared galaxies (LFIR~10^13) discovered in a Spitzer/MIPS survey of the Bootes field of the NOAO Deep Wide-Field Survey (NDWFS). MIPS J142824.0+352619 is a bright 160 micron source with a large infrared-to-optical flux density ratio and a pos
Simone Giombi, Manuela Kulaxizi, Riccardo Ricci, Diego Trancanelli
Solutions of type IIB supergravity which preserve half of the supersymmetries have a dual description in terms of free fermions, as elucidated by the "bubbling AdS" construction of Lin, Lunin and Maldacena. In this paper we study the half-BPS geometry associated with a gas of free fermions in thermodynamic equilibrium obeying the Fermi-Dirac distribution. We
Mikhail Gorchtein
We construct an invariant basis for Compton scattering with two virtual photons (VVCS). The basis tensors are chosen to be gauge invariant and orthogonal to each other. The properties of the corresponding 18 invariant amplitudes are studied in detail. We consider the special case of elastic VVCS with the virtualities of the initial and final photons equal. T
Matthew Stover
In this paper we consider Property (FA) for lattices in SU(2,1). First, we prove that SU(2,1;O_3) has Property (FA). We then prove that the arithmetic lattices in SU(2,1) of second type arising from congruence subgroups studied by Rapoport--Zink and Rogawski cannot split as a nontrivial free product with amalgamation; one such example is Mumford's fake p
Dubravko Horvat, Sasa Ilijic
Solutions for the static spherically symmetric extremally charged dust in the Majumdar--Papapetrou system have been found. For a certain amount of the allocated mass/charge, the solutions have singularities of a type which could render them physically unacceptable, since the corresponding physically relevant quantities are singular as well. These solutions,
Mikhail Gorchtein
The two-photon exchange contribution to the single spin asymmetries with the spin orientation normal to the reaction plane is discussed for elastic electron-proton scattering in the equivalent photon approximation. In this case, hadronic part of the two-photon exchange amplitude describes real Compton scattering (RCS). We show that in the case of the beam no
Guido Altarelli, Ferruccio Feruglio
We formulate and discuss a 4-dimensional SUSY version of an A4 model for tri-bimaximal neutrino mixing which is completely natural. We also study the next-to-the-leading corrections and show that they are small, once the ratios of A4 breaking VEVs to the cutoff are fixed in a specified interval. We also point out an interesting way of presenting the A4 group
Asymptotic Quasinormal Frequencies of Different Spin Fields in Spherically Symmetric Black Holes
gr-qcH. T. Cho
We consider the asymptotic quasinormal frequencies of various spin fields in Schwarzschild and Reissner-Nordström black holes. In the Schwarzschild case, the real part of the asymptotic frequency is ln3 for the spin 0 and the spin 2 fields, while for the spin 1/2, the spin 1, and the spin 3/2 fields it is zero. For the non-extreme charged black holes, the sp
M. Gustafsson, A. Brandenburg, J. L. Lemaire, D. Field
Aim: To study turbulence in the Orion Molecular Cloud (OMC1) by comparing observed and simulated characteristics of the gas motions. Method: Using a dataset of vibrationally excited H2 emission in OMC1 containing radial velocity and brightness which covers scales from 70AU to 30000AU, we present the transversal structure functions and the scaling of the stru
John F. Hawley, Julian H. Krolik
We compute a series of three-dimensional general relativistic magnetohydrodynamic simulations of accretion flows in the Kerr metric to investigate the properties of the unbound outflows that result. The overall strength of these outflows increases sharply with increasing black hole rotation rate, but a number of generic features are found in all cases. The m
K. Hachisuka, A. Brunthaler, K. M. Menten, M. J. Reid
We report phase-referencing VLBA observations of H2O masers near the star-forming region W3(OH) to measure their parallax and absolute proper motions. The measured annual parallax is 0.489 +/- 0.017 milli-arcseconds (2.04 +/- 0.07 kpc), where the error is dominated by a systematic atmospheric contribution. This distance is consistent with photometric distanc
Peter Fiebig
We present an alternative construction of Soergel's category of bimodules associated to a reflection faithful representation of a Coxeter system. We show that its objects can be viewed as sheaves on the associated moment graph. We introduce an exact structure and show that Soergel's "special" bimodules are the projective objects. Then we cons
The Z(2) gauge model revisited: as a possible testbed for the confinement and chiral symmetry phase transition of SU(2) lattice gauge theory
hep-latShinji Hioki
Adopting the cooling technique to smooth the discontinuous Z(2) lattice gauge field, we found that on SU(2) gauge configurations obtained by this smoothing there exists clear discontinuity of the topological property at almost the same point as the confinement-deconfinement phase transition of the original Z(2) gauge theory. This observation suggests the pos
A. L. Kuzemsky
A comprehensive theoretical description is given for the spin relaxation and diffusion in solids. The formulation is made in a general statistical-mechanical way. The method of the nonequilibrium statistical operator (NSO) developed by D. N. Zubarev is employed to analyze a relaxation dynamics of a spin subsystem. Perturbation of this subsystem in solids may
Yosuke Imamura, Hiroshi Isono, Yutaka Matsuo
We generalize the idea of boundary states to the open string channel. They describe emission and absorption of open strings in the presence of intersecting D-branes. We construct the explicit oscillator representation for the free boson and fermionic ghost. The inner product of such states describes a disk amplitude of rectangular shape and possesses modular
H. Nikolic
I present a relativistic covariant version of the Bohmian interpretation of quantum mechanics and discuss the corresponding measurable predictions. The covariance is incoded in the fact that the nonlocal quantum potential transforms as a scalar, which is a consequence of the fact that the nonlocal wave function transforms as a scalar. The measurable predicti
Yu. Kalashnikova, A. Kudryavtsev, A. V. Nefediev, J. Haidenbauer
We estimate the rates for radiative transitions of the lightest scalar mesons f_0(980) and a_0(980) to the vector mesons rho and omega. We argue that measurements of the radiative decays of those scalar mesons can provide important new information on their structure.
Wei Fan
Based on a no-equilibrium STM model, we study Kondo resonance on a surface by self-consistent calculations. The shapes of tunneling spectra are dependent on the energy range of tunneling electrons. Our results show that both energy-cutoff and energy-window of tunneling electrons have significant influence on the shapes of tunneling spectra. If no energy-cuto
H. T. Quan, Y. D. Wang, Yu-xi Liu, C. P. Sun
We propose a quantum analog of the internal combustion engine used in most cars. Specifically, we study how to implement the Otto-type quantum heat engine (QHE) with the assistance of a Maxwell's demon. Three steps are required: thermalization, quantum measurement, and quantum feedback controlled by the Maxwell demon. We derive the positive-work conditio
Bijan Saha, Victor Rikhvitsky, Mihai Visinescu
Within the framework of Bianchi type-I space-time we study the Bel-Robinson tensor and its impact on the evolution of the Universe. We use different definitions of the Bel-Robinson tensor existing in the literature and compare the results. Finally we investigate the so called "dominant super-energy property" for the Bel-Robinson tensor as a generaliz