December 2007 arXiv papers — page 11

Stavros Komineas, Nikos Papanicolaou

We study the dynamics of vortex-antivortex (VA) pairs in an infinitely thin ferromagnetic film with easy-plane anisotropy. These are localized excitations with finite energy that are characterized by a topological (skyrmion) number N = 0,+1,-1. Topologically trivial (N=0) VA pairs undergo Kelvin motion analogous to that encountered in fluid dynamics. In cont

M. A. Gonzalez Leon, J. Mateos Guilarte, M. de la Torre Mayado

The problem of building supersymmetry in the quantum mechanics of two Coulombian centers of force is analyzed. It is shown that there are essentially two ways of proceeding. The spectral problems of the SUSY (scalar) Hamiltonians are quite similar and become tantamount to solving entangled families of Razavy and Whittaker-Hill equations in the first approach

Zbigniew S. Szewczak

It is shown that for sums of functionals of digits in continued fraction expansion the Kolmogorov-Feller weak laws of large numbers and the Khinchine-Lévy-Feller-Raikov characterization of the domain of attraction of the normal law hold.

V. G. Andreev, L. V. Kravchuk, S. G. Lebedev, A. V. Samokhin

The nanocrystallite have the finite number of the oscillation modes. Their number increases proportionally to a cube of the characteristic size. Thus the oscillation spectrum of nanocrystal becomes discrete, and the separate modes of oscillations does not interact with each other, that considerably strengthens all phonon modulated processes in a crystal. Cov

L. Jelinek, R. Marques, F. Mesa, J. D. Baena

Bi-isotropic and isotropic negative refractive index (NRI) 3D metamaterials made from periodic arrangements of chiral split ring resonators (SRRs) are proposed and demonstrated. An analytical theory for the characterization and design of these metamaterials is provided and validated by careful full-wave electromagnetic simulations. The reported results are e

P. E. Verrier, N. W. Evans

We identify a new superintegrable Hamiltonian in 3 degrees of freedom, obtained as a reduction of pure Keplerian motion in 6 dimensions. The new Hamiltonian is a generalization of the Keplerian one, and has the familiar 1/r potential with three barrier terms preventing the particle crossing the principal planes. In 3 degrees of freedom, there are 5 functiona

A. Hujeirat, B. W. Keil, F. Heitsch

Computational gas dynamics has become a prominent research field both in astrophysics and cosmology. In the first part of this review we intend to briefly describe several of the numerical methods used in this field, discuss their range of application and present strategies for converting conditionally-stable numerical methods into unconditionally-stable sol

Jan Wiersig, Jörg Main

We demonstrate that the harmonic inversion technique is a powerful tool to analyze the spectral properties of optical microcavities. As an interesting example we study the statistical properties of complex frequencies of the fully chaotic microstadium. We show that the conjectured fractal Weyl law for open chaotic systems [W. T. Lu, S. Sridhar, and M. Zworsk

Nedzad Limić, Mladen Rogina

We consider a second order differential operator $A(\msx) = -\:\sum_{i,j=1}^d \partial_i a_{ij}(\msx) \partial_j \:+\: \sum_{j=1}^d \partial_j \big(b_j(\msx) \cdot \big)\:+\: c(\msx)$ on ${\bbR}^d$, on a bounded domain $D$ with Dirichlet boundary conditions on $\partial D$, under mild assumptions on the coefficients of the diffusion tensor $a_{ij}$. The obje

L. Campanelli, M. Ruggieri

We study numerically a class of non-topological solitons, the Q-balls, arising in supersymmetric extension of the Standard Model with low-energy, gauge-mediated symmetry breaking. % Taking into account the exact form of the supersymmetric potential giving rise to Q-balls, we find that there is a lower limit on the value of the charge $Q$ in order to make the

J. Kaluzny, I. B. Thompson

We present the results of a search for variable stars in the central part of the globular cluster NGC 6752. The monitored sample included 160 BHB and 107 EHB stars, respectively. A total of 17 variables were detected of which 14 are new identifications. Five variables are BHB/EHB stars. We report also on identification of a detached eclipsing binary being li

Gustavo Fernandez Alcobér, Marta Morigi

Let $γ_i(G)$ and $Z_i(G)$ denote the $i$-th terms of the lower and upper central series of a group $G$, respectively. P. Hall showed that if $γ_{i+1}(G)$ is finite then the index $|G:Z_{2i}(G)|$ is finite. We prove that the same result holds under the weaker hypothesis that $|γ_{i+1}(G):γ_{i+1}(G)\cap Z_i(G)|$ is finite.

Kazumasa Nomura, Paul Terwilliger

Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of $K$-linear transformations $A:V \to V$ and $A^*:V \to V$ that satisfies the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering ${V_i}_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \subseteq V_

L. Lipski, K. Stepien

New determinations of effective temperatures of 23 magnetic, chemically peculiar (mCP) stars were obtained from a fit of metal enhanced model atmospheres to the observed spectral energy distributions (SED) from UV to red. The root-mean-square (RMS) method was used to fit the theoretical SED to the observations corrected for reddening if necessary, with metal

A. Hujeirat, F. -K. Thielemann, J. Dusek, A. Nusser

Internal flows inside gravitationally stable astrophysical objects, such as the Sun, stars and compact stars are compressed and extremely subsonic. Such low Mach number flows are usually encountered when studying for example dynamo action in stars, planets, the hydro-thermodynamics of X-ray bursts on neutron stars and dwarf novae. Treating such flows is nume

Matej Pavsic

We consider the possibility that the basic space of physics is not spacetime, but configuration space. We illustrate this on the example with a system of gravitationally interacting point particles. It turns out that such system can be described by the minimal length action in a multidimensional configuration space C with a block diagonal metric. Allowing fo

M. C. Carrisi, M. A. Mele, S. Pennisi

Recently the 14 moments model of Extended Thermodynamics for dense gases and macromolecular fluids has been considered and an exact solution, of the restrictions imposed by the entropy principle and that of Galilean relativity, has been obtained through a non relativistic limit. Here we prove uniqueness of the above solution and exploit other pertinent condi

Giovanni Alessandrini, Edi Rosset

We prove radial symmetry of singular solutions to an overdetermined boundary value problem for a class of degenerate quasilinear elliptic equations.

R. Nath, P. Pedri, L. Santos

The dynamical stability of dark solitons in dipolar Bose-Einstein condensates is studied. For standard short-range interacting condensates dark solitons are unstable against transverse excitations in two and three dimensions. On the contrary, due to its non local character, the dipolar interaction allows for stable 3D stationary dark solitons, opening a qual

Alejandro Chinea Manrique De Lara, Juan Manuel Moreno, Arostegui Jordi Madrenas, Joan Cabestany

In this paper we shall review the common problems associated with Piecewise Linear Separation incremental algorithms. This kind of neural models yield poor performances when dealing with some classification problems, due to the evolving schemes used to construct the resulting networks. So as to avoid this undesirable behavior we shall propose a modification

Simone Piccinin, Catherine Stampfl, Matthias Scheffler

In this paper we investigate by means of first-principles density functional theory calculations the (111) surface of the Ag-Cu alloy under varying conditions of pressure of the surrounding oxygen atmosphere and temperature. This alloy has been recently proposed as a catalyst with improved selectivity for ethylene epoxidation with respect to pure silver, the

Lluis Manosa, Xavier Moya, Antoni Planes, Oliver Gutfleisch

We report magnetization and differential thermal analysis measurements as a function of pressure accross the martensitic transition in magnetically superelastic Ni-Mn-In alloys. It is found that the properties of the martensitic transformation are significantly affected by the application of pressure. All transition temperatures shift to higher values with i

Luis Vega, Nicola Visciglia

We shall study the following initial value problem: \begin{equation}{\bf i}\partial_t u - Δu + V(x) u=0, \hbox{} (t, x) \in {\mathbf R} \times {\mathbf R}^n, \end{equation} $$u(0)=f,$$ where $V(x)$ is a real short--range potential, whose radial derivative satisfies some supplementary assumptions. More precisely we shall present a family of identities satisfi

S. Kamba, D. Nuzhnyy, R. Nechache, K. Zaveta

Infrared reflectance spectra of an epitaxial Bi2FeCrO6 thin film prepared by pulsed laser deposition on LaAlO3 substrate were recorded between 10 and 900 K. No evidence for a phase transition to the paraelectric phase was observed, but some phonon anomalies were revealed near 600 K. Most of the polar modes exhibit only a gradual softening, which results in a

B. L. Hu, Shih-Yuin Lin

This is a synopsis of our recent work on quantum entanglement, recoherence and information flow between an uniformly accelerated detector and a massless quantum scalar field. The availability of exact solutions to this model enables us to explore the black hole information issue with some quantifiable results and new insights. To the extent this model can be

Fang Xia, Shulin Ren, Yanning Fu

This work is devoted to improving empirical mass-luminosity relations and mass-metallicity-luminosity relation for low mass stars. For these stars, observational data in the mass-luminosity plane or the mass-metallicity-luminosity space subject to non-negligible errors in all coordinates with different dimensions. Thus a reasonable weight assigning scheme is

Dawei Ding, Jie Zhu, Xiaoshu Luo, Yuliang Liu

This paper focuses on Hopf bifurcation control in a dual model of Internet congestion control algorithms which is modeled as a delay differential equation (DDE). By choosing communication delay as a bifurcation parameter, it has been demonstrated that the system loses stability and a Hopf bifurcation occurs when communication delay passes through a critical

D. L. Moskovkin, V. M. Shabaev, W. Quint

The fully relativistic theory of the Zeeman splitting of the $(1s)^2 2s$ hyperfine-structure levels in lithiumlike ions with $Z=6 - 32$ is considered for the magnetic field magnitude in the range from 1 to 10 T. The second-order corrections to the Breit -- Rabi formula are calculated and discussed including the one-electron contributions as well as the inter

G. Magadur, Jean-Sébastien Lauret, V. Alain-Rizzo, C. Voisin

Functionalization of carbon nanotubes with hydrosoluble porphyrins (TPPS) is achieved by "$π$-stacking". The porphyrin/nanotube interaction is studied by means of optical absorption, photoluminescence and photoluminescence excitation spectroscopies. The main absorption line of the porphyrins adsorbed on nanotubes exhibits a 120 meV red shift, which w

Olivier Arnould, François Hild

To characterise (inter)diffusion in materials, concentration profiles can be measured by EDX. It allows one to determine the chemical composition with a very good accuracy if measurement artefacts are accounted for. Standard phenomena (such as X-ray fluorescence) are usually corrected by commercial software. However, the effect of the pear-shaped volume of X

Rainer Avikainen

We consider upper bounds for the approximation error E|g(X)-g(\hat X)|^p, where X and \hat X are random variables such that \hat X is an approximation of X in the L_p-norm, and the function g belongs to certain function classes, which contain e.g. functions of bounded variation. We apply the results to the approximations of a solution of a stochastic differe

S. Gustavsson, I. Shorubalko, R. Leturcq, S. Schön

We measure current by counting single electrons tunneling through an InAs nanowire quantum dot. The charge detector is realized by fabricating a quantum point contact in close vicinity to the nanowire. The results based on electron counting compare well to a direct measurements of the quantum dot current, when taking the finite bandwidth of the detector into

P. F. Chen

This paper reviews recent progress in the research on the initiation and propagation of CMEs. In the initiation part, several trigger mechanisms are discussed; In the propagation part, the observations and modelings of EIT waves/dimmings, as the EUV counterparts of CMEs, are described.

Rabin Banerjee, Subir Ghosh, T. Shreecharan

We consider the extension of the 2+1-dimensional bosonization process in Non-Commutative (NC) spacetime. We show that the large mass limit of the effective action obtained by integrating out the fermionic fields in NC spacetime leads to the NC Chern-Simons action. The present result is valid to all orders in the noncommutative parameter $θ$. We also discuss

Ailin Zhang

The employment of interpolating currents of existed studies of four-quark state and glueball with QCD sum rule approach is analyzed. In terms of suitable currents, the masses of the lowest lying scalar and pseudo-scalar glueball were determined. The masses of some tetraquark states and their first orbital excitations were obtained through a combination of th

Jiang Qian, Pabitra N. Sen

We present an analytical study of the time dependent diffusion coefficient in a dilute suspension of spheres with partially absorbing boundary condition. Following Kirkpatrick (J. Chem. Phys. 76, 4255) we obtain a perturbative expansion for the time dependent particle density using volume fraction $f$ of spheres as an expansion parameter. The exact single pa

D. Csontos, U. Zuelicke

Spin splitting in p-type semiconductor nanowires is strongly affected by the interplay between quantum confinement and spin-orbit coupling in the valence band. The latter's particular importance is revealed in our systematic theoretical study presented here, which has mapped the range of spin-orbit coupling strengths realized in typical semiconductors. L

Bo Sun, Ping Zhang, Xian-Geng Zhao

The electronic structure and properties of PuO$_{2}$ and Pu$_{2}$O$_{3}$ have been studied from first principles by the all-electron projector-augmented-wave (PAW) method. The local density approximation (LDA)+$U$ and the generalized gradient approximation (GGA)+$U$ formalism have been used to account for the strong on-site Coulomb repulsion among the locali

Dong-Jin Lee, Sungchul Kwon, Yup Kim

We study a conserved mass aggregation model with mass-dependent fragmentation in one dimension. In the model, the whole mass $m$ of a site isotropically diffuse with unit rate. With rate $ω$, a mass $m^λ$ is fragmented from the site and moves to a randomly selected nearest neighbor site. Since the fragmented mass is smaller than the whole mass $m$ of a site

V. A. Dzuba, V. V. Flambaum

Dependence of transition frequencies on the fine structure constant $α=e^2/\hbar c$ is calculated for several many-electron systems which are used or planned to be used in the laboratory search for the time variation of the fine structure constant. In systems with a large number of electrons in open shells (from 11 to 15) the relative effects of the variatio

Aiyou Chen, Jin Cao, Tian Bu

The statistical problem for network tomography is to infer the distribution of $\mathbf{X}$, with mutually independent components, from a measurement model $\mathbf{Y}=A\mathbf{X}$, where $A$ is a given binary matrix representing the routing topology of a network under consideration. The challenge is that the dimension of $\mathbf{X}$ is much larger than tha

Jens Hoppe, Ki-Myeong Lee

We explore the 1/2 BPS configurations in BMN matrix theory with SO(3) angular momentum of $SO(3)\times SO(6)$ symmetry. The fluctuation analysis of the BPS configurations near the abelian solutions and also the fuzzy two sphere vacua reveals how nonabelian BPS configurations emerge. Especially the irreducible nonabelian configurations seem to have the maxima

G. A. Wade, J. Silvester, K. Bale, N. Johnson

A small fraction of intermediate-mass main sequence (A and B type) stars have strong, organised magnetic fields. The large majority of such stars, however, show no evidence for magnetic fields, even when observed with very high precision. In this paper we describe a simple model, motivated by qualitatively new observational results, that provides a natural p

Yasunori Mawatari, Kazuhiro Kajikawa

The hysteretic ac loss of a current-carrying conductor in which multiple superconducting strips are polygonally arranged around a cylindrical former is theoretically investigated as a model of superconducting cables. Using the critical state model, we analytically derive the ac loss $Q_n$ of a total of $n$ strips. The normalized loss $Q_n/Q_1$ is determined

F. Ghoulmié, M. Bartolozzi, C. P. Mellen, T. Di Matteo

We extend to the multi-asset case the framework of a discrete time model of a single asset financial market developed in Ghoulmie et al (2005). In particular, we focus on adaptive agents with threshold behavior allocating their resources among two assets. We explore numerically the effect of this diversification as an additional source of complexity in the f

Jindrich Kolorenc, Lubos Mitas

We determine the equation of state of stoichiometric FeO employing the diffusion Monte Carlo method. The fermionic nodes are fixed to those of a wave function having the form of a single Slater determinant. The calculated ambient pressure properties (lattice constant, bulk modulus and cohesive energy) agree very well with available experimental data. At appr

Michael B. Mensky

Extended Everett's Concept (EEC) recently developed by the author to explain the phenomenon of consciousness is considered. A mathematical model is proposed for the principal feature of consciousness assumed in EEC, namely its ability (in the state of sleep, trance or meditation, when the explicit consciousness is disabled) to obtain information from all

M. C. Rabello-Soares, S. G. Korzennik, J. Schou

Using full-disk observations obtained with the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO) spacecraft, we present variations of the solar acoustic mode frequencies caused by the solar activity cycle. High-degree (100 < l < 900) solar acoustic modes were analyzed using global helioseismology analysis techniques over m

Yuan N. Young, Jerzy Blawzdziewicz, Vitorio Cristini, Roy Goodman

It has been shown in our previous publication (Blawzdziewicz,Cristini,Loewenberg,2003) that high-viscosity drops in two dimensional linear creeping flows with a nonzero vorticity component may have two stable stationary states. One state corresponds to a nearly spherical, compact drop stabilized primarily by rotation, and the other to an elongated drop stabi

Jiangyong Jia

We summarize the di-hadron correlation results from RHIC, focusing on the high $p_T$ region and lower $p_T$ region for the away-side. The former is consistent with fragmentation of jets that surviving the medium, while the latter suggests the redistribution of the energy from the quenched jets. We also discuss the role of the jet in the intermediate $p_T$.

Xing Wu, Rong-Gen Cai, Zong-Hong Zhu

We consider the evolution of the vacuum energy in the DGP model according to the holographic principle under the assumption that the relation linking the IR and UV cut-offs still holds in this scenario. The model is studied when the IR cut-off is chosen to be the Hubble scale $H^{-1}$, the particle horizon $R_{\rm ph}$ and the future event horizon $R_{\rm eh

Zong-Hong Zhu, Ming Hu, J. S. Alcaniz, Yu-Xing Liu

Power-law cosmologies, in which the cosmological scale factor evolves as a power law in the age, $a \propto t^α$ with $α\ga 1$, regardless of the matter content or cosmological epoch, is comfortably concordant with a host of cosmological observations.} {In this article, we use recent measurements of the X-ray gas mass fractions in clusters of galaxies to con

Radu A. Ionas

In the generalized Legendre approach, the equation describing an asymptotically locally Euclidean space of type $D_n$ is found to admit an algebraic formulation in terms of the group law on a Weierstrass cubic. This curve has the structure of a Cayley cubic for a pencil generated by two transversal plane conics, that is, it takes the form $Y^2 = \det ({\cal

Radu A. Ionas

The generalized Legendre transform method of Lindstrom and Rocek yields hyperkaehler metrics from holomorphic functions. Its main ingredients are sections of ${\cal O}(2j)$ bundles over the twistor space satisfying a reality condition with respect to antipodal conjugation on the hyperkaehler sphere of complex structures. Formally, the structure of the real $

Jian Song, Steve Zelditch

This article contains a detailed study, in the toric case, of the test configuration geodesic rays defined by Phong-Sturm. We show that the `Bergman approximations&#39; of Phong-Sturm converge in C^1 to the geodesic ray and that the geodesic ray itself is C^{1,1} and no better. The \kahler metrics associated to the geodesic ray of potentials are discontinuou

Radu A. Ionas

This is the first in a series of papers in which we develop a twistor-based method of constructing hyperkaehler metrics from holomorphic functions and elliptic curves. As an application, we revisit the Atiyah-Hitchin manifold and derive in an explicit holomorphic coordinate basis closed-form formulas for, among other things, the metric, the holomorphic sympl

Ryan M. Kalas, D. Blume

Neutral atoms interact through a van der Waals potential which asymptotically falls off as r^{-6}. In ultracold gases, this interaction can be described to a good approximation by the atom-atom scattering length. However, corrections arise that depend on the characteristic length of the van der Waals potential. We parameterize these corrections by analyzing

F. Mazzanti, G. E. Astrakharchik, J. Boronat, J. Casulleras

A variational Monte Carlo calculation of the one-body density matrix and momentum distribution of a system of Fermi hard rods (HR) is presented and compared with the same quantities for its bosonic counterpart. The calculation is exact within statistical errors since we sample the exact ground state wave function, whose analytical expression is known. The nu

T. Aspelmeier

The sample-to-sample fluctuations Delta F_N of the free energy in the Sherrington-Kirkpatrick model are shown rigorously to be related to bond chaos. Via this connection, the fluctuations become analytically accessible by replica methods. The replica calculation for bond chaos shows that the exponent mu governing the growth of the fluctuations with system si

P. Rost, G. Fettweis

In this paper we present several strategies for multiple relay networks which are constrained by a half-duplex operation, i. e., each node either transmits or receives on a particular resource. Using the discrete memoryless multiple relay channel we present achievable rates for a multilevel partial decode-and-forward approach which generalizes previous resul

Ce Meng, Kuang-Ta Chao

In order to explain the observed unusually large dipion transition rates of $Υ(10870)$, the scalar resonance contributions in the re-scattering model to the dipion transitions of $Υ(4S)$ and $Υ(5S)$ are studied. Since the imaginary part of the re-scattering amplitude is expected to be dominant, the large ratios of the transition rates of $Υ(10870)$, which is

Xi Chen, Edward L. Wright

We report the results of an extragalactic point source search using the 61 and 94 GHz (V- and W-band) temperature maps from the Wilkinson Microwave Anisotropy Probe (WMAP). Applying a method that cancels the ``noise&#39;&#39; due to the CMB anisotropy signal, we find in the $|b| > 10\degr$ region 31 sources in the first-year maps and 64 sources in the three-

Julien Garaud, Mikhail S. Volkov

We study the stability properties of the twisted vortex solutions in the semilocal Abelian Higgs model with a global $\mathbf{SU}(2)$ invariance. This model can be viewed as the Weinberg-Salam theory in the limit where the non-Abelian gauge field decouples, or as a two component Ginzburg-Landau theory. The twisted vortices are characterized by a constant glo

Jens Smiatek, Michael P. Allen, Friederike Schmid

On the micro- and nanoscale, classical hydrodynamic boundary conditions such as the no-slip condition no longer apply. Instead, the flow profiles exhibit ``slip`` at the surface, which is characterized by a finite slip length (partial slip). We present a new, systematic way of implementing partial-slip boundary conditions with arbitrary slip length in coarse

K. S. Choi, H. Deng, J. Laurat, H. J. Kimble

Recent developments of quantum information science critically rely on entanglement, an intriguing aspect of quantum mechanics where parts of a composite system can exhibit correlations stronger than any classical counterpart. In particular, scalable quantum networks require capabilities to create, store, and distribute entanglement among distant matter nodes

Jacob J. H. Simmons, Peter Kleban

We calculate boundary operator product expansion coefficients for boundary operators in the first column of the Kac table in conformal field theories. For c=0 we give closed form expressions for all such coefficients. Then we generalize to the augmented minimal models, giving explicit expressions for coefficients valid when ϕ_{1,2} mediates a change from fix

Shravan M. Hanasoge

Comprehending the manner in which magnetic fields affect propagating waves is a first step toward constructing accurate helioseismic models of active region sub-surface structure and dynamics. Here, we present a numerical method to compute the linear interaction of waves with magnetic fields embedded in a solar-like stratified background. The ideal Magneto-H

Ying Zu, Zheng Zheng, G. T. Zhu, Y. P. Jing

Galaxy formation inside dark matter halos, as well as the halo formation itself, can be affected by large-scale environments. Evaluating the imprints of environmental effects on galaxy clustering is crucial for precise cosmological constraints with data from galaxy redshift surveys. We investigate such an environmental impact on both real-space and redshift-

O. Gromenko, V. Privman, M. L. Glasser

The random sequential adsorption (RSA) model is modified to describe damage and crack accumulation. The exclusion for object deposition (for damaged region formation) is not for the whole object, as in the standard RSA, but only for the initial point (or higher-dimensional defect) from which the damaged region or crack initiates. The one-dimensional variant

Evgueny Kochetov, Fabio L. Braghin, Alvaro Ferraz

We discuss the relevance of the improved mean-field slave-fermion theory to describe the Nagaoka ($U=\infty$) limit of the Hubbard model. In this theory the crucial on-site constraint of no double electron occupancy is taken into account rigorously prior to the mean-field approximation. At one-loop approximation the effective mean-field action shows a long-r

The BABAR Collaboration, B. Aubert

Using 226 million BBbar events recorded on the Upsilon(4S) resonance with the BABAR detector at the SLAC e+e- PEPII storage rings, we reconstruct B- -> D*0 e- nubar decays using the decay chain D*0 -> D0 pi0 and D0 -> K pi. From the dependence of their differential rate on w, the dot product of the four-velocities of B and D*0, and using the form factor desc

Jianhui Dai, Qimiao Si, C. J. Bolech

Quantum dissipation induces a critical destruction of a Kondo screened state, which is of interest in the contexts of quantum critical heavy fermion metals and magnetic nanostructures. The sub-ohmic Bose-Fermi Kondo model provides a setting to study this effect. We find that this many-body problem is exactly solvable when the spectrum of the dissipative boso

Volker Braun, Tamaz Brelidze, Michael R. Douglas, Burt A. Ovrut

We extend previous computations of Calabi-Yau metrics on projective hypersurfaces to free quotients, complete intersections, and free quotients of complete intersections. In particular, we construct these metrics on generic quintics, four-generation quotients of the quintic, Schoen Calabi-Yau complete intersections and the quotient of a Schoen manifold with

Gabriela Barenboim, Enrico Lunghi, Paride Paradisi, Werner Porod

The terascale will be explored with the start of the LHC. One of the most fundamental questions which we expect to be answered is the root of electroweak symmetry breaking and whether the Higgs mechanism is realized in nature or not. In this context we pose the question if existing experimental data still allow for a light non-minimal Higgs sector. We tackle

Roban Hultman Kramer, Zoltán Haiman

High-redshift quasars (z >~ 6) drive ionization fronts into the intergalactic medium (IGM). If the thickness of the front can be measured, it can provide a novel constraint on the ionizing spectral energy distribution (SED). Here we follow the propagation of an I-front into a uniform IGM, and compute its thickness for a range of possible quasar spectra and a

Luciano Rezzolla, Enrico Barausse, Ernst Nils Dorband, Denis Pollney

We provide a compact analytic formula to compute the spin of the black hole produced by the coalescence of two black holes. The expression, which uses an analytic fit of numerical-relativity data and relies on four assumptions, aims at modelling generic initial spin configurations and mass ratios. A comparison with numerical-relativity simulations already sh

Jerome P. Gauntlett, Oscar Varela

We consider the most general class of supersymmetric solutions of D=11 supergravity consisting of a warped product of AdS_5 with a six-dimensional internal manifold N_6, which are dual to N=2 super conformal field theories in d=4. For any such N_6 we construct the full non-linear Kaluza-Klein ansatz for the reduction of D=11 supergravity on N_6 down to D=5 S

S. M. Natanzon

This paper proposes an axiomatic for Cyclic Foam Topological Field theories. That is Topological Field theories, corresponding to String theories, where particles are arbitrary graphs. World surfaces in this case are two-manifolds with one-dimensional singularities. We proved that Cyclic Foam Topological Field theories one-to-one correspond to graph-Cardy-Fr

Raphael Bousso, Ben Freivogel, I-Sheng Yang

After commenting briefly on the role of the typicality assumption in science, we advocate a phenomenological approach to the cosmological measure problem. Like any other theory, a measure should be simple, general, well-defined, and consistent with observation. This allows us to proceed by elimination. As an example, we consider the proper time cutoff on a g

S. Alexeyev, N. Popov, M. Startseva, A. Barrau

Gauss-Bonnet gravity provides one of the most promising frameworks to study curvature corrections to the Einstein action in supersymmetric string theories, while avoiding ghosts and keeping second order field equations. Although Schwarzschild-type solutions for Gauss-Bonnet black holes have been known for long, the Kerr-Gauss-Bonnet metric is missing. In thi

R. Percacci

The Higgs phenomenon occurs in theories of gravity in which the connection is an independent dynamical variable. The role of order parameters is played by the soldering form and a fiber metric. The breaking of the original gauge symmetry is linked to the appearance of geometrical structures on spacetime. These facts suggest certain modifications and generali

V. Hankele, D. Zeppenfeld

Multi-lepton signatures appear in many new physics searches at the Large Hadron Collider. We here consider WWZ production with subsequent leptonic decay of the three vector bosons as a SM source of multi-lepton events. We have calculated the next-to-leading order QCD corrections for the full $p p\to 6$ lepton production cross sections in hadronic collisions.

Bin Liu, Ying Liang

We analyze the density of state (DOS) and a non-magnetic impurity effect in electron-doped cuprates starting from two different scenarios: the $d_{x^{2}-y^{2}}$-wave superconductivity coexisting with antiferromagnetic spin density wave (SDW) order versus $d_{x^{2}-y^{2}}$-wave superconductivity with a higher harmonic. We find that in both cases the local den

J. E. Seger

We present a summary of recent photoproduction results in ultra peripheral relativistic heavy ions collisions with STAR. These collisions have impact parameters larger then twice the nuclear radius; the nuclei do not physically collide, but interact via long-range electromagnetic fields. We observe exclusive $\rho^0$ production as well as $AuAu\to Au^*Au^* \

F. Arqueros, F. Blanco, J. Rosado

A model recently proposed for the calculation of air-fluorescence yield excited by electrons is revisited. Improved energy distributions of secondary electrons and a more realistic Monte Carlo simulation including some additional processes have allowed us to obtain more accurate results. The model is used to study in detail the relationship between fluoresce

A. K. Mahapatra

CdS nanotubes with wall thickness comparable to excitonic diameter of the bulk material are synthesized by a chemical route. A change in experimental conditions result in formation of nanowires, and well-separated nanoparticles. The diameter and wall thickness of nanotubes measured to be 14.4 $\pm$ 6.1 and 4.7 $\pm$ 2.2 nm, respectively. A large number of Cd

Sky Bauman, Keith R. Dienes

In this paper, we propose two new regulators for quantum field theories in spacetimes with compactified extra dimensions. We refer to these regulators as the ``extended hard cutoff&#39;&#39; (EHC) and ``extended dimensional regularization&#39;&#39; (EDR). Although based on traditional four-dimensional regulators, the key new feature of these higher-dimension

C. A. Ballon Bayona, Henrique Boschi-Filho, Nelson R. F. Braga

Deep inelastic structure functions can be calculated from supergravity when the Bjorken parameter $x$ satisfies $ x > 1/\sqrt{gN} $. We consider a gauge theory with very large 't Hooft coupling $gN$ in order to investigate the region $x << 1$. In this case the center of mass energy is large enough to increase the number of hadronic constituents of the final

R. R. Metsaev

Using the light-cone gauge approach to relativistic field dynamics, we study arbitrary spin fermionic and bosonic fields propagating in flat space of dimension greater than or equal to four. Generating functions of parity invariant cubic interaction vertices for totally symmetric and mixed-symmetry massive and massless fields are obtained. For the case of to

F. Fiamberti, A. Santambrogio, C. Sieg, D. Zanon

We present the planar four-loop anomalous dimension of the composite operator tr(phi[Z,phi]Z) in the flavour SU(2) sector of the N=4 SYM theory. At this loop order wrapping interactions are present: they give rise to contributions proportional to zeta(5) increasing the level of transcendentality of the anomalous dimension. In a sequel of this paper all the d

Dimitris Lazarou

Quantum Mechanics, almost 80 years after its arrival, is a well established and experimentally not falsified theory. It has predicted and explained a whole series of natural phenomena of a very delicate nature. But its interpretation has not gained universal acceptance. Many scientists have considered the conceptual framework of quantum theory to be unsatisf

Lia Vas

A torsion theory is called differential (higher differential) if a derivation (higher derivation) can be extended from any module to the module of quotients corresponding to the torsion theory. We study conditions equivalent to higher differentiability of a torsion theory. It is known that the Lambek, Goldie and any perfect torsion theories are differential.

Q. Beaufils, R. Chicireanu, T. Zanon, B. Laburthe-Tolra

We report on the production of ^52Cr Bose Einstein Condensates (BEC) with an all-optical method. We first load 5.10^6 metastable chromium atoms in a 1D far-off-resonance optical trap (FORT) from a Magneto Optical Trap (MOT), by combining the use of Radio Frequency (RF) frequency sweeps and depumping towards the ^5S_2 state. The atoms are then pumped to the a

Donald Yau

Classes of $G$-Hom-associative algebras are constructed as deformations of $G$-associative algebras along algebra endomorphisms. As special cases, we obtain Hom-associative and Hom-Lie algebras as deformations of associative and Lie algebras, respectively, along algebra endomorphisms. Chevalley-Eilenberg type homology for Hom-Lie algebras are also constructe

Y. Wiaux, J. D. McEwen, P. Vandergheynst, O. Blanc

A new formalism is derived for the analysis and exact reconstruction of band-limited signals on the sphere with directional wavelets. It represents an evolution of the wavelet formalism developed by Antoine & Vandergheynst (1999) and Wiaux et al. (2005). The translations of the wavelets at any point on the sphere and their proper rotations are still defined

J. Berges, S. Scheffler, D. Sexty

We compute nonequilibrium dynamics for classical-statistical SU(2) pure gauge theory on a lattice. We consider anisotropic initial conditions with high occupation numbers in the transverse plane on a characteristic scale ~ Q_s. This is used to investigate the very early stages of the thermalization process in the context of heavy-ion collisions. We find Weib

J. R. Forshaw, J. F. Gunion, L. Hodgkinson, A. Papaefstathiou

The simplest supersymmetric model that solves the mu problem and in which the GUT-scale parameters need not be finely tuned in order to predict the correct value of the Z boson mass at low scales is the Next-to-Minimal Supersymmetric Standard Model (NMSSM). However, in order that fine tuning be absent, the lightest CP-even Higgs boson h should have mass ~100

Rutger Boels, Christian Schwinn

We derive the analog of the Cachazo-Svrcek-Witten (CSW) diagrammatic Feynman rules for four dimensional Yang-Mills gauge theory coupled to a massive colored scalar. The mass term is shown to give rise to a new tower of vertices in addition to the CSW vertices for massless scalars in non-supersymmetric theories. The rules are derived directly from an action,

Jeff Kahn, Michael Neiman

We give counterexamples and a few positive results related to several conjectures of R. Pemantle and D. Wagner concerning negative correlation and log-concavity properties for probability measures and relations between them. Most of the negative results have also been obtained, independently but somewhat earlier, by Borcea et al. We also give short proofs of

Amand Faessler, Thomas Gutsche, Barry R. Holstein, Valery E. Lyubovitskij

We calculate chiral corrections to the semileptonic vector and axial quark coupling constants using a manifestly Lorentz covariant chiral quark approach up to order O(p4) in the two- and tree-flavor picture. These couplings are then used in the evaluation of the corresponding couplings which govern the semileptonic transitions between octet baryon states. In