June 2007 arXiv papers — page 28

Jaime Merino

The charge ordering transition induced by the nearest-neighbor Coulomb repulsion, V, in the 1/4-filled extended Hubbard model is investigated using Cellular Dynamical Mean-Field Theory. We find a transition to a strongly renormalized charge ordered Fermi liquid at VCO and a metal-to-insulator transition at VMI>VCO. Short range antiferromagnetism occurs conco

Victor Katsnelson, Alexander Kheifets, Peter Yuditskii

The algebraic structure of V.P. Potapov's Fundamental Matrix Inequality (FMI) is discussed and its interpolation meaning is analyzed. Functional model spaces are involved. A general Abstract Interpolation Problem is formulated which seems to cover all the classical and recent problems in the field and the solution set of this problem is described using t

R. Fetzer, M. Rauscher, R. Seemann, K. Jacobs

Experiments on dewetting thin polymer films confirm the theoretical prediction that thermal noise can strongly influence characteristic time-scales of fluid flow and cause coarsening of typical length scales. Comparing the experiments with deterministic simulations, we show that the Navier-Stokes equation has to be extended by a conserved bulk noise term to

Mikhail Shaposhnikov

We describe an extention of the Standard Model (the $ν$MSM) by three light singlet Majorana fermions -- sterile neutrinos, which allows to address simultaneously the problem of neutrino oscillations and the problems of dark matter and baryon asymmetry of the Universe. We discuss the ways these new particles can be searched for in astrophysical, laboratory, a

S. L. Parameswaran, S. Randjbar-Daemi, A. Salvio

We investigate the dynamical stability of warped, axially symmetric compactifications in anomaly free 6D gauged supergravity. The solutions have conical defects, which we source by 3-branes placed on orbifold fixed points, and a smooth limit to the classic sphere-monopole compactification. Like for the sphere, the extra fields that are generically required b

R. Wunsch, S. Silich, J. Palous, G. Tenorio-Tagle

We look for a simple analytic model to distinguish between stellar clusters undergoing a bimodal hydrodynamic solution from those able to drive only a stationary wind. Clusters in the bimodal regime undergo strong radiative cooling within their densest inner regions, which results in the accumulation of the matter injected by supernovae and stellar winds and

Victor Katsnelson

According to V.P.Potapov, a classical interpolation problem can be reformulated in terms of a so-called Fundamental Matrix Inequality (FMI). To show that every solution of the FMI satisfies the interpolation problem, we usualy have to transform the FMI in some special way. In this paper the number of of transformations of the FMI which come into play are mot

L. Schreiber, M. Heidkamp, T. Rohleder, B. Beschoten

The longest spin lifetimes in bulk n-GaAs exceed 100 ns for doping concentrations near the metal-insulator transition (J.M. Kikkawa, D.D. Awschalom, Phys. Rev. Lett. 80, 4313 (1998)). The respective electronic states have yet not been identified. We therefore investigate the energy dependence of spin lifetimes in n-GaAs by time-resolved Kerr rotation. Spin l

P. M. R. Brydon

The extended Falicov-Kimball model, with both an on-site hybridization potential and dispersive narrow band, is examined within the saddle-point approximation to the Kotliar-Ruckenstein slave boson theory. We first set the hybridization potential to zero and find that the phase diagram depends strongly upon the orbital structure: for degenerate orbitals, a c

A. Podlesnyak, V. Pomjakushin, E. Pomjakushina, K. Conder

Inelastic neutron scattering experiments were performed for the spin-trimer compounds Ca3Cu3-xNix(PO4)4 (x=0,1,2) in order to study the dynamic magnetic properties. The observed excitations can be associated with transitions between the low-lying electronic states of linear Cu-Cu-Cu, Cu-Cu-Ni, and Ni-Cu-Ni trimers which are the basic constituents of the titl

A. Capella, E. G. Ferreiro

We present our predictions on multiplicities and $J/ψ$ suppression at LHC energies. Our results take into account shadowing effects in the initial state and final state interactions with the hot medium. We obtain 1800 charged particles at LHC and the $J/ψ$ suppression increases by a factor 5 to 6 compared to RHIC.

Patrice Salzenstein, Jan Cermak, Roland Barillet, Frederic Lefebvre

This paper reports main results of the phase noise comparison that has been performed between october 2005 and december 2006, using two oscillators at 5 and 100 MHz and un DRO at 3.5 GHz. The problem is not to compare the performances of several oscillators, but to compare and to make an evaluation of the uncertainties, and of course the resolution and the r

Yi-Shi Duan, Zhen-Bin Cao

In this paper, based on the gauge potential decomposition and the $ϕ-$mapping theories, we study the topological structures and properties of the cosmic strings that arise in the Abelian-Higgs gauge theory in the zero-thickness limit. After a detailed discussion, we conclude that the topological tensor current introduced in our model is a better and more bas

F. den Hollander, N. Petrelis

In this paper we review some recent results, obtained jointly with Stu Whittington, for a mathematical model describing a copolymer in an emulsion. The copolymer consists of hydrophobic and hydrophilic monomers, concatenated randomly with equal density. The emulsion consists of large blocks of oil and water, arranged in a percolation-type fashion. To make th

Jean-Marc Couveignes

I present examples of mathematical objects that are of interest for public key cryptography. Text for the Journée Annuelle 2007 of the SMF.

S. R. Hildebrandt, R. Rebolo, J. A. Rubiño-Martín, R. A. Watson

We present observations with the new 11 GHz radiometer of the COSMOSOMAS experiment at the Teide Observatory (Tenerife). The sky region between 0 deg <= RA <= 360 deg and 26 deg <= DEC 49 deg (ca. 6500 square degrees) was observed with an angular resolution of 0.9 deg. Two orthogonal independent channels in the receiving system measured total power signals f

V. Pietila, M. Mottonen, S. M. M. Virtanen

We study the energetic and dynamic stability of coreless vortices in nonrotated spin-1 Bose-Einstein condensates, trapped with a three-dimensional optical potential and a Ioffe-Pritchard field. The stability of stationary vortex states is investigated by solving the corresponding Bogoliubov equations. We show that the quasiparticle excitations corresponding

M. Brueggen, S. Heinz, E. Roediger, M. Ruszkowski

Feedback by active galactic nuclei (AGN) is frequently invoked to explain the cut-off of the galaxy luminosity function at the bright end and the absence of cooling flows in galaxy clusters. Meanwhile, there are recent observations of shock fronts around radio-loud AGN. Using realistic 3D simulations of jets in a galaxy cluster, we address the question what

Harry Dym, Victor Katsnelson

The name Schur is associated with many terms and concepts that are widely used in a number of diverse fields of mathematics and engineering. This survey article focuses on Schur&#39;s work in analysis. Here too, Schur&#39;s name is commonplace: The Schur test and Schur-Hadamard multipliers (in the study of estimates for Hermitian forms), Schur convexity, Sch

Arif. I. Shoshi

Recent theoretical progress in understanding high-energy scattering beyond the mean field approximation is reviewed. The role of Lorentz invariance and pomeron loops in the evolution, the relation between high-energy QCD and statistical physics and results for the saturation momentum and the scattering amplitude are discussed.

Richard de Grijs

The Hubble Space Telescope (HST) has been instrumental in the discovery of large numbers of extragalactic young massive star clusters (YMCs), often assumed to be proto-globular clusters (GCs). As a consequence, the field of YMC formation and evolution is thriving, generating major breakthroughs as well as controversies on annual (or shorter) time-scales. Her

Xiaoping Xu

In this paper, we use various ansatzes with undetermined functions and the technique of moving frame to find solutions with parameter functions modulo the Lie point symmetries for the classical non-steady boundary layer problems. These parameter functions enable one to find the solutions of some related practical models and boundary value problems.

Yuki Nagai, Yusuke Kato, Nobuhiko Hayashi, Kunihiko Yamauchi

To determine the superconducting gap function of YNi2B2C, we calculate the local density of states (LDOS) around a single vortex core with the use of Eilenberger theory and the band structure calculated by local density approximation assuming various gap structures with point-nodes at different positions. We also calculate the angular-dependent heat capacity

Bernard Hanzon, Jan M. Maciejowski, Chun Tung Chou

A method is given for solving an optimal H2 approximation problem for SISO linear time-invariant stable systems. The method, based on constructive algebra, guarantees that the global optimum is found; it does not involve any gradient-based search, and hence avoids the usual problems of local minima. We examine mostly the case when the model order is reduced

Xiaoping Xu

In this paper, we introduce a method of imposing asymmetric conditions on the velocity vector with respect to independent variables and a method of moving frame for solving the three dimensional Navier-Stokes equations. Seven families of non-steady rotating asymmetric solutions with various parameters are obtained. In particular, one family of solutions blow

Fabrice Sthal, Xavier Vacheret, Patrice Salzenstein, Serge Galliou

High-stability quartz oscillators are needed in a number of space applications. A short-term stability of parts in 10^{-14} [Allan deviation σy(τ) ] is sometimes required, for integration time τof approximately 1-10 s. The Centre National d&#39;Etudes Spatiales (CNES) and the FEMTO-ST Institute (formerly LPMO and LCEP), have been collaborating for many years

Mary Beth Ruskai

An analytic proof is given of the necessity of the Borland-Dennis conditions for 3-representability of a one particle density matrix with rank 6. This may shed some light on Klyachko&#39;s recent use of Schubert calculus to find general conditions for N-representability.

Patrice Salzenstein, Xavier Jouvenceau, Xavier Vacheret, Gilles Martin

This paper reports the realization of a 5 MHz frequency difference x10 pre-multiplier, developed in the laboratory to replace an obsolete one. The principle we chose is to synthesize a 45 MHz and a 50 MHz from a reference signal and from the signal to be measured, and to subtract one to the other to generate a 5 MHz, whose precision on the measurement is inc

Maria Werner, LiZhe Zhu, Erik Aurell

The Epstein-Barr virus (EBV) infects more than 90% of the human population, and is the cause of several both serious and mild diseases. It is a tumorivirus, and has been widely studied as a model system for gene (de)regulation in human. A central feature of the EBV life cycle is its ability to persist in human B cells in states denoted latency I, II and III.

M. Colpi, S. Callegari, M. Dotti, S. Kazantzidis

We present a study on the dynamics of massive BHs in galaxy mergers, obtained from a series of high-resolution N-Body/SPH simulations. The presence of a gaseous component is essential for the rapid formation of an eccentric (Keplerian) BH binary, that resides at the center of a massive (~10^9 Msun) turbulent nuclear disc. Using physically and/or numerically

Francois Arleo

Single prompt photon and pion spectra in p-p and Au-Au collisions at intermediate RHIC energy, s^1/2 = 62.4 GeV, are computed at large transverse momentum in perturbative QCD. Next-to-leading order calculations in p-p scattering are first presented. The quenching of the prompt photon and pion yield due to energy loss processes in central Au-Au with respect t

N. Kleeorin, I. Rogachevskii

We study a nonlinear quenching of turbulent magnetic diffusion and effective drift velocity of large-scale magnetic field in a developed two-dimensional MHD turbulence at large magnetic Reynolds numbers. We show that transport of the mean-square magnetic potential strongly changes quenching of turbulent magnetic diffusion. In particularly, the catastrophic q

Soeren Wichmann, Dietrich Stauffer, Christian Schulze, Eric W. Holman

An earlier study (Nettle 1999b) concluded, based on computer simulations and some inferences from empirical data, that languages will change the more slowly the larger the population gets. We replicate this study using a more complete language model for simulations (the Schulze model combined with a Barabasi-Albert net- work) and a richer empirical dataset (

B. Binz, A. Vishwanath

Under pressure, the itinerant helimagnet MnSi displays unusual magnetic properties. We have previously discussed a BCC helical spin crystal as a promising starting point for describing the high pressure phenomenology. This state has topologically nontrivial configurations of the magnetization field. Here we note the consequences for magneto-transport that ar

Didier Sornette

A general theory of innovation and progress in human society is outlined, based on the combat between two opposite forces (conservatism/inertia and speculative herding &#34;bubble&#34; behavior). We contend that human affairs are characterized by ubiquitous ``bubbles&#39;&#39;, which involve huge risks which would not otherwise be taken using standard cost/b

Claudio Arezzo, Frank Pacard

In this note we clarify the structure of the moduli space of constant scalar curvature Kaehler metrics as one approaches the boundary of the Kaehler cone on cscK manifolds blown up at finite set of points, in the spirit of the previous work arXiv:math/0504115. Results about which Kaehler classes can be reached and about the position of the blown up points ar

Randal Douc, Eric Moulines, Philippe Soulier

The goal of this paper is to give a short and self contained proof of general bounds for subgeometric rates of convergence, under practical conditions. The main result whose proof, based on coupling, provides an intuitive understanding of the results of Nummelin and Tuominen (1983) and Tuominen and Tweedie (1994). To obtain practical rates, a very general dr

Rohit Deo, Meng-Chen Hsieh, Clifford M. Hurvich, Philippe Soulier

It is generally accepted that many time series of practical interest exhibit strong dependence, i.e., long memory. For such series, the sample autocorrelations decay slowly and log-log periodogram plots indicate a straight-line relationship. This necessitates a class of models for describing such behavior. A popular class of such models is the autoregressive

Sheng Bau

A little general abstract combinatorial nonsense delivered in this note is a presentation of some old and basic concepts, central to discrete mathematics, in terms of new words. The treatment is from a structural and systematic point of view. This note consists essentially of definitions and summaries.

Kaushar Sanchawala, Wen-Ping Chen, Devendra Ojha, Swarna Kanti Ghosh

We have carried out near-infrared (NIR) imaging observations of the Carina Nebula for an area of ~400 sq. arcmin. including the star clusters Trumpler 14 (Tr 14) and Trumpler 16 (Tr 16). With 10 sigma limiting magnitudes of J ~ 18.5, H ~ 17.5 and K_s ~ 16.5, we identified 544 Class II and 11 Class I young star candidates. We find some 40 previously unknown v

Kartik Srinivasan, Andreas Stintz, Sanjay Krishna, Oskar Painter

Photoluminescence spectroscopy of single InAs quantum dots at cryogenic temperatures (~14 K) is performed using a micron-scale optical fiber taper waveguide as a near-field optic. The measured collection efficiency of quantum dot spontaneous emission into the fundamental guided mode of the fiber taper is estimated at 0.1%, and spatially-resolved measurements

J. Rho, T. H. Jarrett, N. N. Chugai, R. A. Chevalier

We report the X-ray detection of the Type II-plateau supernova SN 2004et in the spiral galaxy NGC 6946, using the Chandra X-Ray Observatory. The position of the X-ray source was found to agree with the optical position within ~0.4 arcsec. Chandra also surveyed the region before the 2004 event, finding no X-ray emission at the location of the progenitor. For

John F. Beacom

Neutrino astronomy is on the verge of discovering new sources, and this will lead to important advances in astrophysics, cosmology, particle physics, and nuclear physics. This paper is meant for non-experts, so that they might better understand the basic issues in this field.

Ming-Xian Su, L. Y. Xiao, H. Q. Zheng

We discuss the lightest scalar resonances, $f_0(600)$, $κ(800)$, $a_0(980)$ and $f_0(980)$ in the extended Nambu Jona-Lasinio model. We find that the model parameters can be tuned, but unnaturally, to accommodate for those scalars except the $f_0(980)$. We also discuss problems encountered in the K Matrix unitarization approximation by using $N_c$ counting t

Elias P. Gyftopoulos

Upon reviewing the physical review letter which describes the processes involved in &#34;demonstration of a controllable three-dimensional Brownian motor in symmetric potentials&#34; we conclude that such processes are not compatible with what Einstein and many other physicists and engineers define as Brownian motors or Brownian movements.

M. Sharif

In this paper, we study the behavior of the pseudo-Newtonian force and potential about a higher dimensional rotating black hole. We obtain conditions for the force character from an attractive to repulsive. We also find the conditions under which force attains a maximum value. The results of this paper generalizes the already found structure of force and pot

Lorenzo Sironi, Jeremy Goodman

Afterglows of gamma-ray bursts are believed to require magnetic fields much stronger than that of the compressed pre-shock medium. As an alternative to microscopic plasma instabilities, we propose amplification of the field by macroscopic turbulence excited by the interaction of the shock with a clumpy pre-shock medium, for example a stellar wind. Using a re

Jeremy Goodman, Andrew I. MacFadyen

Geometrical shock dynamics, also called CCW theory, yields approximate equations for shock propagation in which only the conditions at the shock appear explicitly; the post-shock flow is presumed approximately uniform and enters implicitly via a Riemann invariant. The nonrelativistic theory, formulated by G. B. Whitham and others, matches many experimental r

U. I. Safronova, W. R. Johnson, M. S. Safronova

Relativistic many-body perturbation theory is applied to study properties of ions of the francium isoelectronic sequence. Specifically, energies of the 7s, 7p, 6d, and 5f states of Fr-like ions with nuclear charges Z = 87 - 100 are calculated through third order; reduced matrix elements, oscillator strengths, transition rates, and lifetimes are determined fo

A. A. Arellano-Baeza, R. V. Garcia, M. Trejo-Soto

Mexico is one of the most volcanically active regions in North America. Volcanic activity in central Mexico is associated with the subduction of the Cocos and Rivera plates beneath the North American plate. Periods of enhanced microseismic activity, associated with the volcanic activity of the Popocatepetl volcano is compared with periods, during which the m

Luigi Accardi, Satoshi Uchiyama

A classical deterministic, reversible dynamical systems, reproducing the Einstein--Podolsky--Rosen (EPR) correlations in full respect of causality and locality and without the introduction of any ad hoc selection procedure, was constructed in the paper [AIR02]. In the present paper we prove that the above mentioned model is unique (see Theorem (2) in the sen

P. C. Srivastava, I. Mehrotra

Shell model calculations for low lying energy states of neutron rich oxygen isotopes 19O, 20O, 21O, 22O, 23O, 24O, 25O, 26O have been performed using OXBASH code. The configuration space consists of 0d5/2, 1s1/2, 0d3/2 orbital for neutrons outside the 16O core. Different interactions namely, Wildenthal, Preedom-Wildenthal, Wildenthal-Mcgrory and renormalized

J. R. D. Lepine, Wilton S. Dias, Yuri Mishurov

We present a method which allows a direct measurement of the epicycle frequency $κ$ in the galactic disk, using the large database on open clusters completed by our group. The observed velocity vector (amplitude and direction) of the clusters in the galactic plane is derived from the catalog data. In the epicycle approximation, this velocity is the sum of th

Nicholas L. Chapman, Shih-Ping Lai, Lee G. Mundy, Neal J. Evans

We present maps of 7.78 square degrees of the Lupus molecular cloud complex at 24, 70, and $160\:μ$m. They were made with the Spitzer Space Telescope&#39;s Multiband Imaging Photometer for Spitzer (MIPS) instrument as part of the Spitzer Legacy Program, ``From Molecular Cores to Planet-Forming Disks&#39;&#39; (c2d). The maps cover three separate regions in L

Chuanming Zong

This paper determines the optimal upper bound for the simultaneous packing and covering constants of the two-dimensional centrally symmetric convex domains. It solved a problem opening for more than thirty years.

Erwin Miña-Díaz

For a function g(w) analytic and univalent in {w:1<|w|<\infty} with a simple pole at \infty and a continuous extension to {w:|w|\geq 1}, we consider the Faber polynomials F_n(z), n=0,1,2,..., associated to g(w) via their generating function g&#39;(w)/(g(w)-z)=\sum_{n=0}^\infty F_n(z)w^{-(n+1)}. Assuming that g(w) maps the unit circle T onto a piecewise analy

Caucher Birkar

This article contains the notes of a graduate course on birational geometry focusing on the minimal model program. Topics covered include singularities, vanishing, nonvanishing, cone and contraction, base point freeness, finite generation, flips, termination, minimal models and Mori fibre spaces.

Sudarshan Ananth, Stefan Theisen

The Kawai-Lewellen-Tye (KLT) relations derived from string theory tell us that perturbative gravity amplitudes are the &#34;square&#34; of the corresponding amplitudes in gauge theory. Starting from the light-cone Lagrangian for pure gravity we make these relations manifest off-shell, for three- and four-graviton vertices, at the level of the action.

Elizabeth R. Fernandez, Eiichiro Komatsu

Using a simple method to interpret the luminosity function of Ly-alpha emitters, we explore properties of Ly-alpha emitters from 5.7 < z < 8.8 with various assumptions about metallicity and stellar mass spectra. We constrain a mass-to-&#39;observed&#39; light ratio, M_h/L_band. For narrow-band surveys, L_band is simply related to the intrinsic Ly-alpha lumin

Peter R. W. McNamara

In recent years, there has been considerable interest in showing that certain conditions on skew shapes A and B are sufficient for the difference s_A - s_B of their skew Schur functions to be Schur-positive. We determine necessary conditions for the difference to be Schur-positive. Our conditions are motivated by those of Reiner, Shaw and van Willigenburg th

Cesar Seijas

This PhD thesis is devoted to show that differential renormalization is a simple and useful renormalization method that we can use when dealing with gauge theories. In this work, it is shown how the one-loop results of Constraint Differential Renormalization can be fruitfully applied when renormalizing two-loop amplitudes. As an example of this procedure, th

M. D. Girardeau, A. Minguzzi

A generalized Fermi-Bose mapping method is used to determine the exact ground states of several models of mixtures of strongly interacting ultracold gases in tight waveguides, which are generalizations of the Tonks-Girardeau (TG) gas (1D Bose gas with point hard cores) and fermionic Tonks-Girardeau (FTG) gas (1D spin-aligned Fermi gas with infinitely strong

Oisin A. P. Mac Conamhna

Explicit Calabi-Yau metrics are derived that are argued to map to the Maldacena-Nuñez AdS solutions of M-theory and IIB under geometric transitions. In each case the metrics are singular where a H^2 Kähler two-cycle degenerates but are otherwise smooth. They are derived as the most general Calabi-Yau solutions of an ansatz for the supergravity description of

Caucher Birkar

In this paper, we prove that the log minimal model program in dimension $d-1$ implies the existence of log minimal models for effective lc pairs (eg of nonnegative Kodaira dimension) in dimension $d$. In fact, we prove that the same conclusion follows from a weaker assumption, namely, the log minimal model program with scaling in dimension $d-1$. This enable

J. Santos, J. S. Alcaniz, M. J. Reboucas, N. Pires

In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors on physical grounds. We show that in the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) approach to cosmological modeling, where the energy and matter components of the cosmic fluid are unknown, the energy conditions provide model-independent bounds on t

Scott N. Walck, David W. Lyons

Composite quantum states can be classified by how they behave under local unitary transformations. Each quantum state has a stabilizer subgroup and a corresponding Lie algebra, the structure of which is a local unitary invariant. In this paper, we study the structure of the stabilizer subalgebra for n-qubit pure states, and find its maximum dimension to be n

Stefan Kirchner, Qimiao Si

We consider the finite temperature scaling properties of a Kondo-destroying quantum critical point in the Ising-anisotropic Bose-Fermi Kondo model (BFKM). A cluster-updating Monte Carlo approach is used, in order to reliably access a wide temperature range. The scaling function for the two-point spin correlator is found to have the form dictated by a boundar

D0 Collaboration, V. Abazov

We report the first direct observation of the strange b baryon Xi_b^{-}. We reconstruct the decay Xi_b^{-} to J/psi Xi^{-}, with J/psi to dimuons and Xi^{-} to Lambda pion, in ppbar collisions at sqrt(s) = 1.96 TeV. Using 1.3 fb^{-1} of data collected by the D0 detector, we observe 15.2 +/- 4.4(stat.)+ 1.9/-0.4(syst.) Xi_b^{-} candidates at a mass of 5.774 +

Fabian Schmidt, Michele Liguori, Scott Dodelson

Bekenstein&#39;s alternative to general relativity, TeVeS, reduces to Modified Newtonian Dynamics (MOND) in the galactic limit. On cosmological scales, the (potential well <-> overdensity) relationship is quite different than in standard general relativity. Here we investigate the possibility of cross-correlating galaxies with the cosmic microwave background

Roberto D. Pascual-Marqui

Coherence and phase synchronization between time series corresponding to different spatial locations are usually interpreted as indicators of the connectivity between locations. In neurophysiology, time series of electric neuronal activity are essential for studying brain interconnectivity. Such signals can either be invasively measured from depth electrodes

Caroline Lambert, Christiane Rousseau

In this paper we study the confluence of two regular singular points of the hypergeometric equation into an irregular one. We study the consequence of the divergence of solutions at the irregular singular point for the unfolded system. Our study covers a full neighborhood of the origin in the confluence parameter space. In particular, we show how the diverge

Eric C. Rowell, Yong Zhang, Yong-Shi Wu, Mo-Lin Ge

In this paper we describe connections among extraspecial 2-groups, unitary representations of the braid group and multi-qubit braiding quantum gates. We first construct new representations of extraspecial 2-groups. Extending the latter by the symmetric group, we construct new unitary braid representations, which are solutions to generalized Yang-Baxter equat

Ofer Aharony, Alex Buchel, Patrick Kerner

We numerically construct black hole solutions corresponding to the deconfined, chirally symmetric phase of strongly coupled cascading gauge theories at various temperatures. We compute the free energy as a function of the temperature, and we show that it becomes positive below some critical temperature, indicating the possibility of a first order phase trans

Yann Michel, Boris Pioline

Motivated by applications to black hole physics and duality, we study the effect of higher derivative corrections on the dimensional reduction of four-dimensional Einstein, Einstein Liouville and Einstein-Maxwell gravity to one direction, as appropriate for stationary, spherically symmetric solutions. We construct a field redefinition scheme such that the on

Kate Land, Anze Slosar

We revisit the issue of a correlation between the atomic hydrogen gas in our local Galaxy and the Cosmic Microwave Background (CMB), a detection of which has been claimed in some literature. We cross-correlate the 21-cm emission of Galactic atomic hydrogen as traced by the Leiden/Argentine/Bonn Galactic HI survey with the 3-year CMB data from the Wilkinson M

F. A. Chishtie, T. Hanif, D. G. C. McKeon, T. G. Steele

The perturbative effective potential V in the massless $λϕ^4$ model with a global O(N) symmetry is uniquely determined to all orders by the renormalization group functions alone when the Coleman-Weinberg renormalization condition $\frac{d^4V}{dϕ^4}|_{ϕ= μ} = λ$ is used, where $μ$ represents the renormalization scale. Systematic methods are developed to expre

Maximilien Gadouleau, Zhiyuan Yan

The MacWilliams identity, which relates the weight distribution of a code to the weight distribution of its dual code, is useful in determining the weight distribution of codes. In this paper, we derive the MacWilliams identity for linear codes with the rank metric, and our identity has a different form than that by Delsarte. Using our MacWilliams identity,

N. Joshi, A. V. Kitaev, P. A. Treharne

We extend similarity reductions of the coupled (2+1)-dimensional three-wave resonant interaction system to its Lax pair. Thus we obtain new 3x3 matrix Fuchs--Garnier pairs for the third and fifth Painleve&#39; equations, together with the previously known Fuchs--Garnier pair for the fourth and sixth Painleve&#39; equations. These Fuchs--Garnier pairs have an

E. Paladino, M. Sassetti, G. Falci, U. Weiss

We propose a characterisation of the effects of bistable coherent impurities in solid state qubits. We introduce an effective impurity description in terms of a tunable spin-boson environment and solve the dynamics for the qubit coherences. The dominant rate characterizing the asymptotic time limit is identified and signatures of non-Gaussian behavior of the

V. Braude, Ya. M. Blanter

We study AC Josephson effect in a superconductor-ferromagnet heterostructure with a variable magnetic configuration. The system supports triplet proximity correlations whose dynamics is coupled to the magnetic dynamics. This feedback dramatically modifies the behavior of the junction. The current-phase relation becomes double-periodic at both very low and hi

Igor Leite Freire

We show which Lie point symmetries of non-critical semilinear Kohn-Laplace equations on the Heisenberg group $H^1$ are Noether symmetries and we establish their respectives conservations laws.

Kira V. Khmelnytskaya, Vladislav V. Kravchenko

We consider a nonlinear partial differential equation for complex-valued functions which is related to the two-dimensional stationary Schrodinger equation and enjoys many properties similar to those of the ordinary differential Riccati equation as, e.g., the famous Euler theorems, the Picard theorem and others. Besides these generalizations of the classical

I. K. Razumov, Yu. N. Gornostyrev, M. I. Katsnelson

Phase diagram and pattern formation in two-dimensional Ising model with coupling between order parameter and lattice vibrations is investigated by Monte-Carlo simulations. It is shown that if the coupling is strong enough (or phonons are soft enough) a short-range order exists in disordered phase for a broader temperature interval. Different types of this sh

Alexander N. Dranishnikov, Mikhail G. Katz, Yuli B. Rudyak

We prove that manifolds of Lusternik-Schnirelmann category 2 necessarily have free fundamental group. We thus settle a 1992 conjecture of Gomez-Larranaga and Gonzalez-Acuna, by generalizing their result in dimension 3, to all higher dimensions. We examine its ramifications in systolic topology, and provide a sufficient condition for ensuring a lower bound of

Guo-Niu Han, Guoce Xin

We extend Stanley&#39;s work on alternating permutations with extremal number of fixed points in two directions: first, alternating permutations are replaced by permutations with a prescribed descent set; second, instead of simply counting permutations we study their generating polynomials by number of excedances. Several techniques are used: Desarmenien&#39

G. Kiesslich, E. Schoell, T. Brandes, F. Hohls

We show that the intriguing observation of noise enhancement in the charge transport through two vertically coupled quantum dots can be explained by the interplay of quantum coherence and strong Coulomb blockade. We demonstrate that this novel mechanism for super-Poissonian charge transfer is very sensitive to decoherence caused by electron-phonon scattering

Indranil Chakrabarty, Prashant, B. S. Choudhury

It is known that if one could clone an arbitrary quantum state one could send signal faster than the speed of light. However it remains interesting to see that if one can perfectly self replicate an arbitrary quantum state, does it violate the no signalling principle? Here we see that perfect self replication would also lead to superluminal signalling.

Andre de Gouvea

If the Standard Model particle content is extended by gauge singlet fermions (right-handed neutrinos), active neutrinos generically acquire (Majorana) masses, in agreement with our current understanding of the lepton sector. If the right-handed neutrino masses are of the same order as the electroweak symmetry breaking scale, it is usually expected that these

Michael Maziashvili

Recently the spectrum of KK modes in the framework of one flat extra-dimensional scenario was revisited in the paper Phys. Rev. D74 (2006) 124013, (hep-th/0607246) on the basis of self-adjoint extension of the quantum mechanical operator determining the KK masses. In this Letter we note that the range of allowed boundary conditions on the KK modes is overest

E. Follana, C. T. H. Davies, G. P. Lepage, J. Shigemitsu

We determine $D$ and $D_s$ decay constants from lattice QCD with 2% errors, 4 times better than experiment and previous theory: $f_{D_s}$ = 241(3) MeV, $f_D$ = 207(4) MeV and $f_{D_s}/f_D$ = 1.164(11). We also obtain $f_K/f_π$ = 1.189(7) and $(f_{D_s}/f_D)/(f_K/f_π)$ = 0.979(11). Combining with experiment gives $V_{us}$=0.2262(14) and $V_{cs}/V_{cd}$ of 4.43

Markus Fendrich, Joachim Krug

The step edge barrier of a prototypical organic semiconductor molecule, 3,4,9,10-perylene-tetracaboxylic-dianhydride (PTCDA) has been analysed by means of calculations based on emperical potentials. The minimum energy path (MEP) has been calculated for a single molecule on a substrate of three molecular layers between equivalent minimum energy positions with

Alessandro Morbidelli, Kleomenis Tsiganis, Aurelien Crida, Harold F. Levison

We study the orbital evolution of the 4 giant planets of our solar system in a gas disk. Our investigation extends the previous works by Masset and Snellgrove (2001) and Morbidelli and Crida (2007, MC07), which focussed on the dynamics of the Jupiter-Saturn system. The only systems that we found to reach a steady state are those in which the planets are lock

M. Chaichian, M. Mnatsakanova, A. Tureanu, Yu. Vernov

It is proven that the $\star$-product of field operators implies that the space of test functions in the Wightman approach to noncommutative quantum field theory is one of the Gel&#39;fand-Shilov spaces $S^β$ with $β< 1/2$. This class of test functions smears the noncommutative Wightman functions, which are in this case generalized distributions, sometimes c

Hiromichi Kaneko, Yoshihisa Kitazawa, Koichiro Matsumoto

S^3 is a simple principle bundle which is locally S^2 \times S^1. It has been shown that such a space can be constructed in terms of matrix models. It has been also shown that such a space can be realized by a generalized compactification procedure in the S^1 direction. We investigate the effective action of supersymmetric gauge theory on S^3 with an angular

Ivan G. Szendro, Diego Pazó, Miguel A. Rodríguez, Juan M. López

The spatiotemporal dynamics of Lyapunov vectors (LVs) in spatially extended chaotic systems is studied by means of coupled-map lattices. We determine intrinsic length scales and spatiotemporal correlations of LVs corresponding to the leading unstable directions by translating the problem to the language of scale-invariant growing surfaces. We find that the s

B. K. Sahoo, B. P. Das, R. K. Chaudhuri, D. Mukherjee

The present work tests the suitability of the narrow transitions $7s \ ^2S_{1/2} \to 6d ^2D_{3/2}$ and $7s ^2S_{1/2} \to 6d ^2D_{5/2}$ in Ra$^+$ for optical frequency standard studies. Our calculations of the lifetimes of the metastable $6d$ states using the relativistic coupled-cluster theory suggest that they are sufficiently long for Ra$^+$ to be consider

Gabor Kun

We give a poly-time construction for a combinatorial classic known as Sparse Incomparability Lemma, studied by Erdos, Lovasz, Nesetril, Rodl and others: We show that every Constraint Satisfaction Problem is poly-time equivalent to its restriction to structures with large girth. This implies that the complexity classes CSP and Monotone Monadic Strict NP intro

Michael Baake, Daniel Lenz, Christoph Richard

Delone sets of finite local complexity in Euclidean space are investigated. We show that such a set has patch counting and topological entropy 0 if it has uniform cluster frequencies and is pure point diffractive. We also note that the patch counting entropy is 0 whenever the repetitivity function satisfies a certain growth restriction.

Alon E. Faraggi, Mirian Tsulaia

The ten dimensional string theories as well as eleven dimensional supergravity are conjectured to arise as limits of a more basic theory, traditionaly dubbed M--theory. This notion is confined to the ten dimensional supersymmetric theories. String theory, however, also contains ten dimensional nonsupersymmetric theories that have not been incorporated into t

Arnaud Legrand, Corinne Touati

In the context of applied game theory in networking environments, a number of concepts have been proposed to measure both efficiency and optimality of resource allocations, the most famous certainly being the price of anarchy and the Jain index. Yet, very few have tried to question these measures and compare them one to another, in a general framework, which