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February 2007 arXiv papers

Showing 1–100 of 4,165 papers

  1. Chris W. Purcell, James S. Bullock, Andrew R. Zentner

    We make predictions for diffuse stellar mass fractions in dark matter halos from the scales of small spiral galaxies to those of large galaxy clusters. We use an extensively-tested analytic model for subhalo infall and evolution and empirical constraints from galaxy survey data to set the stellar mass in each accreted subhalo to model diffuse light. We add s

  2. Jozsef Garai

    Textbooks introduce the Debye temperature to simplify the integration of the heat capacity. This approach gives the impression that the Debye temperature is a parameter which makes the integration more convenient. The Debye frequency cut occurs when the wavelength of the phonon frequency reaches the size of the smallest unit of the lattice which is the lengt

  3. G. -B. Jo, J. -H. Choi, C. A. Christensen, T. A. Pasquini

    The recombination of two split Bose-Einstein condensates on an atom chip is shown to result in heating which depends on the relative phase of the two condensates. This heating reduces the number of condensate atoms between 10 and 40% and provides a robust way to read out the phase of an atom interferometer without the need for ballistic expansion. The heatin

  4. Ken Hicks

    Current evidence does not favor the existence of the \thplus pentaquark, which was reported by several groups in the years after 2002. The question naturally arises: how could many groups could have seen fluctuations in their data at the level of 3-5 $σ$ statistical significance? An example of a statistical fluctuation is given and the number of $σ$'s ne

  5. Vitali Kapovitch

    We give a proof of the celebrated stability theorem of Perelman stating that for a noncollapsing sequence $X_i$ of Alexandrov spaces with curvature bounded below Gromov-Hausdorff converging to a compact Alexandrov space $X$, $X_i$ is homeomorphic to $X$ for all large $i$.

  6. Plamen L. Simeonov

    This work is an attempt for a state-of-the-art survey of natural and life sciences with the goal to define the scope and address the central questions of an original research program. It is focused on the phenomena of emergence, adaptive dynamics and evolution of self-assembling, self-organizing, self-maintaining and self-replicating biosynthetic systems vie

  7. I. Serban, E. Solano, F. K. Wilhelm

    Motivated by recent experiments, we study the dynamics of a qubit quadratically coupled to its detector, a damped harmonic oscillator. We use a complex-environment approach, explicitly describing the dynamics of the qubit and the oscillator by means of their full Floquet state master equations in phase-space. We investigate the backaction of the environment

  8. Edmond L. Berger, M. M. Block, Chung-I Tan

    We obtain a good analytic fit to the joint Bjorken-x and Q^2 dependences of ZEUS data on the deep inelastic structure function F_2(x, Q^2). At fixed virtuality Q^2, as we showed previously, our expression is an expansion in powers of log (1/x) that satisfies the Froissart bound. Here we show that for each x, the Q^2 dependence of the data is well described b

  9. Christophe Mora, Xavier Waintal

    An intrinsic measure of the quality of a variational wave function is given by its overlap with the ground state of the system. We derive a general formula to compute this overlap when quantum dynamics in imaginary time is accessible. The overlap is simply related to the area under the $E(τ)$ curve, i.e. the energy as a function of imaginary time. This has i

  10. Ivan Vitev

    We use a formal recurrence relation approach to multiple parton scattering to find the complete solution to the problem of medium-induced gluon emission from partons propagating in cold nuclear matter. The differential bremsstrahlung spectrum, where Landau-Pomeranchuk-Migdal destructive interference effects are fully accounted for, is calculated for three di

  11. F. Fumarola, I. L. Aleiner, B. L. Altshuler

    We study a polarized Fermi gas and demonstrate that Fano-Feshbach (FF) resonances lead to the pairing of fermions and holes into long living massive bosonic modes (bifermions and biholes), which can be viewed as signatures of a first order quantum phase transition. These modes, which are neither conventional Cooper pairs nor closed channel bosonic dimers, ha

  12. Jens Koch, Terri M. Yu, Jay Gambetta, A. A. Houck

    Short dephasing times pose one of the main challenges in realizing a quantum computer. Different approaches have been devised to cure this problem for superconducting qubits, a prime example being the operation of such devices at optimal working points, so-called "sweet spots." This latter approach led to significant improvement of $T_2$ times in Coo

  13. Matthias R. Gaberdiel, Ingo Kirsch

    The AdS_3/CFT_2 correspondence is checked beyond the supergravity approximation by comparing correlation functions. To this end we calculate 2- and 3-point functions on the sphere of certain chiral primary operators for strings on AdS_3 x S^3 x T^4. These results are then compared with the corresponding amplitudes in the dual 2-dimensional conformal field th

  14. R. Milson, N. Pelavas

    We prove that a four-dimensional Lorentzian manifold that is curvature homogeneous of order 3, or $\CH_3$ for short, is necessarily locally homogeneous. We also exhibit and classify four-dimensional Lorentzian, $\CH_2$ manifolds that are not homogeneous.

  15. Fritz Gesztesy, Helge Holden, Johanna Michor, Gerald Teschl

    We provide a detailed recursive construction of the Ablowitz-Ladik (AL) hierarchy and its zero-curvature formalism. The two-coefficient AL hierarchy under investigation can be considered a complexified version of the discrete nonlinear Schrödinger equation and its hierarchy of nonlinear evolution equations. Specifically, we discuss in detail the stationary A

  16. P. J. N. Hultzsch, J. Puls, R. H. Mendez, A. W. A. Pauldrach

    Optical high-resolution spectra of five central stars of planetary nebulae (CSPN) in the Galactic Bulge have been obtained with Keck/HIRES in order to derive their parameters. Since the distance of the objects is quite well known, such a method has the advantage that stellar luminosities and masses can in principle be determined without relying on theoretica

  17. Martin B. Einhorn, D. R. Timothy Jones

    We review the calculation of the the effective potential with particular emphasis on cases when the tree potential or the renormalisation-group-improved, radiatively corrected potential exhibits non-convex behaviour. We illustrate this in a simple Yukawa model which exhibits a novel kind of dimensional transmutation. We also review briefly earlier work on th

  18. Steven thomas, John Ward

    In this paper we examine the IR inflation scenario using the DBI action, where we have $N$ multiple branes located near the tip of a warped geometry. At large $N$ the solutions are similar in form to the more traditional single brane models, however we find that it is difficult to simultaneously satisfy the WMAP bounds on the scalar amplitude and the scalar

  19. Alexander Unzicker, Daniel Schmidle

    We present source code for the computer algebra system Mathematica that analyzes the motion of the Pioneer spacecraft using the public available ephemeris data from JPL's website. Within 15 minutes, the reader can verify that the Pioneer anomalous acceleration a_p (1) exists in the order of magnitude of c H_0, (2) is not due to mismodeling of gravitation

  20. Brian Greene, Simon Judes, Janna Levin, Scott Watson

    Low energy effective actions arising from string theory typically contain many scalar fields, some with a very complicated potential and others with no potential at all. The evolution of these scalars is of great interest. Their late time values have a direct impact on low energy observables, while their early universe dynamics can potentially source inflati

  21. Simon Bray, Jae Sik Lee, Apostolos Pilaftsis

    The observed light neutrinos may be related to the existence of new heavy neutrinos in the spectrum of the SM. If a pair of heavy neutrinos has nearly degenerate masses, then CP violation from the interference between tree-level and self-energy graphs can be resonantly enhanced. We explore the possibility of observing CP asymmetries due to this mechanism at

  22. Dan Solomon

    In Dirac's hole theory the vacuum state is generally believed to be the state of minimum energy. However it has recently been shown that this is not the case. In [1] it was shown that energy can be extracted from the hole theory vacuum state through the application of an electric field so that the final state has less energy than the vacuum state. In thi

  23. Richard Watkins, Hume A. Feldman

    We constrain the velocity power spectrum shape parameter $Γ$ in linear theory using the nine bulk-flow and shear moments estimated from four recent peculiar velocity surveys. For each survey, a likelihood function for $Γ$ was found after marginalizing over the power spectrum amplitude $σ_8Ω_m^{0.6}$ using constraints obtained from comparisons between redshif

  24. O. Bertolami, J. Paramos

    We estimate the main systematic effects relevant in a mission to test and characterize the Pioneer anomaly through the flight formation concept, by launching probing spheres from a mother spacecraft and tracking their motion via laser ranging.

  25. CDF collaboration

    We describe a search for anomalous production of events with two leptons ($e$ or $μ$) of the same electric charge in \ppbar collisions at a center-of-mass energy of 1.96 TeV. Many extensions to the standard model predict the production of two leptons of the same electric charge. This search has a significant increase in sensitivity compared to earlier search

  26. O. M. Umurhan, O. Regev, K. Menou

    We study the saturation near threshold of the axisymmetric magnetorotational instability (MRI) of a viscous, resistive, incompressible fluid in a thin-gap Taylor-Couette configuration. A vertical magnetic field, Keplerian shear and no-slip, conducting radial boundary conditions are adopted. The weakly non-linear theory leads to a real Ginzburg-Landau equatio

  27. G. Castelletti, G. Dubner, C. Brogan, N. E. Kassim

    We present new Very Large Array (VLA) radio images at 74 and 324 MHz of the SNR W44. The VLA images, obtained with unprecedented angular resolution and sensitivity for such low frequencies have been used in combination with existing 1442 MHz radio data, Spitzer IR data, and ROSAT and Chandra X-ray data to investigate morphological and spectral properties of

  28. Christian Flindt, Anders S. Sorensen, Mikhail D. Lukin, Jacob M. Taylor

    We propose a semiconductor device that can electrically generate entangled electron spin-photon states, providing a building block for entanglement of distant spins. The device consists of a p-i-n diode structure that incorporates a coupled double quantum dot. We show that electronic control of the diode bias and local gating allow for the generation of sing

  29. Luigi Cappiello, Giancarlo D'Ambrosio

    We analyze the effect of a form factor in the magnetic contribution to K+ --> pi+ pi0 gamma. We emphasize how this can show up experimentally: in particular we try to explore the difference between a possible interference contribution and a form factor in the magnetic part. The form factor used for K+ --> pi+ pi0 gamma is analogous to the one for KL --> pi+

  30. Tim D. Cochran, Shelly Harvey

    We prove that groups that are mod-p-homology equivalent are isomorphic modulo any term of their derived p-series, in precise analogy to Stallings' 1963 result for the lower-central p-series. Similarly spaces that are mod-p-homology equivalent have fundamental groups that are isomorphic modulo any term of their p-derived series. Various authors have relat

  31. William J. Herrera, Rodolfo A. Diaz

    The fact that the capacitance coefficients for a set of conductors are geometrical factors is derived in most electricity and magnetism textbooks. We present an alternative derivation based on Laplace's equation that is accessible for an intermediate course on electricity and magnetism. The properties of Laplace's equation permits to prove many prope

  32. G. Bertoldi, F. Bigazzi, A. L. Cotrone, Jose D. Edelstein

    We employ the string/gauge theory correspondence to study properties of strongly coupled quark-gluon plasmas in thermal gauge theories with a large number of colors and flavors. In particular, we analyze non-critical string duals of conformal (S)QCD, as well as ten dimensional wrapped fivebrane duals of SQCD-like theories. We study general properties of the

  33. Maximilian Kreuzer, Benjamin Nill

    We obtain 866 isomorphism classes of five-dimensional nonsingular toric Fano varieties using a computer program and the database of four-dimensional reflexive polytopes. The algorithm is based on the existence of facets of Fano polytopes having small integral distance from any vertex.

  34. G. Chartas, M. Eracleous, X. Dai, E. Agol

    We present results from Chandra and XMM-Newton observations of the low-ionization broad absorption line (LoBAL) quasar H 1413+117. Our spatial and spectral analysis of a recent deep Chandra observation confirms a microlensing event in a previous Chandra observation performed about 5 years earlier. We present constraints on the structure of the accretion flow

  35. Kai Cieliebak, Klaus Mohnke

    We use Donaldson hypersurfaces to construct pseudo-cycles which define Gromov-Witten invariants for any symplectic manifold which agree with the invariants in the cases where transversality could be achieved by perturbing the almost complex structure.

  36. Bogusław Broda, Piotr Bronowski, Marcin Ostrowski, Michał Szanecki

    An abelian version of standard general relativity in the Cartan-Palatini gauge-like formulation in four dimensions has been introduced. Traditional canonical analysis utilizing similarities to the akin Husain-Kuchar SU(2) version of gravity has been performed. The model has been next quantized in the canonical path-integral Faddeev-Popov formalism yielding a

  37. Y. -Y. Zhang, A. Finoguenov, H. Boehringer, J. -P. Kneib

    We present the X-ray properties and scaling relations of a flux-limited morphology-unbiased sample of 12 X-ray luminous galaxy clusters at redshift around 0.2 based on XMM-Newton observations. The scaled radial profiles are characterized by a self-similar behavior at radii outside the cluster cores (>0.2 r500) for the temperature, surface brightness, entropy

  38. James Laird

    We give a simple order-theoretic construction of a Cartesian closed category of sequential functions. It is based on bistable biorders, which are sets with a partial order -- the extensional order -- and a bistable coherence, which captures equivalence of program behaviour, up to permutation of top (error) and bottom (divergence). We show that monotone and b

  39. Masafumi Udagawa, Yukitoshi Motome

    We present a scenario for the peculiar coexistence of charge fluctuations observed in quasi-2D 1/4-filled organic conductors $θ$-(BEDT-TTF)$_2X$ in the quantum critical regime where the charge ordering is suppressed down to zero temperature. The scenario is explored in the extended Hubbard model including electron-phonon couplings on an anisotropic triangula

  40. V. S. Zuev

    The field of an evanescent wave in a space with a thin metal layer is explored. The wave number of the evanescent wave exceeds many times the wave number of a uniform plane wave in adjoining gaps. In agreement with the results of the Pendry's paper of the 2000 year the field behind the metal layer occurs to be amplified as compared to the field in absenc

  41. Ender Abadoglu, Ercument Ortacgil

    This paper has been withdrawn by the authors

  42. Andrei Khrennikov

    We present a quantum-like (QL) model in that contexts (complexes of e.g. mental, social, biological, economic or even political conditions) are represented by complex probability amplitudes. This approach gives the possibility to apply the mathematical quantum formalism to probabilities induced in any domain of science. In our model quantum randomness appear

  43. Jean-Marie Barbaroux, Thomas Chen, Vitali Vougalter, Semjon Vugalter

    In this note, we determine the ground state energy of the translation invariant Pauli-Fierz model to subleading order $O(α^3)$ with respect to powers of the finestructure constant $α$, and prove rigorous error bounds of order $O(α^{4})$. A main objective of our argument is its brevity.

  44. S. McGlynn, D. J. Clark, A. J. Dean, L. Hanlon

    The spectrometer aboard INTEGRAL, SPI, has the capability to detect the signature of polarised emission from a bright gamma-ray source. GRB 041219a is the most intense burst localised by INTEGRAL and is an ideal candidate for such a study. Polarisation can be measured using multiple events scattered into adjacent detectors because the Compton scatter angle d

  45. Irene D'Amico, Brendon W. Lovett, Timothy P. Spiller

    We show how branching spin chains can be used to both generate and distribute entanglement from their natural dynamics. Such entanglement provides a useful resource, for example for teleportation or distributed quantum processing. Once distributed, this resource can be isolated through mapping or swapping the entanglement into specific qubits at the ends of

  46. Matteo Beccaria, Massimo Campostrini, Alessandra Feo

    We study the transverse quantum ANNNI model in the region of high frustration (k>0.5) using the DMRG algorithm. We obtain a precise determination of the phase diagram, showing clear evidence for the existence of a floating phase, separated from the paramagnetic modulated phase by a high-order critical line ending at the multicritical point. We obtain simple

  47. G. Giacomelli, S. Manzoor, E. Medinaceli, L. Patrizii

    The Searches for classical Dirac Magnetic Monopoles (MMs) at accelerators, for GUT superheavy MMs in the penetrating cosmic radiation and for Intermediate Mass IMMs at high altitudes are discussed. Also the searches for nuclearites and Q-balls are considered.

  48. Lars Hesselholt

    Let A a regular F_p-algebra. The relative K-groups K_q(A[x]/(x^m),(x)) and the Nil-groups Nil_q(A[x]/(x^m)) were evaluated earlier by the author and Madsen in terms of the big de Rham-Witt groups of the ring A. In this paper, we evaluate the maps of relative K-groups and Nil-groups induced by the canonical projection from A[x]/(x^m) to A[x]/(x^n). The result

  49. S. Ansari, J. D. Laenge, I. Sachs

    For a given attractor black hole with generic D6-D4-D2-D0-charges in four dimensions we identify the set of supersymmetric branes, static or stationary in global coordinates, of the corresponding eleven-dimensional near horizon geometry. The set of these BPS states, which includes branes which partially or fully wrap the horizon, should play a role in unders

  50. Kamal Khuri-Makdisi

    Let V be an n-dimensional vector space. We give a direct construction of an exact sequence that gives a GL(V)-equivariant "resolution" of each symmetric power S^t V in terms of direct sums of tensor products of the form \wedge^{i_1} V \otimes ... \otimes \wedge^{i_p} V. This exact sequence corresponds to inverting the relation in the representation r

  51. Ahmet T. Alan, Kerem Cankocak, Durmus A. Demir

    We analyze effects of the CP-odd soft phases in the MSSM on the pair-productions of colored superpartners in pp collisions at the LHC energies. We find that, among all pair-production processes, those of the scalar quarks in the first and second generations are particularly sensitive to the CP-odd phases, more precisely, to the phases of the gluinos and neut

  52. V. V. Gvaramadze, A. Gualandris, S. Portegies Zwart

    Recent proper motion and parallax measurements for the pulsar PSR B1508+55 indicate a transverse velocity of ~1100 km/s, which exceeds earlier measurements for any neutron star. The spin-down characteristics of PSR B1508+55 are typical for a non-recycled pulsar, which implies that the velocity of the pulsar cannot have originated from the second supernova di

  53. K. Shizuya

    The electromagnetic response of graphene in a magnetic field is studied, with particular emphasis on the quantum features of its ground state (vacuum). The graphene vacuum, unlike in conventional quantum Hall systems, is a dielectric medium and carries an appreciable amount of electric and magnetic susceptibilities. The dielectric effect grows rapidly with i

  54. Pavel Fileviez Perez

    We investigate the possibility to find the simplest renormalizable grand unified theory based on the SU(5) gauge symmetry. We find that it is possible to generate all fermion masses with only two Higgs bosons, 5_H and 45_H. In this context the neutrino masses are generated through the type III and type I seesaw mechanisms. The predictions coming from the uni

  55. Subhendu Kahaly, G. Ravindra Kumar

    We observe near 100 % absorption of light in intense ultrashort laser plasma interaction in a metal coated (Au on glass) sub-lambda grating structure under suitable conditions and the subsequent 'hot' electron generation from the grating plasma. In the low intensity regime we determine the conditions in which a monochromatic infrared light (lambda =

  56. Alexandru Dimca

    We explore the relation between the positive dimensional irreducible components of the characteristic varieties of rank one local systems on a smooth surface and the associated (rational or irrational) pencils. Our study, which may viewed as a continuation of D. Arapura's work, yields new geometric insight into the translated components relating them to the

  57. Rafael Roldan, Shan-Wen Tsai, M. Pilar Lopez-Sancho

    The superconducting instability of the Fermi liquid state is investigated by considering anisotropic electron-boson couplings. Both electron-electron interactions and anisotropic electron-boson couplings are treated with a renormalization-group method that takes into account retardation effects. Considering a non-interacting circular Fermi surface, we find a

  58. A. Go, A. Bay

    The neutral B-meson pair produced at the Upsilon(4S) should exhibit a non-local correlation of the type discussed by Einstein, Podolski, and Rosen (EPR). We measure this correlation using the time-dependent flavour asymmetry of semileptonic B0 decays, which we compare with predictions from quantum mechanics and two local realistic models. The data are consis

  59. Hiroyuki Kurihara, Koji Tojo

    Let G/H be a compact 4-symmetric space of inner type such that the dimension of the center Z(H) of H is at most one. In this paper we shall classify involutions of G preserving H for the case where dim Z(H)=0, or H is a centralizer of a toral subgroup of G.

  60. Patrick Letrémy, Marie Cottrell, Eric Esposito, Valérie Laffite

    We propose an easy-to-use methodology to allocate one of the groups which have been previously built from a complete learning data base, to new individuals. The learning data base contains continuous and categorical variables for each individual. The groups (clusters) are built by using only the continuous variables and described with the help of the categor

  61. S. Antusch, P. Huber, S. F. King, T. Schwetz

    The neutrino mixing sum rule $θ_{12} - θ_{13}\cos(δ) \approx θ^ν_{12}$ provides a possibility to explore the structure of the neutrino mass matrix in the presence of charged lepton corrections, since it relates the 1-2 mixing angle from the neutrino mass matrix, $θ_{12}^ν$, to observable parameters of the PMNS mixing matrix. The neutrino mixing sum rule hold

  62. Edoardo Sernesi

    We give upper bounds on the genus of a curve with general moduli assuming that it can be embedded in a projective nonsingular surface $Y$ so that $\dim(|C|) > 0$. We find such bounds for all types of surfaces of intermediate Kodaira dimension and, under mild restrictions, for surfaces of general type whose minimal model $Z$ satisfies the Castelnuovo inequali

  63. Jong-Shi Pang, Gesualdo Scutari, Francisco Facchinei, Chaoxiong Wang

    This paper considers the minimization of transmit power in Gaussian parallel interference channels, subject to a rate constraint for each user. To derive decentralized solutions that do not require any cooperation among the users, we formulate this power control problem as a (generalized) Nash equilibrium game. We obtain sufficient conditions that guarantee

  64. D. Bashkirov, G. Giachetta, L. Mangiarotti, G. Sardanashvily

    Quantization of a Lagrangian field system essentially depends on its degeneracy and implies its BRST extension defined by sets of non-trivial Noether and higher-stage Noether identities. However, one meets a problem how to select trivial and non-trivial higher-stage Noether identities. We show that, under certain conditions, one can associate to a degenerate

  65. Yun Soo Myung, Yong-Wan Kim, Young-Jai Park

    We investigate a universal behavior of thermodynamics and evaporation process for the regular black holes. We newly observe an important point where the temperature is maximum, the heat capacity is changed from negative infinity to positive infinity, and the free energy is minimum. Furthermore, this point separates the evaporation process into the early stag

  66. Hiroyuki Minamoto

    We prove that the category of representations of the N-Kronecker quiver and that of coherent sheaves on the noncommutative projective scheme of $R=k< X_1,...,X_N >/(\sum^N_{i=1}X_i^2)$ are derived equivalent. This equivalence is easily proved by applying Orlov&#39;s Theorem, on the other hand,in our proof,the quadratic relation $\sum_{i=1}^NX_i^2$ naturally

  67. Tatsuya Tate

    An asymptotic formula for the number of states of Boson gas whose Hamiltonian is given by a positive elliptic pseudo-differential operator of order one on a compact manifold is given under a integrality assumption on the spectrum of the Hamiltonian. This is regarded as an analogue of the Meinardus theorem on asymptotics of the number of partitions of a posit

  68. Andrew Coulthurst, Jason Doukas, Kristian L. McDonald

    A five dimensional model containing both left-right and quark-lepton symmetries is constructed, with the gauge group broken by a combination of orbifold compactification and the Higgs mechanism. An analysis of the gauge and scalar sectors is performed and it is shown that the 5d model admits a simpler scalar sector. Bounds on the relevant symmetry breaking s

  69. J. Wang, T. S. Monteiro, S. Fishman, J. P. Keating

    Previous studies of quantum delta-kicked rotors have found momentum probability distributions with a typical width (localization length $L$) characterized by fractional $\hbar$-scaling, ie $L \sim \hbar^{2/3}$ in regimes and phase-space regions close to `golden-ratio&#39; cantori. In contrast, in typical chaotic regimes, the scaling is integer, $L \sim \hbar

  70. Yu Nakayama

    We investigate the black hole - string transition in the two-dimensional Lorentzian black hole system from the exact boundary states that describe the rolling D-brane falling down into the two-dimensional black hole. The black hole - string phase transition is one of the fundamental properties of the non-supersymmetric black holes in string theory, and we wi

  71. Ying Wang, Pierre Moulin

    An analysis of steganographic systems subject to the following perfect undetectability condition is presented in this paper. Following embedding of the message into the covertext, the resulting stegotext is required to have exactly the same probability distribution as the covertext. Then no statistical test can reliably detect the presence of the hidden mess

  72. Jae-Weon Lee, Jaewan Kim, Taeseung Choi

    Using the thermal Green&#39;s function approach we propose a general method to investigate entanglement of the vacuum state or thermal ground states in an arbitrary dimensional space-time. As an application we show quantum separability of the massive thermal scalar field vacuum in the 1+1 dimensional cylindrical space-time. Separability is demonstrated using

  73. Yves Pomeau, David C. Roberts

    We discuss the hydrodynamic boundary condition for a superfluid moving tangentially to a rough surface. Specifically, we argue that the scattering of quantum fluctuations off surface roughness affects the nature of the boundary condition, and that this has important consequences including a new theorized critical speed and the presence of normal fluid at any

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

    In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors $T_{μν}$ in different frameworks, and to derive general results that hold in a variety of general contexts on physical grounds. We show that in the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) approach, where the equation of state of the cosmological f

  75. Vladimir Trifonov

    We present an axiomatic modification of quaternionic quantum mechanics with a possible-worlds semantics capable of predicting essential &#34;nonquantum&#34; features of an observable universe model - the dimensionality and topology of spacetime, the existence, the signature and a specific form of a metric on it, and certain naturally distinguished directions

  76. Keisuke Goda, Eugeniy E. Mikhailov, Osamu Miyakawa, Shailendhar Saraf

    We report on the generation of a stable continuous-wave low-frequency squeezed vacuum field with a squeezing level of $3.8\pm0.1$ dB at 1064 nm, the wavelength at which laser interferometers for gravitational wave (GW) detection operate, using periodically poled KTiOPO$_4$ (PPKTP) in a sub-threshold optical parametric oscillator. PPKTP has the advantages of

  77. Simone De Liberato, Christopher J. Foot

    We investigated the tunnelling dynamics of a zero-temperature Bose-Einstein condensate (BEC) in configuration of four potential wells arranged in a loop. We found three interesting dynamic regimes: (a) flows of matter with small amplitude, (b) steady flow and (c) forced flow of matter for large amplitudes. The regime of quantum self-confinement has been stud

  78. H. T. Quan, Z. D. Wang, C. P. Sun

    We explore a dynamic signature of quantum phase transition (QPT) in an isotropic Lipkin-Meshkov-Glick (LMG) model by studying the time evolution of a central qubit coupled to it. We evaluate exactly the time-dependent purity, which can be used to measure quantum coherence, of the central qubit. It is found that distinctly different behaviors of the purity as

  79. Irina Novikova, Alexey V. Gorshkov, David F. Phillips, Anders S. Sorensen

    We demonstrate experimentally a procedure to obtain the maximum efficiency for the storage and retrieval of light pulses in atomic media. The procedure uses time reversal to obtain optimal input signal pulse-shapes. Experimental results in warm Rb vapor are in good agreement with theoretical predictions and demonstrate a substantial improvement of efficiency

  80. Jiangbin Gong, Paul Brumer

    Control of the transfer of quantum information encoded in quantum wavepackets moving along a spin chain is demonstrated. Specifically, based on a relationship with control in a paradigm of quantum chaos, it is shown that wavepackets with slow dispersion can automatically emerge from a class of initial superposition states involving only a few spins, and that

  81. Vladimir Dzhunushaliev

    It is shown that the non-associative operators in a non-associative quantum theory are unobservables. The observable quantity may be presented only by the elements of some associative subalgebra. It is shown that the elements of the associative subalgebra are extended objects that can be similar to strings. It is assumed that the non-associative quantum fiel

  82. V. G. Benza

    The mechanism of propulsion of host bacteria under the action of actin gel networks is examined by means of a continuum model of the dynamics of F-actin concentration. The model includes the elasticity of the network, its attachment to the host and the polymerization at the interface with it. A formula for the cruise velocity is derived wherefrom the contrib

  83. Jérémie Bourdon, Damien Eveillard

    Biological networks are one of the most studied object in computational biology. Several methods have been developed for studying qualitative properties of biological networks. Last decade had seen the improvement of molecular techniques that make quantitative analyses reachable. One of the major biological modelling goals is therefore to deal with the quant

  84. Gautier Stoll, Jacques Rougemont, Felix Naef

    We study the dynamics of gene activities in relatively small size biological networks (up to a few tens of nodes), e.g. the activities of cell-cycle proteins during the mitotic cell-cycle progression. Using the framework of deterministic discrete dynamical models, we characterize the dynamical modifications in response to structural perturbations in the netw

  85. Grégory Batt, Delphine Ropers, Hidde De Jong, Michel Page

    The switch-like character of gene regulation has motivated the use of hybrid, discrete-continuous models of genetic regulatory networks. While powerful techniques for the analysis, verification, and control of hybrid systems have been developed, the specificities of the biological application domain pose a number of challenges, notably the absence of quantit

  86. R. Ma, A. Schliesser, P. Del&#39;Haye, A. Dabirian

    Quantitative measurements of the vibrational eigenmodes in ultra-high-Q silica microspheres are reported. The modes are efficiently excited via radiation-pressure induced dynamical back-action of light confined in the optical whispering-gallery modes of the microspheres (i.e. via the parametric oscillation instability). Two families of modes are studied and

  87. Atushi Ishikawa

    We report the proof that the extension of Gibrat&#39;s law in the middle scale region is unique and the probability distribution function (pdf) is also uniquely derived from the extended Gibrat&#39;s law and the law of detailed balance. In the proof, two approximations are employed. The pdf of growth rate is described as tent-shaped exponential functions and

  88. Beth Thacker, Abel Diaz, Ann Marie Eligon

    We discuss an inquiry-based curriculum that has been developed specifically for the introductory algebra-based physics course, taking into account the needs, backgrounds, learning styles and career goals of the students in that class. The course is designed to be taught in a laboratory-based environment, however parts of the materials can be used in other se

  89. C. deJager, B. Wojtsekhowski, D. Tedeschi, B. Vlahovic

    A high quality beam of linearly polarized photons of several GeV will become available with the coherent bremsstrahlung technique at JLab. We have developed a polarimeter which requires about two meters of the beam line, has an analyzing power of 20% and an efficiency of 0.02%. The layout and first results of a polarimeter test on the laser back-scattering p

  90. Masanobu Iwanaga

    We present effective optical constants of stratified metal-dielectric metameterial. The effective constants are determined by two complex reflectivity method (TCRM). TCRM reveals full components of effective permittivity and permeability tensors and indicates the remarkable anisotropy of metallic and dielectric components below effective plasma frequency. On

  91. Laura Tolos, Angels Ramos, Eulogio Oset

    The s- and p-wave contributions to the $\bar K N$ interaction in dense nuclear matter are obtained using a chiral unitary approach. We perform a self-consistent calculation of the $\bar K$ self-energy including Pauli blocking effects, meson self-energies modified by short-range correlations and baryon binding potentials. We find that the on-shell factorizati

  92. Toshiki Maruyama, Satoshi Chiba, Hans-Josef Schulze, Toshitaka Tatsumi

    We discuss the properties of the hadron-quark mixed phase in compact stars using a realistic equation of state of hyperonic matter and the MIT bag model. We find that the equation of state of the mixed phase is similar to that given by the Maxwell construction, but that the mixed phase becomes mechanically unstable if the surface tension of the interface bet

  93. O. A. Grachov, B. Metzler, M. Murray, J. Snyder

    The CMS Zero Degree Calorimeters, ZDCs, will measure photons and neutrons emitted with |eta|> 8.6 from Pb+Pb, p+Pb and p+p collisions at sqrt(Snn)=5.5, 8.8 and 14 TeV respectively. The calorimeter consists of an electromagnetic part segmented in the horizontal direction and an hadronic part segmented into four units in depth. In addition CMS will have access

  94. TOF collaboration, M. Abdel-Bary, S. Abdel-Samad, K. -Th. Brinkmann

    The reaction $ pp\to pp\bf ω$ was investigated with the TOF spectrometer, which is an external experiment at the accelerator COSY (Forschungszentrum Jülich, Germany). Total as well as differential cross sections were determined at an excess energy of $93 MeV$ ($p_{beam}=2950 MeV/c$). Using the total cross section of $(9.0\pm 0.7 \pm1.1) μb$ for the reaction

  95. Krzysztof Wozniak

    In the PHOBOS experiment, charged particles are measured in almost the full solid angle. This enables the study of fluctuations and correlations in the particle production over a very wide kinematic range. In this paper, we show results of a direct search for fluctuations identified by an unusual shape of the pseudorapidity distribution. In addition, we use

  96. Gonzague Agez, Marcel G. Clerc, Eric Louvergneaux

    A universal law for the supercritical bifurcation shape of transverse one-dimensional (1D) systems in presence of additive noise is given. The stochastic Langevin equation of such systems is solved by using a Fokker-Planck equation leading to the expression for the most probable amplitude of the critical mode. From this universal expression, the shape of the

  97. Marina Chugunova, Dmitry Pelinovsky

    We study the spectrum of the linear operator $L = - \partial_θ - ε\partial_θ (\sin θ\partial_θ)$ subject to the periodic boundary conditions on $θ\in [-π,π]$. We prove that the operator is closed in $L^2([-π,π])$ with the domain in $H^1_{\rm per}([-π,π])$ for $|ε| < 2$, its spectrum consists of an infinite sequence of isolated eigenvalues and the set of corr

  98. Rami Ahmad El-Nabulsi, Delfim F. M. Torres

    We derive Euler-Lagrange type equations for fractional action-like integrals of the calculus of variations which depend on the Riemann-Liouville derivatives of order $(α,β)$, $α> 0$, $β> 0$, recently introduced by J. Cresson and S. Darses. Some interesting consequences are obtained and discussed.

  99. David Hasler, Ira Herbst

    We consider a class of translation invariant models of non-relativistic QED with net charge. Under certain natural assumptions we prove that ground states do not exist in the Fock space.

  100. A. V. Stoyanovsky

    The paper is a survey of some author&#39;s results related with the Maslov--Shvedov method of complex germ and with quantum field theory. The main idea is that many results of the method of complex germ and of perturbative quantum field theory can be made more simple and natural if instead of the algebra of (pseudo)differential operators one uses the Weyl al