December 2003 arXiv papers — page 8
Showing 701–800 of 3,474 papers
Guido Cognola, Emilio Elizalde, Shin'ichi Nojiri, Sergei D. Odintsov
We propose a multi-graviton theory with non-nearest-neighbor couplings in the theory space. The resulting four-dimensional discrete mass spectrum reflects the structure of a latticized extra dimension. For a plausible mass spectrum motivated by the discretized Randall-Sundrum brane-world, the induced cosmological constant turns out to be positive and may ser
J. Bellorin, A Restuccia
We describe the minimal configurations of the compact D=11 Supermembrane and D-branes when the spatial part of the world-volume is a Kähler manifold. The minima of the corresponding hamiltonians arise at immersions into the target space minimizing the Kähler volume. Minimal immersions of particular Kähler manifolds into a given target space are known to exis
J. Babington, J. Erdmenger, N. Evans, Z. Guralnik
We establish a holographic description of chiral symmetry breaking for a particular confining large N non-supersymmetric gauge theory with matter in the fundamental representation. The gravity dual of this theory is obtained by introducing a D7-brane probe into a deformed Anti-de Sitter background found by Constable and Myers. We numerically compute the \bar
D. L. Henty
A qualitative discussion of possible features of a composite graviton arising out of open string field theory is provided along with expected modifications to the graviton propagator due to such a composite graviton model. Possible implications for the cosmological constant problem are also discussed.
A. Liccardo, R. Marotta, F. Pezzella
We discuss the role played by the divergences appearing in the interaction between a fractional D3 brane dressed with an SU(N) gauge field and a stack of N fractional D3 branes on the orbifolds C^2/Z_2 and C^3/(Z_2 x Z_2). In particular we show that the logarithmic divergences in the closed string channel, interpreted as due to twisted massless tadpoles, are
The Parton Structure of the Nucleon and Precision Determination of the Weinberg Angle in Neutrino Scattering
hep-phS. Kretzer, F. Olness, J. Pumplin, M. H. Reno
A recently completed next-to-leading-order program to calculate neutrino cross sections, including power-suppressed mass correction terms, has been applied to evaluate the Paschos-Wolfenstein relation, in order to quantitatively assess the validity and significance of the NuTeV anomaly. In particular, we study the shift of $\sin^2 θ_{\mathrm{W}}$ obtained in
M. M. Nojiri, G. Polesello, D. R. Tovey
Results are presented of a feasibility study of techniques for measuring the mass of the lightest chargino at the CERN LHC. These results suggest that for one particular mSUGRA model a statistically significant chargino signal can be identified and the chargino mass reconstructed with a precision of order 11% for of order 100 fb-1 of data.
M. M. Nojiri, G. Polesello, D. R. Tovey
When several sparticle masses are known, the kinematics of SUSY decay processes observed at the LHC can be solved if the cascade decays contain sufficient steps. We demonstrate four examples of this full reconstruction technique applied to channels involving leptons, namely a) gluino mass determination, b) sbottom mass determination, c) LSP momentum reconstr
I. Rodriguez, O. A. Sampayo
The process $e^+e^- \to τ\barτγ$ contains configurations of the four-momenta for which the scattering amplitude vanishes (Radiation Zeros or Null Zone). These Radiation Zeros only occur for couplings given by a gauge theory, in particular the standard model. Therefore they are sensitive to physics beyond the standard model as the anomalous magnetic and weak
Abhijit Bandyopadhyay, Sandhya Choubey, Srubabati Goswami, Kamales Kar
In this paper we study the physics potential of the KamLAND detector in probing neutrino oscillation parameters through observation of supernova neutrinos. In particular, we discuss the possibilities of probing the mixing angle $θ_{13}$ and determining the sign of $Δm^2_{32}$ from the total charged current(CC) event rates on the proton and $^{12}{C}$ target,
G. Weiglein
The present status of higher-order results in the electroweak theory is summarised, with particular emphasis on recent two-loop results for the prediction of the W-boson mass in the Standard Model and leading three-loop corrections to the rho parameter. The remaining theoretical uncertainties in the prediction for the W-boson mass and the effective weak mixi
Gosta Gustafson
Different formalisms for unintegrated parton densities are discussed, and some results and applications are presented.
Rikard Enberg, Jeff Forshaw, Leszek Motyka, Gavin Poludniowski
We summarise recent progress in the computation of helicity amplitudes for diffractive vector meson production at large momentum transfer and their comparison to data collected at the HERA collider.
The $μ\to eγ$ and $τ\to μγ$ decays in the general two Higgs Doublet model with the inclusion of one universal extra dimension
hep-phE. Iltan
We study the effect of one universal extra dimension on the branching ratios of the lepton flavor violating processes μ\to eγand τ\to μγin the general two Higgs doublet model. We observe that these new effects are tiny for the small values of the compactification radius R. Furthermore, we see that these effects are comparable with the branching ratio obtaine
Gosta Gustafson
The LDC formalism for DIS can describe HERA structure functions, and also agrees well with CTEQ and MRST gluon distributions. It is also suitable for hadronic collisions, and provides a strong connection between ep and pp reactions. Some preliminary results are presented.
Carlo Giunti
I refute the criticisms of hep-ph/0311241 raised in hep-ph/0312151.
Jacques C. R. Bloch, Attilio Cucchieri, Kurt Langfeld, Tereza Mendes
We perform numerical studies of the running coupling constant alpha_R(p^2) and of the gluon and ghost propagators for pure SU(2) lattice gauge theory in the minimal Landau gauge. Different definitions of the gauge fields and different gauge-fixing procedures are used respectively for gaining better control over the approach to the continuum limit and for a b
Sugumi Kanno, Jiro Soda
To estimate Kaluza-Klein (KK) corrections on gravitational waves emitted by perturbed rotating black strings, we give the effective Teukolsky equation on the brane which is separable equation and hence numerically manageable.
Victor W. Marek, Jeffrey B. Remmel
(We apologize for pidgin LaTeX) Schlipf \cite{sch91} proved that Stable Logic Programming (SLP) solves all $\mathit{NP}$ decision problems. We extend Schlipf's result to prove that SLP solves all search problems in the class $\mathit{NP}$. Moreover, we do this in a uniform way as defined in \cite{mt99}. Specifically, we show that there is a single $\math
Paul Piwek, Kees van Deemter
This paper explains why scripted dialogue shares some crucial properties with discourse. In particular, when scripted dialogues are generated by a Natural Language Generation system, the generator can apply revision strategies that cannot normally be used when the dialogue results from an interaction between autonomous agents (i.e., when the dialogue is not
Paul Piwek, Kees van Deemter
The main aim of this paper is to introduce automated generation of scripted dialogue as a worthwhile topic of investigation. In particular the fact that scripted dialogue involves two layers of communication, i.e., uni-directional communication between the author and the audience of a scripted dialogue and bi-directional pretended communication between the c
Paul Piwek
This paper describes the NECA MNLG; a fully implemented Multimodal Natural Language Generation module. The MNLG is deployed as part of the NECA system which generates dialogues between animated agents. The generation module supports the seamless integration of full grammar rules, templates and canned text. The generator takes input which allows for the speci
Magnetic Quantum Critical Point in YBa_2Cu_3O_{7-delta}? Resolving the Correlation Length Controversy
cond-mat.supr-conR. S. Markiewicz
A mode coupling calculation which previously explained the Mott gap collapse induced in cuprates by electron doping is applied to the analogous problem of hole doping. A plateau in the q-space susceptibility is found to inhibit the rate of susceptibility divergence as T goes to 0. This effect could reconcile neutron and NMR measurements of the correlation le
Structural and electrical properties of c-axis oriented Y1-xCaxBa2(Cu1-yZny)3O7-delta thin films grown by pulsed laser deposition
cond-mat.supr-conS. H. Naqib, R. A. Chakalov, J. R. Cooper
Ca- and Zn-subsituted Y1-xCaxBa2(Cu1-yZny)O7-delta (x = 0, 0.05 and y = 0, 0.02, 0.04, 0.05) thin films were grown on SrTiO3 (100) substrates using the pulsed laser deposition (PLD) technique. Effects of various growth parameters on the quality of the film were studied via X-ray diffraction (XRD), atomic force microscopy (AFM), and in-plane resistivity, rhoa
Adriano de Jesus Holanda, Ivan Torres Pisa, Osame Kinouchi, Alexandre Souto Martinez
A thesaurus is one, out of many, possible representations of term (or word) connectivity. The terms of a thesaurus are seen as the nodes and their relationship as the links of a directed graph. The directionality of the links retains all the thesaurus information and allows the measurement of several quantities. This has lead to a new term classification acc
Yuriy Makhlin, Alexander Shnirman
We analyze the dissipative dynamics of a two-level quantum system subject to low-frequency, e.g. 1/f noise, motivated by recent experiments with superconducting quantum circuits. We show that the effect of transverse linear coupling of the system to low-frequency noise is equivalent to that of quadratic longitudinal coupling. We further find the decay law of
S. Raymond, A. Huxley
Inelastic neutron scattering was used to study the low energy magnetic excitations of the ferromagnetic superconductor UGe$_{2}$. The ferromagnetic fluctuations are of Ising nature with a non-conserved magnetization and have an intermediate behavior between localized and itinerant magnetism.
Out-of-equilibrium critical dynamics at surfaces: Cluster dissolution and non-algebraic correlations
cond-mat.stat-mechMichel Pleimling, Ferenc Igloi
We study nonequilibrium dynamical properties at a free surface after the system is quenched from the high-temperature phase into the critical point. We show that if the spatial surface correlations decay sufficiently rapidly the surface magnetization and/or the surface manifold autocorrelations has a qualitatively different universal short time behavior than
Hung-Ta Chien, Hui-Ting Tang, Chao-Hsien Kuo, Chii-Chang Chen
Using the FDTD method, we investigate the electromagnetic propagation in two-dimensional photonic crystals, formed by parallel air cylinders in a dielectric medium. The corresponding frequency band structure is computed using the standard plane-wave expansion method. It is shown that within partial bandgaps, waves tend to bend away from the forbidden directi
H. De Raedt, S. Miyashita, K. Michielsen, M. Machida
A microscopic model of the molecular magnet V15 is used to study mechanisms for the adiabatic change of the magnetization in time-dependent magnetic fields. Effects of the Dzyaloshinskii-Moriya interaction, the most plausible source for the energy-level repulsions that lead to adiabatic changes of the magnetization, are studied in detail. We find that the en
M. J. de Oliveira, A. Petri, T. Tome
We study the emergence of glassy states after a sudden cooling in lattice models with short range interactions and without any a priori quenched disorder. The glassy state emerges whenever the equilibrium model possesses a sufficient number of coexisting crystalline phases at low temperatures, provided the thermodynamic limit be taken before the infinite tim
NANOTCAD2D: Two-dimensional code for the simulation of nanoelectronic devices and structures
cond-mat.mes-hallG. Curatola, G. Iannaccone
In this paper we present NANOTCAD2D, a code for the simulation of the electrical properties of semiconductor-based nanoelectronic devices and structures in two-dimensional domains. Such code is based on the solution of the Poisson/Schrödinger equation with density functional theory and of the continuity equation of the ballistic current. NANOTCAD2D can be ap
Adolfo Avella, Ferdinando Mancini
The charge and spin sectors, which are intimately coupled to the fermionic one, of the t-t' Hubbard model have been computed self-consistently within the two-pole approximation. The relevant unknown correlators appearing in the causal bosonic propagators have been computed by enforcing the constraints dictated by the hydrodynamics and the algebra of the
T. Ludwig, A. D. Mirlin
We study the amplitude of mesoscopic Aharonov-Bohm oscillations in quasi-one-dimensional (Q1D) diffusive rings. We consider first the low-temperature limit of a fully coherent sample. The variance of oscillation harmonics is calculated as a function of the length of the leads attaching the ring to reservoirs. We further analyze the regime of relatively high
H. J. Limbach, M. Sayar, C. Holm
Using extensive Molecular Dynamics simulations we study the behavior of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction, and the bundle size. We show that for the parameter
Effects of next-nearest-neighbor hopping $t^{\prime}$ on the electronic structure of cuprates
cond-mat.supr-conK. Tanaka, T. Yoshida, A. Fujimori, D. H. Lu
Photoemission spectra of underdoped and lightly-doped Bi$_{2-z}$Pb$_z$Sr$_2$Ca$_{1-x}${\it R}$_{x}$Cu$_2$O$_{8+y}$ ($R=$ Pr, Er) (BSCCO) have been measured and compared with those of La$_{2-x}$Sr$_x$CuO$_4$ (LSCO). The lower-Hubbard band of the insulating BSCCO, like Ca$_2$CuO$_2$Cl$_2$, shows a stronger dispersion than La$_2$CuO$_4$ from ${\bf k}\sim$($π/2,
T. Hickel, W. Nolting
The periodic s-d(f) exchange model is characterized by a wide variety of interesting applications, a simple mathematical structure and a limited number of reliable approximations which take care of the quantum nature of the participating spins. We suggest the use of a projection-operator method for getting information perturbationally, which are not accessib
Bogdan A. Bernevig, George Chapline, Robert B. Laughlin, Zaira Nazario
Recently a new phenomenological Hamiltonian was proposed to describe the superconducting cuprates in which correlations and on-site Coulomb repulsion are introduced by partial Gutzwiller projection. This Gossamer Hamiltonian has an exact ground state and differs from the t-J and Hubbard Hamiltonians in possessing a powerful attractive interaction among elect
Nicolas laflorencie, Heiko Rieger, Anders W. Sandvik, Patrik Henelius
The random antiferromagnetic spin-1/2 XX and XXZ chain is studied numerically for varying strength of the disorder, using exact diagonalization and stochastic series expansion methods. The spin-spin correlation function as well as the stiffness display a clear crossover from the pure behavior (no disorder) to the infinite randomness fixed point or random sin
H. Eisaki, N. Kaneko, D. L. Feng, A. Damascelli
We examine the effect on the superconducting transition temperature (Tc) of chemical inhomogeneities in Bi2201 and Bi2212 single crystals. Cation disorder at the Sr crystallographic site is inherent in these materials and strongly affects the value of Tc. Partial substitution of Sr by Ln (Ln = La, Pr, Nd, Sm, Eu, Gd, and Bi) in Bi_{2}Sr_{1.6}Ln_{0.4}CuO_{6}
Yoshikazu Ohtaki, Hiroshi H. Hasegawa
We consider an ideal closed stock market, in which 100 traders have economic activities. The assets of the traders change through buying and selling stocks. We simulate the assets under conservation of both total currency and total number of stocks. If the traders are identical, then the assets are distributed as a stationary Gaussian. When variety among the
Leo Radzihovsky
In these lectures I discuss long-scale properties of fluctuating polymerized membranes in the presence of network anisotropy and random heterogeneities. Amazingly, even infinitesimal amount of these seemingly innocuous but physically important ingredients in the membrane's internal structure leads to a wealth of striking qualitatively new phenomena. Anis
Superfluid density in the underdoped YBa_2Cu_3O_{7-x}: Evidence for d-density wave order of pseudogap
cond-mat.supr-conM. R. Trunin, Yu. A. Nefyodov, A. F. Shevchun
The investigation of the penetration depth λ_{ab}(T,p) in YBa_2Cu_3O_{7-x} crystals allowed to observe the following features of the superfluid density n_s(T,p)\propto λ_{ab}^{-2}(T,p) as a function of temperature T<Tc/2 and carrier concentration 0.078\le p\le 0.16 in CuO_2 planes: (i) n_s(0,p) depends linearly on p, (ii) the derivative |dn_s(T,p)/dT|_{T\to
Huijie Yang, Yun Zhou, Fangcui Zhao, Beilai Hu
The spreading of SARS will destruct the initial network structure to a new phase, and in turn the spreading process will be weakened effectively and finally halted by this evolution of network structure. This mechanism is called immunity of contact network in this paper. What we can do is to accelerate effectively this process only.
Conductance Characteristics between a Normal Metal and a Superconductor Carrying a Supercurrent
cond-mat.supr-conDegang Zhang, C. S. Ting, C. -R. Hu
The low-temperature conductance (G) characteristics between a normal metal and a clean superconductor (S) carrying a supercurrent $I_s$ parallel to the interface is theoretically investigated. Increasing $I_s$ causes lowering and broadening of (1) coherence peaks of s-wave S, and d-wave S at (100) contact, (2) midgap-states-induced zero-bias conductance peak
C. M. Varma
The claims made for the Resonating Valence Bond ideas for the cuprates in a recent paper by Anderson et al. on the basis of a variational calculation are discussed.
K. Xu, T. Mukaiyama, J. R. Abo-Shaeer, J. K. Chin
Ultra-cold sodium molecules were produced from an atomic Bose-Einstein condensate by ramping an applied magnetic field across a Feshbach resonance. More than $10^5$ molecules were generated with a conversion efficiency of $\sim$4%. Using laser light resonant with an atomic transition, the remaining atoms could be selectively removed, preventing fast collisio
Yuriy Makhlin, Alexander Shnirman
Motivated by recent experiments with Josephson-junction circuits, we analyze the influence of various noise sources on the dynamics of two-level systems at optimal operation points where the linear coupling to low-frequency fluctuations is suppressed. We study the decoherence due to nonlinear (quadratic) coupling, focusing on the experimentally relevant 1/f
P. B. Ivanov, J. C. B. Papaloizou
We consider the tidal interaction of a fully convective primary star and a point mass. Using a normal mode decomposition we calculate the evolution of the primary angular velocity and orbit for arbitrary eccentricity e. The dissipation acting on the tidal perturbation is associated with convective turbulence. A novel feature of the Paper is that, to take int
B. T. Draine
In the interstellar medium of the Milky Way, certain elements -- e.g., Mg, Si, Al, Ca, Ti, Fe -- reside predominantly in interstellar dust grains. These grains absorb, scatter, and emit electromagnetic radiation, heat the interstellar medium by photoelectric emission, play a role in the ionization balance of the gas, and catalyze the formation of molecules,
C. D. Dermer, A. Atoyan
Several lines of evidence point to a relationship between gamma-ray bursts (GRBs) and the high mass stars that explode as supernovae. Arguments that GRB sources accelerate cosmic rays (CRs) are summarized. High-energy neutrino detection from individual GRBs would mean that they are hadronically dominated, that is, that the amount of energy deposited in the f
C. D. Dermer, B. L. Dingus
We derive the minimum observing time scales to detect a blazar at a given flux level with the LAT on GLAST in the scanning and pointing modes. Based upon Phase 1 observations with EGRET, we predict the GLAST detection rate of blazar flares at different flux levels. With some uncertainty given the poor statistics of bright blazars, we predict that a blazar fl
P. Chang, L. Bildsten
We extend our initial study of diffusive nuclear burning (DNB) for neutron stars (NSs) with Hydrogen atmospheres and an underlying layer of proton capturing nuclei. Our initial study showed that DNB can alter the photospheric abundance of Hydrogen on surprisingly short timescales ($10^{2-4}\yrs$). Significant composition evolution impacts the radiated therma
Analysis of a Very Massive DA White Dwarf via the Trigonometric Parallax and Spectroscopic Methods
astro-phC. C. Dahn, P. Bergeron, J. Liebert, H. C. Harris
By two different methods, we show that LHS 4033 is an extremely massive white dwarf near its likely upper mass limit for destruction by unstable electron captures. From the accurate trigonometric parallax reported herein, the effective temperature (T=10,900 K) and the stellar radius (R=0.00368 R_sun) are directly determined from the broad-band spectral energ
P. Hoeflich, C. Gerardy, R. Quimby
We present a brief summary of asphericity effects in thermonuclear and core collapse supernovae (SN), and how to distinguish the underlying physics by their observable signatures. Electron scattering is the dominant process to produce polarization which is one of the main diagnostical tools. Asphericities result in a directional dependence of the luminosity
Paschen beta emission as a tracer of outflow activity from T-Tauri stars, as compared to Optical Forbidden emission
astro-phE. T. Whelan, T. P. Ray, C. J. Davis
The Paschen beta (1.2822 micron) emission line found in the near-infrared spectra of T-Tauri stars (TTSs) is believed to trace the accretion of material onto the central star. We present spectroscopic data which suggests that this may not always be the case. The technique of spectro-astrometry is used by us to measure positional displacements in the Pab emis
A. Mampaso
Results appeared since the last APN meeting on the relation between abundances and PNe morphological features are reviewed here. Statistical analyses of round, elliptical, and bipolar PNe clearly separate the latter group as having larger He and N/O abundances. Studies of individual PNe, including the UV and IR domains, allow a detailed comparison with evolu
R. Garrido, E. Poretti
The different research teams involved in the study of delta Sct stars have slightly changed their strategy in the past years. The observational effort to secure worldwide coverage of case studies is continued, but the specifications become more severe, especially about target characterization and frequency resolution.
D. R. Goncalves, A. Mampaso, S. Navarro, R. M. L. Corradi
The first results on new optical data for R Aquarii (based on observations obtained with the 2.5m INT, the 2.5m NOT and the 3.5m NTT) are presented. The morphology and kinematics of the nebula, based on data obtained with the NTT from 1991 to 2000, are discussed. Physical parameters of the outer nebula and the knotty jet are derived using spectra obtained wi
R. N. Ikhsanov, E. V. Miletsky
We investigate temporal variations of the solar neutrino flux in 1970-1997. The periods of 11, 5 and 2 years have been found in the variations of the neutrino flux. The results indicate that a periodicity close to 5 years is the most significant in the data from both the Homestake and GALLEX experiments. Two groups of the solar activity indices have been dis
Preparing the COROT space mission: Building a photometric and variability database of stars in its field of view
astro-phP. J. Amado, R. Garrido, E. Poretti, E. Michel
The CNES/European space mission COROT will monitor asteroseismic targets located in selected fields to probe stellar interiors. Therefore, suitable candidate targets have to be searched for in order to optimize the scientific return of the mission. However, to be able to use the asteroseismic tools on the stars, their physical parameters must be known in adv
Pedro F. Gonzalez-Diaz
In spite of its rather weird properties which include violation of the dominant-energy condition, the requirement of superluminal sound speed and increasing vacuum-energy density, phantom energy has recently attracted a lot of scientific and popular interests. In this letter it is shown that in the framework of a general k-essence model, vacuum-phantom energ
Yu. Lyubchik, H. R. A. Jones, Ya. V. Pavlenko, S. Viti
We provide a set of atomic lines which are suitable for the description of ultracool dwarf spectra from 10000 to 25000 Å. This atomic linelist was made using both synthetic spectra calculations and existing atlases of infrared spectra of Arcturus and Sunspot umbra. We present plots, which show the comparison of synthetic spectra and observed Arcturus and Sun
T. R. Marsh, G. Nelemans, D. Steeghs
Three periodically variable stars have recently been discovered (V407 Vul, P=9.5 min; ES Cet, P=10.3 min; RX J0806.3+1527, P=5.3 min) with properties that suggest that their photometric periods are also their orbital periods, making them the most compact binary stars known. If true, this might indicate that close, detached, double white dwarfs are able to su
Dynamical Mass Constraints on Low-Mass Pre-Main-Sequence Stellar Evolutionary Tracks: An Eclipsing Binary in Orion with a 1.0 Msun Primary and an 0.7 Msun Secondary
astro-phKeivan G. Stassun, Robert D. Mathieu, Luiz Paulo R. Vaz, Nicholas Stroud
We report the discovery of a double-lined, spectroscopic, eclipsing binary in the Orion star-forming region. We analyze the system spectroscopically and photometrically to empirically determine precise, distance-independent masses, radii, effective temperatures, and luminosities for both components. The measured masses for the primary and secondary, accurate
Takeru K. Suzuki, Susumu Inoue
The energy dissipated by virialization shocks during hierarchical structure formation of the Galaxy can exceed that injected by concomitant supernova (SN) explosions. Cosmic rays (CRs) accelerated by such shocks may therefore dominate over SNe in the production of $^6$Li through $α+ α$ fusion without co-producing Be and B. This process can give a more natura
Coronal Heating and Acceleration of the High/Low-Speed Solar Wind by Fast/Slow MHD Shock Trains
astro-phTakeru K. Suzuki
We investigate coronal heating and acceleration of the high- and low-speed solar wind in the open field region by dissipation of fast and slow magnetohydrodynamical (MHD) waves through MHD shocks. Linearly polarized \Alfven (fast MHD) waves and acoustic (slow MHD) waves travelling upwardly along with a magnetic field line eventually form fast switch-on shock
Haojing Yan, Rogier A. Windhorst
In this paper, we address which sources contributed most of the reionizing photons. Our argument assumes that the reionization ended around z ~ 6 and that it was a relatively quick process, i.e., that there was a non-negligible fraction of neutral hydrogen in the Universe at somewhat earlier epochs. Starting from our earlier estimate of the luminosity functi
L. Raul Abramo, L. Sodre
We show that the thermal Sunyaev-Zeldovich effect caused by hot electrons in the Local Supercluster (LSC) can explain the abnormal quadrupole and octopole of the cosmic microwave background (CMB) that were measured by WMAP and COBE. The distortion needed to account for the low observed quadrupole is a spot in the direction of the LSC with a temperature decre
Derek B. Leinweber, Anthony G. Williams, Jian-bo Zhang, Frank X. Lee
The topological charge is studied on lattices of large physical volume and fine lattice spacing. We illustrate how a parity transformation on the SU(3) link-variables of lattice gauge configurations reverses the sign of the topological charge and leaves the action invariant. Random applications of the parity transformation are proposed to traverse from one t
Stacy McGaugh
I present a model devoid of non-baryonic cold dark matter (CDM) which provides an acceptable fit to the WMAP data for the power spectrum of temperature fluctuations in the cosmic background radiation (CBR). An a priori prediction of such no-CDM models was a first-to-second peak amplitude ratio A1:2 = 2.4. WMAP measures A1:2 = 2.34 +/- 0.09. The baryon conten
J. L. Garcia-Luna, G. Tavares-Velasco, J. J. Toscano
The static electromagnetic properties of the $W$ boson, $Δκ$ and $ΔQ$, are calculated in the $SU_L(3)} \times U_X(1)$ model with right-handed neutrinos. The new contributions from this model arise from the gauge and scalar sectors. In the gauge sector there is a new contribution from a complex neutral gauge boson $Y^0$ and a singly-charged gauge boson $Y^\pm
Pablo A. Ferrari, Beat M. Niederhauser
In the Hammersley harness processes the real-valued height at each site i in Z^d is updated at rate 1 to an average of the neighboring heights plus a centered random variable (the noise). We construct the process "a la Harris" simultaneously for all times and boxes contained in Z^d. With this representation we compute covariances and show L^2 and alm
P. Giovannangeli
Well above the critical temperature hot QCD is described by 3d electrostatic QCD with gauge coupling $g_E$ and Debye mass $m_E$. We integrate out the Debye scales to two loop accuracy and find for the gauge coupling in the resulting magnetostatic action $g_M^2=g_E^2(1-{1\over{48}}{g_E^2N\over{πm_E}} -{17\over{4608}}({g_E^2N\over{πm_E}})^2+O(({g_E^2N\over{πm_
Sharp lines in the absorption edge of EuTe and Pb$_{0.1}$Eu$_{0.9}$Te in high magnetic fields
cond-mat.mtrl-sciL. K. Hanamoto, N. F. Oliveira, A. B. Henriques, P. Rappl
The optical absorption spectra in the region of the \fd transition energies of epitaxial layers of of EuTe and \PbEuTe, grown by molecular beam epitaxy, were studied using circularly polarized light, in the Faraday configuration. Under \sigmam polarization a sharp symmetric absorption line (full width at half-maximum 0.041 eV) emerges at the low energy side
Taisei Kaizoji, Michiyo Kaizoji
In this paper, we describe a newly discovered statistical property of time series data for daily price changes. We conducted quantitative investigation of the {\it calm-time intervals} of price changes for 800 companies listed in the Tokyo Stock Exchange, and for the Nikkei 225 index over a 27-year period from January 4, 1975 to December 28, 2001. A calm-tim
Large-scale magnetic field generation by alpha-effect driven by collective neutrino-plasma interaction
astro-phV. B. Semikoz, D. D. Sokoloff
We suggest a new mechanism for generation of large-scale magnetic field in the hot plasma of early universe which is based on the parity violation in weak interactions and depends neither on helicity of matter turbulence resulting in the standard alpha-effect nor on general rotation. The mechanism can result in a self-excitation of an (almost) uniform cosmol
Ricardo A. Mosna, J. G. Pereira
By using a nonholonomic moving frame version of the general covariance principle, an active version of the equivalence principle, an analysis of the gravitational coupling prescription of teleparallel gravity is made. It is shown that the coupling prescription determined by this principle is always equivalent with the corresponding prescription of general re
H. Enger, C. A. Lütken
We show that B-type $Π$-stable D-branes do not in general reduce to the (Gieseker-) stable holomorphic vector bundles used in mathematics to construct moduli spaces. We show that solutions of the almost Hermitian Yang--Mills equations for the non-linear deformations of Yang--Mills instantons that appear in the low-energy geometric limit of strings exist iff
S. -H. Lee, D. Louca, H. Ueda, S. Park
Our powder inelastic neutron scattering data indicate that \zvo is a system of spin chains that are three dimensionally tangled in the cubic phase above 50 K due to randomly occupied $t_{2g}$ orbitals of V$^{3+}$ ($3d^2$) ions. Below 50 K in the tetragonal phase, the chains become straight due to antiferro-orbital ordering. This is evidenced by the character
Ariel Megevand
We consider first-order phase transitions of the Universe in the radiation-dominated era. We argue that in general the velocity of interfaces is non-relativistic due to the interaction with the plasma and the release of latent heat. We study the general evolution of such slow phase transitions, which comprise essentially a short reheating stage and a longer
Jing-Min Hou, Li-Jun Tian, Mo-lin Ge
We proposed a scheme to realize a controlled-NOT quantum logic gate in a dimer of exchange coupled single-molecule magnets, $[\textrm{Mn}_4]_2$. We chosen the ground state and the three low-lying excited states of a dimer in a finite longitudinal magnetic field as the quantum computing bases and introduced a pulsed transverse magnetic field with a special fr
J. H. McGuire, A. L. Godunov, Kh. Kh. Shakov, Kh. Yu. Rakhimov
We examine how time ordering works in quantum mechanics and in classical mechanics.
Piotr Kielanowski
The main subject of the paper is the description of unstable states in quantum mechanics and quantum field theory. Unstable states in quantum field theory can only be introduced as the intermediate states and not as asymptotic states. The absence of the intermediate unstable states from the asymptotic states is compatible with unitarity. Thus the concept of
Coherent interaction of laser pulses in a resonant optically dense extended medium under the regime of strong field-matter coupling
quant-phV. S. Egorov, V. N. Lebedev, I. B. Mekhov, P. V. Moroshkin
Nonstationary pump-probe interaction between short laser pulses propagating in a resonant optically dense coherent medium is considered. A special attention is paid to the case, where the density of two-level particles is high enough that a considerable part of the energy of relatively weak external laser-fields can be coherently absorbed and reemitted by th
JM Geremia, John K. Stockton, Andrew C. Doherty, Hideo Mabuchi
The shot-noise detection limit in current high-precision atomic magnetometry is a manifestation of quantum fluctuations that scale as the square root of N in an ensemble of N particles. However, there is a general expectation that the reduced projection noise provided by conditional spin-squeezing could be exploited to surpass the conventional shot-noise lim
F. Spineanu, M. Vlad, K. Itoh, S. -I. Itoh
We review the analytical methods of solving the stochastic equations for barrier-type dynamical behavior in plasma systems. The path-integral approach is examined as a particularly efficient method of determination of the statistical properties.
Liang-Shan Chen, Chao-Hsien Kuo, Zhen Ye
We investigate the electromagnetic propagation in two-dimensional photonic crystals, formed by parallel dielectric cylinders embedded a uniform medium. The frequency band structure is computed using the standard plane-wave expansion method, while the propagation and scattering of the electromagnetic waves are calculated by the multiple scattering theory. It
Slawomir Klimek, Witold Kondracki
We study ergodic averages for a class of pseudodifferential operators on the flat N-dimensional torus with respect to the Schrödinger evolution. The later can be consider a quantization of the geodesic flow on $\bT^N$. We prove that, up to semi-classically negligible corrections, such ergodic averages are translationally invariant operators.
A. K. Kwasniewski
An expansion formula of a new type with the rest term of Cauchy type is derived in the operator formulation of generalized umbral calculus
Shi-shyr Roan
We determine all the Kummer-surface-type Calabi-Yau (CY) 3-folds, i.e., those $\hat{T/G}$ which are resolutions of 3-torus-orbifolds $T/G$ with only isolated singularities. There are only two such CY spaces: one with $G= \ZZ_3$ and $T$ being the triple-product of 1-torus carrying an order 3 automorphism, the other with $G= \ZZ_7$ and $T$ being the Jacobian o
M. Cariglia, G. W. Gibbons, R. Guven, C. N. Pope
The non-Abelian plane waves, first found in flat spacetime by Coleman and subsequently generalized to give pp-waves in Einstein-Yang-Mills theory, are shown to be 1/2 supersymmetric solutions of a wide variety of N=1 supergravity theories coupled to scalar and vector multiplets, including the theory of SU(2) Yang-Mills coupled to an axion σand dilaton ϕrecen
A. Bartl, H. Fraas, S. Hesselbach, K. Hidaka
We report on the results of a phenomenological study of top squarks (stop_{1,2}) and bottom squarks (sbottom_{1,2}) in the Minimal Supersymmetric Standard Model (MSSM) with complex parameters A_t, A_b, mu and M_1. In particular we focus on the CP phase dependence of the branching ratios of stop_{1,2} and sbottom_{1,2} decays. We find that the effect of the p
J. Pasupathy, Ritesh K. Singh
The matrix element of the isoscalar axial vector current, $\bar{u}γ_μγ_5u + \bar{d}γ_μγ_5d $, between nucleon states is computed using the external field QCD sum rule method. The external field induced correlator, $<0|\bar{q}γ_μγ_5q|0>$, is calculated from the spectrum of the isoscalar axial vector meson states. Since it is difficult to ascertain, from QCD s
Ahmed Ali
We review the status of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and the CP-violating phases in the CKM-unitarity triangle. The emphasis in these lecture notes is on $B$-meson physics, though we also review the current status and issues in the light quark sector of this matrix. Selected applications of theoretical methods in QCD used in the interp
Johan Alwall, Catherine Biscarat, Stefano Moretti, Johan Rathsman
Charged Higgs boson production in association with a top quark could be the first indication of the existence of Higgs particles. The Tevatron Run-II started data-taking in April 2001 at a centre-of-mass energy of 1960 GeV and could probe the existence of a charged Higgs boson beyond the current mass limit. We study the ppbar -> tbH^+/- production process wi
Gianluca Argentini
In this paper I describe some results on the use of virtual processors technology for parallelize some SPMD computational programs. The tested technology is the INTEL Hyper Threading on real processors, and the programs are MATLAB scripts for floating points computation. The conclusions of the work concern on the utility and limits of the used approach. The
Charles W. Wolgemuth, Raymond E. Goldstein, Thomas R. Powers
Certain bacteria form filamentous colonies when the cells fail to separate after dividing. In Bacillus subtilis, Bacillus thermus, and cyanobacteria, the filaments can wrap into complex supercoiled structures as the cells grow. The structures may be solenoids or plectonemes, with or without branches in the latter case. Any microscopic theory of these morphol
MunJu Kim, James C. Bird, Annemarie J. Van Parys, Kenneth S. Breuer
Escherichia coli and other bacteria use rotating helical filaments to swim. Each cell typically has about four filaments, which bundle or disperse depending on the sense of motor rotation. To study the bundling process, we built a macroscopic scale model consisting of stepper-motor-driven polymer helices in a tank filled with a high-viscosity silicone oil. T
P. Horsch, G. Khaliullin
The density response of a doped Mott-Hubbard insulator is discussed starting from the t-J model in a slave boson 1/N representation. In leading order O(1) the density fluctuation spectra $N({\bf q},ω)$ are determined by an undamped collective mode at large momentum transfer, in striking disagreement with results obtained by exact diagonalization, which revea