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June 2007 arXiv papers — page 16

Showing 1,501–1,600 of 4,521 papers

  1. Thomas G. Rizzo

    High scale conformal physics can lead to unusual unparticle stuff at our low energies. In this paper we discuss how the exchange of unparticles between Standard Model fields can lead to new contact interaction physics as well as a pseudoresonance-like structure, an unresonance, that might be observable at the Tevatron or LHC in, e.g., the Drell-Yan channel.

  2. Oliver Goodman, Michael Shapiro

    Viewing Dehn's algorithm as a rewriting system, we generalise to allow an alphabet containing letters which do not necessarily represent group elements. This extends the class of groups for which the algorithm solves the word problem to include nilpotent groups, many relatively hyperbolic groups including geometrically finite groups and fundamental group

  3. A. B. Balantekin, C. Volpe, J. Welzel

    We explore the effect of the neutrino magnetic moment on neutrino scattering with matter in a core-collapse Supernova. We study the impact both on the neutrino fluxes and on the electron fraction. We find that sizeable modifications require very large magnetic moments both for Dirac and Majorana neutrinos.

  4. E. Levin, J. Miller, and A. Prygarin

    In this paper we argue that in the kinematic range given by $ 1 \ll \ln(1/\as^2) \ll \as Y \ll \frac{1}{\as}$, we can reduce the Pomeron calculus to the exchange of non-interacting Pomerons with the renormalized amplitude of their interaction with the target. Therefore, the summation of the Pomeron loops can be performed using the improved Mueller, Patel, Sa

  5. Eric Jaligot, Alexey Muranov, Azadeh Neman

    We prove that existentially closed $CSA$-groups have the independence property. This is done by showing that there exist words having the independence property relatively to the class of torsion-free hyperbolic groups.

  6. Jocelyn Monroe, Peter Fisher

    Neutrino coherent scattering cross sections can be as large as 10^{-39} cm^2, while current dark matter experiments have sensitivities to WIMP coherent scattering cross sections five orders of magnitude smaller; future experiments plan to have sensitivities to cross sections as small as 10^{-48} cm^2. With large target masses and few keV recoil energy detect

  7. S. Capozziello, V. I. Man'ko, G. Marmo, C. Stornaiolo

    The probability representation, in which cosmological quantum states are described by a standard positive probability distribution, is constructed for minisuperspace models selected by Noether symmetries. In such a case, the tomographic probability distribution provides the classical evolution for the models and can be considered an approach to select "o

  8. V. P. Gusynin, S. G. Sharapov, J. P. Carbotte

    We consider the relationship between the tight-binding Hamiltonian of the two-dimensional honeycomb lattice of carbon atoms with nearest neighbor hopping only and the 2+1 dimensional Hamiltonian of quantum electrodynamics which follows in the continuum limit. We pay particular attention to the symmetries of the free Dirac fermions including spatial inversion

  9. Christopher Gordon, Roberto Trotta

    Bayesian model selection provides a formal method of determining the level of support for new parameters in a model. However, if there is not a specific enough underlying physical motivation for the new parameters it can be hard to assign them meaningful priors, an essential ingredient of Bayesian model selection. Here we look at methods maximizing the prior

  10. M. Mobilia, A. Petersen, S. Redner

    We study the voter model with a finite density of zealots--voters than never change opinion. For equal numbers of zealots of each species, the distribution of magnetization (opinions) is Gaussian in the mean-field limit as well as in one and two dimensions, with a width that is proportional to 1/sqrt{Z}, where Z is the number of zealots, independent of the t

  11. Eli Hawkins

    In the standard example of strict deformation quantization of the symplectic sphere $S^2$, the set of allowed values of the quantization parameter $\hbar$ is not connected; indeed, it is almost discrete. Li recently constructed a class of examples (including $S^2$) in which $\hbar$ can take any value in an interval, but these examples are badly behaved. Here

  12. Alan Barros de Oliveira, Paulo A. Netz, Marcia C. Barbosa

    Using molecular dynamics simulations and integral equations we investigate the structure, the thermodynamics and the dynamics of a system of particles interacting through a continuous core- softened ramp-like interparticle potential. We found density, dynamic and structural anomalies similar to that found in water. Analysis of the radial distribution functio

  13. D. Carollo, T. C. Beers, Y. S. Lee, M. Chiba

    The halo of the Milky Way provides unique elemental abundance and kinematic information on the first objects to form in the Universe, which can be used to tightly constrain models of galaxy formation and evolution. Although the halo was once considered a single component, evidence for its dichotomy has slowly emerged in recent years from inspection of small

  14. V. I. Shnyrkov, A. A. Soroka, S. I. Melnik

    In this paper we discuss solid-state nanoelectronic realizations of Josephson flux qubits with large tunneling amplitude between the two macroscopic states. The latter can be controlled via the height and wells form of the potential barrier, which is determined by quantum-state engineering of the flux qubit circuit. The simplest circuit of the flux qubit is

  15. Jean-Christophe Novelli, Anne Schilling

    We study properties of the forgotten monoid which appeared in work of Lascoux and Schutzenberger and recently resurfaced in the construction of dual equivalence graphs by Assaf. In particular, we provide an explicit characterization of the forgotten classes in terms of inversion numbers and show that there are n^2-3n+4 forgotten classes in the symmetric grou

  16. Jungkai A. Chen, Meng Chen

    Let $V$ be a complex nonsingular projective 3-fold of general type. We prove $P_{12}(V)>0$ and $P_{24}(V)>1$ (which answers an open problem of J. Kollar and S. Mori). We also prove that the canonical volume has an universal lower bound $\text{Vol}(V) \geq 1/2660$ and that the pluri-canonical map $Φ_m$ is birational onto its image for all $m\geq 77$. As an ap

  17. K. A. Hochmuth, S. T. Petcov, W. Rodejohann

    We consider corrections to vanishing U_{e3} and maximal atmospheric neutrino mixing originating from the relation U = U_ell^dagger U_nu, where U is the PMNS mixing matrix and U_ell (U_nu) is associated with the diagonalization of the charged lepton (neutrino) mass matrix. We assume that in the limit of U_ell or U_nu being the unit matrix, one has U_{e3} = 0

  18. M. Napsuciale, E. Oset, K. Sasaki, C. A. Vaquera-Araujo

    We study the e^{+}e^{-} to phi pi pi reaction for pions in an isoscalar s-wave which is dominated by loop mechanisms. For kaon loops we start from the conventional RCHPT, but use the unitarized amplitude for KbarK-pipi scattering and the full kaon form factor instead of the lowest order terms. We study also effects of vector mesons using RCHPT supplemented w

  19. A. Morandi, S. Ettori

    [Abridged] The entropy distribution of the intracluster gas reflects both accretion history of the gas and processes of feedback which provide a further non-gravitational energy besides the potential one. In this work, we study the profiles and the scaling properties of the gas entropy in 24 hot (kT_{gas} > 6 keV) galaxy clusters observed with Chandra in the

  20. V. V. Cheianov, V. I. Falko, B. L. Altshuler, I. L. Aleiner

    Transport in undoped graphene is related to percolating current patterns in the networks of {\em N-} and {\em P}-type regions reflecting the strong bipolar charge density fluctuations. Transmissions of the {\em P-N} junctions, though small, are vital in establishing the macroscopic conductivity. We propose a random resistor network model to analyze scaling d

  21. A. Matzkin

    A model for two entangled systems in an EPR setting is shown to reproduce the quantum-mechanical outcomes and expectation values. Each system is represented by a small sphere containing a point-like particle embedded in a field. A quantum state appears as an equivalence class of several possible particle-field configurations. Contrarily to Bell-type hidden v

  22. F. Alouani Bibi, J. Binney, K. Blundell, H. Omma

    We analyzed the feedback of AGN jets on cooling flow clusters using three-dimensional AMR hydrodynamic simulations. We studied the interaction of the jet with the intracluster medium and creation of low X-ray emission cavities (Bubbles) in cluster plasma. The distribution of energy input by the jet into the system was quantified in its different forms, i.e.

  23. H. De Raedt, K. Michielsen, S. Miyashita, K. Keimpema

    The general conclusion of Seevinck and Larsson is that our model exploits the so-called coincidence-time loophole and produces sinusoidal (quantum-like) correlations but does not model the singlet state because it does not violate the relevant Bell inequality derived by Larsson and Gill, since in order to obtain the sinusoidal correlations the probability of

  24. Luis F. Rojas-Ochoa, Ramon Castaneda-Priego, Vladimir Lobaskin, Anna Stradner

    We determine the structure of charge-stabilized colloidal suspensions at low ionic strength over an extended range of particle volume fractions using a combination of light and small angle neutron scattering experiments. The variation of the structure factor with concentration is analyzed within a one-component model of a colloidal suspension. We show that t

  25. R. V. Harlander, L. Mihaila, M. Steinhauser

    A consistent evolution of the strong coupling constant $α_s$ from $M_Z$ to the GUT scale is presented, involving three-loop running and two-loop decoupling. The two-loop transition from the MS- to the DR-scheme is properly taken into account. In the second part of the paper, the bottom quark mass in the DR-scheme at the electroweak/SUSY scale is evaluated wi

  26. Rafael Sánchez, Sigmund Kohler, Peter Hänggi, Gloria Platero

    We study the transport properties of two double quantum dots in a parallel arrangement at temperatures of a few Kelvin. Thereby, we show that decoherence entailed by the substrate phonons affects the shot noise. For asymmetric coupling between the dots and the respective lead, the current noise is sub-Poissonian for resonant tunneling, but super-Poissonian i

  27. Pulak Ranjan Giri

    The existence of bound state of the polarizable neutral atom in the inverse square potential created by the electric field of single walled charged carbon nanotube (SWNT) is shown to be theoretically possible. The consideration of inequivalent boundary conditions due to self-adjoint extensions lead to this nontrivial bound state solution. It is also shown th

  28. Ki-Seok Kim, Mun Dae Kim

    We study Kondo physics in the algebraic spin liquid, recently proposed to describe $ZnCu_{3}(OH)_{6}Cl_{2}$ [Phys. Rev. Lett. {\bf 98}, 117205 (2007)]. Although spin dynamics of the algebraic spin liquid is described by massless Dirac fermions, this problem differs from the Pseudogap Kondo model, because the bulk physics in the algebraic spin liquid is gover

  29. Michal Kreps

    During the past year many interesting results were published in heavy quark baryon spectroscopy. In addition to several refined measurements, new states were directly observed both in the charm and the bottom sector. In this paper we review recent results on heavy quark baryons from B-factories and Tevatron experiments.

  30. C. Ciofi degli Atti, L. L. Frankfurt, L. P. Kaptari, M. I. Strikman

    It is widely discussed in the literature that the wave function of the nucleon bound in a nucleus is modified due to the interaction with the surrounding medium. We argue that the modification should strongly depend on the momentum of the nucleon. We study such an effect in the case of the point-like configuration component of the wave function of a nucleon

  31. Antonio Pipino, Annibale D'Ercole, Francesca Matteucci

    The scope of this paper is two-fold: i) to test and improve our previous models of an outside-in formation for the majority of ellipticals in the context of the SN-driven wind scenario, by means of a careful study of gas inflows/outflows; ii) to explain the observed slopes, either positive or negative, in the radial gradient of the mean stellar [alpha/Fe], a

  32. Benjamin J. Wilson

    Let g denote a Lie algebra, and let T(g) denote the tensor product of g with a ring of truncated polynomials. The Lie algebra T(g) is called a truncated current Lie algebra. The highest-weight representation theory of T(g) is developed, and a reducibility criterion for the Verma modules is described.

  33. Federico Ardila, Mike Develin

    We study the combinatorial properties of a tropical hyperplane arrangement. We define tropical oriented matroids, and prove that they share many of the properties of ordinary oriented matroids. We show that a tropical oriented matroid determines a subdivision of a product of two simplices, and conjecture that this correspondence is a bijection.

  34. Tadas K. Nakamura

    The possibility of an alternative way to formulate the Hawking radiation in a static Schwarzschild spacetime has been explored. To calculate the Hawking radiation, there can be two possible choices of the spacetime wedge pairs in the Krucal-Szekeres coordinates. One is the wedge pair consists of exterior spacetime of a black hole and the exterior spacetime o

  35. Abraham I. Harte

    We study the dynamics of extended test bodies in flat Friedmann-Robertson-Walker spacetimes. It is shown that such objects can usually alter their inertial mass, spin, and center-of-mass trajectory purely through the use of internal deformations. Many of these effects do not have Newtonian analogs, and exist despite the presence of conserved momenta associat

  36. Jon Yard, Igor Devetak

    Consider many instances of an arbitrary quadripartite pure state of four quantum systems ABCD. Alice holds the AC part of each state, Bob holds B, while D represents all other parties correlated with ABC. Alice is required to redistribute the C systems to Bob while asymptotically preserving the overall purity. We prove that this is possible using Q qubits of

  37. Rahul Vaze, Robert W. Heath

    A multiple input multiple output (MIMO) two-way relay channel is considered, where two sources want to exchange messages with each other using multiple relay nodes, and both the sources and relay nodes are equipped with multiple antennas. Both the sources are assumed to have equal number of antennas and have perfect channel state information (CSI) for all th

  38. Chang-Young Ee, Daeho Lee, Myungseok Yoon

    We study the entropy of Schwarzschild black holes on DGP brane. The radius of event horizon on DGP brane is obtained by a numerical method. It is smaller than that of Einstein gravity in the conventional branch, and is larger in the accelerated branch. However, the difference is very small. The entropy of the black hole is calculated by using the improved br

  39. Sang Chul Kim, Myung Gyoon Lee, Doug Geisler, Ata Sarajedini

    We present the result of a wide-field survey of globular clusters (GCs) in M31 covering a 3deg x 3deg field c. We have searched for GCs on CCD images taken with Washington CMT1 filters at the KPNO 0.9 m telescope using steps: (1) inspection of morphological parameters given by the SExtractor package such as stellarity, full maximum, and ellipticity; (2) cons

  40. Nora Ganter

    This paper studies connections between generalized moonshine and elliptic cohomology with a focus on the action of the Hecke correspondence and its implications for the notion of replicability.

  41. Boris L. Altshuler

    The magnetic fluxbrane solution with a strongly warped throat is studied in the Type IIA supergravity theory with co-dimension one local source which surves as $Z_{2}$-symmetric UV boundary of the throat. Overall volume of extra space is stabilized since introduction of the local source breaks the no-scale structure of the theory and evades the no-go theorem

  42. Fatihcan M. Atay, Turker Biyikoglu, Juergen Jost

    We consider synchronization of weighted networks, possibly with asymmetrical connections. We show that the synchronizability of the networks cannot be directly inferred from their statistical properties. Small local changes in the network structure can sensitively affect the eigenvalues relevant for synchronization, while the gross statistical network proper

  43. Nick Seymour, Brigitte Rocca-Volmerange, Valerie de Lapparent

    We present a detailed reduction of a mid-infrared 12um (LW10 filter) ISOCAM open time observation performed on the ESO-Sculptor Survey field (Arnouts et al. 1997). A complete catalogue of 142 sources (120 galaxies and 22 stars), detected with high significance (equivalent to 5sigma), is presented above an integrated flux density of 0.24mJy. Star/galaxy separ

  44. E. E. Gabev, Evgeni B. Gabev, E. E. Gabev, M. V. Bogoeva

    It is now evident that the commonly accepted strategy for treatment of HIV/AIDS by highly active antiretroviral therapy (HAART) will not lead to eradication of HIV in a reasonable time. This is straightforward from the typical exponential viral load decay upon treatment revealing initial considerable but incomplete reduction of plasma HIV RNA with subsequent

  45. Nathan S. Greeney, John A. Scales

    In analogy with optical near-field scanning methods, we use tapered dielectric waveguides as probes for a millimeter wave vector network analyzer. By scanning thin samples between two such probes we are able to map the spatially varying dielectric properties of materials with sub-wavelength resolution; using a 150 GHz probe in transmision mode we see spatial

  46. M. C. Rodriguez

    We point out the production of the charginos and neutralinos in electron-electron process in several supersymmetric models, in order to show that the International Linear Collider can discover double charged charginos if these particles really exist in nature.

  47. Luca Amendola, Marco Baldi, Christof Wetterich

    We investigate quintessence cosmologies with a matter component consisting of particles with an increasing mass. While negligible in early cosmology, the appearance of a growing matter component has stopped the evolution of the cosmon field at a redshift around six. In turn, this has triggered the accelerated expansion of the Universe. We propose to associat

  48. Ilya A. Shkrob, Ross E. Larsen, William J. Glover, Benjamin J. Schwartz

    Femtosecond PTHB spectroscopy was expected to demonstrate the existence of distinct s-p absorption subbands originating from the three nondegenerate p-like excited states of hydrated electron in anisotropic solvation cavity. Yet no conclusive experimental evidence either for this subband structure or the reorientation of the cavity on the picosecond time sca

  49. Erich Elsen, V. Vishal, Mike Houston, Vijay Pande

    Commercial graphics processors (GPUs) have high compute capacity at very low cost, which makes them attractive for general purpose scientific computing. In this paper we show how graphics processors can be used for N-body simulations to obtain improvements in performance over current generation CPUs. We have developed a highly optimized algorithm for perform

  50. B. Z. Kopeliovich, H. -J. Pirner, I. K. Potashnikova, Ivan Schmidt

    We propose a solution for the long standing puzzle of a too steeply falling fragmentation function for a quark fragmenting into a pion, calculated by Berger [1] in the Born approximation. Contrary to the simple anticipation that gluon resummation worsens the problem, we find good agreement with data. Higher quark Fock states slow down the quark, an effect wh

  51. J. C. González, M. Muñoz, N. García, J. Barzola-Quiquia

    We present a study of the magnetoresistance of highly oriented pyrolytic graphite (HOPG) as a function of the sample size. Our results show unequivocally that the magnetoresistance reduces with the sample size even for samples of hundreds of micrometers size. This sample size effect is due the large mean free path and Fermi wavelength of carriers in graphite

  52. Paul Bourgade, Ashkan Nikeghbali, Alain Rouault

    This note presents some equalities in law for $Z_N:=\det(\Id-G)$, where $G$ is an element of a subgroup of the set of unitary matrices of size $N$, endowed with its unique probability Haar measure. Indeed, under some general conditions, $Z_N$ can be decomposed as a product of independent random variables, whose laws are explicitly known. Our results can be o

  53. H. -Th. Janka, A. Marek, F. -S. Kitaura

    The neutrino-heating mechanism remains a viable possibility for the cause of the explosion in a wide mass range of supernova progenitors. This is demonstrated by recent two-dimensional hydrodynamic simulations with detailed, energy-dependent neutrino transport. Neutrino-driven explosions were not only found for stars in the range of 8-10 solar masses with ON

  54. Thierry Barbot, Virginie Charette, Todd Drumm, William M. Goldman

    The Einstein universe is the conformal compactification of Minkowski space. It also arises as the ideal boundary of anti-de Sitter space. The purpose of this article is to develop the synthetic geometry of the Einstein universe in terms of its homogeneous submanifolds and causal structure, with particular emphasis on dimension $2 + 1$, in which there is a ri

  55. Øyvind Lind-Johansen, Kristian Seip, Johannes Skaar

    The resolution associated with the so-called perfect lens of thickness $d$ is $-2πd/\ln(|χ+2|/2)$. Here the susceptibility $χ$ is a Hermitian function in $H^2$ of the upper half-plane, i.e., a $H^2$ function satisfying $χ(-ω)=\bar{χ(ω)}$. An additional requirement is that the imaginary part of $χ$ be nonnegative for nonnegative arguments. Given an interval $

  56. Jay P. Dunn, D. Michael Crenshaw, S. B. Kraemer, J. R. Gabel

    We present a survey of 72 Seyfert galaxies and quasars observed by the it Far Ultraviolet Spectroscopic Explorer (FUSE). We have determined that 72 of 253 available active galactic nuclei (AGN) targets are viable targets for detection of intrinsic absorption lines. We examined these spectra for signs of intrinsic absorption in the O VI doublet (lambda 1031.9

  57. Brad M. S. Hansen, Travis Barman

    We identify two classes of transiting planet, based on their equilibrium temperatures and Safronov numbers. We examine various possible explanations for the dichotomy. It may reflect the influence of planet or planetesimal scattering in determining when planetary migration stops. Another possibility is that some planets lose more mass to evaporation than oth

  58. P. Rabl, P. Zoller

    We study collective excitations of rotational and spin states of an ensemble of polar molecules, which are prepared in a dipolar crystalline phase, as a candidate for a high fidelity quantum memory. While dipolar crystals are formed in the high density limit of cold clouds of polar molecules under 1D and 2D trapping conditions, the crystalline structure prot

  59. Giovanni Villadoro, Fabio Zwirner

    Exploiting the fact that Kaluza-Klein monopoles and the associated generalized orbifold planes are sources for geometrical fluxes, omega, we show that the standard constraint omega.omega=0, valid for superstring compactifications on twisted tori, can be consistently relaxed. This leads to novel possibilities for constructing superstring models with fluxes an

  60. Alicia M. Soderberg

    Over the past few years, long-duration gamma-ray bursts (GRBs), including the subclass of X-ray flashes (XRFs), have been revealed to be a rare variety of Type Ibc supernova (SN Ibc). While all these events result from the death of massive stars, the electromagnetic luminosities of GRBs and XRFs exceed those of ordinary Type Ibc SNe by many orders of magnitu

  61. Chia-Hsien Lin, H. M. Antia, Sarbani Basu

    Recent downward revision of solar heavy-element abundances using three-dimensional atmospheric model has introduced serious discrepancies between standard solar models and helioseismic inferences about solar structure. In this paper, we investigate the possibility of determining the heavy-element abundances using helioseismic inversion techniques with the ho

  62. Paul Vojta

    In 1941, L. Ahlfors gave another proof of a 1933 theorem of H. Cartan on approximation to hyperplanes of holomorphic curves in P^n. Ahlfors' proof built on earlier work of H. and J. Weyl (1938), and proved Cartan's theorem by studying the associated curves of the holomorphic curve. This work has subsequently been reworked by H.-H. Wu in 1970, using d

  63. David K. Lai, Jennifer A. Johnson, Michael Bolte, Sara Lucatello

    We present carbon and strontium abundances for 100 metal-poor stars measured from R$\sim $7000 spectra obtained with the Echellette Spectrograph and Imager at the Keck Observatory. Using spectral synthesis of the G-band region, we have derived carbon abundances for stars ranging from [Fe/H]$=-1.3$ to [Fe/H]$=-3.8$. The formal errors are $\sim 0.2$ dex in [C/

  64. Juraj Topolancik, Rob Ilic, Frank Vollmer

    We demonstrate experimentally that structural perturbations imposed on highly-dispersive photonic crystal-based waveguides give rise to spectral features that bear signatures of Anderson localization. Sharp resonances with the effective Qs of over 30,000 are found in scattering spectra of disordered waveguides. The resonances are observed in a ~20-nm bandwid

  65. D. Burns, V. Guillemin, A. Uribe

    For a Kahler manifold (X, ω) with a holomorphic line bundle L and metric h such that the Chern form of L is ω, the spectral measures are the measures μ_N = \sum |s_{N,i}|^2 ν, where \{s_{N,i}\}_i is an L^2-orthonormal basis for H^0(X, L^{\otimes N}), and νis Liouville measure. We study the asymptotics in N of μ_N for (X, L) a Hamiltonian toric manifold, and

  66. Adolfo Avella, Ferdinando Mancini

    A fully self-consistent calculation of the bosonic dynamics of the Hubbard model is developed within the Composite Operator Method. From one side we consider a basic set of fermionic composite operators (Hubbard fields) and calculate the retarded propagators. On the other side we consider a basic set of bosonic composite operators (charge, spin and pair) and

  67. Diego J. Munoz, Diego Mardones, Guido Garay, David Rebolledo

    We report observations of dust continuum emission at 1.2 mm toward the star forming region NGC 6334 made with the SEST SIMBA bolometer array. The observations cover an area of $\sim 2$ square degrees with approximately uniform noise. We detected 181 clumps spanning almost three orders of magnitude in mass (3\Msun$-6\times10^3$ \Msun) and with sizes in the ra

  68. PHENIX Collaboration, S. Afanasiev

    The PHENIX experiment has measured the dielectron continuum in sqrt{s_NN} = 200 GeV Au+Au collisions. In minimum bias collisions the dielectron yield in the mass range between 150 and 750 MeV/c^2 is enhanced by a factor of 3.4 +/- 0.2(stat.) +/- 1.3(syst.) +/- 0.7(model) compared to the expectation from our model of hadron decays. The integrated yield increa

  69. Songxue Chi, F. Ye, Pengcheng Dai, J. A. Fernandez-Baca

    We use neutron scattering to study the lattice and magnetic structure of the layered half-doped manganite Pr$_{0.5}$Ca$_{1.5}$MnO$_4$. On cooling from high temperature, the system first becomes charge- and orbital- ordered (CO/OO) near $T_{CO}=300$ K and then develops checkerboard-like antiferromagnetic (AF) order below $T_{N}=130$ K. At temperatures above $

  70. C. -P. Lajoie, P. Bergeron

    We present a comparative study of effective temperatures determined from the hydrogen Balmer lines and from the UV energy distribution for 140 DA white dwarfs drawn from the IUE archive. Our results indicate that the optical and UV temperatures of the majority of stars below T~40,000 K and within ~75 pc are in fairly good agreement given the uncertainties. A

  71. David M. Bradley

    Integral transformations are used to estimate high order derivatives of various special functions. Applications are given to numerical integration, where estimates of high order derivatives of the integrand are needed to achieve bounds on the error. The main idea is to find a suitable integral representation of the function whose derivatives are to be estima

  72. G. Pancheri, O. Shekhovtsova, G. Venanzoni

    Final state radiation in the process $e^+e^-\toπ^+π^-$ is considered for the cuts used in the analysis of KLOE data at large angles. By means of a Monte Carlo event generator FEVA, effects of non-pointlike behaviour of pions are estimated in the framework of Resonance Perturbation Theory. An additional complication related with the $ϕ$ meson intermediate sta

  73. Silas R. Beane, Thomas C. Luu, Kostas Orginos, Assumpta Parreno

    The I=2 pipi scattering length is calculated in fully-dynamical lattice QCD with domain-wall valence quarks on the asqtad-improved coarse MILC configurations (with fourth-rooted staggered sea quarks) at four light-quark masses. Two- and three-flavor mixed-action chiral perturbation theory at next-to-leading order is used to perform the chiral and continuum e

  74. I. Serban, F. K. Wilhelm

    We investigate macroscopic dynamical quantum tunneling (MDQT) in the driven Duffing oscillator, charateristic for Josephson junction physics and nanomechanics. Under resonant conditions between stable coexisting states of such systems we calculate the tunneling rate. In macroscopic systems coupled to a heat bath, MDQT can be masked by driving-induced activat

  75. Olaf Stenull, T. C. Lubensky

    We study two aspects of the elasticity of smectic-$A$ elastomers that make these materials genuinely and qualitatively different from conventional uniaxial rubbers. Under strain applied parallel to the layer normal, monodomain smectic-$A$ elastomers exhibit a drastic change in Young's modulus above a threshold strain value of about 3%, as has been measur

  76. Mark Barham, Jurij W. Darewych

    The variational method, within the Hamiltonian formalism of reformulated QED is used to determine relativistic wave equations for a system of three fermions of arbitrary mass interacting electromagnetically. The interaction kernels of the equations are, in essence, the invariant $\mathcal{M}$ matrices in lowest order. The equations are used to obtain relativ

  77. Manuel Bibes, Agnes Barthelemy

    Concomitant with the development of metal-based spintronics in the late 1980's and 1990's, important advances were made on the growth of high-quality oxide thin films and heterostructures. While this was at first motivated by the discovery of high-temperature superconductivity in perovskite Cu oxides, this technological breakthrough was soon applied

  78. Sylvain Schwartz, Gilles Feugnet, Evguenii Lariontsev, Jean-Paul Pocholle

    We report experimental and theoretical study of a rotating diode-pumped Nd-YAG ring laser with active beat note stabilization. Our experimental setup is described in the usual Maxwell-Bloch formalism. We analytically derive a stability condition and some frequency response characteristics for the solid-state ring laser gyroscope, illustrating the important r

  79. Guillaume Blanchon, A. Bonaccorso, D. M. Brink, A. García-Camacho

    We call "projectile fragmentation" of neutron halo nuclei the elastic breakup (diffraction) reaction, when the observable studied is the neutron-core relative energy spectrum. This observable has been measured in relation to the Coulomb breakup on heavy target and recently also on light targets. Such data enlighten the effect of the neutron final sta

  80. C. Alexandrou, G. Koutsou, Th. Leontiou, J. W. Negele

    We evaluate the nucleon axial form factor, $G_A(q^2)$, and induced pseudoscalar form factor, $G_p(q^2)$, as well as the pion-nucleon form factor, $G_{πN N}(q^2)$, in lattice QCD. We also evaluate the corresponding nucleon to $Δ$ transition form factors, $C_5^A(q^2)$ and $C_6^A(q^2)$, and the pion-nucleon-$Δ$ form factor $G_{πNΔ}(q^2)$. The nucleon form facto

  81. Max-K. Von Renesse, Marc Yor, Lorenzo Zambotti

    We study absolute-continuity properties of a class of stochastic processes, including the gamma and the Dirichlet processes. We prove that the laws of a general class of non-linear transformations of such processes are locally equivalent to the law of the original process and we compute explicitly the associated Radon-Nikodym densities. This work unifies and

  82. Cyrille Chavet, Philippe Coussy, Pascal Urard, Eric Martin

    This paper presents a methodology to efficiently explore the design space of communication adapters. In most digital signal processing (DSP) applications, the overall performance of the system is significantly affected by communication architectures, as a consequence the designers need specifically optimized adapters. By explicitly modeling these communicati

  83. Areski Flissi, Philippe Merle

    Deployment of distributed applications on large systems, and especially on grid infrastructures, becomes a more and more complex task. Grid users spend a lot of time to prepare, install and configure middleware and application binaries on nodes, and eventually start their applications. The problem is that the deployment process is composed of many heterogene

  84. Poul H. Damgaard, So Matsuura

    We show how to derive Catterall's supersymmetric lattice gauge theories directly from the general principle of orbifolding followed by a variant of the usual deconstruction. These theories are forced to be complexified due to a clash between charge assignments under U(1)-symmetries and lattice assignments in terms of scalar, vector and tensor components

  85. Yuri Berest, Oleg Chalykh, Farkhod Eshmatov

    The aim of this paper is to clarify the relation between the following objects: $ (a) $ rank 1 projective modules (ideals) over the first Weyl algebra $ A_1(\C)$; $ (b) $ simple modules over deformed preprojective algebras $ Π_λ(Q) $ introduced by Crawley-Boevey and Holland; and $ (c) $ simple modules over the rational Cherednik algebras $ H_{0,c}(S_n) $ ass

  86. A. N. Vamivakas, M. Atature, J. Dreiser, S. T. Yilmaz

    Through the utilization of index-matched GaAs immersion lens techniques we demonstrate a record extinction (12%) of a far-field focused laser by a single InAs/GaAs quantum dot. This contrast level enables us to report for the first time resonant laser transmission spectroscopy on a single InAs/GaAs quantum dot without the need for phase-sensitive lock-in det

  87. H. J. Weber

    Starting from the Rodrigues representation of polynomial solutions of the general hypergeometric-type differential equation complementary polynomials are constructed using a natural method. Among the key results is a generating function in closed form leading to short and transparent derivations of recursion relations and an addition theorem. The complementa

  88. Matti Selg

    Exactly solvable rererence potentials of several smoothly joined Morse-type components were constructed for the lowest two excimer states of Ar2 molecule. The parameters of the potentials have been ascertained by fitting to the experimental data, and they are reliable in a wide range of nuclear separations. A large number of quantum mechanical Franck-Condon

  89. Myriam Gitti, Rocco Piffaretti, Sabine Schindler

    We report on the analysis of XMM-Newton observations of RX J1347.5-1145 (z=0.451), the most X-ray-luminous galaxy cluster. We present a detailed total and gas mass determination up to large distances (~1.7 Mpc), study the scaling properties of the cluster, and explore the role of AGN heating in the cluster cool core. By means of spatially resolved spectrosco

  90. Myriam Gitti, Chiara Ferrari, Wilfried Domainko, Luigina Feretti

    We report on new VLA radio observations of the distant cluster RX J1347.5-1145, which is the most luminous in X-rays. We aim at investigating the possible presence of diffuse and extended radio emission in this very peculiar system which shows both a massive cooling flow and merging signatures. New low resolution (~18 arcsec) VLA radio observations of this c

  91. A. Soha

    We present recent results from the Collider Detector at Fermilab (CDF) and D0 experiments using data from proton-antiproton collisions with sqrt(s) = 1.96 TeV at Run II of the Fermilab Tevatron. New physics may appear in events with high transverse momentum objects, including photons and quark or gluon jets. The results described here are of signature-based

  92. S. Kawasaki, G. Catalan, H. Fan, M. M. Saad

    The International Roadmap for Ferroelectric Memories requires three-dimensional integration of high-dielectric materials onto metal interconnects or bottom electrodes by 2010. We report the first integration of high-dielectric oxide films onto carbon nanotube electrodes with an aim of ultra-high integration density of FeRAMs (Tb/in2).

  93. Abdul Wahab El Kaffas, Odd Magne Ogreid, Per Osland

    We confront the Two-Higgs-Doublet Model with a variety of experimental constraints as well as theoretical consistency conditions. The most constraining data are the \bar B\to X_sγdecay rate (at low values of M_{H^\pm}), and Δρ(at both low and high M_{H^\pm}). We also take into account the B\bar B oscillation rate and R_b, or the width Γ(Z\to b\bar b) (both o

  94. Don Hadwin, Vern I. Paulsen

    We give new proofs for many injectivity results in analysis that make more careful use of the duality between unital abelian C*-algebras and compact Hausdorff spaces. We then extend many of these results to incorporate group actions. Our approach uses only elementary topological constructions and eliminates the need for results from the theory of Boolean alg

  95. Daniel Harsono, Roberto De Propris

    We derive deep luminosity functions (to $M_z=-15$) for galaxies in Abell 1835 ($z=0.25$) and AC 114 ($z=0.31$) and compare these with the local $z&#39;$ luminosity function for 69 clusters. The data show that the faint-end upturn, the excess of galaxies above a single Schechter function at $M_z < -17$, does not exist in the higher redshift clusters. This sug

  96. C. Distefano

    We present the results of Monte Carlo simulation studies of the capability of the proposed NEMO km$^3$ telescope to detect TeV muon neutrinos from Galactic microquasars. In particular we determined the detector sensitivity to each known microquasar, optimizing the event selection in order to reject the atmospheric background. We also determined the expected

  97. J. Rzepecki, M. Lombardi, P. Rosati, A. Bignamini

    We present a detailed mass reconstruction of the cluster RCS0224-0002 at $z=0.773$ from the strong lensing features observed with HST/WFPC2. The mass profile is reconstructed using a parametric approach. We introduce a novel method to fit extended multiple images based on the Modified Hausdorff Distance between observed arcs and the arcs reproduced by the mo

  98. Yakov Itin

    In this paper, the axion contribution to the electromagnetic wave propagation is studied. First we show how the axion electrodynamics model can be embedded into a premetric formalism of Maxwell electrodynamics. In this formalism, the axion field is not an arbitrary added Chern-Simon term of the Lagrangian, but emerges in a natural way as an irreducible part

  99. Thomas Erik Danielson

    Forward jet and multijet production has been measured at low Bjorken x at HERA. The measured cross sections and correlations were compared to predictions from DGLAP-based fixed-order calculations. Further comparisons were made to DGLAP-based and CCFM-based leading-order Monte Carlo predictions, as well as to Colour-Dipole model predictions. For the majority

  100. N. Tsoneva, H. Lenske

    Low-energy dipole excitations have been investigated theoretically in N=50, several N=82 isotones and the Z=50 Sn isotopes. For this purpose a method incorporating both HFB and multi-phonon QPM theory is applied. A concentration of one-phonon dipole strength located below the neutron emission threshold has been calculated in these nuclei. The analysis of the