January 2007 arXiv papers — page 5
Showing 401–500 of 4,539 papers
S. Colafrancesco, F. Giordano
We study the impact of an intracluster magnetic field on the main structural properties of clusters and groups of galaxies: the radial density and entropy profiles, the S-T relation and the L_X-T relation for groups and clusters of galaxies. To this aim, we develop a description of the intra-cluster gas based on the Hydrostatic Equilibrium condition and on t
S. Colafrancesco, F. Giordano
We discuss the impact of magnetic field on the mass - temperature relation for groups and clusters of galaxies based on the derivation of the general Magnetic Virial Theorem. The presence of a magnetic field B yields a decrease of the virial temperature T for a fixed mass M: such a decrease in T is stronger for low-mass systems than for high-mass systems. We
Hsiang-Kuang Chang, Jau-Shian Liang, Chih-Yuan Liu, Sun-Kun King
Millisecond dips in the RXTE/PCA light curve of Sco X-1 were reported recently (Chang et al. 2006), which were interpreted as the occultation of X-rays from Sco X-1 caused by Trans-Neptunian Objects (TNO) of hundred-meter size. Inconclusive signatures of possible instrumental effects in many of these dip events related to high-energy cosmic rays were later f
High velocity spectroscopic binary orbits from photoelectric radial velocities: BD +30 2129 A
astro-phA. Bartkevicius, J. Sperauskas
The spectroscopic orbit of a high proper motion visual binary system BD +30 2129 component A is determined from 22 CORAVEL-type radial velocity measurements. A period of P = 32.79 days and a moderate eccentricity e = 0.29 are obtained. The visual system AB has a projected spatial separation ~580 AU. The system's barycenter velocity V0 = -35.95 km/s and t
L. L. Kitchatinov, G. Ruediger
The questions of how strong magnetic fields can be stored in rotating stellar radiative zones without being subjected to pinch-type instabilities and how much radial mixing is produced if the fields are unstable are addressed. Linear equations are derived for weak disturbances of magnetic and velocity fields which are global in horizontal dimensions but shor
Y. F. Huang, Y. Lu, A. Y. L. Wong, K. S. Cheng
Due to the relativistic motion of gamma-ray burst remnant and its deceleration in the circumburst medium, the equal arrival time surfaces at any moment are not spherical, but should be distorted ellipsoids. This will leave some imprints in the afterglows. In this article, we study the effect of equal arrival time surfaces numerically under various conditions
Makoto Nagai, Kunihiko Tanaka, Kazuhisa Kamegai, Tomoharu Oka
We estimated physical conditions of molecular gas in the central molecular zone (CMZ) of the Galaxy, using our CO J=3-2 data obtained with the Atacama Submillimeter Telescope Experiment (ASTE) in conjunction with J=1-0 12CO and 13CO data previously observed with the NRO 45m telescope. The large velocity gradient (LVG) approximation was employed. Distribution
High Resolution Mappings of the L=1.3 deg Complex in Molecular Lines : Discovery of a Proto-Superbubble
astro-phKunihiko Tanaka, Kazuhisa Kamegai, Makoto Nagai, Tomoharu Oka
We report the results of molecular line observations toward the l=1.3 deg complex, ananomalous cloud complex in the central molecular zone of the Galaxy. We have taken high resolution maps of the CO J=1-0, HCN J=1-0, HCO+ J=1-0, SiO J=1-0 and J=2-1 lines. The complex is found to be rich in shells and arcs of dense molecular gas. We have identified 9 expandin
Tomoharu Oka, Makoto Nagai, Kazuhisa Kamegai, Kunihiko Tanaka
We have surveyed the central molecular zone (CMZ) of our Galaxy in the CO J=3-2 line with the Atacama Submillimeter-wave Telescope Experiment (ASTE). Molecular gas in the Galactic center shows high J=3-2/J=1-0 intensity ratio (~ 0.9) while gas in the spiral arms in the Galactic disk shows the lower ratio (~ 0.5). The high-velocity compact cloud CO 0.02-0.02
Igor Chilingarian, Philippe Prugniel, Olga Sil'chenko, Victor Afanasiev
We present the first 3D observations of a diffuse elliptical galaxy (dE). The good quality data (S/N up to 40) reveal the kinematical signature of an embedded stellar disc, reminiscent of what is commonly observed in elliptical galaxies, though similarity of their origins is questionable. Colour map built from HST ACS images confirms the presence of this dis
E. M. Henley
Review of neutrino properties; double beta decay; very high energy neutrinos; leptogenesis
Simon Wicks, Miklos Gyulassy
With the QGP opacity computed perturbatively and with the global entropy constraints imposed by the observed dNch/dy~1000, radiative energy loss alone cannot account for the observed suppression of single non-photonic electrons. Collisional energy loss is comparable in magnitude to radiative loss for both light and heavy jets. Two aspects that significantly
Damien Martin
One of the postulates of quantum mechanics is that the Hamiltonian is Hermitian, as this guarantees that the eigenvalues are real. Recently there has been an interest in asking if $H^\dagger = H$ is a necessary condition, and has lead to the development of PT-symmetric quantum mechanics. This note shows that any finite physically acceptable non-Hermitian Ham
Joern Putschke
Systematic measurements of pseudorapidity ($Δη$) and azimuthal ($Δϕ$) correlations between high-$p_t$ charged hadrons in $\sqrt{s_{NN}}$=200 GeV Au+Au collisions are presented. An enhancement of correlated yield at large $Δη$ on the near-side is observed. This effect persists up to trigger $p_{t}^{trig}$ $\sim$ 9 GeV/c, indicating that it is associated with
Felix Finster
We analyze the level sets of the norm of the Witten spinor in an asymptotically flat Riemannian spin manifold of positive scalar curvature. Level sets of small area are constructed. We prove curvature estimates which quantify that, if the total mass becomes small, the manifold becomes flat with the exception of a set of small surface area. These estimates in
Johanna Knapp, Harun Omer
We consider matrix factorizations and homological mirror symmetry on the torus T^2 using a Landau-Ginzburg description. We identify the basic matrix factorizations of the Landau-Ginzburg superpotential and compute the full spectrum, taking into account the explicit dependence on bulk and boundary moduli. We verify homological mirror symmetry by comparing thr
Gerardo Adesso, Fabrizio Illuminati
We review the theory of continuous-variable entanglement with special emphasis on foundational aspects, conceptual structures, and mathematical methods. Much attention is devoted to the discussion of separability criteria and entanglement properties of Gaussian states, for their great practical relevance in applications to quantum optics and quantum informat
Nanoscale Dynamical Mean-Field Theory for Molecules and Mesoscopic Devices in the Strong-Correlation Regime
cond-mat.str-elSerge Florens
We develop a nanoscale dynamical mean-field theory (nano-DMFT) to deal with strong Coulomb interaction effects in physical systems that are intermediate in size between atoms and bulk materials, taking into account the tunneling into nearby electrodes. Focusing on a simplified treelike geometry, the usual DMFT loop simply stops when the finite lattice is ful
Manuela Campanelli, Carlos O. Lousto, Yosef Zlochower, David Merritt
We report the first results from evolutions of a generic black-hole binary, i.e. a binary containing unequal mass black holes with misaligned spins. Our configuration, which has a mass ratio of 2:1, consists of an initially non-spinning hole orbiting a larger, rapidly spinning hole (specific spin a/m = 0.885), with the spin direction oriented -45 degrees wit
Michele Arzano, Antonino Marciano
There has been a certain interest in some recent works in the derivation of Noether charges for Hopf-algebra space-time symmetries. Such analyses relied rather heavily on delicate manipulations of the fields of non-commuting coordinates whose charges were under study. Here we derive the same charges in a "coordinate-independent" symplectic-geometry t
Michael Koppitz, Denis Pollney, Christian Reisswig, Luciano Rezzolla
The final evolution of a binary black-hole system gives rise to a recoil velocity if an asymmetry is present in the emitted gravitational radiation. Measurements of this effect for non-spinning binaries with unequal masses have pointed out that kick velocities $\sim~175$ km/s can be reached for a mass ratio $\simeq 0.36$. However, a larger recoil can be obta
Witold Skiba, David Tucker-Smith
We illustrate the utility of jet mass distributions as probes of new physics at the LHC, focusing on a heavy vector-quark doublet that mixes with the top as a concrete example. For 1 TeV vector-quark masses, we find that signals with greater than 5 sigma significance can be achieved after 100 fb^-1. More generally, jet mass distributions have the potential t
Coherent phonon scattering effects on thermal transport in thin semiconductor nanowires
cond-mat.dis-nnP. G. Murphy, J. E. Moore
The thermal conductance by phonons of a quasi-one-dimensional solid with isotope or defect scattering is studied using the Landauer formalism for thermal transport. The conductance shows a crossover from localized to Ohmic behavior, just as for electrons, but the nature of this crossover is modified by delocalization of phonons at low frequency. A scalable n
Francois David, Christian Hagendorf, Kay Joerg Wiese
The Laessig-Wiese (LW) field theory for the freezing transition of random RNA secondary structures is generalized to the situation of an external force. We find a second-order phase transition at a critical applied force f = f_c. For f < f_c forces are irrelevant. For f > f_c, the extension L as a function of pulling force f scales as (f-f_c)^(1/gamma-1). Th
Ronald Fintushel, B. Doug Park, Ronald J. Stern
We introduce a general procedure called `reverse engineering' that can be used to construct infinite families of smooth 4-manifolds in a given homeomorphism type. As one of the applications of this technique, we produce an infinite family of pairwise nondiffeomorphic 4-manifolds homeomorphic to CP^2#3(-CP^2).
André P. Vieira, José S. Andrade, Hans J. Herrmann, Roberto F. S. Andrade
We investigate a set of directed sandpile models on the Apollonian network, which are inspired on the work by Dhar and Ramaswamy (PRL \textbf{63}, 1659 (1989)) for Euclidian lattices. They are characterized by a single parameter $q$, that restricts the number of neighbors receiving grains from a toppling node. Due to the geometry of the network, two and thre
Pierre Mathieu, David Ridout
The minimal models M(p',p) with p' > 2 have a unique (non-trivial) simple current of conformal dimension h = (p' - 2) (p - 2) / 4. The representation theory of the extended algebra defined by this simple current is investigated in detail. All highest weight representations are proved to be irreducible: There are thus no singular vectors in the ex
Teodor Banica, Julien Bichon, Benoit Collins
We consider the hypercube in $\mathbb R^n$, and show that its quantum symmetry group is a $q$-deformation of $O_n$ at $q=-1$. Then we consider the graph formed by $n$ segments, and show that its quantum symmetry group is free in some natural sense. This latter quantum group, denoted $H_n^+$, enlarges Wang's series $S_n^+,O_n^+,U_n^+$.
L. Lamata, J. Leon, T. Schaetz, E. Solano
We present a method of simulating the Dirac equation in 3+1 dimensions for a free spin-1/2 particle in a single trapped ion. The Dirac bispinor is represented by four ionic internal states, and position and momentum of the Dirac particle are associated with the respective ionic variables. We show also how to simulate the simplified 1+1 case, requiring the ma
Alex Monras, Matteo G. A. Paris
We address the estimation of the loss parameter of a bosonic channel probed by Gaussian signals. We derive the ultimate quantum bound on precision and show that no improvement may be obtained by having access to the environment degrees of freedom. We found that, for small losses, the variance of the optimal estimator is proportional to the loss parameter its
Thomas Alazard, Rémi Carles
We consider the nonlinear Schrodinger equation with defocusing, smooth, nonlinearity. Below the critical Sobolev regularity, it is known that the Cauchy problem is ill-posed. We show that this is even worse: there is a loss of regularity, in the same spirit as the result due to G.Lebeau in the case of the wave equation. We use an isotropic change of variable
Andrew Ranicki, Michael Weiss
The algebraic $L$-groups $L_*(\A,X)$ are defined for an additive category $\A$ with chain duality and a $Δ$-set $X$, and identified with the generalized homology groups $H_*(X;\LL_{\bullet}(\A))$ of $X$ with coefficients in the algebraic $L$-spectrum $\LL_{\bullet}(\A)$. Previously such groups had only been defined for simplicial complexes $X$.
A. G. Bedregal, A. Aragón-Salamanca, M. R. Merrifield, N. Cardiel
Based on FORS2-VLT long-slit spectroscopy, the analysis of the central absorption line indices of 9 S0 galaxies in the Fornax Cluster is presented. Central indices correlate with central velocity dispersions as observed in ellipticals. However, the stellar population properties of these S0s indicates that the observed trends are produced by relative differen
Tonguç Rador
We discuss the possibility of obtaining the present acceleration of the universe via f(R) gravity theories which recently attracted much attention. It is known that f(R) theories generally have room for this. In this work we stress that the requirement for the stabilization of extra dimensions is naturally incorporated in such a generalization of Einstein gr
Andrea Ossicini
The purpose of the work is to furnish a complete study of a discrete and special function, discovered by the author and named with the Arabian letter "SHIN" {The letter SHIN is the thirteenth letter of the Arabian alphabet}. It includes three other papers, published in the International journal "Kragujevac Journal of Mathematics". The methods
Cosma Rohilla Shalizi
This expository note describes how to apply the method of maximum likelihood to estimate the parameters of the ``$q$-exponential'' distributions introduced by Tsallis and collaborators. It also describes the relationship of these distributions to the classical Pareto distributions.
Th. Richter, W. Vogel
Characteristic functions are shown to be useful for highly sensitive measurements. Redistributions of motional Fock states of a trapped atom can be directly monitored via the most fragile nonclassical part of the characteristic function. The method can also be used for decoherence measurements in optical quantum-information systems.
Sagar Chaki, Christian Schallhart, Helmut Veith
In many industries, the importance of software components provided by third-party suppliers is steadily increasing. As the suppliers seek to secure their intellectual property (IP) rights, the customer usually has no direct access to the suppliers' source code, and is able to enforce the use of verification tools only by legal requirements. In turn, the
Supratik Pal, Sayan Kar
We propose new braneworld models arising from a scalar field in the bulk. In these examples, the induced on--brane line element is de Sitter (or anti de Sitter) and the bulk (five dimensional) Einstein equations can be exactly solved to obtain warped spacetimes. The solutions thus derived are single and two-brane models -- one with {\em thin} branes while th
Wojciech Broniowski, Enrique Ruiz Arriola
The vector and axial pion-photon transition distribution amplitudes are analyzed in the Spectral Quark Model. We proceed by the evaluation of double distributions through the use of a manifestly covariant calculation based on the alpha representation of propagators. As a result polynomiality is incorporated and calculations become rather simple. Explicit for
J. Grain, A. Barrau
Quantum mechanics around black holes has shown to be one of the most fascinating fields of theoretical physics. It involves both general relativity and particle physics, opening new eras to establish the principles of unified theories. In this article, we show that quantum bound states with no classical equivalent -- as it can easily be seen at the dominant
Robert H. Gowdy, B. Douglas Edmonds
New boundary conditions are imposed on the familiar cylindrical gravitational wave vacuum spacetimes. The new spacetime family represents cylindrical waves in a flat expanding (Kasner) universe. Space sections are flat and nonconical where the waves have not reached and wave amplitudes fall off more rapidly than they do in Einstein-Rosen solutions, permittin
Damien Easson, Ruth Gregory, Gianmassimo Tasinato, Ivonne Zavala
We analyse the dynamics of a probe D3-(anti-)brane propagating in a warped string compactification, making use of the Dirac-Born-Infeld action approximation. We also examine the time dependent expansion of such moving branes from the ``mirage cosmology'' perspective, where cosmology is induced by the brane motion in the background spacetime. A range
Wung-Hong Huang
The density matrix of a two-anyon system is evaluated and used to investigate the "statistical interparticle potential" following the theory of Uhlenbeck. The main purpose is to see how the statistical potential will depend on the fractional statistical parameter $α$. The result shows that the statistical potential for a two-anyon system with $α\ge {
Marc Daumas, Guillaume Melquiond
Gappa uses interval arithmetic to certify bounds on mathematical expressions that involve rounded as well as exact operators. Gappa generates a theorem with its proof for each bound treated. The proof can be checked with a higher order logic automatic proof checker, either Coq or HOL Light, and we have developed a large companion library of verified facts fo
Hanno Essen
Darwin (1920) noted that when radiation can be neglected it should be possible to eliminate the radiation degrees-of-freedom from the action of classical electrodynamics and keep the discrete particle degrees-of-freedom only. Darwin derived his well known Lagrangian by series expansion in $v/c$ keeping terms up to order $(v/c)^2$. Since radiation is due to a
K. Kechedzhi, Vladimir I. Fal'ko, E. McCann, B. L. Altshuler
Bilayer graphene (two coupled graphitic monolayers arranged according to Bernal stacking) is a two-dimensional gapless semiconductor with a peculiar electronic spectrum different from the Dirac spectrum in the monolayer material. In particular, the electronic Fermi line in each of its valleys has a strong p -> -p asymmetry due to a trigonal warping, which su
Michel Planat, Metod Saniga
A comprehensive graph theoretical and finite geometrical study of the commutation relations between the generalized Pauli operators of N-qudits is performed in which vertices/points correspond to the operators and edges/lines join commuting pairs of them. As per two-qubits, all basic properties and partitionings of the corresponding Pauli graph are embodied
Reply to ``On the Systematic Errors in the Detection of the Lense-Thirring Effect with a Mars Orbiter '', by Giampiero Sindoni, Claudio Paris and Paolo Ialongo
gr-qcLorenzo Iorio
In this note we reply to the criticisms by Sindoni, Paris and Ialongo concerning some aspects of the recent frame-dragging test performed by Iorio with the Mars Global Surveyor (MGS) spacecraft in the gravitational field of Mars.
Frank Gurski
Clique-width is a well-known graph parameter. Many NP-hard graph problems admit polynomial-time solutions when restricted to graphs of bounded clique-width. The same holds for NLC-width. In this paper we study the behavior of clique-width and NLC-width under various graph operations and graph transformations. We give upper and lower bounds for the clique-wid
S. M. Troshin, N. E. Tyurin
Proceeding from optical analogy we propose a new physical interpretation of unitarity saturation leading to antishadowing as a reflective scattering. This interpretation of antishadowing is related to the non-perturbative aspects of strong interactions and follows from the specific property of the unitarity saturation when elastic $S$-matrix $S(s,b)|_{b=0}\t
L. Ambrosio, A. Figalli
We study Brenier's variational models for incompressible Euler equations. These models give rise to a relaxation of the Arnold distance in the space of measure-preserving maps and, more generally, measure-preserving plans. We analyze the properties of the relaxed distance, we show a close link between the Lagrangian and the Eulerian model, and we derive
Tomas Everaert, Marino Gran, Tim Van der Linden
We use Janelidze's Categorical Galois Theory to extend Brown and Ellis's higher Hopf formulae for homology of groups to arbitrary semi-abelian monadic categories. Given such a category A and a chosen Birkhoff subcategory B of A, thus we describe the Barr-Beck derived functors of the reflector of A onto B in terms of centralization of higher extension
Maxim Markevitch, Alexey Vikhlinin
Table of contents (abridged): COLD FRONTS Origin and evolution of merger cold fronts Cold fronts in cluster cool cores . . . Simulations of gas sloshing. Origin of density discontinuity. . . . Effect of sloshing on cluster mass estimates and cooling flows. Zoology of cold fronts COLD FRONTS AS EXPERIMENTAL TOOL Velocities of gas flows Thermal conduction and
B. D'Auria
In this paper we investigate an M/M/$\infty$ queue whose parameters depend on an external random environment that we assume to be a semi-Markovian process with finite state space. For this model we show a recursive formula that allows to compute all the factorial moments for the number of customers in the system in steady state. The used technique is based o
M. S. Leite, G. Medeiros-Ribeiro, T. I. Kamins, R. Stanley Williams
The different mechanisms involved in the alloying of epitaxial nanocrystals are reported in this letter. Intermixing during growth, surface diffusion and intra-island diffusion were investigated by varying the growth conditions and annealing environments during chemical vapor deposition. The relative importance of each mechanism was evaluated in determining
Joerg Hoffmann, Carla Gomes, Bart Selman
In Verification and in (optimal) AI Planning, a successful method is to formulate the application as boolean satisfiability (SAT), and solve it with state-of-the-art DPLL-based procedures. There is a lack of understanding of why this works so well. Focussing on the Planning context, we identify a form of problem structure concerned with the symmetrical or as
Lorenzo Iorio
I discuss some aspects of the recent test of frame-dragging performed by me by exploiting the Root-Mean-Square (RMS) orbit overlap differences of the out-of-plane component N of the orbit of the Mars Global Surveyor (MGS) spacecraft in the gravitational field of Mars. A linear fit of the full time series of the entire MGS data (4 February 1999-14 January 200
Fei Xue, Yu-xi Liu, C. P. Sun, Franco Nori
We study a device consisting of a dc-SQUID with two sections of its loop acting as two mechanical resonators. An analog of the parametric down-conversion process in quantum optics can be realized with this device. We show that a two-mode squeezed state can be generated for two overdamped mechanical resonators, where the damping constants of the two mechanica
Karl Oeljeklaus, Matei Toma
In this paper we describe logarithmic moduli spaces of pairs (S,D) consisting of minimal surfaces S of class VII with positive second Betti number b_2 together with reduced divisors D of b_2 rational curves. The special case of Enoki surfaces has already been considered by Dloussky and Kohler. We use normal forms for the action of the fundamental group of th
Claudio Fontanari
We investigate the (small) quantum cohomology ring of the moduli spaces of stable n-pointed curves of genus 0. In particular, we determine an explicit presentation in the case n=5 and we outline a computational approach to the case n=6.
T. Mineo, P. Romano, V. Mangano, A. Moretti
The detector at the focal plane of the Swift X-ray Telescope (XRT) supports four readout modes, automatically changed on board, to cover the dynamical range of fluxes and rapid variability expected from GRB afterglows. The Windowed Timing (WT) mode is used for sources with flux higher than a few mCrab and is obtained by compressing 10 rows into a single row,
J. J. M. in 't Zand, P. G. Jonker, C. B. Markwardt
Ultracompact X-ray binaries (UCXBs) appear able to sustain accretion onto the compact accretor at rates lower than in wider X-ray binaries. This may be understood by the smaller accretion disks in UCXBs: a lower X-ray luminosity suffices to keep a disk completely ionized through irradiation and, thus, keep the viscosity at a sufficiently high level to allow
V. Mangano, V. La Parola, E. Troja, G. Cusumano
We have computed the luminosity rest frame light curves of the first 40 Gamma-ray bursts (GRBs) detected by Swift with well established redshift. We studied average properties of the light curves in the four subsamples of bursts given by z<1, 1<z<2, 2<z<=4, and z>=4. We conclude that all the last three subsamples share the same morphology and the same lumino
Ahmad Sheykhi, Bin Wang, Rong-Gen Cai
We disclose the deep connection between the thermodynamics and gravity in a general braneworld model with curvature correction terms on the brane and in the bulk, respectively. We show that the Friedmann equations on the 3-brane embedded in the 5D spacetime with curvature correction terms can be written directly in the form of the first law of thermodynamics
Anne Pichereau, Geert Van de Weyer
In this note, we give a description of the graded Lie algebra of double derivations of a path algebra as a graded version of the necklace Lie algebra equipped with the Kontsevich bracket. Furthermore, we formally introduce the notion of double Poisson-Lichnerowicz cohomology for double Poisson algebras, and give some elementary properties. We introduce the n
Jean-Baptiste Trebbia, Carlos Leonardo Garrido Alzar, Ronald Cornelussen, Christoph I. Westbrook
We present a method to suppress the potential roughness of a wire-based, magnetic atom guide: modulating the wire current at a few tens of kHz, the potential roughness, which is proportional to the wire current, averages to zero. Using ultra-cold $^{87}{\rm Rb}$ clouds, we show experimentally that modulation reduces the roughness by at least of a factor five
M. J. Russcher
Results are presented from an ongoing analysis of direct photon production with the STAR experiment at RHIC. The direct photon measurement in d+Au collisions and the neutral pion spectrum in p+p collisions are found to be in agreement with NLO pQCD calculations.
Interchain-Frustration-Induced Metallic State in Quasi-One-Dimensional Mott Insulators
cond-mat.str-elM. Tsuchiizu, Y. Suzumura, C. Bourbonnais
The mechanism that drives a metal-insulator transition in an undoped quasi-one-dimensional Mott insulator is examined in the framework of the Hubbard model with two different hoppings t_{perp 1} and t_{perp 2} between nearest-neighbor chains. By applying an N_{perp}-chain renormalization group method at the two-loop level, we show how a metallic state emerge
Greg McShane, Hugo Parlier
Using geodesic length functions, we define a natural family of real codimension 1 subvarieties of Teichmüller space, namely the subsets where the lengths of two distinct simple closed geodesics are of equal length. We investigate the point set topology of the union of all such hypersurfaces using elementary methods. Finally, this analysis is applied to inves
Francesco Cianfrani, Irene Milillo, Giovanni Montani
The dimensional reduction of Papapetrou equations is performed in a 5-dimensional Kaluza-Klein background and Dixon-Souriau results for the motion of a charged spinning body are obtained. The splitting provides an electric dipole moment, and, for elementary particles, the induced parity and time-reversal violations are explained.
Yue-Lei Cui, Bao-Xi Sun
The first order self-energy corrections of the kaon in the symmetric nuclear matter are calculated from kaon-nucleon scattering matrix elements using a chiral Lagrangian within the framework of relativistic mean field approximation. It shows that the effective mass and the potential of K^+ meson are identical with those of K^- meson in the nuclear matter, re
Quantum q-breathers in a finite Bose-Hubbard chain: The case of two interacting bosons
cond-mat.mes-hallJean Pierre Nguenang, R. A. Pinto, Sergej Flach
We study the spectrum and eigenstates of the quantum discrete Bose-Hubbard Hamiltonian in a finite one-dimensional lattice containing two bosons. The interaction between the bosons leads to an algebraic localization of the modified extended states in the normal mode space of the noninteracting system. Weight functions of the eigenstates in the space of norma
T. S. Mahesh, Nageswaran Rajendran, Xinhua Peng, Dieter Suter
Several physics-based algorithms for factorizing large number were recently published. A notable recent one by Schleich et al. uses Gauss sums for distinguishing between factors and non-factors. We demonstrate two NMR techniques that evaluate Gauss sums and thus implement their algorithm. The first one is based on differential excitation of a single spin mag
Sergey P. Tarabrin
We analyze the interaction of plane '+'-polarized gravitational waves with a Fabry-Perot cavity in the local Lorentz frame of the cavity input mirror outside of the range of long-wave approximation with the force of radiation pressure taken into account. The obtained detector response signal is represented as a sum of two parts: (i) the phase shift d
Miao Li, Wei Song, Yushu Song
We quantize a string in the de Sitter background, and we find that the mass spectrum is modified by a term which is quadratic in oscillating numbers, and also proportional to the square of the Hubble constant.
M. Weides, H. Kohlstedt, R. Waser, M. Kemmler
We present a study on low-$T_c$ superconductor-insulator-ferromagnet-superconductor (SIFS) Josephson junctions. SIFS junctions have gained considerable interest in recent years because they show a number of interesting properties for future classical and quantum computing devices. We optimized the fabrication process of these junctions to achieve a homogeneo
Kenichiro Konya
We study the emission of gravitons by a homogeneous brane with the Gauss-Bonnet term into an Anti de Sitter five dimensional bulk spacetime. It is found that the graviton emission depends on the curvature scale and the Gauss-Bonnnet coupling and that the amount of emission generally decreases. Therefore nucleosynthesis constraints are easier to satisfy by in
Intrinsic anomalous Hall effect in ferromagnetic metals studied by the multi d-orbital tight-binding model
cond-mat.str-elH. Kontani, T. Tanaka, K. Yamada
To elucidate the origin of anomalous Hall effect (AHE) in ferromagnetic transition metals, we study the intrinsic AHE based on a multi-orbital (xz,yz)-tight-binding model. We find that a large anomalous velocity comes from the off-diagonal (inter-orbital) hopping. By this reason, the present model shows a large intrinsic anomalous Hall conductivity (AHC) whi
L. C. Garcia de Andrade
Curvature and helicity topological bounds for the magnetic energy of the streamlines magnetic structures of a kinematic dynamo flow are computed. The existence of the filament dynamos are determined by solving the magnetohydrodynamic equations for 3D flows and the solution is used to determine these bounds. It is shown that in the limit of zero resistivity f
Alberto Saa
A recently proposed approach to the construction of the Vaidya metric in double-null coordinates for generic mass functions is extended to the $n$-dimensional $(n>2)$ case and to allow the inclusion of a cosmological constant. The approach is based on a qualitative study of the null-geodesics, allowing the description of light-cones and revealing many featur
Anar Akhmedov, B. Doug Park
Let $M$ be $\CP#2\CPb$, $3\CP#4\CPb$ or $(2n-1)\CP#2n\CPb$ for any integer $n\geq 3$. We construct an irreducible symplectic 4-manifold homeomorphic to $M$ and also an infinite family of pairwise non-diffeomorphic irreducible non-symplectic 4-manifolds homeomorphic to $M$. We also construct such exotic smooth structures when $M$ is $\CP#4\CPb$ or $3\CP# k \C
Global well-posedness and a decay estimate for the critical dissipative quasi-geostrophic equation in the whole space
math.APHongjie Dong, Dapeng Du
We study the critical dissipative quasi-geostrophic equations in $\bR^2$ with arbitrary $H^1$ initial data. After showing certain decay estimate, a global well-posedness result is proved by adapting the method in [11] with a suitable modification. A decay in time estimate for higher order homogeneous Sobolev norms of solutions is also discussed.
Dissipative quasi-geostrophic equations in critical Sobolev spaces: smoothing effect and global well-posedness
math.APHongjie Dong
We study the critical and super-critical dissipative quasi-geostrophic equations in $\bR^2$ or $\bT^2$. Higher regularity of mild solutions with arbitrary initial data in $H^{2-γ}$ is proved. As a corollary, we obtain a global existence result for the critical 2D quasi-geostrophic equations with periodic $\dot H^1$ data. Some decay in time estimates are also
G. L. Li, S. Mao, Y. P. Jing, W. P. Lin
We use high-resolution N-body numerical simulations to study the number of predicted large-separation multiply-imaged systems produced by clusters of galaxies in the SDSS photometric and spectroscopic quasar samples. We incorporate the condensation of baryons at the centre of clusters by (artificially) adding a brightest central galaxy (BCG) as a truncated i
Remigiusz Augusiak, Julia Stasińska
We consider rotationally invariant states in $\mathbb{C}^{N_{1}}\ot \mathbb{C}^{N_{2}}$ Hilbert space with even $N_{1}\geq 4$ and arbitrary $N_{2}\geq N_{1}$, and show that in such case there always exist states which are inseparable and remain positive after partial transposition, and thus the PPT criterion does not suffice to prove separability of such sys
Concentration and purification of entanglement for qubit systems with ancillary cavity fields
quant-phC. D. Ogden, M. Paternostro, M. S. Kim
We propose schemes for entanglement concentration and purification for qubit systems encoded in flying atomic pairs. We use a cavity-quantum electrodynamics setting as the paradigmatic scenario within which our proposals can be implemented. Maximally entangled pure states of qubits can be produced as a result of our protocols. In particular, the concentratio
Giacomo Mauro D'Ariano
A C*-algebra formulation of Quantum Mechanics is derived from purely operational axioms in which the primary role is played by the "transformations" that the system undergoes in the course of an "experiment". The notion of the {\em adjoint} of a transformation is based on the postulated existence of "faithful states" that allows one t
On the precise connection between the GRW master-equation and master-equations for the description of decoherence
quant-phB. Vacchini
We point out that the celebrated GRW master-equation is invariant under translations, reflecting the homogeneity of space, thus providing a particular realization of a general class of translation-covariant Markovian master-equations. Such master-equations are typically used for the description of decoherence due to momentum transfers between system and envi
Giacomo Mauro D'Ariano
Within a general operational framework I show that a-causality at a distance of "local actions" (the so-called "no-signaling") is a direct consequence of commutativity of local transformations, i.e. of dynamical independence. On the other hand, the tensor product of Quantum Mechanics is not just a consequence of such dynamical independence, b
C. F. Roos, M. Chwalla, K. Kim, M. Riebe
Entanglement is recognized as a key resource for quantum computation and quantum cryptography. For quantum metrology, the use of entangled states has been discussed and demonstrated as a means of improving the signal-to-noise ratio. In addition, entangled states have been used in experiments for efficient quantum state detection and for the measurement of sc
J. Julve, F. J. de Urries
We analytically compute the time evolution of an initial infinite plane wave in the presence of a 1-dimensional square quantum barrier. This calculation generalizes the analysis of the shutter problem and sets the basis for the calculation of the transmission of general wave packets, aiming to work out the explicit contribution of the resonant (Gamow) states
Arash Ashourvan, MirFaez Miri, Ramin Golestanian
The lateral Casimir force is employed to propose a design for a potentially wear-proof rack and pinion with no contact, which can be miniaturized to nano-scale. The robustness of the design is studied by exploring the relation between the pinion velocity and the rack velocity in the different domains of the parameter space. The effects of friction and added
A. Vukics, H. Ritsch
We present a framework for efficiently performing Monte Carlo wave-function simulations in cavity QED with moving particles. It relies heavily on the object-oriented programming paradigm as realised in C++, and is extensible and applicable for simulating open interacting quantum dynamics in general. The user is provided with a number of ``elements'',
Cevdet Tezcan, Metin Aktas, Ozlem Yesiltas Ramazan Sever
Exact solution of Schrodinger equation for the pseudoharmonic potential is obtained for an arbitrary angular momentum. The energy eigenvalues and corresponding eigenfunctions are calculated by Nikiforov-Uvarov method. Wavefunctions are expressed in terms of Jacobi polynomials. The energy eigenvalues are calculated numerically for some values of l and n with
E. G. Cavalcanti, M. D. Reid
We develop criteria sufficient to enable detection of macroscopic coherence where there are not just two macroscopically distinct outcomes for a pointer measurement, but rather a spread of outcomes over a macroscopic range. The criteria provide a means to distinguish a macroscopic quantum description from a microscopic one based on mixtures of microscopic su
Philippe Gaspar, Jean-Yves Georges, Arnaud Lenoble, Sandra Ferraroli
Tracks of marine animals in the wild, now increasingly acquired by electronic tagging of individuals, are of prime interest not only to identify habitats and high-risk areas, but also to gain detailed information about the behaviour of these animals. Using recent satellite-derived current estimates and leatherback turtle (Dermochelys coriacea) tracking data,
Mobility of Min-proteins in Escherichia coli measured by fluorescence correlation spectroscopy
q-bio.SCG. Meacci, J. Ries, E. Fischer-Friedrich, N. Kahya
In the bacterium Escherichia coli, selection of the division site involves pole-to-pole oscillations of the proteins MinD and MinE. Different oscillation mechanisms based on cooperative effects between Min-proteins and on the exchange of Min-proteins between the cytoplasm and the cytoplasmic membrane have been proposed. The parameters characterizing the dyna
J. J. Lunazzi
Archaeological mirrors from the Olmec civilization were analyzed in the context of bibliography produced in the last two decades. Photographs of its images are showed as a proof of its good quality. Some suggestions are made on its probable utilization.
Experimental evidence for phase synchronization transitions in human cardio-respiratory system
physics.data-anRonny Bartsch, Jan W. Kantelhardt, Thomas Penzel, Shlomo Havlin
Transitions in the dynamics of complex systems can be characterized by changes in the synchronization behavior of their components. Taking the human cardio-respiratory system as an example and using an automated procedure for screening the synchrograms of 112 healthy subjects we study the frequency and the distribution of synchronization episodes under diffe