January 2007 arXiv papers — page 16

Alessio Mucciarelli, Francesco R. Ferraro, Livia Origlia, Flavio Fusi Pecci

We have used deep high-resolution Hubble Space Telescope ACS observations to image the cluster NGC 1978 in the Large Magellanic Cloud. This high-quality photometric data set allowed us to confirm the high ellipticity (~0.30+-0.02) of this stellar system. The derived Color Magnitude Diagram allowed a detailed study of the main evolutionary sequences: in parti

Sean Matt, Ralph E. Pudritz

We review the theoretical efforts to understand why pre-main-sequence stars spin much more slowly than expected. The first idea put forward was that massive stellar winds may remove substantial angular momentum. Since then, it has become clear that the magnetic interaction between the stars and their accretion disks explains many of the observed emission pro

Prasad Subramanian

We present an up-to-date review of the physics of electron acceleration in solar noi se storms. We describe the observed characteristics of noise storm emission, emphasi zing recent advances in imaging observations. We briefly describe the general method ology of treating particle acceleration problems and apply it to the specific proble m of electron accele

M. Spavone, E. Iodice, G. Longo, M. Paolillo

We present a kinematical and photometrical study of a member, NGC4778, of the nearest (z=0.0137) compact group: Hickson 62. Our analysis reveals that Hickson 62a, also known as NGC4778, is an S0 galaxy with kinematical and morphological peculiarities, both in its central regions (r < 5&#39;&#39;) and in the outer halo. In the central regions, the rotation cu

D. M. Russell, R. P. Fender, E. Gallo, C. R. Kaiser

We present H-alpha and [O III] (5007 Angstroms) images of the nebula powered by the jet of the black hole candidate and microquasar Cygnus X-1, observed with the 2.5m Isaac Newton Telescope (INT). The ring-like structure is luminous in [O III] and there exists a thin outer shell with a high [O III] / H-alpha flux ratio. This outer shell probably originates i

Christian M. Holler, Tak Kaneko, Michael E. Jones, Keith Grainge

Aims: We describe a 6-12 GHz analogue correlator that has been developed for use in radio interferometers. Methods: We use a lag-correlator technique to synthesis eight complex spectral channels. Two schemes were considered for sampling the cross-correlation function, using either real or complex correlations, and we developed prototypes for both of them. We

Shijun Yoshida, Naofumi Ohnishi, Shoichi Yamada

The so-called &#34;acoustic revival mechanism&#34; of core-collapse supernova proposed recently by the Arizona group is an interesting new possibility. Aiming to understand the elementary processes involved in the mechanism, we have calculated the eigen frequencies and eigen functions for the g-mode oscillations of a non-rotating proto neutron star. The poss

Stephane Schanne, Diego Gotz, Lucie Gerard, Patrick Sizun

The Vela region has been observed for 1.7 Ms in November 2005 by the INTEGRAL satellite. We present preliminary spectral and temporal results of Vela X-1, an eclipsing neutron star hosted in a wind-accreting high-mass X-ray binary system. Using data from ISGRI, SPI and JEM-X, we firmly confirm the existence of cyclotron resonant scattering features (CRSF) at

Stephane Schanne, Patrick Sizun, David Maurin, Bertrand Cordier

The Vela region is a promising target for the detection of 1.8 MeV gamma-rays emitted by the decays of radioactive 26Al isotopes produced in hydrostatic or explosive stellar nucleosynthesis processes. COMPTEL has claimed 1.8 MeV gamma-ray detection from Vela at a 3sigma level with a flux of 3.6 10^-5 ph/cm^2/s. In this paper, we present first results of our

Feng Yuan

This paper reviews our current understanding of low-luminosity AGNs (LLAGNs) in the context of the advection-dominated accretion flow. The best investigated source, the supermassive black hole in our galactic center, Sgr A*, is emphasized since the physics of accretion should be the same for various LLAGNs except for their different accretion rates. The impo

Masao Hayashi, Kazuhiro Shimasaku, Kentaro Motohara, Makiko Yoshida

We use the BzK color selection proposed by Daddi et al. (2004) to obtain a sample of 1092 faint star-forming galaxies (hereafter sBzKs) from 180 arcmin^2 in the Subaru Deep Field. This sample represents star-forming galaxies at 1.4 < z < 2.5 down to K(AB)=23.2, which roughly corresponds to a stellar-mass limit of ~ 1 x 10^{10} Msun. We measure the angular co

C. R. O&#39;Dell, W. J. Henney, G. J. Ferland

[Abridged] We use new HST and archived images to clarify the nature of the knots in the Helix Nebula. We employ published far infrared spectrophotometry and existing 2.12 micron images to establish that the population distribution of the lowest ro-vibrational states of H2 is close to the distribution of a gas in LTE at 988 +- 119 K. We derive a total flux fr

A. de la Macorra

We study the possibility that dark energy decays in the future and the universe stops accelerating. The fact thatthe cosmological observations prefer an equation of state of dark energy smaller than -1 can be a signal that dark energy will decay in the future. This conclusion is based in interpreting a w<-1 as a signal of dark energy interaction with another

Manoj Thulasidas

The softening of a Gamma Ray Burst (GRB) afterglow bears remarkable similarities to the frequency evolution in a sonic boom. At the front end of the sonic boom cone, the frequency is infinite, much like a GRB. Inside the cone, the frequency rapidly decreases to infrasonic ranges and the sound source appears at two places at the same time, mimicking the doubl

M. H. van Emden, B. Moa

Expressions are not functions. Confusing the two concepts or failing to define the function that is computed by an expression weakens the rigour of interval arithmetic. We give such a definition and continue with the required re-statements and proofs of the fundamental theorems of interval arithmetic and interval analysis. Revision Feb. 10, 2009: added refer

Alexey A. Kovalev, Mario F. Borunda, T. Jungwirth, L. W. Molenkamp

We study the quantum interference effects induced by the Aharonov-Casher phase in a ring structure in a two-dimensional heavy hole (HH) system with spin-orbit interaction realizable in narrow asymmetric quantum wells. The influence of the spin-orbit interaction strength on the transport is investigated analytically. These analytical results allow us to expla

L. Stawarz, J. G. Kirk

We investigate a magnetized plasma in which injected high energy gamma-rays annihilate on a soft photon field, that is provided by the synchrotron radiation of the created pairs. For a very wide range of magnetic fields, this process involves gamma-rays between 0.3 GeV and 30 TeV. We derive a simple dynamical system for this process, analyze its stability to

Mirjam Cvetic, Tao Liu, Michael B. Schulz

We construct a class of geometric twists of Calabi-Yau manifolds of Voisin-Borcea type (K3 x T^2)/Z_2 and study the superpotential in a type IIA orientifold based on this geometry. The twists modify the direct product by fibering the K3 over T^2 while preserving the Z_2 involution. As an important application, the Voisin-Borcea class contains T^6/(Z_2 x Z_2)

Corina S. Pasareanu, Radek Pelanek, Willem Visser

We propose an abstraction-based model checking method which relies on refinement of an under-approximation of the feasible behaviors of the system under analysis. The method preserves errors to safety properties, since all analyzed behaviors are feasible by definition. The method does not require an abstract transition relation to be generated, but instead e

Patrick Huber, Joachim Kopp, Manfred Lindner, Mark Rolinec

We present Version 3.0 of the GLoBES (``General Long Baseline Experiment Simulator&#39;&#39;) software, which is a simulation tool for short- and long-baseline neutrino oscillation experiments. As a new feature, GLoBES 3.0 allows for user-defined systematical errors, which can also be used to simulate experiments with multiple discrete sources and detectors.

Edward L. Wright

The luminosity distance vs. redshift law is now measured using supernovae and gamma ray bursts, and the angular size distance is measured at the surface of last scattering by the CMB and at z = 0.35 by baryon acoustic oscillations. In this paper this data is fit to models for the equation of state with w = -1, w = const, and w(z) = w_0+w_a(1-a). The last mod

Kaustubh Agashe, Hooman Davoudiasl, Gilad Perez, Amarjit Soni

We study the production and decay of Kaluza-Klein (KK) gravitons at the Large Hadron Collider (LHC), in the framework of a warped extra dimension in which the Standard Model (SM) fields propagate. Such a scenario can provide solutions to both the Planck-weak hierarchy problem and the flavor puzzle of the SM. In this scenario, the production via $q \bar{q}$ a

K. Zioutas, M. Tsagri, Y. Semertzidis, Th. Papaevangelou

The working principle of axion helioscopes can be behind unexpected solar X-ray emission, being associated with solar magnetic fields, which become the catalyst. Solar axion signals can be transient brightenings as well as continuous radiation. The energy range below 1 keV is a window of opportunity for direct axion searches. (In)direct signatures support ax

Yuri Bakhtin

A dynamical system perturbed by white noise in a neighborhood of an unstable fixed point is considered. We obtain the exit asymptotics in the limit of vanishing noise intensity. This is a refinement of a result by Kifer (1981).

K. Gallmeister, U. Mosel

Using QCD-inspired time dependent cross sections for pre-hadrons we provide a combined analysis of available experimental data on hadron attenuation in DIS off nuclei as measured by HERMES with 12 and 27 GeV and by EMC with 100 and 280 GeV lepton beam energies. We extract the complete four-dimensional evolution of the pre-hadrons using the JETSET-part of PYT

Daegene Song

Quantum theory reveals astonishing and counterintuitive phenomena not found in classical physics, such as wave-particle duality, where entities like electrons and photons exhibit both wave-like and particle-like behaviors. In this paper, we leverage advancements in quantum information science to gain new insights into this phenomenon. We specifically examine

F. Igloi, R. Juhasz, Z. Zimboras

We study the entanglement entropy of blocks of contiguous spins in non-periodic (quasi-periodic or more generally aperiodic) critical Heisenberg, XX and quantum Ising spin chains, e.g. in Fibonacci chains. For marginal and relevant aperiodic modulations, the entanglement entropy is found to be a logarithmic function of the block size with log-periodic oscill

A. V. Dodonov, S. S. Mizrahi, V. V. Dodonov

We propose an experimental scheme to probe the form of one-count operation used in the theory of continuous photodetection in cavities. Two main steps are: 1) an absorption of a single photon by an atom passing through a high-Q cavity containing electromagnetic field in a thermal or coherent state, 2) a subsequent measurement of the photon statistics in the

Victor H. Cardenas

In a recent paper, Liddle and Urena-Lopez suggested that to have a unified model of inflation and dark matter is imperative to have a proper reheating process where part of the inflaton field remains. In this paper I propose a model where this is possible. I found that, incorporating the effect of plasma masses generated by the inflaton products, enable us t

Michael Creutz

A popular approximation in lattice gauge theory is an extrapolation in the number of fermion species away from the four fold degeneracy natural with the staggered fermion formulation. I show that the extrapolation procedure mutilates the expected continuum holomorphic behavior in the quark masses. The conventional resolution proposes canceling the unphysical

Andrei Galiautdinov

Building on the previous results of the Weyl chamber steering method, we demonstrate how to generate high-fidelity controlled-not by direct application of certain, physically relevant Hamiltonians with fixed coupling constants containing Rabi terms. Such Hamiltonians are often used to describe two superconducting qubits driven by local rf-pulses. It is found

I. Hleiqawi, K. Hicks, D. Carman, T. Mibe

Differential cross sections for the reaction $γp \to K^{*0} Σ^+$ are presented at nine bins in photon energy in the range from 1.7 to 3.0 GeV. The \kstar was detected by its decay products, $K^+π^-$, in the CLAS detector at Jefferson Lab. These data are the first \kstar photoproduction cross sections ever published over a broad range of angles. Comparison wi

F. A. R. Navarro, M. S. Reis, E. K Lenzi, I. S. Olivera

In this paper a composed A+B magnetic system, with spins J_A=2 and J_B=3/2, is considered within the mean-field approximation, in the framework of Tsallis nonextensive statistics. Our motivation is twofold: (1) to approach the existing experimental data of manganese oxides (manganites), where Mn^{3+} and Mn^{4+} form two magnetic sublattices, and (2) to inve

Sergiu I. Vacaru

We formulate a statistical analogy of regular Lagrange mechanics and Finsler geometry derived from Grisha Perelman&#39;s functionals generalized for nonholonomic Ricci flows. There are elaborated explicit constructions when nonholonomically constrained flows of Riemann metrics result in Finsler like configurations, and inversely, and geometric mechanics is m

A. C. Seridonio, M. Yoshida, L. N. Oliveira

We show that the conductance of a quantum wire side-coupled to a quantum dot, with a gate potential favoring the formation of a dot magnetic moment, is a universal function of the temperature. Universality prevails even if the currents through the dot and the wire interfere. We apply this result to the experimental data of Sato et al.[Phys. Rev. Lett. 95, 06

Tulika Maitra, Roser Valenti

In view of recent controversy regarding the orbital order in the frustrated spinel ZnV2O4, we analyze the orbital and magnetic groundstate of this system within an ab initio density functional theory approach. While LDA+U calculations in the presence of a cooperative Jahn-Teller distortion stabilize an A-type staggered orbital order, the consideration of rel

Pedro Marronetti, Wolfgang Tichy, Bernd Bruegmann, Jose Gonzalez

Binary black hole simulations have traditionally been computationally very expensive: current simulations are performed in supercomputers involving dozens if not hundreds of processors, thus systematic studies of the parameter space of binary black hole encounters still seem prohibitive with current technology. Here we show how the multi-layered refinement l

Guanliang Li, Lidia A. Braunstein, Sergey V. Buldyrev, Shlomo Havlin

We study the distribution $P(σ)$ of the equivalent conductance $σ$ for Erdős-Rényi (ER) and scale-free (SF) weighted resistor networks with $N$ nodes. Each link has conductance $g\equiv e^{-ax}$, where $x$ is a random number taken from a uniform distribution between 0 and 1 and the parameter $a$ represents the strength of the disorder. We provide an iterativ

A. Labiano, C. P. O&#39;Dea, P. D. Barthel, W. H. de Vries

AIMS: Search for star formation regions in the hosts of potentially young radio galaxies (Gigahertz Peaked Spectrum and Compact Steep Spectrum sources). METHODS: Near-UV imaging with the Hubble Space Telescope Advanced Camera for Surveys.} RESULTS: We find near-UV light which could be the product of recent star formation in eight of the nine observed sources

Marek Kowalski, Anna Mohr

A novel method is presented which will enhance the sensitivity of neutrino telescopes to identify transient sources such as Gamma-Ray Bursts (GRBs) and core-collapse Supernovae (SNe). Triggered by the detection of high energy neutrino events from IceCube or other large scale neutrino telescopes, an optical follow-up program will allow the identification of t

Michael Usher

Modulo trivial exceptions, we show that smoothly nontrivial symplectic sums of symplectic 4-manifolds along surfaces of positive genus are never rational or ruled, and we enumerate each case in which they have Kodaira dimension zero (i.e., are blowups of symplectic 4-manifolds with torsion canonical class). In particular, a symplectic four-manifold of Kodair

John A. Scales, L. D. Carr, D. B. McIntosh, Valentin Freilikher

We exploit millimeter wave technology to measure the reflection and transmission response of random dielectric media. Our samples are easily constructed from random stacks of identical, sub-wavelength quartz and Teflon wafers. The measurement allows us to observe the characteristic transmission resonances associated with localization. We show that these reso

Panos Papasoglu, Eric Swenson

Let G be a one-ended group acting discretely and co-compactly on a CAT(0) space X. We show that the boundary of X has no cut points and that one can detect splittings of $G$ over two-ended groups and recover its JSJ decomposition from the boundary. We show that any discrete action of a group G on a CAT(0) space X satisfies a convergence type property. This i

Xiong-Jun Liu, Xin Liu, L. C. Kwek, C. H. Oh

We propose fractional spin hall effect (FSHE) by coupling pseudospin states of cold bosonic atoms to optical fields. The present scheme is an extension to interacting bosonic system of the recent work \cite{liu,zhu} on optically induced spin hall effect in non-interacting atomic system. The system has two different types of ground states. The 1st type of gro

Cesar Gomez, Rafael Hernandez

The dispersion relation for planar N=4 supersymmetric Yang-Mills is identified with the Casimir of a quantum deformed two-dimensional kinematical symmetry, E_q(1,1). The quantum deformed symmetry algebra is generated by the momentum, energy and boost, with deformation parameter q=e^{2πi/λ}. Representing the boost as the infinitesimal generator for translatio

Shrawan Kumar, George Lusztig, Dipendra Prasad

In this paper we show how a theorem of Jantzen relating the character of a finite dimensional irreducible representation of a disconnected semisimple algebraic group on elements outside the connected component of identity to character of an irreducible representation of another connected semisimple algebraic group can be deduced from properties of the canoni

Cyril Pitrou, Jean-Philippe Uzan

This note derives the analogue of the Mukhanov-Sasaki variables both for scalar and tensor perturbations in the 1+3 covariant formalism. The possibility of generalizing them to non-flat Friedmann-Lemaitre universes is discussed.

Biswajit Pandey, Somnath Bharadwaj

We compare quantitative estimates of the filamentarity of the galaxy distribution in seven nearly two dimensional sections from the survey against the predictions of LCDM N-body simulations. The filamentarity of the actual galaxy distribution is known to be luminosity dependent. It is also known that the filamentarity of the simulated galaxy distribution is

Mirela Ciperiani, Daniel Krashen

In this paper we develop techniques for computing the relative Brauer group of curves, focusing particularly on the case where the genus is 1. We use these techniques to show that the relative Brauer group may be infinite (for certain ground fields) as well as to determine this group explicitly for certain curves defined over the rational numbers. To connect

Herve Gaussier, Alexandre Sukhov

We give a characterization of the complex Euclidean space C^n, proving a global Newlander-Nirenberg&#39;s theorem on the representability of complex structures close to the standard complex structure on C^n.

Veronique Bruyere, Jean-Francois Raskin

In this paper, we study the model-checking and parameter synthesis problems of the logic TCTL over discrete-timed automata where parameters are allowed both in the model (timed automaton) and in the property (temporal formula). Our results are as follows. On the negative side, we show that the model-checking problem of TCTL extended with parameters is undeci

Seungwon Baek, David London

We perform a fit to the 2006 B -> pi K data and show that there is a disagreement with the standard model. That is, the B -> pi K puzzle is still present. In fact, it has gotten worse than in earlier years. Assuming that one new-physics (NP) operator dominates, we show that a good fit is obtained only when the electroweak penguin amplitude is modified. The N

Hsiu-Hui Huang, Werner Becker

We report on XMM-Newton observations of the &#34;Black Widow pulsar&#34;, PSR B1957+20. The pulsar&#39;s X-ray emission is non-thermal and best modeled with a single powerlaw spectrum of photon index 2.03(+0.51/-0.36). No coherent X-ray pulsations at the pulsar&#39;s spin-period could be detected, though a strong binary-phase dependence of the X-ray flux is

Alain Barrat, E. Trizac, M. H. Ernst

The solutions of the one-dimensional homogeneous nonlinear Boltzmann equation are studied in the QE-limit (Quasi-Elastic; infinitesimal dissipation) by a combination of analytical and numerical techniques. Their behavior at large velocities differs qualitatively from that for higher dimensional systems. In our generic model, a dissipative fluid is maintained

Laszlo B. Kish, Janusz Smulko, Peter Heszler, Claes-Goran Granqvist

Information theoretical tools are applied for the study of the sensitivity and selectivity enhancements of resistive fluctuation-enhanced sensors. General considerations are given for the upper limit of selectivity enhancement. The signal-to-noise ratio and information channel capacity of fluctuation-enhanced chemical sensors is compared to that of classical

Jae-Weon Lee, Jungjai Lee, Hyeong-Chan Kim

We suggest that vacuum entanglement energy associated with the entanglement entropy of the universe is the origin of dark energy. The observed properties of dark energy can be explained by using the nature of entanglement energy without modification of gravity or exotic matter. From the number of degrees of freedom in the standard model, we obtain the equati

M. Asoudeh, V. Karimipour, A. Sadrolashrafi

Using the matrix product formalism, we introduce a two parameter family of exactly solvable $xyz$ spin 1/2 Heisenberg chains in magnetic field (with nearest neighbor interactions) and calculate the ground state and correlation functions in compact form. The ground state has a very interesting property: all the pairs of spins are equally entangled with each o

Aslak Bakke Buan, Dagfinn F. Vatne

In this paper we give the derived equivalence classification of cluster-tilted algebras of type An. We show that the bounded derived category of such an algebra depends only on the number of 3-cycles in the quiver of the algebra.

F. Selsis, B. Chazelas, P. Borde, M. Ollivier

Planets less massive than about 10 MEarth are expected to have no massive H-He atmosphere and a cometary composition (50% rocks, 50% water, by mass) provided they formed beyond the snowline of protoplanetary disks. Due to inward migration, such planets could be found at any distance between their formation site and the star. If migration stops within the hab

Maxim Krikun

This note answers one question in [math.PR/0505668], concerning the connected allocation for the Poisson process in R^2. The proposed solution makes use of the Riemann map from the plane minus the minimal spanning forest of the Poisson point process to the halfplane. A picture of a numerically simulated example is included.

Bjoern Baeuchle, Yun Cheng, Laszlo P. Csernai, Volodymyr K. Magas

Ultra-Relativistic Heavy Ion Collisions at an energy $\sqrt{s_{NN}} = 65 {\rm GeV}$ are studied in a three-dimensional Fluid Dynamical model. The results of a hydrodynamical evolution using the PIC-method are shown. The importance and diagnostic value of a proper reaction plane determination is emphasized, and the time development of collective measurables i

L. Pezze, A. Smerzi, G. Khoury, J. F. Hodelin

We study a Mach-Zehnder interferometer fed by a coherent state in one input port and vacuum in the other. We explore a Bayesian phase estimation strategy to demonstrate that it is possible to achieve the standard quantum limit independently from the true value of the phase shift and specific assumptions on the noise of the interferometer. We have been able t

Wei Wang, Xijun Hu, Yiming Long

There is a long standing conjecture in Hamiltonian analysis which claims that there exist at least $n$ geometrically distinct closed characteristics on every compact convex hypersurface in $\R^{2n}$ with $n\ge 2$. Besides many partial results, this conjecture has been only completely solved for $n=2$. In this paper, we give a confirmed answer to this conject

Ahmad Sheykhi, Bin Wang, Rong-Gen Cai

In this paper we first obtain Friedmann equations for the $(n-1)$-dimensional brane embedded in the $(n+1)$-dimensional bulk, with intrinsic curvature term of the brane included in the action (DGP model). Then, we show that one can always rewrite the Friedmann equations in the form of the first law of thermodynamics, $dE=TdS+WdV$, at apparent horizon on the

Ion I Cotăescu

Approximative analytic solutions of the Dirac equation in the geometry of Schwarzschild black holes are derived obtaining information about the discrete energy levels and the asymptotic behavior of the energy eigenspinors.

Daniele Bettinelli, Ruggero Ferrari, Andrea Quadri

Recently a perturbative theory has been constructed, starting from the Feynman rules of the nonlinear sigma model at the tree level in the presence of an external vector source coupled to the flat connection and of a scalar source coupled to the nonlinear sigma model constraint (flat connection formalism). The construction is based on a local functional equa

Ion I Cotăescu

Starting with a new theory of symmetries generated by isometries in field theories with spin, one finds the generators of the spinor representation in backgrounds with a given symmetry. In this manner one obtains a collection of conserved operators from which one can chose the complete sets of commuting operators defining quantum modes. In this framework, th

Andrew Das Arulsamy, Xiangyuan Cui, Catherine Stampfl, Kurunathan Ratnavelu

The evolution of resistivity versus temperature ($ρ(T)$) curve for different doping elements, and in the presence of various defects and clustering are explained for both diluted magnetic semiconductors (DMS) and manganites. Here, we provide unambiguous evidence that the concept of ionization energy ($E_I$), which is explicitly associated with the atomic ene

J. I. Silva-Marcos

For a RS model, with SM fields in the bulk and the Higgs boson on the TeV-brane, we suggest two specific structures for the Yukawa couplings, one based on a permutation symmetry and the other on the Universal Strength of Yukawa couplings hypothesis (USY). In USY, all Yukawa couplings have equal strength and the difference in the Yukawa structure lies in some

Minh-Dung Dang, Patrick Bellot

In this article, we are interested in the physical model of general quantum protocols implementing secure two-party computations in the light of Mayers&#39; and Lo&#39;s & Chau&#39;s no-go theorems of bit commitment and oblivious transfer. In contrast to the commonly adobted quantum pure two-party model in the literature where classical communication is norm

Elemer E Rosinger

A recent general model of entanglement, [5], that goes much beyond the usual one based on tensor products of vector spaces is further developed here. It is shown that the usual Cartesian product can be seen as two extreme particular instances of non-entanglement. Also the recent approach to entanglement in [8] is incorporated in the general model in [5]. The

Lars Grant, K. Narayan

We study the half-BPS mesonic chiral ring of the N=1 superconformal quiver theories arising from N D3-branes stacked at Y^pq and L^abc Calabi-Yau conical singularities. We map each gauge invariant operator represented on the quiver as an irreducible loop adjoint at some node, to an invariant monomial, modulo relations, in the gauged linear sigma model descri

E. Levin, A. Prygarin

In this paper we address two problems in the BFKL Pomeron calculus in zero transverse dimensions: the summation of the Pomeron loops and the calculation of the processes of multiparticle generation. We introduce a new generating functional for these processes and obtain the evolution equation for it. We argue that in the kinematic range given by $ 1 \ll \ln(

Franz J. Wegner

Explicit solutions of the two-dimensional floating body problem (bodies that can float in all positions) for relative density different from 1/2 and of the tire track problem (tire tracks of a bicycle, which do not allow to determine, which way the bicycle went) are given, which differ from circles. Starting point is the differential equation given by the au

Ben Green, Terence Tao

We obtain quantitative versions of the Balog-Szemeredi-Gowers and Freiman theorems in the model case of a finite field geometry F_2^n, improving the previously known bounds in such theorems. For instance, if A is a subset of F_2^n such that |A+A| <= K|A| (thus A has small additive doubling), we show that there exists an affine subspace V of F_2^n of cardinal

Bernhard K. Meister

An extension of the Wigner-Araki-Yanase theorem to multiplicative conserved quantities is presented and approximate versions of the theorem are discussed.

I. I. Ryabtsev, D. B. Tretyakov, I. I. Beterov, V. M. Entin

We have developed a simple analytical model describing multi-atom signals that are measured in experiments on dipole-dipole interaction at resonant collisions of a few Rydberg atoms. It has been shown that finite efficiency of the selective field-ionization detector leads to the mixing up of the spectra of resonant collisions registered for various numbers o

L. Dang, L. Li, X. H. Zhong, P. Z. Ning

The momentum dependent $K^{-}$-nucleus optical potentials are obtained based on the relativistic mean-field theory. By considering the quarks coordinates of $K^-$ meson, we introduced a momentum-dependent &#34;form factor&#34; to modify the coupling vertexes. The parameters in the form factors are determined by fitting the experimental $K^{-}$-nucleus scatte

Diego Cirilo-Lombardo

Relativistic geometrical action for a quantum particle in the superspace is analyzed from theoretical group point of view. To this end an alternative technique of quantization outlined by the authors in a previous work and that is based in the correct interpretation of the square root Hamiltonian, is used. The obtained spectrum of physical states and the Foc

Roland Zarzycki

Let F be the Thompson&#39;s group. We study the structure of F-limit groups. Consider a sequence of groups marked by three elements, each isomorphic to F. Assume that the this sequence is convergent in the space of marked groups. We prove that no HNN-extension of F over a cyclic subgroup occurs as an F-limit group of such a sequence.

J. Kikuchi, M. Takigawa, H. Sugawara, H. Sato

We have performed 31P nuclear magnetic resonance (NMR) experiments on the filled skutterudite compound PrFe4P12 to investigate the exotic ordered phase at low temperatures and low magnetic fields. Analysis of the NMR line splitting in the ordered phase indicates that totally symmetric (Γ_1-type) staggered magnetic multipoles are induced by magnetic fields. T

Y. Meurice

We review recent results concerning the renormalization group (RG) transformation of Dyson&#39;s hierarchical model (HM). This model can be seen as an approximation of a scalar field theory on a lattice. We introduce the HM and show that its large group of symmetry simplifies drastically the blockspinning procedure. Several equivalent forms of the recursion

Zhi-Gang Wang

In this article, we calculate the strong coupling constants of the $ρNN$, $ρΣΣ$ and $ρΞΞ$ in the framework of the light-cone QCD sum rules approach. The strong coupling constants of the meson-baryon-baryon are the fundamental parameters in the one-boson exchange model which describes the baryon-baryon interactions successfully. The numerical values are in ag

Catherine Greenhill, Brendan D. McKay

Let S and T be vectors of positive integers with the same sum. We study the uniform distribution on the space of simple bipartite graphs with degree sequence S in one part and T in the other; equivalently, binary matrices with row sums S and column sums T. In particular, we find precise formulae for the probabilities that a given bipartite graph is edge-disj

Hirotsugu Doi, Kentaro Takami, Ryo Yamazaki

The observational diversity of optical emission, which coincides with prompt gamma-ray bursts (GRBs), has been discovered in the recent Swift era. We show that on the assumption of the synchrotron radiation for the observed energy range below the X-ray band, the observed diversity can be explained using the internal shock model by taking into account a high-

K. J. Jiang, L. Deng, M. G. Payne

Using a single channel active Raman gain medium we show a $(220\pm 20)$ns advance time for an optical pulse of $τ_{FWHM}=15.4 μ$s propagating through a 10 cm medium, a lead time that is comparable to what was reported previously. In addition, we have verified experimentally all the features associated with this single channel Raman gain system. Our results s

A. M. Zagoskin, S. Savel&#39;ev, Franco Nori

We map adiabatic quantum evolution on the classical Hamiltonian dynamics of a 1D gas (Pechukas gas) and simulate the latter numerically. This approach turns out to be both insightful and numerically efficient, as seen from our example of a CNOT gate simulation. For a general class of Hamiltonians we show that the escape probability from the initial state sca

A. Bouda, A. Mohamed Meziane

In a stationary case and for any potential, we solve the three-dimensional quantum Hamilton-Jacobi equation in terms of the solutions of the corresponding Schrodinger equation. Then, in the case of separated variables, by requiring that the conjugate momentum be invariant under any linear transformation of the solutions of the Schrodinger equation used in th

S. Anderloni, F. Benatti, R. Floreanini

In phenomenological applications the time evolution of subsystems immersed in an external environment are sometimes described by Markovian semigroups of Redfield type that result non-positive: the appearence of negative probabilities is avoided by restricting the admissible initial conditions to those states that remain positive under the action of the dynam

Ozlem Yesiltas, Ramazan Sever

PT-/non-PT-symmetric and non-Hermitian deformed Morse and Poschl-Teller potentials are studied first time by quantum Hamilton-Jacobi approach. Energy eigenvalues and eigenfunctions are obtained by solving quantum Hamilton-Jacobi equation.

Daniel Reitzner

Results of the experiments carried out in [Shahriar S. Afshar, Proc. SPIE bf 5866 (2005) 229-244] and [Shahriar S. Afshar, AIP Cof. Proc. 810, (2006) 294-299] are reviewed and their interpretation by the authors is questioned. Arguments are supported by numerical simulations.

Juan Carlos Garcia-Escartin, Pedro Chamorro-Posada

In communication networks many different channels must share a limited amount of resources. In order to allow for multiple simultaneous communications, multiple access techniques are routinely employed. With quantum communication, it is possible to share a new kind of resource. All of the system channels can be accommodated into a single channel in a larger

F. Haas

The quantum Zakharov system is described in terms of a Lagrangian formalism. A time-dependent Gaussian trial function approach for the envelope electric field and the low-frequency part of the density fluctuation leads to a coupled, nonlinear system of ordinary differential equations. In the semiclassic case, linear stability analysis of this dynamical syste

P. J. Reece, E. M. Wright, K. Dholakia

In this Letter we report observations of optically induced self-organization of colloidal arrays in the presence of un-patterned counter-propagating evanescent waves. The colloidal arrays formed along the laser propagation-axis are shown to be linked to the break-up of the incident field into optical spatial solitons, the lateral spacing of the arrays being

Carlos L. Garrido Alzar, Plamen G. Petrov, Daniel Oblak, Joerg H. Mueller

The design and implementation of a current driver for the quadrupole coil of a magneto-optical trap are presented. The control and the power stages of the driver, both based on a push-pull configuration with high-speed transistors, are separated, allowing for a protection of the control electronics. Moreover, the coil current can be set by an analog voltage,

Van-Hoang Le, Anh-Thu Le, Rui-Hua Xie, C. D. Lin

We report theoretical investigations of the tomographic procedure suggested by Itatani {\it et al.} [Nature, {\bf 432} 867 (2004)] for reconstructing highest occupied molecular orbitals (HOMO) using high-order harmonic generation (HHG). Using the limited range of harmonics from the plateau region, we found that under the most favorable assumptions, it is sti

Andre Kietzmann, Bastian Holst, Ronald Redmer, Michael P. Desjarlais

We have performed quantum molecular dynamics simulations for dense helium to study the nonmetal-to-metal transition at high pressures. We present new results for the equation of state and the Hugoniot curve in the warm dense matter region. The optical conductivity is calculated via the Kubo-Greenwood formula from which the dc conductivity is derived. The non

Ali Mahmoudi, Reza Azalzadeh

Fresnel lens has a long history in optics. This concept at non-optical wavelengths is also applicable. In this paper we report design and fabrication of a half and quarter wave dielectric Fresnel lens made of Plexiglas, and a Fresnel reflector at 11.1 GHz frequency. We made two lenses and one reflector at same frequency and compare their gain and radiation p

P. Delogu, M. E. Fantacci, I. Gori, A. Preite Martinez

We are developing a computer-aided detection (CAD) system for the identification of small pulmonary nodules in screening CT scans. The main modules of our system, i.e. a dot-enhancement filter for nodule candidate selection and a neural classifier for false positive finding reduction, are described. The preliminary results obtained on the so-far collected da

P. Delogu, M. E. Fantacci, P. Kasae, A. Retico

Evaluating the degree of malignancy of a massive lesion on the basis of the mere visual analysis of the mammogram is a non-trivial task. We developed a semi-automated system for massive-lesion characterization with the aim to support the radiological diagnosis. A dataset of 226 masses has been used in the present analysis. The system performances have been e