December 2008 arXiv papers — page 50
Showing 4,901–5,000 of 5,096 papers
The point spread function of electrons in a magnetic field, and the decay of the free neutron
nucl-exD. Dubbers, L. Raffelt, B. Maerkisch, F. Friedl
Experiments in nuclear and particle physics often use magnetic fields to guide charged reaction products to a detector. Due to their gyration in the guide field, the particles hit the detector within an area that can be considerably larger than the diameter of the source where the particles are produced. This blurring of the image of the particle source on t
Robert M. Ziff, Hang Gu
Lattices that can be represented in a kagome-like form are shown to satisfy a universal percolation criticality condition, expressed as a relation between P_3, the probability that all three vertices in the triangle connect, and P_0, the probability that none connect. A linear approximation for P_3(P_0) is derived and appears to provide a rigorous upper boun
Cosmic rays and the magnetic field in the nearby starburst galaxy NGC 253 I. The distribution and transport of cosmic rays
astro-phV. Heesen, R. Beck, M. Krause, R. -J. Dettmar
The diffusive and convective CR transport in NGC 253 from the disk into the halo is investigated using the local CR bulk speed. The connection between the CR transport and the galactic wind is outlined. We observed NGC 253 with the VLA at lambda 6.2 cm in a mosaic with 15 pointings. The missing zero-spacing flux density of the VLA mosaic was filled in using
Christoph Ditsche, Bastian Kubis, Ulf-G. Meißner
We re-evaluate the electromagnetic corrections to eta --> 3 pi decays at next-to-leading order in the chiral expansion, arguing that effects of order e^2(m_u-m_d) disregarded so far are not negligible compared to other contributions of order e^2 times a light quark mass. Despite the appearance of the Coulomb pole in eta --> pi+ pi- pi0 and cusps in eta --> 3
L. Calibbi, L. Ferretti, A. Romanino, R. Ziegler
We consider field sets that do not form complete SU(5) multiplets, but exactly preserve the one-loop MSSM prediction for $α_3(M_Z)$ independently of the value of their mass. Such fields can raise the unification scale in different ways, through a delayed convergence of the gauge couplings, a fake unified running below the GUT scale, or a postponed unificatio
A Matlab Implementation of a Flat Norm Motivated Polygonal Edge Matching Method using a Decomposition of Boundary into Four 1-Dimensional Currents
cs.CVSimon P. Morgan, Wotao Yin, Kevin R. Vixie
We describe and provide code and examples for a polygonal edge matching method.
Yang Qi, Cenke Xu
We study the global phase diagram of magnetic orders and lattice structure in the Fe-pnictide materials at zero temperature within one unified theory, tuned by both doping and pressure. On the low doping and high pressure side of the phase diagram, there is one single transition, which is described by a $z=2$ mean field theory with very weak run-away flows;
Mark Durkee
This paper studies various properties of the Pomeransky-Sen'kov doubly-spinning black ring spacetime. I discuss the structure of the ergoregion, and then go on to demonstrate the separability of the Hamilton-Jacobi equation for null, zero energy geodesics, which exist in the ergoregion. These geodesics are used to construct geometrically motivated coordi
Alexey Boyarsky, Julien Lesgourgues, Oleg Ruchayskiy, Matteo Viel
We revisit Lyman-alpha bounds on the dark matter mass in Lambda Warm Dark Matter (Lambda-WDM) models, and derive new bounds in the case of mixed Cold plus Warm models (Lambda-CWDM), using a set up which is a good approximation for several theoretically well-motivated dark matter models. We combine WMAP5 results with two different Lyman-alpha data sets, inclu
Deepshikha Shukla, Andreas Nogga, Daniel R. Phillips
Motivated by the fact that a polarized ${}^3$He nucleus behaves as an `effective' neutron target, we examine manifestations of neutron electromagnetic polarizabilities in elastic Compton scattering from the Helium-3 nucleus. We calculate both unpolarized and double-polarization observables using chiral perturbation theory to next-to-leading order (${\mat
Chul Kim, Thomas Mehen
One possible extension of the Standard Model scalar sector includes SU(2)_L doublet scalars that are color octets rather than singlets. We focus on models in which the couplings to fermions are consistent with the principle of minimal flavor violation (MFV), in which case these color octet scalars couple most strongly to the third generation of quarks. When
S. Brendle
Let (M,g) be an Einstein manifold of dimension n \geq 4 with nonnegative isotropic curvature. We show that (M,g) is locally symmetric.
Ralph Blumenhagen
We investigate gauge coupling unification for F-theory respectively Type IIB orientifold constructions of SU(5) GUT theories with gauge symmetry breaking via non-trivial hypercharge flux. This flux has the non-trivial effect that it splits the values of the three MSSM gauge couplings at the string scale, thus potentially spoiling the celebrated one-loop gaug
Igor A. Bandos
We review the spinor moving frame formulations and generalized action principle for super-p-branes, describe in detail the superembedding approach to superstring in general type IIB supergravity background and present the complete superembedding description of type IIB superstring in the AdS(5)xS*5 superspace.
Lu-Jing Hou, Alexander Piel, P. K. Shukla
We perform Brownian dynamics simulations for studying the self-diffusion in two-dimensional (2D) dusty plasma liquids, in terms of both mean-square displacement and velocity autocorrelation function (VAF). Super-diffusion of charged dust particles has been observed to be most significant at infinitely small damping rate $γ$ for intermediate coupling strength
Taro Kimura
Withdrawn: replaced by e-Print: arXiv:0907.3774
Marco Baiesi, Lorenzo Bongini, Lapo Casetti, Lorenzo Tattini
In systems characterized by a rough potential energy landscape, local energetic minima and saddles define a network of metastable states whose topology strongly influences the dynamics. Changes in temperature, causing the merging and splitting of metastable states, have non trivial effects on such networks and must be taken into account. We do this by means
Andreas Athenodorou, Barak Bringoltz, Michael Teper
We calculate the energy spectrum of a k=2 flux tube that is closed around a spatial torus, as a function of its length l. We do so for SU(4) and SU(5) gauge theories in 2 space dimensions. We find that to a very good approximation the eigenstates belong to the irreducible representations of the SU(N) group rather than just to its center, Z_N. We obtain convi
A step towards testing general relativity using weak gravitational lensing and redshift surveys
astro-phYong-Seon Song, Olivier Doré
Using the linear theory of perturbations in General Relativity, we express a set of consistency relations that can be observationally tested with current and future large scale structure surveys. We then outline a stringent model-independent program to test gravity on cosmological scales. We illustrate the feasibility of such a program by jointly using sever
A. Allais, M. Caselle
We study the flux tube thickness of a generic Lattice Gauge Theory near the deconfining phase transition. It is well known that the effective string model predicts a logarithmic increase of the flux tube thickness as a function of the interquark distance for any confining LGT at zero temperature. It is perhaps less known that this same model predicts a linea
C. S. Chang, E. Ros, Y. Y. Kovalev, M. L. Lister
A bright feature 100 pc away from the core in the powerful jet of M 87 shows mysterious properties. Earlier radio, optical and X-ray observations have shown that this feature, labelled HST-1, is superluminal, and is possibly connected with the TeV flare detected by HESS in 2005. To examine the possible blazar-like nature of HST-1, we analyzed 2 cm VLBA data
Ageing as a price of cooperation and complexity: Self-organization of complex systems causes the ageing of constituent networks
q-bio.MNHuba J. M. Kiss, Agoston Mihalik, Tibor Nanasi, Balint Ory
The network concept is increasingly used for the description of complex systems. Here we summarize key aspects of the evolvability and robustness of the hierarchical network-set of macromolecules, cells, organisms, and ecosystems. Listing the costs and benefits of cooperation as a necessary behaviour to build this network hierarchy, we outline the major hypo
Tao Liu, Yu-Yu Zhang, Qing-Hu Chen, Ke-Lin Wang
Within the numerically exact solution to the Dicke model proposed previously, we study the quantum criticality in terms of the ground-state (GS) energy, fidelity, and the order parameter. The finite size scaling analysis for the average fidelity susceptibility (FS) and second derivative of GS energy are performed. The correlation length exponent is obtained
Neutrino Signals from Annihilating/Decaying Dark Matter in the Light of Recent Measurements of Cosmic Ray Electron/Positron Fluxes
hep-phJunji Hisano, Masahiro Kawasaki, Kazunori Kohri, Kazunori Nakayama
The excess of cosmic-ray electron and positron fluxes measured by the PAMELA satellite and ATIC balloon experiments may be interpreted as the signals of the dark matter annihilation or decay into leptons. In this letter we show that the dark matter annihilation/decay which reproduces the electron/positron excess may yield a significant amount of high-energy
Modelling two-dimensional Crystals with Defects under Stress: Superelongation of Carbon Nanotubes at high Temperatures
cond-mat.softJ. Dietel, H. Kleinert
We calculate analytically the phase diagram of a two-dimensional square crystal and its wrapped version with defects under external homogeneous stress as a function of temperature using a simple elastic lattice model that allows for defect formation. The temperature dependence turns out to be very weak. The results are relevant for recent stress experiments
Eduardo V Teixeira, Lei Zhang
For free boundary problems on Euclidean spaces, the monotonicity formulas of Alt-Caffarelli-Friedman and Caffarelli-Jerison-Kenig are cornerstones for the regularity theory as well as the existence theory. In this article we establish the analogs of these results for the Laplace-Beltrami operator on Riemannian manifolds. As an application we show that our mo
Jose Reslen, Sougato Bose
We study the ground state as well as the dynamics of chains of bosons with local repulsive interactions and nearest-neighbour exchange using numerical techniques based on density matrix decimation. We explore the development of entanglement between the terminal sites of such chains as mechanisms are invoked to concentrate population in these sites. We find t
Benno van den Berg, Richard Garner
We define a notion of weak omega-category internal to a model of Martin-Löf type theory, and prove that each type bears a canonical weak omega-category structure obtained from the tower of iterated identity types over that type. We show that the omega-categories arising in this way are in fact omega-groupoids.
Dorota Sokolowska, Maria Krawczyk, K. A. Kanishev
The most general Two Higgs Doublet Model (2HDM) allows both for the explicit and the spontaneous CP violation in the scalar sector. Here we discuss CP violation in terms of basis-independent quantities and show how using two different sets of known CP-odd weak-basis invariants one can distinguish between CP conservation, explicit CP violation and spontaneous
Jure Drobnak, Svjetlana Fajfer, Jernej F. Kamenik
Among other roles the LHC will play a role of the top "factory" and it will give us unique possibility to study new physics signatures in different ways. Many scenarios of new physics allow top quark FCNC decays. Using most general model independent Lagrangian of new physics we investigate possible experimental signals of new physics in t --> c(u) l+
Christopher Townsend
It it shown that geometric morphisms between elementary toposes can be represented as adjunctions between the corresponding categories of locales. These adjunctions are characterised as those that preserve the order enrichment, commute with the double power locale monad and whose right adjoints preserve finite coproduct. They are also characterised as those
Yasushi Komori, Masatoshi Noumi, Jun'ichi Shiraishi
A unified approach is given to kernel functions which intertwine Ruijsenaars difference operators of type A and of type BC. As an application of the trigonometric cases, new explicit formulas for Koornwinder polynomials attached to single columns and single rows are derived.
Martin Andersson
We provide a new approach to stable ergodicity of systems with dominated splittings, based on a geometrical analysis of global stable and unstable manifolds of hyperbolic points. Our method suggests that the lack of uniform size of Pesin's local stable and unstable manifolds - a notorious problem in the theory of non-uniform hyperbolicity - is often less
Collective dynamics of water in the living cell and in bulk liquid. New physical models and biological inferences
physics.bio-phEugen A. Preoteasa, Marian V. Apostol
In the frame of collective dynamics in water, models built on elementary excitations and long-range electromagnetic interactions in the cell and bulk liquid are presented. Making use of the low effective mass of water coherence domains (CDs), we examined the relevance of simple quantum models to cellular characteristics. A hypothesis of CDs Bose-type condens
Francesco Fidaleo, Daniele Guido, Tommaso Isola
We investigate the Bose-Einstein Condensation on nonhomogeneous amenable networks for the model describing arrays of Josephson junctions. The resulting topological model, whose Hamiltonian is the pure hopping one given by the opposite of the adjacency operator, has also a mathematical interest in itself. We show that for the nonhomogeneous networks like the
S Sivakumar
Entanglement of bosonic modes of material oscillators is studied in the context of two bilinearly coupled, nonlinear oscillators. These oscillators are realizable in the vibrational-cum-bending motions of C-H bonds in dihalomethanes. The bilinear coupling gives rise to invariant subspaces in the Hilbert space of the two oscillators. The number of separable s
Shoji Fujiyama, Makoto Tsubota
This paper reports results of the computation of the drag force exerted on an oscillating object in quantum turbulence in superfluid $^4$He. The drag force is calculated on the basis of numerical simulations of quantum turbulent flow about the object. The drag force is proportional to the square of the magnitude of the oscillation velocity, which is similar
The OPAL collaboration
A search is made for charged Higgs bosons predicted by Two-Higgs-Doublet extensions of the Standard Model (2HDM) using electron-positron collision data collected by the OPAL experiment at sqrt(s)=189-209 GeV, corresponding to an integrated luminosity of approximately 600 pb-1. Charged Higgs bosons are assumed to be pair-produced and to decay into q qbar, tau
Luis S. Froufe-Pérez, William Guerin, Rémi Carminati, Robin Kaiser
We address the problem of achieving an optical random laser with a cloud of cold atoms, in which gain and scattering are provided by the same atoms. The lasing threshold can be defined using the on-resonance optical thickness b0 as a single critical parameter. We predict the threshold quantitatively, as well as power and frequency of the emitted light, using
Mindaugas Karciauskas, Konstantinos Dimopoulos, David H. Lyth
We suppose that a vector field perturbation causes part of the primordial curvature perturbation. The non-Gaussianity parameter fNL is then, in general, statistically anisotropic. We calculate its form and magnitude in the curvaton scenario and in the end-of-inflation scenario. We show that this anisotropy could easily be observable.
A. Skopenkov
We obtain estimations for isotopy classes of embeddings of closed k-connected n-manifolds into R^{2n-k-1} for n>2k+5 and k\ge0. This is done in terms of an exact sequence involving the Whitney invariants and an explicitly constructed action of H_{k+1}(N;Z_2) on the set of embeddings. (For k\ne1 classification results were obtained by algebraic methods withou
Searching bifurcations in high-dimensional parameter space via a feedback loop breaking approach
q-bio.MNSteffen Waldherr, Frank Allgöwer
Bifurcations leading to complex dynamical behaviour of non-linear systems are often encountered when the characteristics of feedback circuits in the system are varied. In systems with many unknown or varying parameters, it is an interesting, but difficult problem to find parameter values for which specific bifurcations occur. In this paper, we develop a loop
Ying-Dan Wang, Yong Li, Fei Xue, C. Bruder
We study the role of qubit dephasing in cooling a mechanical resonator by quantum back-action. With a superconducting flux qubit as a specific example, we show that ground-state cooling of a mechanical resonator can only be realized if the qubit dephasing rate is sufficiently low.
Yoav Yair, Yukihiro Takahashi, Roy Yaniv, Ute Ebert
Sprites are a spectacular type of transient luminous events (TLE) which occur above thunderstorms immediately after lightning. They have shapes of giant jellyfish, carrots or columns and last tens of milliseconds. In Earth's atmosphere, sprites mostly emit in red and blue wavelengths from excited N2 and N2+ and span a vertical range between 50 and 90 km
T. C. Dorlas, A. M. Povolotsky, V. B. Priezzhev
We propose a model of semi-vicious walkers, which interpolates between the totally asymmetric simple exclusion process and the vicious walkers model, having the two as limiting cases. For this model we calculate the asymptotics of the survival probability for $m$ particles and obtain a scaling function, which describes the transition from one limiting case t
R. Pink, D. Rössler
We give a new proof of the Adams-Riemann-Roch theorem for a smooth projective morphism $X\to Y$, in the situation where $Y$ is a regular scheme, which is quasi-projective over $\mF_p$. We also partially answer a question of B. Köck.
V. S. Gurin
A series of endofullerenes M@C60 were calculated from the first principles (unrestricted Hartree Fock and DFT B3LYP) methods with effective core potential (M = Ag, Cs) and all-electronic basis set (M = Li, Na, Cu). An arbitrary symmetry distortion (down to C1 point group) was assumed. The geometrical and electronic properties of M@C60 are compared for this s
V. Dexheimer, S. Schramm
We study different stages of the neutron star cooling by computing neutron star properties at various temperatures and entropies using an effective chiral model including hadronic and quark degrees of freedom. Macroscopic properties of the star such as mass and radius are calculated and compared with observations. It can be seen that the effects of chiral re
G. K. Chaudhary, Amit K Chattopadhyay, R. Ramakumar
In this paper, we present a theoretical study of a Bose-Einstein condensate of interacting bosons in a quartic trap in one, two, and three dimensions. Using Thomas-Fermi approximation, suitably complemented by numerical solutions of the Gross-Pitaevskii equation, we study the ground sate condensate density profiles, the chemical potential, the effects of cro
Miguel Sánchez
The notion of a causal boundary for a spacetime has been a controversial topic during the last three decades. Moreover, recently the role of the boundary in the AdS/CFT correspondence for plane waves, have stimulated its redefinition with some possible alternatives. Our aim is threefold. First, to review the different classical approaches to boundaries of sp
S. Chiacchiera, T. Lepers, M. Urban, D. Davesne
Due to Pauli blocking of intermediate states, the scattering matrix (or $T$ matrix) of two fermionic atoms in a Fermi gas becomes different from that of two atoms in free space. This effect becomes particularly important near a Feshbach resonance, where the interaction in free space is very strong but becomes effectively suppressed in the medium. We calculat
International Comparison of Labor Productivity Distribution for Manufacturing and Non-Manufacturing Firms
q-fin.GNYuichi Ikeda, Wataru Souma
Labor productivity was studied at the microscopic level in terms of distributions based on individual firm financial data from Japan and the US. A power-law distribution in terms of firms and sector productivity was found in both countries' data. The labor productivities were not equal for nation and sectors, in contrast to the prevailing view in the fie
Lianyi He, Yin Jiang, Pengfei Zhuang
Applying the Hellmann-Feynman theorem to a charged pion gas, the quark and gluon condensates at low isospin density are determined by precise pion properties. At intermediate density around $ f_π^2m_π$, from both the estimation for the dilute pion gas and the calculation with Nambu--Jona-Lasinio model, the quark condensate is strongly and monotonously suppre
Manoranjan Kumar, S. Ramasesha, Z. G. Soos
Theoretical and computational studies of the quantum phase diagram of the one-dimensional half-filled extended Hubbard model (EHM) indicate a narrow bond order wave (BOW) phase with finite magnetic gap $E_m$ for on-site repulsion $U < U^*$, the critical point, and nearest neighbor interaction $V_c \approx U/2$ near the boundary of the charge density wave (CD
Measurement of the quadratic Zeeman shift of ^{85}Rb hyperfine sublevels using stimulated Raman transitions
physics.atom-phRunbing Li, Lin Zhou, Jin Wang, Mingsheng Zhan
We demonstrate a technique for directly measuring the quadratic Zeeman shift using stimulated Raman transitions.The quadratic Zeeman shift has been measured yielding [delta][nju] = 1296.8 +/-3.3 Hz/G^{2} for magnetically insensitive sublevels (5S1/2, F = 2,mF = 0 -> 5S1/2, F = 3,mF = 0) of ^{85}Rb by compensating the magnetic eld and cancelling the ac Stark
Weiliang Wang, Ningsheng Xu, Zhibing Li
Analytical solutions of the edge states were obtained for the (N, 0) type carbon nanotubes with distorted ending bonds. It was found that the edge states are mixed via the distortion. The total energies for N=5 and N>=7 are lower in the asymmetric configurations of ending bonds than those having axial rotation symmetry. Thereby the symmetry is breaking spont
Eun Kyung Park, Pyung Seong Kwon
We argue that in ($p+3$)d string theory the existence of NS-NS type $p$-brane with negative tension is essential to obtain background geometry $R_2$ or $R_2 / Z_n$ on the transverse dimensions, and the usual codimension-2 brane solutions with these background geometries already contain the negative tension NS-brane implicity in their ansatz. Such an argument
Jung Hoon Lee
Casson and Gordon gave the rectangle condition for strong irreducibility of Heegaard splittings [1]. We give a parity condition for irreducibility of Heegaard splittings of irreducible manifolds. As an application, we give examples of non-stabilized Heegaard splittings by doing a single Dehn twist.
M. V. Movshev
We translate the classical Atiyah-Ward correspondence into the L-infinity language. We extend the correspondence to a quasi-isomorphism between the algebra of the self-dual four-manifold X and the algebra of the holomorphic BF-theory in the twistor space T(X).
Cryogenic spectroscopy of ultra-low density colloidal lead chalcogenide quantum dots on chip-scale optical cavities towards single quantum dot near-infrared cavity QED
quant-phRanojoy Bose, Jie Gao, James F. McMillan, Alex D. Williams
We present evidence of cavity quantum electrodynamics from a sparse density of strongly quantum-confined Pb-chalcogenide nanocrystals (between 1 and 10) approaching single-dot levels on moderately high-Q mesoscopic silicon optical cavities. Operating at important near-infrared (1500-nm) wavelengths, large enhancements are observed from devices and strong mod
On bi-hamiltonian geometry of some integrable systems on the sphere with cubic integral of motion
nlin.SIA V Vershilov, A V Tsiganov
We obtain bi-Hamiltonian structure for a family of integrable systems on the sphere S with an additional integral of third order in momenta. These results are applied to the Goryachev system and Goryachev-Chaplygin top for which we give an explicit procedure to find the separated coordinates and the separated relations.
Satoshi Murai
In this paper, we characterize all possible h-vectors of 2-dimensional Buchsbaum simplicial complexes.
Oleg Pikhurko
The stability method is very useful for obtaining exact solutions of many extremal graph problems. Its key step is to establish the stability property which, roughly speaking, states that any two almost optimal graphs of the same order $n$ can be made isomorphic by changing o(n^2) edges. Here we show how the recently developed theory of graph limits can be u
Walter Craig, Steven Weinstein
We study the initial value problem for the wave equation and the ultrahyperbolic equation for data posed on initial surface of mixed signature (both spacelike and timelike). Under a nonlocal constraint, we show that the Cauchy problem on codimension-one hypersurfaces has global unique solutions in the Sobolev spaces $H^{m}$, thus it is well-posed. In contras
Entangling photons by means of the nonlinear response of quantum wells to an ultrashort pulse
cond-mat.mes-hallMikhail Erementchouk, Michael N. Leuenberger
We show that many-body correlations among excitons originating from the Pauli exclusion principle in a quantum well embedded inside a microcavity provide a possibility to produce pairs of entangled photons by ultrashort laser pulses with a yield of $\sim 10^{-2}$. The quantum-field theoretical two-particle density matrix in second quantization is used to cal
Victor Tourtchine
The paper describes a natural splitting in the rational homology and homotopy of the spaces of long knots. This decomposition presumably arises from the cabling maps in the same way as a natural decomposition in the homology of loop spaces arises from power maps. The generating function for the Euler characteristics of the terms of this splitting is presente
Matthew C. Martino, Hans F. Stabenau, Ravi K. Sheth
Modifications to the gravitational potential affect the nonlinear gravitational evolution of large scale structures in the Universe. To illustrate some generic features of such changes, we study the evolution of spherically symmetric perturbations when the modification is of Yukawa type; this is non-trivial, because we should not and do not assume that Birkh
Jose Martinez-Bernal, Rafael H. Villarreal
Let I be the toric ideal of a homogeneous normal configuration. We prove that I is generated by circuits if and only if each unbalanced circuit of I has a "connector" which is a linear combination of circuits with a square-free term. In particular if each circuit of I with non-square-free terms is balanced, then I is generated by circuits. As a conse
Response to arXiv:0811.1802 "Comment on 'Conjectures on exact solution of three-dimensional (3D) Ising lattices'" by Perk and Singularities at/near infinite temperature: Reply to Perk's Rejoinder arXiv:0901.2935
cond-mat.stat-mechZ. D. Zhang
Part I: The error of eq. (15b) in my article [Z.D. Zhang, Phil. Mag. 87, 5309 (2007), arXiv:0705.1045] in the application of the Jordan-Wigner transformation does not affect the validity of the putative exact solution, since the solution is not derived directly from it. Other objections of Perk's Comment arXiv:0811.1802v2 are the same as those in Wu et a
Contention Resolution in Optical Burst Switched Networks using Spectral- Amplitude-Coding Optical Code Division Multiple Access
cs.NIMohamed Y. S. Sowailem, Mohamed H. S. Morsy, Hossam M. H. Shalaby
This paper has been withdrawn by the authors.
Mohamed H. S. Morsy, Mohammad Y. S. Sowailem, Hossam M. H. Shalaby
This paper has been withdrawn
Friedwardt Winterberg
The Centurion-Halite experiment demonstrated the feasibility of igniting a deuterium-tritium micro-explosion with an energy of not more than a few megajoule, and the Mike test, the feasibility of a pure deuterium explosion with an energy of more than 10^6 megajoule. In both cases the ignition energy was supplied by a fission bomb explosive. While an energy o
M. Z. Rafat, M. S. Wheatland, T. R. Bedding
We investigate a variation of the simple double pendulum in which the two point masses are replaced by square plates. The double square pendulum exhibits richer behavior than the simple double pendulum and provides a convenient demonstration of nonlinear dynamics and chaos. It is also an example of an asymmetric compound double pendulum, which has not been s
The Calibration of Stromgren uvby-Hbeta Photometry for Late-Type Stars -- a Model Atmosphere Approach
astro-phA. Önehag, B. Gustafsson, K. Eriksson, B. Edvardsson
We aim to test the power of theoretical calibrations based on a new generation of MARCS models by comparisons with observational photomteric data. We calculate synthetic uvby-Hbeta colour indices from synthetic spectra. A sample of 388 field stars as well as stars in globular clusters is used for a direct comparison of the synthetic indices versus empirical
Mauricio Vargas
This is a paper with the aim of give the student a detailed calculation of magnetic monopole's Dirac theory.
The ubiquitous $ζ$-function and some of its "usual" and "unusual" meromorphic properties
math-phKlaus Kirsten, Paul Loya, Jinsung Park
In this contribution we announce a complete classification and new exotic phenomena of the meromorphic structure of $\z$-functions associated to conic manifolds proved in \cite{KLP1}. In particular, we show that the meromorphic extensions of these $\z$-functions have, in general, countably many logarithmic branch cuts on the nonpositive real axis and unusual
Andrea Vattani
The k-means algorithm is a well-known method for partitioning n points that lie in the d-dimensional space into k clusters. Its main features are simplicity and speed in practice. Theoretically, however, the best known upper bound on its running time (i.e. O(n^{kd})) can be exponential in the number of points. Recently, Arthur and Vassilvitskii [3] showed a
T. Lanting, A. J. Berkley, B. Bumble, P. Bunyk
A general method for directly measuring the low-frequency flux noise (below 10 Hz) in compound Josephson junction superconducting flux qubits has been used to study a series of 85 devices of varying design. The variation in flux noise across sets of qubits with identical designs was observed to be small. However, the levels of flux noise systematically varie
Sergio Blanes, Fernando Casas, Ander Murua
We provide a comprehensive survey of splitting and composition methods for the numerical integration of ordinary differential equations (ODEs). Splitting methods constitute an appropriate choice when the vector field associated with the ODE can be decomposed into several pieces and each of them is integrable. This class of integrators are explicit, simple to
Asantha Cooray, Daniel E. Holz, Robert Caldwell
The gravitational lensing distortion of distant sources by the large-scale distribution of matter in the Universe has been extensively studied. In contrast, very little is known about the effects due to the large-scale distribution of dark energy. We discuss the use of Type Ia supernovae as probes of the spatial inhomogeneity and anisotropy of dark energy. W
Probing Electron Correlation via Attosecond XUV Pulses in the Two-Photon Double Ionization of Helium
physics.atom-phJ. Feist, S. Nagele, R. Pazourek, E. Persson
Recent experimental developments of high-intensity, short-pulse XUV light sources are enhancing our ability to study electron-electron correlations. We perform time-dependent calculations to investigate the so-called "sequential" regime (photon energy above 54.4 eV) in the two-photon double ionization of helium. We show that attosecond pulses allow to induce
Nikolay Gravin
Let $c\geq 2$ and $p\geq c$ be two integers. We will call a proper coloring of the graph $G$ a \textit{$(c,p)$-nondegenerate}, if for any vertex of $G$ with degree at least $p$ there are at least $c$ vertices of different colors adjacent to it. In our work we prove the following result, which generalizes Brook's Theorem. Let $D\geq 3$ and $G$ be a graph
Shou-Wu Zhang
The aim of this paper is to study the modified diagonal cycle in the triple product of a curve over a global field defined by Gross and Schoen. Our main result is an identity between the height of this cycle and the self-intersection of the relative dualising sheaf. We have some applications to the following problems in number theory and algebraic geometry.
Eric V. Linder
Control of systematic uncertainties in the use of Type Ia supernovae as standardized distance indicators can be achieved through contrasting subsets of observationally-characterized, like supernovae. Essentially, like supernovae at different redshifts reveal the cosmology, and differing supernovae at the same redshift reveal systematics, including evolution
Gustavo Burdman, Leandro Da Rold, Oscar Eboli, Ricardo Matheus
We study extensions of the standard model with a strongly coupled fourth generation. This occurs in models where electroweak symmetry breaking is triggered by the condensation of at least some of the fourth-generation fermions. With focus on the phenomenology at the LHC, we study the pair production of fourth-generation down quarks, D4. We consider the typic
On the Time Variability of Geometrically-Thin Black Hole Accretion Disks II: Viscosity-Induced Global Oscillation Modes in Simulated Disks
astro-phSean M. O'Neill, Christopher S. Reynolds, M. Coleman Miller
We examine the evolution and influence of viscosity-induced diskoseismic modes in simulated black hole accretion disks. Understanding the origin and behavior of such oscillations will help us to evaluate their potential role in producing astronomically observed high-frequency quasi-periodic oscillations in accreting black hole binary systems. Our simulated d
Young L Dwarfs Identified in the Field: A Preliminary Low-Gravity, Optical Spectral Sequence from L0 to L5
astro-phKelle L. Cruz, J. Davy Kirkpatrick, Adam J. Burgasser
We present an analysis of 23 L dwarfs whose optical spectra display unusual features. Twenty-one were uncovered during our search for nearby, late-type objects using the Two Micron All-Sky Survey while two were identified in the literature. The unusual spectral features, notably weak FeH molecular absorption and weak Na I and K I doublets, are attributable t
T. Decressin, S. Mathis, A. Palacios, L. Siess
(Abridged) We present a detailed analysis of the main physical processes responsible for the transport of angular momentum and chemical species in the radiative regions of rotating stars. We focus on cases where meridional circulation and shear-induced turbulence only are included in the simulations. Our analysis is based on a 2-D representation of the secul
A. A. Rangelov, N. V. Vitanov, B. W. Shore
Stimulated Raman adiabatic passage (STIRAP) is a well established technique for producing coherent population transfer in a three-state quantum system. We here exploit the resemblance between the Schrodinger equation for such a quantum system and the Newton equation of motion for a classical system undergoing torque to discuss several classical analogs of ST
John M. Cornwall
The functional Schrodinger equation (FSE) for QCD gives a unique perspective on generation of a gluon mass m, as required for center vortices. The FSE, which yields a special d=3 gauge action, combined with lattice calculations strictly in d=3 give a value for the dimensionless ratio of d=3 coupling to mass g_3^2/m. From this we infer a reasonably accurate v
Andrew R. Zentner, Suman Bhattacharya
We study the utility of a large sample of type Ia supernovae that might be observed in an imaging survey that rapidly scans a large fraction of the sky for constraining dark energy. We consider information from the traditional luminosity distance test as well as the spread in SNeIa fluxes at fixed redshift induced by gravitational lensing. We include a treat
Comment on "Twofold Advance in the Theoretical Understanding of Far-From-Equilibrium Properties of Interacting Nanostructures"
cond-mat.str-elL. Borda, A. Zawadowski
Boulat, Saleur and Schmitteckert (BSS) reported results on the full $I-V$ characteristics of the interacting resonant level model (IRLM) exhibiting region with unexpected negative differential conductance (NDC). Using time-dependent density matrix renormalization group complemented with the exact solution performed at a special point (the self-dual point) in
Vesselin Petkov
In this essay, dedicated to the one hundredth anniversary of Hermann Minkowski's talk "Space and Time", I argue that physicists should face the issue of the reality of spacetime and worldtubes of physical objects for two reasons. First, this issue is not a philosophical question, as some appear to think, since the kinematical special relativistic
M. Czakon, A. Mitov
We uncover a contribution to the NLO/NLL threshold resummed total cross section for top quark pair production at hadron colliders, which has not been taken into account in earlier literature. We derive this contribution - the difference between the singlet and octet hard (matching) coefficients - in exact analytic form. The numerical impact of our findings o
Christoph Baranec, Michael Hart, N. Mark Milton, Thomas Stalcup
We describe results from the first astronomical adaptive optics system to use multiple laser guide stars, located at the 6.5-m MMT telescope in Arizona. Its initial operational mode, ground-layer adaptive optics (GLAO), provides uniform stellar wavefront correction within the 2 arc minute diameter laser beacon constellation, reducing the stellar image widths
Maurizio Giannotti, Emil Mottola
The trace anomaly of quantum fields in electromagnetic or gravitational backgrounds implies the existence of massless scalar poles in physical amplitudes involving the stress-energy tensor. Considering first the axial anomaly and using QED as an example, we compute the full one-loop triangle amplitude of the fermionic stress tensor with two current vertices,
Fedor Simkovic, Amand Faessler, Petr Vogel
The measured occupancies of valence orbits in $^{76}$Ge and $^{76}$Se are used as a guideline for modification of the effective mean field energies that results in better description of these quantities. With them, in combination with the selfconsitent renormalized quasiparticle random phase approximation (SRQRPA) method that ensures conservation of the mean
Probing For New Physics and Detecting non linear vacuum QED effects using gravitational wave interferometer antennas
physics.ins-detG. Zavattini, E. Calloni
Low energy non linear QED effects in vacuum have been predicted since 1936 and have been subject of research for many decades. Two main schemes have been proposed for such a 'first' detection: measurements of ellipticity acquired by a linearly polarized beam of light passing through a magnetic field and direct light-light scattering. The study of the
David Delphenich
It is shown that one can obtain canonically-defined dynamical equations for non-conservative mechanical systems by starting with a first variation functional, instead of an action functional, and finding their zeroes. The kernel of the first variation functional, as an integral functional, is a 1-form on the manifold of kinematical states, which then represe
Satoru Katsuda, Hiroshi Tsunemi, Hiroyuki Uchida, Masashi Kimura
The X-ray structure of Kepler's supernova remnant shows a rounded shape delineated by forward shocks. We measure proper motions of the forward shocks on overall rims of the remnant, by using archival Chandra data taken in two epochs with time difference of 6.09 yr. The proper motions of the forward shocks on the northern rim are measured to be from 0.076