June 2004 arXiv papers — page 9
Showing 801–900 of 3,692 papers
Measurement of Coherent Emission and Linear Polarization of Photons by Electrons in the Strong Fields of Aligned Crystals
hep-exNA59 Collaboration, A. Apyan, R. O. Avakian, B. Badelek
We present new results regarding the features of high energy photon emission by an electron beam of 178 GeV penetrating a 1.5 cm thick single Si crystal aligned at the Strings-Of-Strings (SOS) orientation. This concerns a special case of coherent bremsstrahlung where the electron interacts with the strong fields of successive atomic strings in a plane and fo
Linear to Circular Polarisation Conversion using Birefringent Properties of Aligned Crystals for Multi-GeV Photons
hep-exNA59 Collaboration, A. Apyan, R. O. Avakian, B. Badelek
We present the first experimental results on the use of a thick aligned Si crystal acting as a quarter wave plate to induce a degree of circular polarisation in a high energy linearly polarised photon beam. The linearly polarised photon beam is produced from coherent bremsstrahlung radiation by 178 GeV unpolarised electrons incident on an aligned Si crystal,
Coherent Pair Production by Photons in the 20-170 GeV Energy Range Incident on Crystals and Birefringence
hep-exNA59 Collaboration, A. Apyan, R. O. Avakian, B. Badelek
The cross section for coherent pair production by linearly polarised photons in the 20-170 GeV energy range was measured for photon aligned incidence on ultra-high quality diamond and germanium crystals. The theoretical description of coherent bremsstrahlung and coherent pair production phenomena is an area of active theoretical debate and development. Howev
Florian Girelli, Etera R. Livine, Daniele Oriti
We argue that a (slightly) curved space-time probed with a finite resolution, equivalently a finite minimal length, is effectively described by a flat non-commutative space-time. More precisely, a small cosmological constant (so a constant curvature) leads the kappa-deformed Poincaré flat space-time of deformed special relativity (DSR) theories. This point o
Claus Kiefer
A perturbed black hole has characteristic frequencies (quasi-normal modes). Here I apply a quantum measurement analysis of the quasi-normal mode frequency in the limit of high damping. It turns out that a measurement of this mode necessarily adds noise to it. For a Schwarzschild black hole, this corresponds exactly to the Hawking temperature. The situation f
L. K. Chavda, Abhijit L. Chavda
The principle of nuclear democracy is invoked to prove the formation of stable quantized gravitational bound states of primordial black holes called Holeums. The latter come in four varieties: ordinary Holeums H, Black Holeums BH, Hyper Holeums HH and the massless Lux Holeums LH.These Holeums are invisible because the gravitational radiation emitted by their
G. A. Ososkov, S. G. Dmitrievskiy, A. V. Stadnik
Self-organizing neural networks are used for brick finding in OPERA experiment. Self-organizing neural networks and wavelet analysis used for recognition and extraction of car numbers from images.
Comment on cond-mat/0406502 by V. Yukalov and E. Yukalova on Coherent Nuclear Radiation
cond-mat.mes-hallE. M. Chudnovsky, D. A. Garanin
We show that the argument of Yukalov and Yukalova that dipole-dipole interaction prevents a system of magnetic dipoles from exhibiting superradiance unless assisted by a resonator is incorrect.
J. E. Williams, N. Nygaard, C. W. Clark
We calculate the phase diagrams for a harmonically trapped ideal gas mixture of fermionic atoms and bosonic molecules in chemical and thermal equilibrium, where the internal energy of the molecules can be adjusted relative to that of the atoms by use of a tunable Feshbach resonance. We plot the molecule fraction and the fraction of Bose-condensed molecules a
H. Hoehler, N. Atodiresei, K. Schroeder, R. Zeller
The electrical field gradient (EFG), measured e.g. in perturbed angular correlation (PAC) experiments, gives particularly useful information about the interaction of probe atoms like 111In / 111Cd with other defects. The interpretation of the EFG is, however, a difficult task. This paper aims at understanding the interaction of Cd impurities with vacancies a
V. A. Gasparov, M. P. Kulakov, N. S. Sidorov, I. I. Zver'kova
We report on measurements of the temperature dependence of resistivity, $ρ(T)$, for single crystal samples of ZrB$_{12}$, ZrB$_{2}$ and polycrystalline samples of MgB$_{2}$. It is shown that cluster compound ZrB$_{12}$ behaves like a simple metal in the normal state, with a typical Bloch -- Grüneisen $ρ(T)$ dependence. However, the resistive Debye temperatur
Michael Slutsky
Many important transport phenomena are described by simple mathematical models rooted in the diffusion equation. Geometrical constraints present in such phenomena often have influence of a universal sort and manifest themselves in scaling relations and stable distribution functions. In this paper, I present a treatment of a random walk confined to a half--sp
Emptiness formation probability at finite temperature for the isotropic Heisenberg chain
cond-mat.stat-mechF. Göhmann, A. Klümper, A. Seel
We present an integral formula for a special correlation function of the isotropic spin-1/2 antiferromagnetic Heisenberg chain. The correlation function describes the probability for the occurrence of a string of consecutive up-spins as a function of temperature, magnetic field and length of the string.
F. de los Santos, J. M. Tavares, M. Tasinkevych, M. M. Telo da Gama
Deposits of dipolar particles are investigated by means of extensive Monte Carlo simulations. We found that the effect of the interactions is described by an initial, non-universal, scaling regime characterized by orientationally ordered deposits. In the dipolar regime, the order and geometry of the clusters depend on the strength of the interactions and the
Non Destructive Determination Of Elastic Moduli By Two Dimensional Fourier Transformation And Laser Ultrasonic Technique
cond-mat.mtrl-sciXinya Zhang, Emmanuel Lafond, Ted Jackson
Broadband laser ultrasonics and two dimensional Fourier transformation are used to characterize the properties of varieties of foils and plates. Laser ultrasonics generation is achieved by use of a pulsed laser which deposits pulsed laser energy on the surface of the specimen. The displacement amplitude of the resulting broadband ultrasonic modes are monitor
Edwin Langmann, Mats Wallin
It is well-known from unrestricted Hartree-Fock computations that the 2D Hubbard model does not have homogeneous mean field states in significant regions of parameter space away from half filling. This is incompatible with standard mean field theory. We present a simple extension of the mean field method that avoids this problem. As in standard mean field th
M. J. Alava, S. N. Dorogovtsev
We study aggregation as a mechanism for the creation of complex networks. In this evolution process vertices merge together, which increases the number of highly connected hubs. We study a range of complex network architectures produced by the aggregation. Fat-tailed (in particular, scale-free) distributions of connections are obtained both for networks with
A. Taraphder, F. Guinea
We analyzed the possible magnetic and orbital orderings of double perovskites, using a simple extension of the double exchange model well suited for these compounds. Orbital ordering is favored by the on site repulsion at the Fe ions. We obtain a rich phase diagram, including ferri- and antiferromagnetic phases, which can, in turn, be metallic or insulating,
Nicolae A. Enaki, Vitalie Eremeev
The problem of the two-photon coherent generation of entanglement photon pairs in Quantum Optics has been intensively studied for the last years. It is important to note that the two-quantum cooperative effects play a main role in other fields of physics as well. The collective processes in Condensed Matter have many analogical proprieties with cooperative r
Mark A. Miller, Daan Frenkel
The structure of the Baxter adhesive hard sphere fluid is examined using computer simulation. The radial distribution function (which exhibits unusual discontinuities due to the particle adhesion) and static structure factor are calculated with high accuracy over a range of conditions and compared with the predictions of Percus--Yevick theory. We comment on
D. V. Khakhar, Ashish V. Orpe, J. M. Ottino
Granular surface flows are common in industrial practice and natural systems, however, theoretical description of such flows is at present incomplete. Two prototype systems involving surface flow are compared: heap formation by pouring at a point and rotating cylinders. Continuum models for analysis of these flows are reviewed, and experimental results for q
G. Balakrishnan, O. A. Petrenko, M. R. Lees, D. McK. Paul
Compounds with a Kagome type lattice are known to exhibit magnetic frustration. Large single crystals of two compounds Ni3V2O8 and Co3V2O8, which are variants of a Kagome net lattice, have been grown successfully by the floating zone technique using an optical image furnace. The single crystals are of high quality and exhibit intriguing magnetic properties.
Houman Falakshahi, Xavier Waintal
We study the quantum melting of the two-dimensional Wigner crystal using a fixed node quantum Monte-Carlo approach. In addition to the two already known phases (Fermi liquid at large density and Wigner crystal at low density), we find a third stable phase at intermediate values of the density. The third phase has hybrid behaviors in between a liquid and a so
Saket Asthana, D. Bahadur, A. K. Nigam, S. K. Malik
Magnetic and transport properties of (Pr1/3Sm2/3)2/3A1/3MnO3 (A = Ca, Sr and Ba) compounds, prepared by the citrate gel route, have been investigated. These compounds are found to crystallize in the orthorhombic structure. Charge ordering transport behavior is indicated only in Ca-substituted compound. The Sr- and Ba-substituted compounds show metal-insulato
Matthias Paessens
A hyperscaling relation for the critical exponents of absorbing phase transitions is tested in the bosonic pair contact process with diffusion. To this end spreading is considered, i.e. the time evolution out of an initial seed. It is shown that like in the case of spatial homogeneous initial conditions the autocorrelation function exhibits a phase transitio
G. Chiappe, E. Louis, E. Anda, J. A. Verges
It is shown that recent experimental data on electronic transport through Pt nanocontacts in the presence of hydrogen admit an explanation in terms of topological and electron-electron correlation grounds. A model Hamiltonian, which incorporates two orbitals on Pt atoms, a single orbital on hydrogens, and the on-site Coulomb repulsion on the H atoms, is solv
Analytical treatment of the dHvA frequency combinations due to chemical potential oscillations in an idealized two-band Fermi liquid
cond-mat.stat-mechJ. -Y. Fortin, E. Perez, A. Audouard
de Haas-van Alphen oscillation spectrum is studied for an idealized two-dimensional Fermi liquid with two parabolic bands in the case of canonical (fixed number of quasiparticles) and grand canonical (fixed chemical potential) ensembles. As already reported in the literature, oscillations of the chemical potential in magnetic field yield frequency combinatio
Isao Maruyama, Naokazu Shibata, Kazuo Ueda
Properties of a nonmagnetic impurity in Kondo insulators are investigated by considering a one-dimensional Kondo lattice model with depletion of a localized spin. The ground-state phase diagram determined by the Lanczos method shows that the magnetic moment is more stable than in ordinary metals. Temperature dependence of impurity susceptibilities is also st
Isao Maruyama, Naokazu Shibata, Kazuo Ueda
With the Finite temperature Density Matrix Renormalization Group method (FT-DMRG), we depeloped a method to calculate thermo-dynamical quantities and the conductance of a quantum dot system. Conductance is written by the local density of states on the dot. The density of states is calculated with the numerical analytic continuation from the thermal Green'
J. Schnack, F. Ouchni
Motivated by magnetization studies of the "telephon number compound" Sr_14Cu_24O_41 we investigate doped Heisenberg spin rings by means of complete numerical diagonalization of a Heisenberg Hamiltonian that depends parametrically on hole positions. A comparison with experimental magnetization data reveals rather accurate information about the screene
Matthias Paessens, Gunter M. Schuetz
The microscopic structure and movement of reaction fronts in reaction diffusion systems far from equilibrium are investigated. We show that some three-site interaction models exhibit exact diffusive shock measures, i.e. domains of different densities connected by a sharp wall without correlations. In all cases fluctuating domains grow at the expense of order
Electronic Structure and Magnetic Exchange Coupling in Ferromagnetic Full Heusler Alloys
cond-mat.mtrl-sciYasemin Kurtulus, Richard Dronskowski, German Samolyuk, Vladimir P. Antropov
Density-functional studies of the electronic structures and exchange interaction parameters have been performed for a series of ferromagnetic full Heusler alloys of general formula Co$_2$MnZ (Z = Ga, Si, Ge, Sn), Rh$_2$MnZ (Z = Ge, Sn, Pb), Ni$_2$MnSn, Cu$_2$MnSn and Pd$_2$MnSn, and the connection between the electronic spectra and the magnetic interactions
Oleg L. Berman, Yurii E. Lozovik, David W. Snoke, Rob D. Coalson
The theory of what happens to a superfluid in a random field, known as the ``dirty boson'' problem, directly relates to a real experimental system presently under study by several groups, namely excitons in coupled semiconductor quantum wells. We consider the case of bosons in two dimensions in a random field, when the random field can be large compa
Crystal Structure and Magnetic Properties of the Tri-layered Perovskite Sr4Rh3O10: A New Member of the Strontium Rhodates Family
cond-mat.str-elK. Yamaura, Q. Huang, D. P. Young, E. Takayama-Muromachi
The tri-layered perovskite Sr4Rh3O10 is reported for the first time. High-pressure and high-temperature heating (6 GPa and 1500 C) brought about successful preparation of a polycrystalline sample of the expected member at n=3 of Srn+1RhnO3n+1. Neutron-diffraction studies revealed the orthorhombic crystal structure (Pbam) at room temperature and 3.4 K. Local
X-ray study of the liquid potassium surface: structure and capillary wave excitations
cond-mat.stat-mechOleg Shpyrko, Patrick Huber, Peter S. Pershan, Holger Tostmann
We present x-ray reflectivity and diffuse scattering measurements from the liquid surface of pure potassium. They strongly suggest the existence of atomic layering at the free surface of a pure liquid metal with low surface tension. Prior to this study, layering was observed only for metals like Ga, In and Hg, the surface tensions of which are 5-7 fold highe
Surface Structure of Liquid Metals and the Effect of Capillary Waves: X-ray Studies on Liquid Indium
cond-mat.mtrl-sciHolger Tostmann, Oleg Shpyrko, Peter S. Pershan, Elaine Dimasi
We report x-ray reflectivity (XR) and small angle off-specular diffuse scattering (DS) measurements from the surface of liquid Indium close to its melting point of $156^\circ$C. From the XR measurements we extract the surface structure factor convolved with fluctuations in the height of the liquid surface. We present a model to describe DS that takes into ac
Takashi Ichinomiya
We study the frequency-synchronization of randomly coupled oscillators. By analyzing the continuum limit, we obtain the sufficient condition for the mean-field type synchronization. We especially find that the critical coupling constant $K$ becomes 0 in the random scale free network, $P(k)\propto k^{-γ}$, if $2 < γ\le 3$. Numerical simulations in finite netw
Oleg Shpyrko, Masafumi Fukuto, Peter Pershan, Ben Ocko
Recent measurements show that the free surfaces of liquid metals and alloys are always layered, regardless of composition and surface tension; a result supported by three decades of simulations and theory. Recent theoretical work claims, however, that at low enough temperatures the free surfaces of all liquids should become layered, unless preempted by bulk
Anatoly B. Kolomeisky, Evgeny B. Stukalin, Alex A. Popov
Kinesins are processive motor proteins that move along microtubules in a stepwise manner, and their motion is powered by the hydrolysis of ATP. Recent experiments have investigated the coupling between the individual steps of single kinesin molecules and ATP hydrolysis, taking explicitly into account forward steps, backward steps and detachments. A theoretic
Negative differential conductivity and population inversion in the double-dot system connected to three terminals
cond-mat.mes-hallLev G. Murokh, Anatoly Yu. Smirnov
We examine transport and microwave properties of two coupled quantum dots taken in parallel connection to the common left lead and connected to separate leads at their right side. In addition, the area between the left lead and the double-dot structure is threaded by Aharonov-Bohm magnetic flux. We determine the energies and populations of double-dot levels
Manabu Takahashi, Jun-ichi Igarashi, Kunitomo Hirai
Using ab-initio band structure calculation based on the local density approximation, Cr K-edge resonant X-ray magnetic scattering spectra are analyzed in the spin density wave (SDW) state of chromium. We perform band structure calculation, assuming an ideal bcc lattice structure with the lattice constant observed at the spin-flip temperature T_{SF} and a com
Thermal Effects on the Magnetic Field Dependence of Spin Transfer Induced Magnetization Reversal
cond-mat.mtrl-sciD. Lacour, J. A. Katine, N. Smith, M. J. Carey
We have developed a self-aligned, high-yield process to fabricate CPP (current perpendicular to the plane) magnetic sensors of sub 100 nm dimensions. A pinned synthetic antiferromagnet (SAF) is used as the reference layer which minimizes dipole coupling to the free layer and field induced rotation of the reference layer. We find that the critical currents fo
Yunsic Shim, Jacques G. Amar
The standard kinetic Monte Carlo algorithm is an extremely efficient method to carry out serial simulations of dynamical processes such as thin-film growth. However, in some cases it is necessary to study systems over extended time and length scales, and therefore a parallel algorithm is desired. Here we describe an efficient, semi-rigorous synchronous subla
Flavio S. Nogueira, Karl-Heinz Bennemann
We consider the tunnel spin current between two ferromagnetic metals from a perspective similar to the one used in superconductor/superconductor tunnel junctions. We use fundamental arguments to derive a Josephson-like spin tunnel current $I_J^{\rm spin}\propto\sin(θ_1-θ_2)$. Here the phases are associated with the planar contribution to the magnetization, $
Uwe Grimm
Level-spacing distributions of the Gaussian Unitary Ensemble (GUE) of random matrix theory are expressed in terms of solutions of coupled differential equations. Series solutions up to order 50 in the level spacing are obtained, thus providing a very good description of the small-spacing part of the level-spacing distribution, which can be used to make compa
L. Borda, A. Halbritter, A. Zawadowski
This paper was withdrawn by the authors.
Douglas Scott, George Smoot
This is a complete re-write of the mini-review for the Review of Particle Physics (a.k.a the Partcicle Data Book), which includes an assessment of the CMB anisotropy results and their interpretation up until the end of 2003. It forms a compact overview of the field at this time. Sections headings are: Introduction; Description of CMB Anisotropies; Cosmologic
H. Beuther, Q. Zhang, L. J. Greenhill, M. G. Reid
We present the first 865 mu continuum image with sub-arcsecond resolution obtained with the Submillimeter Array. These data resolve the Orion-KL region into the hot core, the nearby radio source I, the sub-mm counterpart to the infrared source n (radio source L), and new sub-mm continuum sources. The radio to submillimeter emission from source I may be model
Globular Cluster and Galaxy Formation: M31, the Milky Way and Implications for Globular Cluster Systems of Spiral Galaxies
astro-phD. Burstein, Y. Li, K. C. Freeman, J. E. Norris
The globular cluster (GC) systems of the Milky Way and of our neighboring spiral galaxy, M31, comprise 2 distinct entities, differing in 3 respects. 1. M31 has young GCs, ages from ~100 Myr to 5 Gyr old, as well as old globular clusters. No such young GCs are known in the Milky Way. 2. We confirm that the oldest M31 GCs have much higher nitrogen abundances t
Yuriy Mishchenko, Chueng-Ryong Ji
We study in details the distribution of mass in galaxy cluster CL0024+1654 inferred using the method of strong gravitational lensing by Tyson {\it et al.} (1998). We show that a linear correlation exists between total, visible and dark matter distributions on log-log scale with consistent coefficients. The shape and parameters of log-log-linear correlation a
Duncan Farrah, Robert Priddey, Richard Wilman, Martin Haehnelt
We present a deep XMM-Newton observation of the z=6.30 QSO SDSS J1030+0524, the second most distant quasar currently known. The data contain sufficient counts for spectral analysis, demonstrating the ability of XMM-Newton to measure X-ray spectral shapes of z~6 QSOs with integration times >100ks. The X-ray spectrum is well fit by a power law with index Gamma
Near Infrared Spectroscopy of High Redshift Active Galactic Nuclei. II. Disappearing Narrow Line Regions and the Role of Accretion
astro-phH. Netzer, O. Shemmer, R. Maiolino, E. Oliva
We present new near infrared spectroscopic measurements for 29 luminous high-z quasars and use the data to discuss the size and other properties of the NLRs in those sources. The high resolution spectra have been used to carefully model the Fe II blends and to provide reliable [O III], Fe II and Hb measurements. We find that about 2/3 of all high luminosity
Near Infrared Spectroscopy of High Redshift Active Galactic Nuclei. I. A Metallicity-Accretion Rate Relationship
astro-phO. Shemmer, H. Netzer, R. Maiolino, E. Oliva
We present new near infrared spectroscopic measurements of the H_beta region for a sample of 29 luminous high redshift quasars. We have measured the width of H_beta in those sources, and added archival H_beta width measurements, to create a sample of 92 active galactic nuclei (AGNs) for which H_beta width and rest-frame UV measurements of N V λ1240 and C IV
L. J. Goicoechea, V. Shalyapin, J. Gonzalez-Cadelo, A. Oscoz
We introduce a new scheme to study the nature of the central engine in a lensed QSO. The compact emission regions could have different sizes in different optical wavelengths, and our framework permits to obtain the source size ratios when a microlensing special high-magnification event (e.g., a caustic crossing event, a two-dimensional maximum crossing event
M. Haverkorn, P. Katgert, A. G. de Bruyn
We describe a first attempt to derive properties of the regular and turbulent Galactic magnetic field from multi-frequency polarimetric observations of the diffuse Galactic synchrotron background. A single-cell-size model of the thin Galactic disk is constructed which includes random and regular magnetic fields and thermal and relativistic electrons. The dis
Scott J. Kenyon, Benjamin C. Bromley
We describe analytical and numerical collisional evolution calculations for the size distribution of icy bodies in the Kuiper Belt. For a wide range of bulk properties, initial masses, and orbital parameters, our results yield power-law cumulative size distributions, N_C propto r^{-q}, with q_L = 3.5 for large bodies with radii of 10-100 km, and q_s = 2.5-3
A. Ferrara, R. Salvaterra
The consequences of energy injection associated with stellar activity in galaxies have been often referred to as ``feedback effects''. Assessing the detailed physics and the role of such effects are central issues in modern theories of galaxy formation and evolution. In these Lectures we present a brief review of various aspects related to feedback w
V. Beckmann, N. Gehrels, P. Favre, R. Walter
We present first INTEGRAL and XMM-Newton observations of a Seyfert galaxy, the type 2 AGN NGC 4388. Several INTEGRAL observations performed in 2003 allow us to study the spectrum in the 20 - 300 keV range. In addition two XMM-Newton observations give detailed insight into the 0.2 - 10 keV emission. The measurements presented here and comparison with previous
R. Hirschi, G. Meynet, A. Maeder
We describe the latest developments of the Geneva stellar evolution code in order to model the pre-supernova evolution of rotating massive stars. Rotating and non-rotating stellar models at solar metallicity with masses equal to 12, 15, 20, 25, 40 and 60 solar masses were computed from the ZAMS until the end of the core silicon burning phase. We took into ac
Miguel Santander-Garcia, Romano L. M. Corradi, Bruce Balick, Antonio Mampaso
The structure and kinematics of the bipolar nebula Mz 3 have been investigated by means of HST, CTIO and ESO images and spectra. At least four distinct outflows have been identified which, from the inside to the outside, are the following: a pair of bright bipolar lobes, two opposite highly collimated column-shaped outflows, a conical system of radial struct
Simon Portegies Zwart
In this lecture we investigate the formation and evolution of black holes in star clusters. The star clusters under consideration are generally rich, containing more than 10^4 stars, and with a density exceeding 10^4 stars/pc^3. Among these are young dense clusters (YoDeCs), globular cluster and the nuclei of galaxies. We will also address the the possible e
D. Stamatellos, A. P. Whitworth
We present 2D Monte Carlo radiative transfer simulations of flattened prestellar cores. We argue the importance of observing prestellar cores near the peak of their emission spectra, and we point out observable characteristic features on isophotal maps of asymmetric cores at FIR wavelengths that are indicative of the cores' density and temperature struct
E. Meyer-Hofmeister
In the canonical understanding of transient X-ray sources the accretion during quiescence occurs via a geometrically thin disk in the outer part and via an advection-dominated hot coronal flow/ADAF in the inner part. The inner part important for the radiation yields a hard spectrum. In most sources the luminosity increase during outburst causes a change over
Tomas Dahlen, Louis-Gregory Strolger, Adam G. Riess, Bahram Mobasher
We use a sample of 42 supernovae detected with the Advanced Camera for Surveys on-board the Hubble Space Telescope as part of the Great Observatories Origins Deep Survey to measure the rate of core collapse supernovae to z~0.7 and type Ia supernovae to z~1.6. This significantly increases the redshift range where supernova rates have been estimated from obser
The Hubble Higher-Z Supernova Search: Supernovae to z=1.6 and Constraints on Type Ia Progenitor Models
astro-phL. -G. Strolger, A. G. Riess, T. Dahlen, M. Livio
We present results from the Hubble Higher-z Supernova Search, the first space-based open field survey for supernovae (SNe). In cooperation with the Great Observatories Origins Deep Survey, we have used the Hubble Space Telescope with the Advanced Camera for Surveys to cover 300 square arcmin in the area of the Chandra Deep Field South and the Hubble Deep Fie
Measuring mass and angular momentum of black holes with high-frequency quasi-periodic oscillations
astro-phB. Aschenbach
3:2 and/or 3:1 twin high frequency quasi-periodic oscillations (HFQPOs) have been measured for the three microquasars GRO J1655-40, XTE J1550-564 and GRS 1915+105. For a test particle orbiting a rotating black on a stable circular orbit there exist two different orbits at which the vertical and radial epicyclic oscillations are in either a 3:1 or 3:2 paramet
D. Baines, R. D. Oudmaijer, A. Mora, C. Eiroa
In this paper we present multi-epoch observations of the pre-main sequence binary HK Ori. These data have been drawn from the EXPORT database and are complemented by high quality spectro-astrometric data of the system. The spectroscopic data appear to be very well represented by a combination of an A dwarf star spectrum superposed on a (sub-)giant G-type spe
P. Stauber, S. D. Doty, E. F. van Dishoeck, J. K. Jorgensen
We have studied the influence of far ultraviolet (UV) radiation from a massive young stellar object (YSO) on the chemistry of its own envelope by extending the models of Doty et al. (2002) to include a central source of UV radiation. The models are applied to the massive star-forming region AFGL 2591 for different inner UV field strengths. Depth-dependent ab
Beppo-SAX temperature maps of galaxy clusters in the Corona Borealis supercluster: A2061, A2067 and A2124
astro-phF. Marini, S. Bardelli, E. Zucca, S. De Grandi
In this paper we present the analysis of Beppo-SAX observations of the cluster pairs A2061-A2067 and A2122-A2124, located in the Corona Borealis supercluster, which have been selected as candidate merging clusters. The aim of this work is to study the physics of the intracluster medium and to look for the possible presence of merging signatures. We derived t
Veronique Sanglard
The EDELWEISS experiment is a direct detection Dark Matter Search, under the form of WIMPs. It uses heat and ionization Ge cryogenic detectors. We present the latest results obtained by the experiment with three new 320g bolometers. At present, EDELWEISS I is the most sensitive experiment for all WIMP masses compatible with accelerator constraints (Mwimp>30
XMM-Newton observations of the relaxed, high-redshift galaxy cluster ClJ0046.3+8530 at z=0.62
astro-phB. J. Maughan, L. R. Jones, D. Lumb, H. Ebeling
A detailed analysis of XMM observations of ClJ0046.3+8530 (z=0.624) is presented. The cluster has a moderate temperature (kT=4.1+/-0.3keV) and appears to be relaxed. Emission is detected at >3 sigma significance to a radius of 88% of R200 (the radius enclosing an overdensity of 200 times the critical density at z=0.624) in a surface-brightness profile. A tem
R. Surendiranath, S. R. Pottasch, P. Garcia Lario
ISO and IUE spectra of the round planetary nebula Me 2-1 are combined with visual spectra taken from the literature to obtain for the first time a complete extinction-corrected spectrum. With this, the physico-chemical characteristics of the nebula and its central star are determined by various methods including photoionization modeling using Cloudy. The res
Shlomo Dado, Arnon Dar, A. De Rujula
Taylor, Frail, Berger and Kulkarni have made precise VLBI measurements of the size and position of the source of the radio afterglow of GRB 030329. They report a size evolution compatible with standard fireball models, proper motion limits inconsistent with the cannonball model, and a double source, i.e. "an additional compact component" on day 51 af
Tao Zhou, Bing-Hong Wang
A new model about cascading occurrences caused by perturbation is established to search after the mechanism because of which catastrophes in networks occur. We investigate the avalanche dynamics of our model on 2-dimension Euclidean lattices and scale-free networks and find out the avalanche dynamic behaviors is very sensitive to the topological structure of
Sanjib Sharma, Matthias Steinmetz
(Abridged) We report results of a series of non radiative N-body/SPH simulations in a LCDM cosmology. We find that the spin of the baryonic component is on average larger than that of the dark matter (DM) component and we find this effect to be more pronounced at lower redshifts. A significant fraction f of gas has negative angular momentum and this fraction
Rodolfo A. Diaz, R. Martinez, Carlos E. Sandoval
Constraints on the whole spectrum of lepton flavor violating vertices are shown in the context of the standard two Higgs doublet model. The vertex involving the $e-τ$ mixing is much more constrained than the others, and the decays proportional to such vertex are usually very supressed. On the other hand, bounds on the quark sector are obtained from leptonic
David M. Goldberg, Timothy D. Jones, Fiona Hoyle, Randall R. Rojas
We estimate the Mass Function of void galaxies in the second public data release of the Sloan Digital Sky Survey from a sample of 1000 galaxies with local density contrasts of delta_v < -0.6. The galaxy sample is split into ellipticals and spirals using a color-Sersic index criteria. We estimate the virial masses of ellipticals using the measured spectral li
Thomas Strobl
A framework for constructing new kinds of gauge theories is suggested. Essentially it consists in replacing Lie algebras by Lie or Courant algebroids. Besides presenting novel topological theories defined in arbitrary spacetime dimensions, we show that equipping Lie algebroids E with a fiber metric having sufficiently many E-Killing vectors leads to an aston
Ana Maria Rey, P. Blair Blakie, Guido Pupillo, Carl J. Williams
We study Bragg spectroscopy of ultra-cold atoms in one-dimensional optical lattices as a method for probing the excitation spectrum in the Mott insulator phase, in particular the one particle-hole excitation band. Within the framework of perturbation theory we obtain an analytical expression for the dynamic structure factor $S(q,ω)$ and use it to calculate t
Bhaskar Dutta, Yukihiro Mimura, R. N. Mohapatra
It has recently been shown that a minimal SO(10) model with a single {\bf 10} and single {\bf 126} Higgs field breaking B-L symmetry predicts large solar and atmospheric mixings in agreement with observations if it is assumed that the neutrino mass obeys the type II seesaw formula. No additional symmetries need to be assumed for this purpose. Understanding C
M. M. Sheikh-Jabbari
We conjecture that the discrete light-cone quantization (DLCQ) of strings on the maximally supersymmetric type IIB plane-wave background in the sector with J units of light-cone momentum is a supersymmetric 0+1 dimensional U(J) gauge theory (quantum mechanics) with PSU(2|2)x PSU(2|2)x U(1) superalgebra. The conjectured Hamiltonian for the plane-wave matrix (
Free Energy Approach to the Formation of an Icosahedral Structure during the Freezing of Gold Nanoclusters
physics.atm-clusH. -S. Nam, Nong M. Hwang, B. D. Yu, D. -Y. Kim
The freezing of metal nanoclusters such as gold, silver, and copper exhibits a novel structural evolution. The formation of the icosahedral (Ih) structure is dominant despite its energetic metastability. This important phenomenon, hitherto not understood, is studied by calculating free energies of gold nanoclusters. The structural transition barriers have be
K. Saifullah
Matter collineations (MCs) are the vector fields along which the energy-momentum tensor remains invariant under the Lie transport. Invariance of the metric, the Ricci and the Riemann tensors have been studied extensively and the vectors along which these tensors remain invariant are called Killing vectors (KVs), Ricci collineations (RCs) and curvature collin
R. Schleser, E. Ruh, T. Ihn, K. Ensslin
We present measurements on a quantum dot and a nearby, capacitively coupled, quantum point contact used as a charge detector. With the dot being weakly coupled to only a single reservoir, the transfer of individual electrons onto and off the dot can be observed in real time in the current signal from the quantum point contact. From these time-dependent trace
01 Collaboration
The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the $\sim 100 \mathrm{MeV}$ to $1 \mathrm{TeV}$ range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12
Markus Grassl
We provide a partial solution to the problem of constructing mutually unbiased bases (MUBs) and symmetric informationally complete POVMs (SIC-POVMs) in non-prime-power dimensions. An algebraic description of a SIC-POVM in dimension six is given. Furthermore it is shown that several sets of three mutually unbiased bases in dimension six are maximal, i.e., can
Maarten Schmidt
The GUSBAD catalog of gamma-ray bursts (GRBs) is based on archival BATSE DISCLA data covering the full 9.1 years of the Compton Gamma Ray Observatory mission. The catalog contains 2204 GRBs, including 589 bursts not listed in the Current BATSE Burst Catalog. The GUSBAD catalog is uniform in the sense that the detection criteria are the same throughout and th
Bruno Iochum, Thomas Schucker
There is a natural homomorphism of Lie pseudoalgebras from local vector fields to local rotations on a Riemannian manifold. We address the question whether this homomorphism is unique and give a positive answer in the perturbative regime around the flat metric.
Observations of the X-ray Pulsar GX 301-2 with the ART-P Telescope of the Granat Observatory
astro-phS. S. Tsygankov, A. A. Lutovinov, S. A. Grebenev, M. R. Gilfanov
The variability of the X-ray flux from the pulsar GX 301-2 is analyzed by using data from the ART-P telescope of the Granat Observatory. The intensity variations with time scales of several thousand seconds are studied at various orbital phases. The high-state flux from the source exceeds its low-state flux by as much as a factor of 10. The hardness and spec
Yuji Okawa, Barton Zwiebach
We construct the Neveu-Schwarz sector of heterotic string field theory using the large Hilbert space of the superghosts and the multi-string products of bosonic closed string field theory. No picture-changing operators are required as in Wess-Zumino-Witten-like open superstring field theory. The action exhibits a novel kind of nonpolynomiality: in addition t
M. Cvetic, H. Lu, C. N. Pope
We construct a general class of non-extremal charged Kerr-de Sitter black holes in five dimensions, in which the two rotation parameters are set equal. There are three non-trivial parameters, namely the mass, charge and angular momentum. All previously-known cases, supersymmetric and non-supersymmetric, that have equal angular momenta are encompassed as spec
Didier Fraix-Burnet
The Hubble tuning fork diagram, based on morphology, has always been the preferred scheme for classification of galaxies and is still the only one originally built from historical/evolutionary relationships. At the opposite, biologists have long taken into account the parenthood links of living entities for classification purposes. Assuming branching evoluti
IR Mergers and IR QSOs with Galactic Winds. II. NGC 5514, two Extra-nuclear Starburts/LINERs with a Supergiant Bubble in the Rupture Phase
astro-phS. Lipari, E. Mediavilla, B. Garcia-Lorenzo, R. Diaz
A study of morphology, kinematics and ionization structure of the IR merger NGC 5514, is presented. This study is based mainly on Integral 2D spectroscopy obtained on 4.2 m William Herschel Telescope (La Palma, Spain) and data from CASLEO (Argentina). Clear evidence of two extra-nuclear starbursts with young outflows and LINER activity are reported. One of t
A. Brigatti, A. Ianni, P. Lombardi, G. Ranucci
A facility to test the photomultiplier tubes (PMTs) for the solar neutrino detector Borexino was built at the Gran Sasso laboratory. Using the facility 2200 PMTs with optimal characteristics were selected from the 2350 delivered from the manufacturer. The details of the hardware used are presented.
Ingemar Bengtsson
A complete set of N+1 mutually unbiased bases (MUBs) exists in Hilbert spaces of dimension N = p^k, where p is a prime number. They mesh naturally with finite affine planes of order N, that exist when N = p^k. The existence of MUBs for other values of N is an open question, and the same is true for finite affine planes. I explore the question whether the exi
H. Nikolic
Conventional relativistic quantum mechanics, based on the Klein-Gordon equation, does not possess a natural probabilistic interpretation in configuration space. The Bohmian interpretation, in which probabilities play a secondary role, provides a viable interpretation of relativistic quantum mechanics. We formulate the Bohmian interpretation of many-particle
Polarons in semiconductor quantum-dots and their role in the quantum kinetics of carrier relaxation
cond-mat.mes-hallJ. Seebeck, T. R. Nielsen, P. Gartner, F. Jahnke
While time-dependent perturbation theory shows inefficient carrier-phonon scattering in semiconductor quantum dots, we demonstrate that a quantum kinetic description of carrier-phonon interaction predicts fast carrier capture and relaxation. The considered processes do not fulfill energy conservation in terms of free-carrier energies because polar coupling o
Nicholas Petropoulos
We have used the Cornwall--Jackiw--Tomboulis method of composite operators and its formulation at finite temperature by Amelino-Camelia and Pi, in order to calculate the effective potential of the O(4) linear sigma model beyond the Hartree approximation. We have obtained a system of gap equations for the effective mass of sigma and the pions as well as for t
P. Q. Hung
The early petite unification (PUT) of quarks and leptons at TeV scales with sin^2 theta_W(M^2_Z) used as a constraint, necessitates the introduction of extra quarks and leptons with unconventional electric charges (up to 4/3 for the quarks and 2 for the leptons). This talk, in honor of Paul Frampton's 60th birthday, will be devoted to the motivation and
Black hole-black string phase transitions in thermal 1+1-dimensional supersymmetric Yang-Mills theory on a circle
hep-thOfer Aharony, Joe Marsano, Shiraz Minwalla, Toby Wiseman
We review and extend earlier work that uses the AdS/CFT correspondence to relate the black hole-black string transition of gravitational theories on a circle to a phase transition in maximally supersymmetric 1+1-dimensional SU(N) gauge theories at large N, again compactified on a circle. We perform gravity calculations to determine a likely phase diagram for