May 2007 arXiv papers — page 4
Showing 301–400 of 4,683 papers
Manfred Bucher
The largest failure of the old, Bohr-Sommerfeld quantum theory was with the helium atom. It brought about the theory's demise. I show that this failure does not originate, as commonly believed, with the orbit concept per se. Instead, it was caused by the wrong choice of orbits, compounded by ignorance of the exclusion principle. Choosing semiclassical el
The NMSSM Solution to the Fine-Tuning Problem, Precision Electroweak Constraints and the Largest LEP Higgs Event Excess
hep-phRadovan Dermisek, John F. Gunion
We present an extended study of how the Next to Minimal Supersymmetric Model easily avoids fine-tuning in electroweak symmetry breaking for a SM-like light Higgs with mass in the vicinity of $100\gev$, as beautifully consistent with precision electroweak data, while escaping LEP constraints due to the dominance of $h\to aa$ decays with $m_a<2m_b$ so that $a\
Coexistence of Antiferromagnetism and Superconductivity in Electron-doped High-Tc Superconductors
cond-mat.supr-conW. Yu, J. S. Higgins, P. Bach, R. L. Greene
We present magnetotransport evidence for antiferromagnetism in films of the electron-doped cuprates Pr$_{2-x}$Ce$_x$CuO$_4$. Our results show clear signature of static antiferromagnetism up to optimal doping x=0.15, with a quantum phase transition close to x=0.16, and a coexistence of static antiferromagnetism and superconductivity for 0.12$\le$x$\le$0.15.
Gordan Zitkovic
We introduce a linear space of finitely additive measures to treat the problem of optimal expected utility from consumption under a stochastic clock and an unbounded random endowment process. In this way we establish existence and uniqueness for a large class of utility maximization problems including the classical ones of terminal wealth or consumption, as
Edoardo M Airoldi, David M Blei, Stephen E Fienberg, Eric P Xing
Observations consisting of measurements on relationships for pairs of objects arise in many settings, such as protein interaction and gene regulatory networks, collections of author-recipient email, and social networks. Analyzing such data with probabilisic models can be delicate because the simple exchangeability assumptions underlying many boilerplate mode
Alexander V. Savin, Yuri S. Kivshar
We study large-amplitude oscillations of carbon nanotubes with chiralities $(m,0)$ and $(m,m)$ and predict the existence of localized nonlinear modes in the form of {\em discrete breathers}. In nanotubes with the index $(m,0)$ {\em three types} of localized modes can exist, namely longitudinal, radial, and twisting breathers; however only the twisting breath
V. V. Nesvizhevsky, G. Pignol, K. V. Protasov
We present preliminary results on sensitivity of experiments with slow neutrons to constrain additional forces in a wide distance range: from picometers to micrometers. In the sub-nanometer range, available data on lengths of neutron scattering at nuclei provide the most competitive constraint. We show that it can be improved significantly in a dedicated mea
Dynamical heterogeneities and the breakdown of the Stokes-Einstein and Stokes-Einstein-Debye relations in simulated water
cond-mat.stat-mechMarco G. Mazza, Nicolas Giovambattista, H. Eugene Stanley, Francis W. Starr
We study the Stokes-Einstein (SE) and the Stokes-Einstein-Debye (SED) relations using molecular dynamics simulations of the extended simple point charge model of water. We find that both the SE and SED relations break down at low temperature. To explore the relationship between these breakdowns and dynamical heterogeneities (DH), we also calculate the SE and
Study of Damage Propagation at the Interface Localization-Delocalization Transition of the Confined Ising Model
cond-mat.stat-mechM. Leticia Rubio Puzzo, Ezequiel V. Albano
The propagation of damage in a confined magnetic Ising film, with short range competing magnetic fields ($h$) acting at opposite walls, is studied by means of Monte Carlo simulations. Due to the presence of the fields, the film undergoes a wetting transition at a well defined critical temperature $T_w(h)$. In fact, the competing fields causes the occurrence
Gabriele Ghisellini
The discovery that the bolometric energetics (and/or peak luminosity) of Gamma Ray Bursts correlates with their spectral properties has allowed to standardize the burst energetics to such a degree to enable their use for constraining the cosmological parameters, in the same way as SN Ia. With respect to SN Ia, there is the advantage of having sources free fr
Dynamic response of Ag monolayers adsorbed on Au(100) upon an oscillatory variation of the chemical potential: A Monte Carlo simulation study
cond-mat.stat-mechM. Cecilia Gimenez, Ezequiel V. Albano
Based on the fact that the underpotential electrochemical deposition of Ag atoms on the $Au(100)$ surface exhibits sharp first-order phase transitions at well-defined values of the (coexistence) chemical potential ($μ_{coex}$), we performed extensive simulations aimed at investigating the hysteretic dynamic behavior of the system close to coexistence upon th
Oleg Kochukhov, Saul J. Adelman, Austin F. Gulliver, Nikolai Piskunov
The formation of long-lasting structures at the surfaces of stars is commonly ascribed to the action of strong magnetic fields. This paradigm is supported by observations of evolving cool spots in the Sun and active late-type stars, and stationary chemical spots in the early-type magnetic stars. However, results of our seven-year monitoring of mercury spots
G. Y. Qin, J. Ruppert, S. Turbide, C. Gale
The nuclear modification factor R_AA for charged hadron production at the LHC is predicted from jet energy loss induced by gluon bremsstrahlung. The Arnold, Moore, and Yaffe formalism is used, together with an ideal hydrodynamical model.
Robert Quimby, Peter Höflich, J. Craig Wheeler
HET Optical spectra covering the evolution from about 6 days before to about 5 weeks after maximum light and the ROTSE-IIIb unfiltered light curve of the "Branch-normal" Type Ia Supernova SN 2005hj are presented. The host galaxy shows HII region lines at redshift of z=0.0574, which puts the peak unfiltered absolute magnitude at a somewhat over-lumino
A Model for Damage Spreading with Damage Healing: Monte Carlo Study of the two Dimensional Ising Ferromagnet
cond-mat.stat-mechM. Leticia Rubio Puzzo, Ezequiel V. Albano
An Ising model for damage spreading with a probability of damage healing ($q = 1 - p$) is proposed and studied by means of Monte Carlo simulations. In the limit $p \to 1$ the new model is mapped to the standard Ising model. It is found that, for temperatures above the Onsager critical temperature ($T_{C}$), there exist a no trivial finite value of $p$ that s
A. G. Petukhov, Igor Zutic, Steven C. Erwin
We propose a model of carrier-mediated ferromagnetism in semiconductors that accounts for the temperature dependence of the carriers. The model permits analysis of the thermodynamic stability of competing magnetic states, opening the door to the construction of magnetic phase diagrams. As an example we analyze the stability of a possible reentrant ferromagne
J. Levinsen, N. Cooper, V. Gurarie
We study theoretically a dilute gas of identical fermions interacting via a p-wave resonance. We show that, depending on the microscopic physics, there are two distinct regimes of p-wave resonant superfluids, which we term "weak" and "strong". Although expected naively to form a BCS-BEC superfluid, a strongly-resonant p-wave superfluid is in
Jacek Niemiec, Martin Pohl
We present preliminary results of Particle-In-Cell simulations of magnetic turbulence production by isotropic cosmic-ray ions streaming upstream of supernova remnant shocks. The studies aim at testing the MHD predictions by Bell (2004, 2005) of a strong amplification of short-wavelength nonresonant wave modes and at studying the subsequent evolution of the m
Towards a Comprehensive Fueling-Controlled Theory on the Growth of Massive Black Holes and Host Spheroids
astro-phAndres Escala
We study the relation between nuclear massive black holes and their host spheroid gravitational potential. Using AMR numerical simulations, we analyze how gas is transported in the nuclear (central kpc) regions of galaxies. We study the gas fueling onto the inner accretion disk (sub-pc scale) and the star formation in a massive nuclear disk like those genera
E. M. L. Humphreys
Despite theoretical predictions of the existence of many submillimeter masers, and some pioneering observational discoveries over the past few decades, these lines have remained relatively unstudied due to (i) challenges associated with observing at shorter wavelength; and, (ii) lack of possibility of high (< 14'' at 345 GHz) angular resolution obser
Two Modes of Magnetization Switching in a Simulated Iron Nanopillar in an Obliquely Oriented Field
cond-mat.stat-mechS. H. Thompson, G. Brown, P. A. Rikvold, M. A. Novotny
Finite-temperature micromagnetics simulations are employed to study the magnetization-switching dynamics driven by a field applied at an angle to the long axis of an iron nanopillar. A bi-modal distribution in the switching times is observed, and evidence for two competing modes of magnetization-switching dynamics is presented. For the conditions studied her
The inefficiency of the first-order Fermi process in UHECR production at relativistic shocks
astro-phJacek Niemiec, Michal Ostrowski, Martin Pohl
The question of the origin of ultra-high-energy cosmic rays at relativistic shock waves is discussed in the light of results of recent Monte Carlo studies of the first-order Fermi particle acceleration (Niemiec & Ostrowski 2006, Niemiec et al. 2006). The models of the turbulent magnetic field near the shock considered in these simulations include realistic f
Nikolai V. Priezjev
Molecular dynamics simulations are used to investigate the influence of molecular-scale surface roughness on the slip behavior in thin liquid films. The slip length increases almost linearly with the shear rate for atomically smooth rigid walls and incommensurate structures of the liquid/solid interface. The thermal fluctuations of the wall atoms lead to an
Martina Hentschel, Georg Roeder, Denis Ullmo
Many-body phenomena, a key interest in the investigation of bulk solid state systems, are studied here in the context of the x-ray edge problem for mesoscopic systems. We investigate the many-body effects associated with the sudden perturbation following the x-ray excitation of a core electron into the conduction band. For small systems with dimensions at th
Einstein against quantum mechanics: randomness, ignorance and our ignorance about randomness
physics.hist-phJuan Pablo Paz
Albert Einstein made fundamental contributions to the development of quantum mechanics. However, he was never satisfied with the quantum worldview. In fact, during most of his life he attempted to find inconsistencies and paradoxes within quantum mechanics. His famous quote "God does not play dice" shows how disturbing was to Einstein one of the most
Santo Fortunato
Community structure represents the local organization of complex networks and the single most important feature to extract functional relationships between nodes. In the last years, the problem of community detection has been reformulated in terms of the optimization of a function, the Newman-Girvan modularity, that is supposed to express the quality of the
O. Linnyk, E. L. Bratkovskaya, W. Cassing, H. Stoecker
The formation and suppression dynamics of J/Psi, Chi_c and Psi-Prime mesons is studied within the HSD transport approach for Au+Au reactions at the top RHIC energy of sqrt(S)=200 GeV. Two prominent models, which have been discussed for more than a decade, are incorporated, i.e. the 'hadronic comover absorption and reformation' model as well as the &#
Olimpia Lombardi
With his General Theory of Relativity, Albert Einstein produced a revolution in our conception of reality and of the knowledge we can obtain from it. This revolution can be viewed from philosophy as leading to one of the great paradigms in the history of thought which, together with the Aristotelian and the Newtonian paradigms, embodied the different ways of
Xiuxiong Chen, Brian Weber
We consider the moduli space of the extremal Kähler metrics on compact manifolds. We show that under the conditions of two-sided total volume bounds, $L^{n\over2}$-norm bounds on $\Riem$, and Sobolev constant bounds, this Moduli space can be compactified by including (reduced) orbifolds with finitely many singularities. Most of our results go through for cer
Anders Jensen, Niels Lauritzen, Bjarke Roune
Maximal lattice free bodies are maximal polytopes without interior integral points. Scarf initiated the study of maximal lattice free bodies relative to the facet normals in a fixed matrix. In this paper we give an efficient algorithm for computing the maximal lattice free bodies of an integral matrix A. An important ingredient is a test set for a certain in
The origin of power-law distributions in deterministic walks: the influence of landscape geometry
cond-mat.dis-nnM. C. Santos, D. Boyer, O. Miramontes, G. M. Viswanathan
We investigate the properties of a deterministic walk, whose locomotion rule is always to travel to the nearest site. Initially the sites are randomly distributed in a closed rectangular ($A/L \times L)$ landscape and, once reached, they become unavailable for future visits. As expected, the walker step lengths present characteristic scales in one ($L \to 0$
M. A. Gonzalez Leon, J. L. Hernandez Pastora
We investigate the exact relation existing between the stability equation for the solutions of a mechanical system and the geodesic deviation equation of the associated geodesic problem in the Jacobi metric constructed via the Maupertuis-Jacobi Principle. We conclude that the dynamical and geometrical approaches to the stability/instability problem are not e
S. Andrea, A. Restuccia, A. Sotomayor
A complete proof of the recursive gradient approach is presented. It gives a construction of all the hierarchy structures of N=1 Super KdV, including the non-local one. A precise definition of the ring of superfields involved in the non-local construction is given. In particular, new non-local conserved quantities of N=1 Super KdV are found.
A. O. Sboychakov, K. I. Kugel, A. L. Rakhmanov
The two-band Hubbard model is used to analyze a possibility of a non-uniform charge distribution in a strongly correlated electron system with two types of charge carriers. It is demonstrated that in the limit of strong on-site Coulomb repulsion, such a system has a tendency to phase separation into the regions with different charge densities even in the abs
Tomaso Belloni
Relativistic jets from Active Galactic Nuclei are known since decades, but the study of the connection between accretion and ejection in these systems is hampered by the long time scales associated to these events. The past decade has seen a rapid advancement due to the observation of similar radio jets in galactic X-ray binaries, where the time scales are m
S. K. Antiochos, C. R. DeVore, J. T. Karpen, Z. Mikic
The solar magnetic field is the primary agent that drives solar activity and couples the Sun to the Heliosphere. Although the details of this coupling depend on the quantitative properties of the field, many important aspects of the corona - solar wind connection can be understood by considering only the general topological properties of those regions on the
Electron electric dipole moment experiment using electric-field quantized slow cesium atoms
physics.atom-phJason M. Amini, Charles T. Munger, Harvey Gould
A proof-of-principle electron electric dipole moment (e-EDM) experiment using slow cesium atoms, nulled magnetic fields, and electric field quantization has been performed. With the ambient magnetic fields seen by the atoms reduced to less than 200 pT, an electric field of 6 MV/m lifts the degeneracy between states of unequal mF and, along with the low (appr
M. A. Sumour, A. H. El-Astal, M. M. Shabat, M. A. Radwan
Mortality, birth rates and retirement play a major role in demographic changes. In most cases, mortality rates decreased in the past century without noticeable decrease in fertility rates, this leads to a significant increase in population growth. In many poor countries like Palestinian territories the number of births has fallen and the life expectancy incr
E. Iskrenova-Tchoukova, M. S. Safronova, U. I. Safronova
We present results of the first-principles calculation of Cs dipole static polarizabilities for the Ns (N = 6 - 12), Np_j (N = 6 - 10), and Nd_j (N = 5 - 10) states using the relativistic all-order method. In our implementation of the all-order method, single and double excitations of Dirac-Fock wave functions are included to all orders in perturbation theor
Magnetic fluctuations in n-type high-$T_c$ superconductors reveal breakdown of fermiology
cond-mat.supr-conF. Krüger, S. D. Wilson, L. Shan, S. Li
By combining experimental measurements of the quasiparticle and dynamical magnetic properties of optimally electron-doped Pr$_{0.88}$LaCe$_{0.12}$CuO$_4$ with theoretical calculations we demonstrate that the conventional fermiology approach cannot possibly account for the magnetic fluctuations in these materials. In particular, we perform tunneling experimen
Evidence for nonlinear diffusive shock acceleration of cosmic-rays in the 2006 outburst of the recurrent nova RS Ophiuchi
astro-phV. Tatischeff, M. Hernanz
Spectroscopic observations of the 2006 outburst of the recurrent nova RS Ophiuchi at both infrared (IR) and X-ray wavelengths have shown that the blast wave has decelerated at a higher rate than predicted by the standard test-particle adiabatic shock-wave model. Here we show that the observed evolution of the nova remnant can be explained by the diffusive sh
Exploring CP Violation and Penguin Effects through $B^0_d \to D^+ D^-$ and $B^0_s \to D^+_s D^-_s$
hep-phRobert Fleischer
The decay $B^0_d \to D^+ D^-$ offers an interesting probe of CP violation, but requires control of penguin effects, which can be done through $B^0_s \to D^+_s D^-_s$ by means of the $U$-spin flavour symmetry of strong interactions. Recently, the Belle collaboration reported indications of large CP violation in the $B^0_d$ decay, which were, however, not conf
Non equilibrium velocity distributions of H- ions in H2 plasmas and photodetachment measurements
physics.plasm-phP. Diomede, S. Longo, M. Capitelli
A theoretical study of the energy distribution function of the negative hydrogen ion H- in typical conditions for multicusp ion sources is presented. The case of H/H2 mixture is studied by a Monte Carlo solution of the kinetic equation for H- transport. A simple analytical model is obtained for the case of a fully dissociated H plasma and uniform reduced ele
A. Drago, G. Pagliara, J. Schaffner-Bielich
We analyse the occurrence of quiescent times in the temporal structure of the Gamma-Ray-Bursts (GRBs) light curves. We show that if a long quiescent time is present, it is possible to divide the total duration of GRBs into three periods: the pre-quiescence emission, the quiescent time and the post-quiescence emission. We then discuss a model of the GRBs inne
Alexander V. Milovanov, Jens Juul Rasmussen, Kristoffer Rypdal
This paper is concerned with the connection between the properties of dielectric relaxation and ac (alternating-current) conduction in disordered dielectrics. The discussion is divided between the classical linear-response theory and a self-consistent dynamical modeling. The key issues are, stretched exponential character of dielectric relaxation, power-law
Caterina Guiot, Nicola Pugno, Pier Paolo Delsanto, Thomas S. Deisboeck
Invasiveness, one of the hallmarks of tumor progression, represents the tumor's ability to expand into the host tissue by means of several complex biochemical and biomechanical processes. Since certain aspects of the problem present a striking resemblance with well known physical mechanisms, such as the mechanical insertion of a solid inclusion in an ela
Carine André, Alain Ghio, Christian Cavé, Bernard Teston
Since perception tests are highly time-consuming, there is a need to automate as many operations as possible, such as stimulus generation, procedure control, perception testing, and data analysis. The computer-driven system we are presenting here meets these objectives. To achieve large flexibility, the tests are controlled by scripts. The system's core
E. Plekhanov, A. Avella, F. Mancini
We present a study of entanglement in the case of the 1D extended anisotropic Heisenberg model. We investigate two quantum phase transitions (QPTs) within the previously found ergodicity phase diagram [E. Plekhanov, A. Avella, and F. Mancini Phys. Rev. B \textbf{74}, 115120 (2006)]. Our calculations are done by means of the numerically exact Lanczos method a
Aid to Percutaneous Renal Access by Virtual Projection of the Ultrasound Puncture Tract onto Fluoroscopic Images
physics.med-phPierre Mozer, Pierre Conort, Antoine Leroy, Michael Baumann
Background and Purpose: Percutaneous renal access in the context of percutaneous nephrolithotomy (PCNL) is a difficult technique, requiring rapid and precise access to a particular calix. We present a computerized system designed to improve percutaneous renal access by projecting the ultrasound puncture tract onto fluoroscopic images. Materials and Methods:
Direct diameter measurement of a star filling its Roche Lobe: The semi-detached binary SS Leporis spatially resolved with VINCI/VLTI
astro-phT. Verhoelst, E. van Aarle, B. Acke
Stellar evolution in close binary systems is strongly influenced by mass transfer from one star to the other when one component fills its zero-velocity surface or Roche Lobe. SS Lep is a fairly nearby close binary showing the Algol paradox and a shell spectrum, both indicative of (past) mass transfer. To study the process of mass transfer and its evolutionar
Anders Kock
In the context of Synthetic Differential Geometry, we describe a notion of higher connection with values in a cubical groupoid. We do this by exploiting a certain structure of cubical complex derived from the first neighbourhood of the diagonal of a manifold. This cubical complex consists of infinitesimal parallelelpipeda.
Anthony H. Minter, Fernando Camilo, Scott M. Ransom, Jules P. Halpern
We have used the Green Bank Telescope to measure HI absorption against the anomalous X-ray pulsar XTE J1810-197. Assuming a flat rotation curve, we find that XTE J1810-197 is located at a distance of 3.4(+0.5,-0.7) kpc. For a rotation curve that incorporates a model of the Galactic bar, we obtain a distance of 4.0(+0.3,-0.8) kpc. Using a rotation curve that
What the Infrared Behaviour of QCD Vertex Functions in Landau gauge can tell us about Confinement
hep-phR. Alkofer, C. S. Fischer, F. Llanes-Estrada, K. Schwenzer
The infrared behaviour of Landau gauge QCD vertex functions is investigated employing a skeleton expansion of the Dyson-Schwinger and Renormalization Group equations. Results for the ghost-gluon, three-gluon, four-gluon and quark-gluon vertex functions are presented. Positivity violation of the gluon propagator, and thus gluon confinement, is demonstrated. R
Li-Xin Li
By dividing a sample of 48 long-duration gamma-ray bursts (GRBs) into four groups with redshift from low to high and fitting each group with the Amati relation log Eiso = a + b log Epeak, I find that parameters a and b vary with the mean redshift of the GRBs in each group systematically and significantly. The results suggest that GRBs evolve strongly with th
D. Terwagne, S. Dorbolo, N. Vandewalle
When a droplet is gently laid onto the surface of the same liquid, it stays at rest for a moment before coalescence. The coalescence can be delayed and sometimes inhibited by injecting fresh air under the droplet. This can happen when the surface of the bath oscillates vertically, in this case the droplet basically bounces on the interface. The lifetime of t
Spitzer-IRAC GLIMPSE of high mass protostellar objects. I Infrared point sources and nebulae
astro-phM. S. N. Kumar, J. M. C. Grave
The GLIMPSE archive was used to obtain 3.6--8.0micron, point source photometry and images for 381 massive protostellar candidates lying in the Galactic mid-plane. The colours, magnitudes and spectral indicies of sources in each of the 381 target fields were analysed and compared with the predictions of 2D radiative transfer model simulations. Although no dis
Martin Bojowald
While observational cosmology has recently progressed fast, it revealed a serious dilemma called dark energy: an unknown source of exotic energy with negative pressure driving a current accelerating phase of the universe. All attempts so far to find a convincing theoretical explanation have failed, so that one of the last hopes is the yet to be developed qua
V. Barger, M. Bishai, D. Bogert, C. Bromberg
This report provides the results of an extensive and important study of the potential for a U.S. scientific program that will extend our knowledge of neutrino oscillations well beyond what can be anticipated from ongoing and planned experiments worldwide. The program examined here has the potential to provide the U.S. particle physics community with world le
Ab initio correlation effects on the electronic and transport properties of metal(II)-phthalocyanine based devices
cond-mat.softArrigo Calzolari, Andrea Ferretti, Marco Buongiorno Nardelli
Using first principles calculations in the framework of Density Functional Theory, we investigated the electronic and transport properties of metal(II)-phthalocyanine (M(II)Pc) systems, both in a single molecule configuration and in a model-device geometry. In particular, using the Copper(II)- and Manganese(II)-Pc as prototypical examples, we studied how ele
Gwendal Fève, Adrien Mahé, Jean-Marc Berroir, Takis Kontos
We report on the electron analog of the single photon gun. On demand single electron injection in a quantum conductor was obtained using a quantum dot connected to the conductor via a tunnel barrier. Electron emission is triggered by application of a potential step which compensates the dot charging energy. Depending on the barrier transparency the quantum e
R. V. Yusupov, V. V. Kabanov, D. Mihailovic, K. Conder
Magnetic properties of high purity stoichiometric La$_2$CuO$_4$ nanoparticles are systematically investigated as a function of particle size. Ferromagnetic single-domain spin clusters are shown to spontaneously form at the surface of fine grains as well as paramagnetic defects. Hysteresis loops and thermomagnetic irreversibility are observed in a wide temper
Riad Nechache, Louis-Philippe Carignan, Lina Gunawan, Catalin Harnagea
Epitaxial thin films of Bi2FeCrO6 have been synthesized by pulsed laser deposition on SrRuO3 on (100)- and (111)-oriented SrTiO3 substrates. Detailed X-ray diffraction and cross-section transmission electron microscopy analysis revealed a double perovskite crystal structure of the Bi2FeCrO6 epitaxial films very similar to that of BiFeO3 along with a particul
Rafael Ferraro
Physics was in crisis at the beginning of the twentieth century because the newborn Maxwell's electromagnetism defied mechanistic preconceptions. Albert Einstein understood that the solution to the crisis required an audacious reworking of the concepts of space and time. Special Relativity deeply modified our way of regarding space and time, in order to
Ralf Schützhold, Gernot Schaller, Dietrich Habs
Electrons moving in a strong periodic electromagnetic field (e.g., laser or undulator) may convert quantum vacuum fluctuations into pairs of entangled photons, which can be understood as a signature of the Unruh effect. Apart from verifying this striking phenomenon, the considered effect may allow the construction of a table-top source for entangled photons
U. A. Mofiz, B. J. Ahmedov
We consider electrostatic plasma modes along the open field lines of a rotating neutron star. Goldreich-Julian charge density in general relativity is analyzed for the neutron star with zero inclination. It is found that the charge density is maximum at the polar cap and it remains almost same in certain extended region of the pole. For a steady state Goldre
José X. Martini
Art history linked some early 20th Century avant-garde visual art movements to contemporary systems of ideas in mathematics and theoretical physics. One of the proposed connections is the one that might have existed between Cubism and Relativity, or more precisely, between Picasso and Einstein. The suggested links are similarity (in a weak version) or identi
F. Mazzanti, G. E. Astrakharchik, J. Boronat, J. Casulleras
A quantum Monte Carlo simulation of a system of hard rods in one dimension is presented and discussed. The calculation is exact since the analytical form of the wavefunction is known, and is in excellent agreement with predictions obtained from asymptotic expansions valid at large distances. The analysis of the static structure factor and the pair distributi
R. Roychoudhury, P. Roy
We obtain closed form expression of the C(x,y) operator for the PT symmetric Scarf I potential. It is also shown that the eigenfunctions are complete.
D. Doenitz, R. Kleiner, D. Koelle, T. Scherer
We present low-temperature scanning electron microscopy (LTSEM) investigations of superconducting microbridges made from ultrathin NbN films as used for hot electron bolometers. LTSEM probes the thermal structure within the microbridges under various dc current bias conditions, either via electron-beam-induced generation of an unstable hotspot, or via the be
R. A. Brownlee, P. Houston, J. Levesley, S. Rosswog
In this paper we consider two sources of enhancement for the meshfree Lagrangian particle method smoothed particle hydrodynamics (SPH) by improving the accuracy of the particle approximation. Namely, we will consider shape functions constructed using: moving least-squares approximation (MLS); radial basis functions (RBF). Using MLS approximation is appealing
Relationship between the linear entropy, the von Neumann entropy and the atomic Wehrl entropy for the Jaynes-Cummings model
quant-phFaisal A. A. El-Orany
The linear entropy, the von Neumann entropy and the atomic Wehrl entropy are frequently used to quantify entanglement in the quantum systems. These relations provide typical information on the entanglement in the Jaynes-Cummings model (JCM). In this Letter, we explain the origin of this analytically and derive a closed form for the atomic Wehrl entropy. More
Stable simulation of fluid flow with high-Reynolds number using Ehrenfests' steps
cond-mat.stat-mechR. A. Brownlee, A. N. Gorban, J. Levesley
The Navier--Stokes equations arise naturally as a result of Ehrenfests' coarse-graining in phase space after a period of free-flight dynamics. This point of view allows for a very flexible approach to the simulation of fluid flow for high-Reynolds number. We construct regularisers for lattice Boltzmann computational models. These regularisers are based o
Asymptotic conformal Yano-Killing tensors for asymptotic anti-de Sitter spacetimes and conserved quantities
gr-qcJacek Jezierski
Conformal rescaling of conformal Yano--Killing tensors and relations between Yano and CYK tensors are discussed. Pullback of these objects to a submanifold is used to construct all solutions of a CYK equation in anti-de Sitter and de Sitter spacetimes. Properties of asymptotic conformal Yano--Killing tensors are examined for asymptotic anti-de Sitter spaceti
Peter Kornerup, Vincent Lefèvre, Jean-Michel Muller
We introduce two algorithms for accurately evaluating powers to a positive integer in floating-point arithmetic, assuming a fused multiply-add (fma) instruction is available. We show that our log-time algorithm always produce faithfully-rounded results, discuss the possibility of getting correctly rounded results, and show that results correctly rounded in d
Extending the range of error estimates for radial approximation in Euclidean space and on spheres
math.NAR. A. Brownlee, E. H. Georgoulis, J. Levesley
We adapt Schaback's error doubling trick [R. Schaback. Improved error bounds for scattered data interpolation by radial basis functions. Math. Comp., 68(225):201--216, 1999.] to give error estimates for radial interpolation of functions with smoothness lying (in some sense) between that of the usual native space and the subspace with double the smoothnes
Thorsten Kuhl
Results for the production of charm and beauty quarks in proton anti-proton collisions at ECM=1.96 TeV (Tevatron) with the two multi purpose experiments CDF and D0 using an integrated luminosity of up to 1 fb^-1 are presented. With the data measurement of the production me chanism for charm and beauty quarks are done. These measurements are leading to a bett
Hai Fu, Alan Stockton
We present Gemini integral field spectroscopy and Keck II longslit spectroscopy of the extended emission-line region (EELR) around the quasar 4C 37.43. The velocity structure of the ionized gas is complex and cannot be explained globally by a simple dynamical model. The spectra from the clouds are inconsistent with shock or ``shock + precursor'' ioni
On the k-Symplectic, k-Cosymplectic and Multisymplectic Formalisms of Classical Field Theories
math-phNarciso Roman-Roy, Angel M. Rey, Modesto Salgado, Silvia Vilarino
The objective of this work is twofold: First, we analyze the relation between the k-cosymplectic and the k-symplectic Hamiltonian and Lagrangian formalisms in classical field theories. In particular, we prove the equivalence between k-symplectic field theories and the so-called autonomous k-cosymplectic field theories, extending in this way the description o
Lev Sakhnovich
We consider the Knizhnik-Zamolodchikov system of linear differential equations. The coefficients of this system are rational functions generated by elements of the symmetric group $S_{n}$. We assume that parameter $ρ=\pm{1}$. In previous paper we proved that the fundamental solution of the corresponding KZ-equation is rational. Now we construct this solution
E. Plekhanov, A. Avella, F. Mancini
By using Density Matrix Renormalization Group (DMRG) technique we study the 1D extended anisotropic Heisenberg model. We find that starting from the ferromagnetic phase, the system undergoes two quantum phase transitions (QPTs) induced by frustration. By increasing the next-nearest-neighbor (NNN) interaction, the ground state of the system changes smoothly f
Walter Petry
The redshift of galaxies is in general explained by the expansion of space. The flat space time theory of gravitation suggests an additional interpretation. In this theory gravitation is explained analogously to Maxwell's theory on a flat space-time metric and gravitation is described by a field (potentials) with which the proper time (atomic time) is de
I. Montvay
In these lecture notes some applications of Monte Carlo integration methods in Quantum Field Theory - in particular in Quantum Chromodynamics - are introduced and discussed.
Leonid Golinskii, Mikhail Kudryavtsev
For finite dimensional CMV matrices the classical inverse spectral problems are considered. We solve the inverse problem of reconstructing a CMV matrix by its Weyl's function, the problem of reconstructing the matrix by two spectra of CMV matrices with different "boundary conditions", and the problem of reconstructing the CMV matrix by its spectr
Wei Chao
In the supersymmetric left-right model, the light neutrino masses are given by the Type-II seesaw mechanism. A duality property about this mechanism indicates that there exist eight possible Higgs triplet Yukawa couplings which result in the same neutrino mass matrix. In this paper, We work out the one-loop renormalization group equations for the effective n
Numerical Study on Stellar Core Collapse and Neutrino Emission: Probe into the Spherically Symmetric Black Hole Progenitors with 3 - 30Msun Iron Cores
astro-phKen'ichiro Nakazato, Kohsuke Sumiyoshi, Shoichi Yamada
The existence of various anomalous stars, such as the first stars in the universe or stars produced by stellar mergers, has been recently proposed. Some of these stars will result in black hole formation. In this study, we investigate iron core collapse and black hole formation systematically for the iron-core mass range of 3 - 30Msun, which has not been stu
Pedro F. Gonzalez-Diaz, Prado Martin-Moruno, Artyom V. Yurov
In this paper we work out a multiverse scenario whose physical characteristics enable us to advance the following the conjecture that whereas the physics of particles and fields is confined to live in the realm of the whole multiverse formed by finite-time single universes, that for our observable universe must be confined just in one of the infinite number
Sensitivity of the neutron crystal diffraction experiment to the neutron EDM and to the nuclear P-,T-violating forces
hep-phV. G. Baryshevsky, S. L. Cherkas
We establish a link between an angle of the neutron polarization rotation in a crystal diffraction experiment and constants of the P-,T- violating interactions. The consideration applies to the energy range of thermal and resonance neutrons.
T. Tanigawa, M. Ikoma
We construct an analytic model for the rate of gas accretion onto a planet embedded in a protoplanetary disk as a function of planetary mass, disk viscosity, disk scale height, and unperturbed surface density in order to study the long-term accretion and final masses of gas giant planets. We first derive an analytical formula for surface density profile near
Vector and Spinor Decomposition of SU(2) Gauge Potential, their quivalence and Knot Structure in SU(2) Chern-Simons Theory
hep-thYi-Shi Duan, Ji-Rong Ren, Ran Li
In this paper, spinor and vector decomposition of SU(2) gauge potential are presented and their equivalence is constructed using a simply proposal. We also obtain the action of Faddeev nonlinear O(3) sigma model from the SU(2) massive gauge field theory which is proposed according to the gauge invariant principle. At last, the knot structure in SU(2) Chern-S
Ji-Rong Ren, Ran Li, Yi-Shi Duan
In light of $ϕ$-mapping topological current theory, the inner topological structure of Hopf invariant is investigated. It is revealed that Hopf invariant is just the winding number of Gauss mapping. According to the inner structure of topological current, a precise expression for Hopf invariant is also presented. It is the total sum of all the self-linking a
I. Stetcu, B. R. Barrett, U. van Kolck, J. P. Vary
We apply the general principles of effective field theories to the construction of effective interactions suitable for few- and many-body calculations in a no-core shell model framework. We calculate the spectrum of systems with three and four two-component fermions in a harmonic trap. In the unitary limit, we find that three-particle results are within 10%
Jonathan A. Cohen
Coherence theorems for covariant structures carried by a category have traditionally relied on the underlying term rewriting system of the structure being terminating and confluent. While this holds in a variety of cases, it is not a feature that is inherent to the coherence problem itself. This is demonstrated by the theory of iterated monoidal categories,
Ebrahim Samei
Let $A$ be a C$^*$-algebra, and let $X$ be a Banach $A$-bimodule. B. E. Johnson showed that local derivations from $A$ into $X$ are derivations. We extend this concept of locality to the higher cohomology of a $C^*$-algebra %for $n$-cocycles from $A^{(n)}$ into $X$ and show that, for every $n\in \N$, bounded local $n$-cocycles from $A^{(n)}$ into $X$ are $n$
Feasibility for p+/p- flow-ratio evaluation in the 0.5 - 1.5 TeV primary energy range, based on Moon-shadow muon measurements, to be carried out in the Pyramid of the Sun, Teotihuacan, Experiment
physics.ins-detV Grabski, A Morales, R Reche, O Orozco
Calculations are presented to demonstrate the feasibility of Moon shadow observations for mean primary energies in the region 0.5-1.5 TeV using a muon detector operating under the Pyramid of the Sun at Teotihuacan, Mexico. Due to the small height of that monument (65 m), the experiment is capable of providing considerably high statistics, although with reduc
Kunming Xu
Euclidean space and linear algebra do not characterize dynamic electronic orbitals satisfactorily for even the motion of both electrons in an inert helium atom cannot be defined in reasonable details. Here the author puts forward a novel two-dimensional spacetime model from scratch in the context of defining both electrons in a helium atom. Space and time ar
M. Bartolozzi
Avalanches, or Avalanche-like, events are often observed in the dynamical behaviour of many complex systems which span from solar flaring to the Earth's crust dynamics and from traffic flows to financial markets. Self-organized criticality (SOC) is one of the most popular theories able to explain this intermittent charge/discharge behaviour. Despite a la
Huagui Duan, Yiming Long
In this paper we prove that for every bumpy Finsler metric $F$ on every rationally homological $n$-dimensional sphere $S^n$ with $n\ge 2$, there exist always at least two distinct prime closed geodesics.
David Gabai, Robert Meyerhoff, Peter Milley
This paper is the second in a series whose goal is to understand the structure of low-volume complete orientable hyperbolic 3-manifolds. Using Mom technology, we prove that any one-cusped hyperbolic 3-manifold with volume <= 2.848 can be obtained by a Dehn filling on one of 21 cusped hyperbolic 3-manifolds. We also show how this result can be used to constru
Rings of Algebraic Numbers in Infinite Extensions of $\Q$ and Elliptic Curves Retaining Their Rank
math.NTAlexandra Shlapentokh
We show that elliptic curves whose Mordell-Weil groups are finitely generated over some infinite extensions of $\Q$, can be used to show the Diophantine undecidability of the rings of integers and bigger rings contained in some infinite extensions of rational numbers.
Z. X. Liang, Xi Dong, Z. D. Zhang, Biao Wu
The speed of sound of a Bose-Einstein condensate in an optical lattice is studied both analytically and numerically in all three dimensions. Our investigation shows that the sound speed depends strongly on the strength of the lattice. In the one-dimensional case, the speed of sound falls monotonically with increasing lattice strength. The dependence on latti