June 2004 arXiv papers — page 15
Showing 1,401–1,500 of 3,692 papers
The effects of non-universal extra dimensions on the radiative lepton flavor decays μ\to eγand τ\to μγin the two Higgs doublet model
hep-phE. O. Iltan
We study the effect of non-universal extra dimensions on the branching ratios of the lepton flavor violating processes μ\to eγand τ\to μγin the general two Higgs doublet model. We observe that these effects are small for a single extra dimension, however, in the case of two extra dimensions there is a considerable enhancement in the additional contributions.
U. Al Khawaja
The center-of-mass dynamics of a vortex in the surface region of a Bose-Einstein condensate is investigated both analytically using a variational calculation and numerically by solving the time-dependent Gross-Pitaevskii equation. We find, in agreement with previous works, that away from the Thomas-Fermi surface, the vortex moves parallel to the surface of t
Charles H-T Wang
A new approach to quantum gravity is presented based on a nonlinear quantization scheme for canonical field theories with an implicitly defined Hamiltonian. The constant mean curvature foliation is employed to eliminate the momentum constraints in canonical general relativity. It is, however, argued that the Hamiltonian constraint may be advantageously retai
O. Entin-Wohlman, A. Aharony, Y. Meir
We study the Kondo effect of a quantum dot placed in a complex mesoscopic structure. Assuming that electronic interactions are taking place solely on the dot, and focusing on the infinite Hubbard interaction limit, we use a decoupling scheme to obtain an explicit analytic approximate expression for the dot Green function, which fulfills certain Fermi-liquid
Alessandro D. A. M. Spallicci, Sofiane Aoudia, Jose De Freitas Pacheco, Giorgio Frossati
For future configurations, we study the relation between the abatement of the noise sources and the Signal to Noise Ratio (SNR) for coalescing binaries. Our aim is not the proposition of a new design, but an indication of where in the bandwidth or for which noise source, a noise reduction would be most efficient. We take VIRGO as the reference for our consid
V. Dzhunushaliev
It is shown that in 5D Kaluza-Klein theory there are everywhere regular wormhole-like solutions in which the magnetic field at the center is the origin of a rotation on the peripheral part of these solutions. The time on the peripheral part is topologically non-trivial and magnetic field is suppressed in comparison with the electric one.
Thomas G. Draper, Samuel A. Kutin, Eric M. Rains, Krysta M. Svore
We present an efficient addition circuit, borrowing techniques from the classical carry-lookahead arithmetic circuit. Our quantum carry-lookahead (QCLA) adder accepts two n-bit numbers and adds them in O(log n) depth using O(n) ancillary qubits. We present both in-place and out-of-place versions, as well as versions that add modulo 2^n and modulo 2^n - 1. Pr
Masaki Owari, Keiji Matsumoto, Mio Murao
It is shown that the order property of pure bipartite states under SLOCC (stochastic local operations and classical communications) changes radically when dimensionality shifts from finite to infinite. In contrast to finite dimensional systems where there is no pure incomparable state, the existence of infinitely many mutually SLOCC incomparable states is sh
Xian-Ting Liang
In this paper, we calculate the entanglement-assisted classical information capacity of amplitude damping channel and compare it with the particular mutual information which is considered as the entanglement-assisted classical information capacity of this channel in Ref. 6. It is shown that the difference between them is very small. In addition, we point out
Jin-Yuan Hsieh, Che-Ming Li
A quantum single-error-correcting scheme can be derived from a one-way entanglement purification protocol in purifying one Bell state from a finite block of five Bell states. The main issue to be concerned with in the theory of such an error-correction is to create specific linear Boolean functions that can transform the sixteen error syndromes occurring in
"Superluminal" tunnelling, quantum measurements and the speed of information transfer
quant-phD. Sokolovski, A. Z. Msezane, V. R. Shaginyan
We exploit the analogy between tunnelling across a potential barrier and Aharonov's weak measurements to resolve the long standing paradox between the impossibility to exceed the speed of light and the seemingly 'superluminal' behaviur of the tunnelling particle in the barrier. We demonstrate that 'superluminality' occurs when the value o
Bo Gao
We present a systematic understanding of the rotational structure of a long-range (vibrationally highly-excited) diatomic molecule. For example, we show that depending on a quantum defect, the least-bound vibrational state of a diatomic molecule with $-C_n/r^n$ ($n>2$) asymptotic interaction can have only 1, 2, and up to a maximum of $n-2$ rotational states.
P. Z. Bi
The modified model emission function S(x,p), with a uniform radial expansion mode and mass reduction, is used to study the single particle spectra and two particle correlation of pions. The calculated HBT radii and one particle spectra are compared with the data from $\sqrt(S_NN)$=130 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). We see
Energy dependence of elliptic flow over a large pseudorapidity range in Au+Au collisions at RHIC
nucl-exPHOBOS Collaboration
This paper describes the measurement of the energy dependence of elliptic flow for charged particles in Au+Au collisions using the PHOBOS detector at the Relativistic Heavy Ion Collider (RHIC). Data taken at collision energies of $\sqrt{s_{_{NN}}} =$ 19.6, 62.4, 130 and 200 GeV are shown over a wide range in pseudorapidity. These results, when plotted as a f
Sergiu I. Vacaru
We outline a new geometric method of constructing exact solutions of gravitational field equations parametrized by generic off-diagonal metrics, anholonomic frames and possessing, in general, nontrivial torsion and nonmetricity. The formalism of nonlinear connections is elaborated for (pseudo) Riemannian and Einstein-Cartan-Weyl spaces.
E. Ostrovsky, L. Sirota
In this article we investigate the Fourier series and transforms for the functions defined on the $ [0, 2 π]^ d $ or $ R^d $ and belonging to the exponential Orlicz and some other rearrangement invariant (r.i.) spaces.
Hyuk Han, Seunghyun Seo
Let the Bessel number of the second kind B(n,k) be the number of set partitions of [n] into k blocks of size one or two, and let the Bessel number of the first kind b(n,k) be a certain coefficient in n-th Bessel polynomial. In this paper, we show that Bessel numbers satisfy two properties of Stirling numbers: The two kinds of Bessel numbers are related by in
Hajime Nagoya
We propose quantum Painlevé systems of type $A_l^{(1)}$. These systems, for $l=1$ and $l\ge 2$, should be regarded as quantizations of the second Painlevé equation and the differential systems with the affine Weyl group symmetries of type $A_l^{(1)}$ studied by M. Noumi and Y. Yamada \cite{NYhigherorder}, respectively. These quantizations enjoy the affine We
Bertrand Toen, Gabriele Vezzosi
This is the first of a series of papers devoted to lay the foundations of Algebraic Geometry in homotopical and higher categorical contexts (for part II, see math.AG/0404373). In this first part we investigate a notion of higher topos. For this, we use S-categories (i.e. simplicially enriched categories) as models for certain kind of \infty-categories, and w
Noncommutative Field Theory on Yang's Space-Time Algebra, Covariant Moyal Star Product and Matrix Model
hep-thSho Tanaka
Noncommutative field theory on Yang's quantized space-time algebra (YSTA) is studied. It gives a theoretical framework to reformulate the matrix model as quantum mechanics of $D_0$ branes in a Lorentz-covariant form. The so-called kinetic term ($\sim {\hat{P_i}}^2)$ and potential term ($\sim {[\hat{X_i},\hat{X_j}]}^2)$ of $D_0$ branes in the matrix model
Han-Ying Guo, Chao-Guang Huang, Yu Tian, Zhan Xu
Weakening the Euclidean assumption in special relativity and the coordinate-independence hypothesis in general relativity for the de Sitter space, we propose a de Sitter invariant special relativity with two universal constants of speed $c$ and length $R$ based on the principle of relativity and the postulate of universal constants $c$ and $R$ on de Sitter s
R. Teodorescu, E. Bettelheim, O. Agam, A. Zabrodin
In general or normal random matrix ensembles, the support of eigenvalues of large size matrices is a planar domain (or several domains) with a sharp boundary. This domain evolves under a change of parameters of the potential and of the size of matrices. The boundary of the support of eigenvalues is a real section of a complex curve. Algebro-geometrical prope
A. Nehme
We consider electromagnetic corrections to the non-leptonic kaon decay, $K^+\toπ^+π^0π^0$, due to explicit virtual photons only. The decay amplitude is calculated at one-loop level in the framework of Chiral Perturbation Theory. The interest in this process is twofold: It is actually measured by the NA48 collaboration from one side, and, the value of the amp
Sean A. Hayward, Hiroko Koyama
The theoretical construction of a traversable wormhole from a Schwarzschild black hole is described, using analytic solutions in Einstein gravity. The matter model is pure phantom radiation (pure radiation with negative energy density) and the idealization of impulsive radiation is employed.
Akihisa Koga, Norio Kawakami, T. M. Rice, Manfred Sigrist
We investigate the Mott transitions in the two-orbital Hubbard model with different bandwidths. By combining dynamical mean field theory with the exact diagonalization, we discuss the stability of itinerant quasi-particle states in each band. We demonstrate that separate Mott transitions occur at different Coulomb interaction strengths in general, which merg
Elad Shopen, Yuval Gefen, Yigal Meir
This is a qualitative description of a systematic analysis carried out by us. We address the question of whether fractionally charged particles, in the context of the fractional quantum Hall effect (FQHE) can tunnel through a potential barrier (around which the density of the quantum Hall liquid is practically zero). Setting the barrier in a multiply-connect
J. Smiseth, E. Smorgrav, A. Sudbo
The critical properties of $N$-color London model are studied in $d=2+1$ dimensions. The model is dualized to a theory of $N$ vortex fields interacting through a Coulomb and a screened potential. The model with N=2 shows two anomalies in the specific heat. From the critical exponents $α$ and $ν$, the mass of the gauge field, and the vortex correlation functi
R. E. Mason, G. Wright, Y. Pendleton, A. Adamson
We present new spectroscopic observations of the 3.4 micron absorption feature in the Seyfert galaxies, NGC1068 and NGC7674, and the ultraluminous infrared galaxy, IRAS08572+3915. A signature of C-H bonds in aliphatic hydrocarbons, the 3.4 micron feature indicates the presence of organic material in Galactic and extragalactic dust. Here we compare the 3.4 mi
Alice C. Quillen, Eric G. Blackman, Adam Frank, Peggy Varniere
Spitzer observations of the young star CoKuTau/4 reveal a disk with a 10 AU hole that is most likely caused by a newly formed planet. Assuming that the planet opened a gap in the viscous disk, we estimate that the planet mass is greater than 0.1 Jupiter masses. This estimate depends on a lower limit to the disk viscosity derived from the time scale needed to
Moncy V. John
The apparent magnitude-redshift data of SNe Ia call for modifications in the standard model energy densities. Under the circumstance that this modification cannot be limited to the addition of a mere cosmological constant, a serious situation has emerged in cosmology, in which the energy densities in the universe have become largely speculative. In this situ
K. Bekki, W. J. Couch, M. A. Beasley, D. A. Forbes
The Large Magellanic Cloud (LMC) has a unique cluster formation history in that nearly all of its globular clusters were formed either $\sim$ 13 Gyr ago or less than $\sim$ 3 Gyr ago. It is not clear what physical mechanism is responsible for the most recent cluster formation episode and thus the mysterious age gap between the LMC clusters. We first present
Kenji Bekki, Warrick J. Couch, Michael J. Drinkwater, Yasuhiro Shioya
Recently, very massive compact stellar systems have been discovered in the intracluster regions of galaxy clusters and in the nuclear regions of late-type disk galaxies. It is unclear how these compact stellar systems -- known as ``ultra-compact dwarf'' (UCD) galaxies or ``nuclear clusters'' (NCs) -- form and evolve. By adopting a formation s
David J. Jeffery
We propose a bipolar jet model for supernova polarization. Light from the main component of the supernova (which we call the bulk supernova for short) scatters off electrons in the jets and is polarized: this polarized light is added to the direct emission from the bulk supernova and causes the overall supernova emission to be polarized. The motivation for t
Elena R. Loubenets
For linear combinations of quantum product averages in an arbitrary bipartite state, we derive new quantum Bell-form and CHSH-form inequalities with the right-hand sides expressed in terms of a bipartite state. This allows us to specify in a general setting bipartite state properties sufficient for the validity of a classical CHSH-form inequality and the per
James Conant, Karen Vogtmann
Using Kontsevich's identification of the homology of the Lie algebra l_infty with the cohomology of Out(F_r), Morita defined a sequence of 4k-dimensional classes mu_k in the unstable rational homology of Out(F_{2k+2}). He showed by a computer calculation that the first of these is non-trivial, so coincides with the unique non-trivial rational homology cl
Peter Hasenfratz
As a non-perturbative and gauge invariant regularization the lattice provides a tool for deeper understanding of the celebrated Yang-Mills theory, QCD and chiral gauge theories. For illustration, I discuss some analytic developments on the lattice related to chiral symmetry, chiral fermions and improvement programs. Chiral symmetry on the lattice has an amaz
Failure properties of loaded fiber bundles having a lower cutoff in fiber threshold distribution
cond-mat.stat-mechSrutarshi Pradhan, Alex Hansen
Presence of lower cutoff in fiber threshold distribution may affect the failure properties of a bundle of fibers subjected to external load. We investigate this possibility both in a equal load sharing (ELS) fiber bundle model and in local load sharing (LLS) one. We show analytically that in ELS model, the critical strength gets modified due to the presence
Andrea Mori
Let x be a CM point on a modular or Shimura curve and p a prime of good reduction, split in the CM field K. We define an expansion of an holomorphic modular form f in the p-adic neighborhood of x and show that the expansion coefficients give information on the p-adic ring of definition of f. Also, we show that letting x vary in its Galois orbit, the expansio
Mark D. Roberts
In a certain sense a perfect fluid is a generalization of a point particle. This leads to the question as to what is the corresponding generalization for extended objects. The lagrangian formulation of a perfect fluid is much generalized and this has as a particular example a fluid which is a classical generalization of a membrane, however there is as yet no
D. V. Vassilevich
We study quantisation of noncommutative gravity theories in two dimensions (with noncommutativity defined by the Moyal star product). We show that in the case of noncommutative Jackiw-Teitelboim gravity the path integral over gravitational degrees of freedom can be performed exactly even in the presence of a matter field. In the matter sector, we study possi
Francois Englert
From its inception in statistical physics to its role in the construction and in the development of the asymmetric Yang-Mills phase in quantum field theory, the notion of spontaneous broken symmetry permeates contemporary physics. This is reviewed with particular emphasis on the conceptual issues.
Piotr T. Chrusciel
We show that positivity of energy for stationary, or strongly uniformly Schwarzschildian, asymptotically flat, non-singular domains of outer communications can be proved using Galloway's null rigidity theorem.
Oded Hod, Eran Rabani, Roi Baer
We demonstrate the physical principles for the construction of a nanometer sized magnetoresistance device based on the Aharonov-Bohm effect. The proposed device is made of a short single-walled carbon nanotube (SWCNT) placed on a substrate and coupled to a tip. We consider conductance due to motion of electrons along the circumference of the tube (as opposed
Mun Dae Kim, Jongbae Hong
We study the current-phase relation of the superconductor/normal/superconductor (SNS) junction imbedded in a superconducting loop. Considering the current conservation and free energy minimum conditions, we obtain the persistent currents of the normal/superconductor (NS) loop. At finite temperature we can explain the experimentally observed highly non-sinuso
Ultralong coherence times in the purely electronic zero-phonon line emission of single molecules
quant-phAlper Kiraz, Moritz Ehrl, Christoph Bräuchle, Andreas Zumbusch
We report the observation of ultralong coherence times in the purely electronic zero-phonon line emission of single terrylenediimide molecules at 1.4 K. Vibronic excitation and spectrally resolved detection with a scanning Fabry-Perot spectrum analyzer were used to measure a linewidth of 65 MHz. This is within a factor of 1.6 of the transform limit. It there
Bruno Galvan
A new hidden variable theory is proposed, according to which particles follows definite trajectories, as in Bohmian Mechanics or Nelson's stochastic mechanics; in the new theory, however, the trajectories are classical, i.e. Newtonian. This result is obtained by developing the following concepts: (i) the essential elements of a hidden variable theory are
Discovery of Daemons Makes Power Generation by Daemon-Assisted Catalysis of Light Nuclei Fusion in a Ball Lightning a Reality
physics.gen-phE. M. Drobyshevski
In 1997, we proposed a model of the ball lightning (BL) whose activity is accounted for by energy release in the fusion of light nuclei, most probably, carbon in organic fibers (Proc. ISBL 97, p.157). The fusion is provided by catalytic action of superheavy negative particles making up the Galactic Dark Matter. We called them DArk Electric Matter Objects, or
T. Di Matteo, T. Aste, M. Gallegati
A detailed empirical analysis of the productivity of non financial firms across several countries and years shows that productivity follows a non-Gaussian distribution with power law tails. We demonstrate that these empirical findings can be interpreted as consequence of a mechanism of exchanges in a social network where firms improve their productivity by d
Denes Molnar
The influence of spacetime dynamics in hadronization via parton coalescence at RHIC is investigated using covariant parton transport theory. Key observables, the quark number scaling of elliptic flow and the enhancement of the p/pi ratio, show strong dynamical effects and differ from earlier results based on the simple coalescence formulas.
Fariel Shafee
We propose a new way of defining entropy of a system, which gives a general form which may be nonextensive as Tsallis entropy, but is linearly dependent on component entropies, like Renyi entropy, which is extensive. This entropy has a conceptually novel but simple origin and is mathematically easy to define by a very simple expression, though the probabilit
Dyon Solution in Einstein-Yang-Mills Theory on a Cylindrical Symmetric Space Time with Cosmological Constant
math-phReinoud J. Slagter
We investigated numerically dyon-like solutions of the SU(2) Einstein-Yang-Mills system on a cylindrically symmetric space time with a cosmological constant. We find a new kind of behaviour not found in the spherically symmetric models. For positive values of $Λ$ we have an oscillatory behaviour of the magnetic component of the YM field around the r-axis, so
Nataliya M. Ivanova
We investigate conservation laws of diffusion-convection equations to construct first-order potential systems corresponding to these equations. We do two iterations of the construction procedure, looking, in the second step, for the first-order conservation laws of the potential systems obtained in the first step.
Atiyah-Sutcliffe Conjectures for Almost Collinear Configurations and Some New Conjectures for Symmetric Functions
math.AGDragutin Svrtan, Igor Urbiha
In 2001 Sir M. F. Atiyah formulated a conjecture (C1) and later with P. Sutcliffe two stronger conjectures (C2) and (C3). These conjectures, inspired by physics (spin-statistics theorem of quantum mechanics), are geometrically defined for any configuration of points in the Euclidean three space. The conjecture (C1) is proved for n=3,4 and for general n only
Hagen Knaf
A not necessarily noetherian local ring O is called regular if every finitely generated ideal I of O possesses finite projective dimension. In the article localizations O of a finitely presented, flat algebra A over a Pruefer domain R at a prime q are investigated with respect to regularity: this property of O is shown to be equivalent to the finiteness of t
Mike Roth, Ravi Vakil
We define the affine stratification number asn X of a scheme X. For X equidimensional, it is the minimal number k such that there is a stratification of X by locally closed affine subschemes of codimension at most k. We show that the affine stratification number is well-behaved, and bounds many aspects of the topological complexity of the scheme, such as van
Krzysztof Maslanka
In this paper we present a new formula relating Stieltjes numbers $γ_{n}$ and Laurent coefficinets $η_{n}$ of logarithmic derivative of the Riemann's zeta function. Using it we derive an explicit formula for the oscillating part of Li's numbers $\overset{\sim}λ_{n}$ which are connected with the Riemann hypothesis.
R. F. Sobreiro, S. P. Sorella, D. Dudal, H. Verschelde
The effect of the dynamical mass generation on the gluon and ghost propagators in Euclidean Yang-Mills theory in the Landau gauge is analysed within Zwanziger's local formulation of the Gribov horizon.
Hongbo Cheng, Zhengyan Gu
In this letter the nontopological scalar solitons with a self-interaction potential are investigated in a static de Sitter spacetime and their field equations are derived. In particular, with series expansion we prove analytically the nonexistence of the solutions under the boundary conditions, which show that some nontopological solitons can not live in the
Dimensional Reduction of ten-dimensional Supersymmetric Gauge Theories in the N=1, D=4 Superfield Formalism
hep-phP. Manousselis, G. Zoupanos
A ten-dimensional supersymmetric gauge theory is written in terms of N=1, D=4 superfields. The theory is dimensionally reduced over six-dimensional coset spaces. We find that the resulting four-dimensional theory is either a softly broken N=1 supersymmetric gauge theory or a non-supersymmetric gauge theory depending on whether the coset spaces used in the re
Harald Fritzsch, Zhi-zhong Xing
We reexamine the democratic neutrino mixing ansatz, in which the mass matrices of charged leptons and Majorana neutrinos arise respectively from the explicit breaking of S(3)_L x S(3)_R and S(3) flavor symmetries. It is shown that a democracy term in the neutrino sector can naturally allow the ansatz to fit the solar neutrino mixing angle θ_sun \approx 33^\c
J. Manjavidze, V. Voronyuk
The t`Hooft's ansatz reduces the classical Yang--Mills theory to the $λϕ^4$ one. It is shown that in the frame of this ansatz the real-time classical solutions for the arbitrary SU(N) gauge group is obtained by embedding $SU(2)\times SU(2)$ into SU(N). It is argued that this group structure is the only possibility in the frame of the considered ansatz. N
A. Cervera Villanueva
The first physics results of the HARP experiment are presented. We emphasize the high performance of the forward part of the apparatus. The differential raw pion yield and its efficiency correction up to polar angles of 250 mrad are shown. The analysed setting is 12.9 GeV/c incident protons in a 5% interacion legth aluminium target.
Naida Lacevic, Sharon C. Glotzer
The relationship between spatially heterogeneous dynamics (SHD) and jamming is studied in a glass-forming binary Lennard-Jones system via molecular dynamics simulations. It has been suggested that the probability distribution of interparticle forces $P(F)$ develops a peak at the glass transition temperature $T_g$, and that the large force inhomogeneities, re
V. M. Somsikov
The irreversibility of the dynamics of the conservative systems on example of hard disks and potentially of interacting elements is investigated in terms of laws of classical mechanics. The equation of the motion of interacting systems and the formula, which expresses the entropy through the generalized forces, are obtained. The explanation of irreversibilit
A. Sen, S. L. Chaplot, R. Mittal
Possible variations in the dynamical behaviour of LiYF$_{4}$ due to its structural changes following several pressure-induced phase transitions are examined by making use of the complementary techniques of quasi-harmonic lattice dynamics and molecular dynamics simulation. The phonon spectra in the entire Brillouin zone and the respective Gibbs free energies
Askhat Gazizov, Marek P. Kowalski
We present the high-energy neutrino Monte Carlo event generator ANIS (All Neutrino Interaction Simulation). The program provides a detailed and flexible neutrino event simulation for high-energy neutrino detectors, such as AMANDA, ANTARES or ICECUBE. It generates neutrinos of any flavor according to a specified flux and propagates them through the Earth. In
ISO Observations of the 53W002 Group at 6.7 microns: In Search of the Oldest Stellar Populations at z=2.4
astro-phW. C. Keel, W. Wu, P. P. van der Werf, R. A. Windorst
We present a deep ISO observation at 6.7 microns of the 53W002 group of galaxies and AGN at z=2.4. This approximately samples the emitted K band. The faint, blue star-forming objects are not detected, as expected from their very blue color across the emitted optical and UV. However, 53W002 itself is detected at the 3-sigma level, with an emitted V-K color ap
Spectroscopy of Very Low Mass Stars and Brown Dwarfs in IC2391: Lithium depletion and Halpha emission
astro-phDavid Barrado y Navascues, John R. Stauffer, Ray Jayawardhana
We have obtained intermediate-resolution optical spectroscopy of 44 candidate very low mass members of the nearby young open cluster IC2391. Of these, 26 spectra are totally new, 14 were already analyzed in a previous paper and another four are in common. These spectra, taken at the Cerro Tololo 4-meter and Magellan I and II telescopes, allow us to confirm 3
Marcella Brusa
Observations at high energies yield important information on the structure and nature of AGN; when coupled with deep optical and near-infrared (photometric and spectroscopic) follow-up, they provide constraints on the mass of the growing black holes and, therefore, are essential to better understand the nature of the various components of the X-ray backgroun
Lara B. Anderson, James T. Wheeler
Biconformal spaces contain the essential elements of quantum mechanics, making the independent imposition of quantization unnecessary. Based on three postulates characterizing motion and measurement in biconformal geometry, we derive standard quantum mechanics, and show how the need for probability amplitudes arises from the use of a standard of measurement.
Andrés Sicard, Mario Vélez, Juan Ospina
The term `hypermachine' denotes any data processing device (theoretical or that can be implemented) capable of carrying out tasks that cannot be performed by a Turing machine. We present a possible quantum algorithm for a classically non-computable decision problem, Hilbert's tenth problem; more specifically, we present a possible hypercomputation mo
Ioannis V. Sideris, Courtlandt L. Bohn
We investigate how collective modes and colored noise conspire to produce a beam halo with much larger amplitude than could be generated by either phenomenon separately. The collective modes are lowest-order radial eigenmodes calculated self-consistently for a configuration corresponding to a direct-current, cylindrically symmetric, warm-fluid Kapchinskij-Vl
Jaume Garriga, Massimo Porrati
There have been some recent claims that brane-worlds of co-dimension two in a 6D bulk with compact extra dimensions may lead to self-tuning of the effective 4D cosmological constant. Here we show that if a phase transition occurs on a flat brane, so as to change its tension, then the brane will not remain flat. In other words, there is really no self-tuning
Marek Biskup
We study the asymptotic growth of the diameter of a graph obtained by adding sparse "long" edges to a square box in $\Z^d$. We focus on the cases when an edge between $x$ and $y$ is added with probability decaying with the Euclidean distance as $|x-y|^{-s+o(1)}$ when $|x-y|\to\infty$. For $s\in(d,2d)$ we show that the graph diameter for the graph red
Allen Hatcher, Karen Vogtmann
We prove that the quotient map from Aut(F_n) to Out(F_n) induces an isomorphism on homology in dimension i for n at least 2i+4. This corrects an earlier proof by the first author and significantly improves the stability range. In the course of the proof, we also prove homology stability for a sequence of groups which are natural analogs of mapping class grou
C. P. Hughes, A. Nikeghbali
In this paper we deduce a universal result about the asymptotic distribution of roots of random polynomials, which can be seen as a complement to an old and famous result of Erdos and Turan. More precisely, given a sequence of random polynomials, we show that, under some very general conditions, the roots tend to cluster near the unit circle, and their angle
M. Hossein Partovi, Eliza J. Morris
The popular demonstration involving a permanent magnet falling through a conducting pipe is treated as an axially symmetric boundary value problem. Specifically, Maxwell's equations are solved for an axially symmetric magnet moving coaxially inside an infinitely long, conducting cylindrical shell of arbitrary thickness at nonrelativistic speeds. Analytic
C. Hernandez-Monteagudo, R. Genova-Santos, F. Atrio-Barandela
By cross-correlating templates constructed from the 2 Micron All Sky Survey (2MASS) Extended Source (XSC) catalogue with WMAP's first year data, we search for the thermal Sunyaev-Zel'dovich signature induced by hot gas in the local Universe. Assuming that galaxies trace the distribution of hot gas, we select regions on the sky with the largest projec
The HERMES Collaboration, A. Airapetian
Hard exclusive electroproduction of $π^+π^-$ pairs off hydrogen and deuterium targets has been studied by the HERMES experiment at DESY. Legendre moments $<P_1>$ and $<P_3>$ of the angular distributions of $π^+$ mesons in the center-of-mass frame of the pair have been measured for the first time. Their dependence on the $π^+π^-$ invariant mass can be underst
M. Czakon, J. Gluza, T. Riemann
We define a complete set of scalar master integrals (MIs) for massive 2-loop QED Bhabha scattering. Among others, there are thirty three 2-loop box type MIs. Five of them have been published in (semi-)analytical form, one is determined here, the rest remains to be calculated. Further, the last four so far unknown 2-loop 3-point MIs are identified and also co
Giorgi Japaridze
Computability logic is a formal theory of computational tasks and resources. Its formulas represent interactive computational problems, logical operators stand for operations on computational problems, and validity of a formula is understood as being a scheme of problems that always have algorithmic solutions. A comprehensive online source on the subject is
S. L. Bud'ko, E. Morosan, P. C. Canfield
Temperature- and field-dependent Hall effect measurements are reported for YbAgGe, a heavy fermion compound exhibiting a field-induced quantum phase transition, and for two other closely related members of the RAgGe series: a non-magnetic analogue, LuAgGe and a representative, ''good local moment'', magnetic material, TmAgGe. Whereas the temp
Antonio Padilla
We consider a single 3-brane sitting in between two different five dimensional spacetimes. On each side of the brane, the bulk is a solution to Gauss-Bonnet gravity, although the bare cosmological constant, funda mental Planck scale, and Gauss-Bonnet coupling can differ. This asymmetry leads to weighted junction conditions across the brane and interesting br
S. Laycock, R. H. D. Corbet, M. J. Coe, F. E. Marshall
Results of a 4 year monitoring campaign of the SMC using the Rossi X-ray timing Explorer (RXTE) are presented. This large dataset makes possible detailed investigation of a significant sample of SMC X-ray binaries. 8 new X-ray pulsars were discovered and a total of 20 different systems were detected. Spectral and timing parameters were obtained for 18. In th
Optimal Free-Space Management and Routing-Conscious Dynamic Placement for Reconfigurable Devices
cs.DSAli Ahmadinia, Christophe Bobda, Sandor Fekete, Juergen Teich
We describe algorithmic results for two crucial aspects of allocating resources on computational hardware devices with partial reconfigurability. By using methods from the field of computational geometry, we derive a method that allows correct maintainance of free and occupied space of a set of n rectangular modules in optimal time Theta(n log n); previous a
Csaba Schneider
We adopt the $p$-group generation algorithm to classify small-dimensional nilpotent Lie algebras over small fields. Using an implementation of this algorithm, we list the nilpotent Lie algebras of dimension at most~9 over $\F_2$ and those of dimension at most~7 over $\F_3$ and $\F_5$.
V. K. Dobrev
We give character formulae for the positive energy unitary irreducible representations of the N-extended D=4 conformal superalgebras su(2,2/N). Using these we also derive decompositions of long superfields as they descend to the unitarity threshold. These results are also applicable to irreps of the complex Lie superalgebras sl(4/N). Our derivations use resu
A. Dainese, C. Loizides, G. Paic
Parton energy loss effects in heavy-ion collisions are studied with the Monte Carlo program PQM (Parton Quenching Model) constructed using the BDMPS quenching weights and a realistic collision geometry. The merit of the approach is that it contains only one free parameter that is tuned to the high-pt nuclear modification factor measured in central Au-Au coll
D. K. Hong, S. D. Hsu, F. Sannino
We investigate new models of dynamical electroweak symmetry breaking resulting from the condensation of fermions in higher representations of the technicolor group. These models lie close to the conformal window, and are free from the flavor-changing neutral current problem despite small numbers of flavors and colors. Their contribution to the S parameter is
Reducing the mirrors coating noise in laser gravitational-wave antennae by means of double mirrors
gr-qcF. Ya. Khalili
Recent researches show that the fluctuations of the dielectric mirrors coating thickness can introduce a substantial part of the future laser gravitational-wave antennae total noise budget. These fluctuations are especially large in the high-reflectivity end mirrors of the Fabry-Perot cavities which are being used in the laser gravitational-wave antennae. We
B. Grbic, C. Ellenberger, T. Ihn, K. Ensslin
High-quality C-doped p-type AlGaAs heterostructures with mobilities exceeding 150 000 cm$^2$/Vs are investigated by low-temperature magnetotransport experiments. We find features of the fractional quantum Hall effect as well as a highly resolved Shubnikov-de Haas oscillations at low magnetic fields. This allows us to determine the densities, effective masses
Alexandra Olaya-Castro, Neil F. Johnson
Semiconductor quantum dots integrated with ultrafast spectroscopy technology are prime candidates for building scalable architectures for Quantum Information Processing. In this review paper we survey the current state of theoretical proposals concerning all-optical control of nanostructure qubits and their interactions. These schemes offer potential for ult
P. Busch, P. J. Lahti
Three notions of complementarity - operational, probabilistic, and value complementarity - are reanalysed with respect to the question of joint measurements and compared with reference to some examples of canonically conjugate observables. It is shown that the joint measurability of noncommuting observables is a consequence of the quantum formalism if unshar
D. Huard, H. Kröger, G. Melkonyan, L. P. Nadeau
We consider a mixed chaotic Hamiltonian system and compare classical with quantum chaos. As alternative to the methods of enegy level spacing statistics and trace formulas, we construct a quantum action and a quantum analogue phase space to analyse quantum chaos.
Nguyen Ba An
We propose an entanglement-based protocol for two people to simultaneously exchange their messages. We show that the protocol is asymptotically secure against the disturbance attack, the intercept-and-resend attack and the entangle-and-measure attack. Our protocol is experimentally feasible within current technologies.
Edward W. Piotrowski, J. Sladkowski
This is a short review of the background and recent development in quantum game theory and its possible application in economics and finance. The intersection of science and society is also discussed. The review is addressed to non--specialists.
H. H. Adamyan, G. Yu. Kryuchkyan
We explore in detail the possibility of intracavity generation of continuous-variable (CV) entangled states of light beams under mode phase-locked conditions. We show that such quantum states can be generated in self-phase locked nondegenerate optical parametric oscillator (NOPO) based on a type-II phase-matched down-conversion combined with linear mixer of
Stefan Scheel
We develop an abstract look at linear optical networks from the viewpoint of combinatorics and permanents. In particular we show that calculation of matrix elements of unitarily transformed photonic multi-mode states is intimately linked to the computation of permanents. An implication of this remarkable fact is that all calculations that are based on evalua
Thomas B. Bahder
A quantum positioning system (QPS) is proposed that can provide a user with all four of his space-time coordinates. The user must carry a corner cube reflector, a good clock, and have a two-way classical channel of communication with the origin of the reference frame. Four pairs of entangled photons (biphotons) are sent through four interferometers: three in
Silvio R. Dahmen, Jon Links, Ross H. McKenzie, Huan-Qiang Zhou
We study the distribution of energy level spacings in two models describing coupled single-mode Bose-Einstein condensates. Both models have a fixed number of degrees of freedom, which is small compared to the number of interaction parameters, and is independent of the dimensionality of the Hilbert space. We find that the distribution follows a universal Pois