December 2005 arXiv papers — page 34

M. Coleman Miller

Observations of the centers of galaxies continue to evolve, and it is useful to take a fresh look at the constraints that exist on alternatives to supermassive black holes at their centers. We discuss constraints complementary to those of Maoz (1998) and demonstrate that an extremely wide range of other possibilities can be excluded. In particular, we presen

G. Voyatzis, L. Vlahos, S. Ichtiaroglou, D. Papadopoulos

The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in

Nicholas M. Law, Simon T. Hodgkin, Craig D. Mackay, John E. Baldwin

We present preliminary results from the first part of the LuckyCam late M-dwarf binarity survey. We survey a sample of 48 nearby ($<$40 pc) and red (M5-M9) stars with the novel high angular resolution visible light imaging technique Lucky Imaging, in only 8 hours of 2.5m telescope time. We discover 10 new binaries; although the survey is sensitive to brown d

Yael Fuchs, L. Koch Miramond, P. Abraham

We present mid-infrared (2-12 micron) spectra of the microquasar SS 433 obtained with the Infrared Space Observatory (spectroscopic mode of ISOPHOT and ISOCAM). We compare them to the spectra of four Wolf-Rayet stars: WR78, WR134, WR136, and WR147 in the same wavelength range. The mid-infrared spectrum of SS 433 mainly shows HI and HeI emission lines and is

Boris Rockenfeller, Coryn A. L. Bailer-Jones, Reinhard Mundt, Mansur A. Ibrahimov

We present simultaneous UV-G-R-I monitoring of 19 M dwarfs that revealed a huge flare on the M9 dwarf 2MASSW J1707183+643933 with an amplitude in the UV of at least 6 magnitudes. This is one of the strongest detections ever of an optical flare on an M star and one of the first in an ultracool dwarf (UCD, spectral types later than about M7). Four intermediate

Ciro Bigongiari

MAGIC (Major Atmospheric Gamma Imaging Cherenkov telescope) is presently the largest ground-based gamma ray telescope. MAGIC has been taking data regularly since October 2004 at the Roque de los Muchachos Observatory on the island of La Palma. In this paper the MAGIC telescope status, its performances and some preliminary results on observed gamma ray source

Jonathan Braithwaite

We present numerical models of hydromagnetic instabilities under the conditions prevailing in a stably stratified, non-convective stellar interior, and compare them with previous results of analytic work on instabilities in purely toroidal fields. We confirm that an $m=1$ mode (`kink&#39;) is the dominant instability in a toroidal field in which the field st

D. Fargion

The Fermi Lab Liquid ARgon experiment, FLARE, a huge neutrino argon-liquid project detector of 50 kt mass, might in a near future enlarge the neutrino telescope accuracy revealing in detail solar, supernova, atmospheric as well as largest solar flares neutrino. Indeed the solar energetic (E_p > 100 MeVs) flare particles (protons, alpha) while scattering amon

Naomi Ota, Tetsu Kitayama, Kuniaki Masai, Kazuhisa Mitsuda

An observational approach is presented to constrain the global structure and evolution of the intracluster medium based on the ROSAT and ASCA distant cluster sample. From statistical analysis of the gas density profile and the connection to the LX-T relation under the beta-model, the scaled gas profile is nearly universal for the outer region and the LX(>0.2

T. Yan, D. M. Wei, Y. Z. Fan

If X-ray flashes (XRFs) and X-ray rich Gamma-ray Bursts(XRRGs) have the same origin with Gamma-ray Bursts (GRBs) but are viewed from larger angles of structured jets, their early afterglows may differ from those of GRBs. When the ultra-relativistic outflow interact with the surrounding medium, there are two shocks formed, one is a forward shock, the other is

K. Ohsuga

We investigate the time evolution of luminous accretion disks around black holes, conducting the two-dimensional radiation-hydrodynamic simulations. We adopt the alpha prescription for the viscosity. The radial-azimuthal component of viscous stress tensor is assumed to be proportional to the total pressure in the optically thick region, while the gas pressur

Izumi S. Ohta, Makoto Hattori, Hiroshi Matsuo

We propose the development of an instrument by the Martin & Puplett-type Fourier Transform Spectrometer to applying the aperture synthesis technique in millimeter and submillimeter waves. We call this equipment the Multi-Fourier Transform interferometer (MuFT). MuFT performs a wide band imaging, spectroscopy and polarimetry in millimeter and submillimeter wa

Jun Ma, Xu Zhou, David Burstein, Jiansheng Chen

In this paper, we give the spectral energy distributions of 42 M81 globular clusters in 13 intermediate-band filters from 4000 to 10000 A, using the CCD images of M81 observed as part of the BATC multicolor survey of the Sky. The BATC multicolor filter system is specifically designed to exclude most of the bright and variable night-sky emission lines includi

Jun Ma, Xu Zhou, David Burstein, Yanbin Yang

This paper presents accurate spectral energy distributions (SEDs) of 16 M31 globular clusters (GCs) confirmed by spectroscopy and/or high spatial-resolution imaging, as well as 30 M31 globular cluster candidates detected by Mochejska et al. Most of these candidates have m_V > 18, deeper than previous searches, and these candidates have not yet been confirmed

Jun Ma, Sidney van den Bergh, Hong Wu, Yanbin Yang

037-B327 is of interest because it is both the most luminous and the most highly reddened cluster known in M31. Deep observations with the Advanced Camera for Surveys on the Hubble Space Telescope provide photometric data in the F606W band, and also show that this cluster is crossed by a dust lane. We determined the structural parameters of 037-B327 by fitti

A. Tamm, P. Tenjes

A photometric study of 22 disk galaxies at redshifs z=0.5-2.6 is conducted, using deep NICMOS J and H band and STIS open mode observations of the HDF-S NICMOS parallel field. Rest-frame B-profiles and (U-V) color profiles are constructed. A number of disks show steeper decrease of luminosity than exponential, referring to disk truncation. Shape of the lumino

C. F. Doran, M. G. Faux, S. J. Gates,, T. Hubsch

In this paper we discuss off-shell representations of N-extended supersymmetry in one dimension, ie, N-extended supersymmetric quantum mechanics, and following earlier work on the subject codify them in terms of certain graphs, called Adinkras. This framework provides a method of generating all Adinkras with the same topology, and so also all the correspondi

Jack Laiho, Ruth S. Van de Water

We calculate the B -> D and B -> D* form factors at zero recoil in Staggered Chiral Perturbation Theory. We consider heavy-light mesons in which only the light (u, d, or s) quark is staggered; current lattice simulations generally use a highly improved action such as the Fermilab or NRQCD action for the heavy (b or c) quark. We work to lowest nontrivial orde

E. M. Cackett, R. Wijnands, C. O. Heinke, D. Pooley

We present a 19 ks Chandra ACIS-S observation of the globular cluster Terzan 1. Fourteen sources are detected within 1.4 arcmin of the cluster center with 2 of these sources predicted to be not associated with the cluster (background AGN or foreground objects). The neutron star X-ray transient, X1732-304, has previously been observed in outburst within this

Bastien Aracil, Todd M. Tripp, David V. Bowen, Jason X. Proschaska

We present high-resolution UV spectra of absorption-line systems toward the low-z QSO HS0624+6907 (z=0.3700). Coupled with spectroscopic galaxy redshifts, we find that many of these absorbers are integalactic gas clouds distributed within large-scale structures. The gas is cool (T<10^5 K) and has relatively high metallicity (Z/Z_sol>0.9). STIS data reveal a

Sameer Hemmady, Xing Zheng, James Hart, Thomas M. Antonsen

Statistical fluctuations in the eigenvalues of the scattering, impedance and admittance matrices of 2-Port wave-chaotic systems are studied experimentally using a chaotic microwave cavity. These fluctuations are universal in that their properties are dependent only upon the degree of loss in the cavity. We remove the direct processes introduced by the non-id

Charles D. Dermer, Markus Boettcher

Recent HESS observations show that microquasars in high-mass systems are sources of VHE gamma-rays. A leptonic jet model for microquasar gamma-ray emission is developed. Using the head-on approximation for the Compton cross section and taking into account angular effects from the star&#39;s orbital motion, we derive expressions to calculate the spectrum of g

P. Bressler, A. Gorokhovsky, R. Nest, B. Tsygan

This is the first in a series of articles devoted to deformation quantization of gerbes. Here we give basic definitions and interpret deformations of a given gerbe as Maurer-Cartan elements of a differential graded Lie algebra (DGLA). We classify all deformations of a given gerbe on a symplectic manifold, as well as provide a deformation-theoretic interpreta

Piotr T. Chrusciel, Paul Tod

We show that static electro--vacuum black hole space--times containing an asymptotically flat spacelike hypersurface with compact interior and with both degenerate and non--degenerate components of the event horizon do not exist. This is done by a careful study of the near-horizon geometry of degenerate horizons, which allows us to eliminate the last restric

Benjamin C. Allanach, Fernando Quevedo, Kerim Suruliz

Soft supersymmetry breaking terms were recently derived for type IIB string flux compactifications with all moduli stabilised. Depending on the choice of the discrete input parameters of the compactification such as fluxes and ranks of hidden gauge groups, the string scale was found to have any value between the TeV and GUT scales. We study the phenomenologi

Lam Hui, Patrick B. Greene

Large scale structure introduces two different kinds of errors in the luminosity distance estimates from standardizable candles such as supernovae Ia (SNe) - a Poissonian scatter for each SN and a coherent component due to correlated fluctuations between different SNe. Increasing the number of SNe helps reduce the first type of error but not the second. The

Adam Rej, Didina Serban, Matthias Staudacher

Recently it was established that a certain integrable long-range spin chain describes the dilatation operator of N=4 gauge theory in the su(2) sector to at least three-loop order, while exhibiting BMN scaling to all orders in perturbation theory. Here we identify this spin chain as an approximation to an integrable short-ranged model of strongly correlated e

Maximiliano C. Pivato, Nelson D. Padilla, Diego G. Lambas

We perform statistical analyses of the infall of dark-matter onto clusters in numerical simulations within the concordance LCDM model. By studying the infall profile around clusters of different mass, we find a linear relation between the maximum infall velocity and mass which reach 900km/s for the most massive groups. The maximum infall velocity and the gro

M. J. D. Hamilton

We extend a result of M. Katz on conformal systoles to all four-manifolds with b^+=1 which have odd intersection form. The same result holds for all four-manifolds with b^+=1 with even intersection form and which are symplectic or satisfy the so-called 5/4-conjecture.

Lenny Fukshansky, Sinai Robins

Let $N \geq2$ and let $1 < a_1 < ... < a_N$ be relatively prime integers. Frobenius number of this $N$-tuple is defined to be the largest positive integer that cannot be expressed as $\sum_{i=1}^N a_i x_i$ where $x_1,...,x_N$ are non-negative integers. The condition that $gcd(a_1,...,a_N)=1$ implies that such number exists. The general problem of determining

Grazyna Odyniec

Selected results from the first five years of RHIC data taking are reviewed with emphasis on evidence for thermalization in central Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV.

T. Ferrus, R. George, C. H. W. Barnes, N. Lumpkin

Sodium impurities are diffused electrically to the oxide-semiconductor interface of a silicon MOSFET to create an impurity band. At low temperature and at low electron density, the band is split into an upper and a lower sections under the influence of Coulomb interactions. We used magnetoconductivity measurements to provide evidence for the existence of Hub

N. Akopian, N. H. Lindner, E. Poem, Y. Berlatzky

Tomographic analysis demonstrates that the polarization state of pairs of photons emitted from a biexciton decay cascade becomes entangled when spectral filtering is applied. The measured density matrix of the photon pair satisfies the Peres criterion for entanglement by more than 3 standard deviations of the experimental uncertainty and violates Bell&#39;s

Lenny Fukshansky

We discuss existence of explicit search bounds for zeros of polynomials with coefficients in a number field. Our main result is a theorem about the existence of polynomial zeros of small height over the field of algebraic numbers outside of unions of subspaces. All bounds on the height are explicit.

Lenny Fukshansky

Let $N \geq 2$ be an integer, $F$ a quadratic form in $N$ variables over $\bar{\mathbb Q}$, and $Z \subseteq \bar{\mathbb Q}^N$ an $L$-dimensional subspace, $1 \leq L \leq N$. We prove the existence of a small-height maximal totally isotropic subspace of the bilinear space $(Z,F)$. This provides an analogue over $\bar{\mathbb Q}$ of a well-known theorem of V

B. A. DiDonna, Alex J. Levine

We report on the nonlinear mechanical properties of a statistically homogeneous, isotropic semiflexible network cross-linked by polymers containing numerous small unfolding domains, such as the ubiquitous F-actin cross-linker Filamin. We show that the inclusion of such proteins has a dramatic effect on the large strain behavior of the network. Beyond a strai

Eloy Ayón-Beato, Mokhtar Hassaïne

We consider nonminimally coupled scalar fields to explore the Siklos spacetimes in three dimensions. Their interpretation as exact gravitational waves propagating on AdS restrict the source to behave as a pure radiation field. We show that the related pure radiation constraints single out a unique self-interaction potential depending on one coupling constant

R. Gurau, V. Rivasseau, F. Vignes-Tourneret

In this paper we provide exact expressions for propagators of noncommutative Bosonic or Fermionic field theories after adding terms of the Grosse-Wulkenhaar type in order to ensure Langmann-Szabo covariance. We emphasize the new Fermionic case and we give in particular all necessary bounds for the multiscale analysis and renormalization of the noncommutative

Laszlo Erdos, Manfred Salmhofer, Horng-Tzer Yau

We consider random Schrödinger equations on $\bR^d$ for $d\ge 3$ with a homogeneous Anderson-Poisson type random potential. Denote by $λ$ the coupling constant and $ψ_t$ the solution with initial data $ψ_0$. The space and time variables scale as $x\sim λ^{-2 -κ/2}, t \sim λ^{-2 -κ}$ with $0< κ< κ_0(d)$. We prove that, in the limit $λ\to 0$, the expectation o

Steven A. Abel, Mark D. Goodsell

We develop techniques for one-loop diagrams on intersecting branes. The one-loop propagator of chiral intersection states on D6 branes is calculated exactly and its finiteness is shown to be guaranteed by RR tadpole cancellation. The result is used to demonstrate the expected softening of power law running of Yukawa couplings at the string scale. We also dev

Durmus A. Demir, S. Hanif Tanyildizi

We discuss effective interactions among brane matter induced by modifications of higher dimensional Einstein gravity via the replacement of Einstein-Hilbert term with a generic function f(R) of the curvature scalar R. After deriving the graviton propagator, we analyze impact of virtual graviton exchanges on particle interactions, and conclude that f(R) gravi

Kristin Warnick, Alexander Knebe

We present a detailed analysis of the velocity distribution and orientation of orbits of subhaloes in high resolution cosmological simulations of dark matter haloes. We find a trend for substructure to preferentially revolve in the same direction as the sense of rotation of the host halo: there is an excess of prograde satellite haloes. Throughout our suite

A. G. Akeroyd, A. Alves, M. A. Diaz, O. J. P. Eboli

Fermiophobic Higgs bosons $h_f$ exhibiting large branching ratios to two photons can arise in models with two or more scalar doublets and/or triplets. In such models the conventional production mechanisms at hadron colliders may be rendered ineffective due to severe mixing angle suppression. In this scenario, double fermiophobic Higgs production may proceed

Ozren Perse

Let L(n-l+1/2,0) be the vertex operator algebra associated to an affine Lie algebra of type B_l^(1) at level n-l+1/2, for a positive integer n. We classify irreducible L(n-l+1/2,0)-modules and show that every L(n-l+1/2,0)-module is completely reducible. In the special case n=1, we study a category of weak L(-l+3/2,0)-modules which are in the category $\cal{O

F. A. Majeed, R. A. Radhi

Electroexcitations of the dominantly T=1 particle-hole states of C-12 are studied in the framework of the harmonic oscillator shell model. All possible T=1 single-particle-hole states of all allowed angular momenta are considered in a basis including single-particle states up to the 1f-2p shell. The Hamiltonian is diagnoalized in this space in the presence o

Tomonori Totani, Nobuyuki Kawai, George Kosugi, Kentaro Aoki

The gamma-ray burst (GRB) 050904 at z = 6.3 provides the first opportunity of probing the intergalactic medium (IGM) by GRBs at the epoch of the reionization. Here we present a spectral modeling analysis of the optical afterglow spectrum taken by the Subaru Telescope, aiming to constrain the reionization history. The spectrum shows a clear damping wing at wa

Pankaj Jain, Subhayan Mandal

We study the possibility of evading astrophysical bounds on light pseudoscalars. We argue that the solar bounds can be evaded if we have a sufficiently strong self coupling of the pseudoscalars. The required couplings do not conflict with any known experimental bounds. We show that it is possible to find a coupling range such that the results of the recent P

Claire P. Massen, Jonathan P. K. Doye

Preferential attachment is one possible way to obtain a scale-free network. We develop a self-consistent method to determine whether preferential attachment occurs during the growth of a network, and to extract the preferential attachment rule using time-dependent data. Model networks are grown with known preferential attachment rules to test the method, whi

A. V. Bratchikov

Deformation quantization of Poisson manifolds is studied within the framework of an expansion in powers of derivatives of Poisson structures. We construct the Lie group associated with a Poisson bracket algebra which defines a second order deformation in the derivative expansion.

P. Saracco, A. Fiano, G. Chincarini, E. Vanzella

[Abridged] We present the rest-frame Js-band and Ks-band luminosity function of a sample of about 300 galaxies selected in the HDF-S at Ks<23 (Vega). We use calibrated photometric redshift together with spectroscopic redshift for 25% of the sample. The sample has allowed to probe the evolution of the LF in the three redshift bins [0;0.8), [0.8;1.9) and [1.9;

D. A. Morozov

Measurements by the STAR collaboration of neutral pion production at large Feynman $x$ ($x_F$) in the first polarized proton collisions at $\sqrt{s}=200$ GeV were reported previously. During the following two runs additional statistics were acquired with an improved forward calorimeter for the $\pi^0$ cross-section and analyzing power measurements. First dat

Su Houng Lee, Youngshin Kwon, Youngjoon Kwon

We explore the possibility of observing the anti-charmed pentaquark state from the $Θ_c \bar{n} π^+$ decay of $B$ meson produced at $B$-factory experiments. We first show that the observed branching ratio of the $B^+$ to $ Λ^-_c p π^+$, as well as its open histograms, can be remarkably well explained by assuming that the decay proceeds first through the $π^+

Matteo Bertolini, Marco Billo, Alberto Lerda, Jose F. Morales

We develop systematic string techniques to study brane world effective actions for models with magnetized (or equivalently intersecting) D-branes. In particular, we derive the dependence on all NS-NS moduli of the kinetic terms of the chiral matter in a generic non-supersymmetric brane configurations with non-commuting open string fluxes. Near a N=1 supersym

Shinichi Deguchi, Kaoru Kitsukawa

Dirac&#39;s quantization condition, $eg=n/2$ ($n \in \Bbb Z$), and Schwinger&#39;s quantization condition, $eg=n$ ($n \in \Bbb Z$), for an electric charge $e$ and a magnetic charge $g$ are derived by utilizing the Atiyah-Singer index theorem in two dimensions. The massless Dirac equation on a sphere with a magnetic-monopole background is solved in order to c

K. Debicki, A. B. Dieker, T. Rolski

We study stochastic tree fluid networks driven by a multidimensional Levy process. We are interested in (the joint distribution of) the steady-state content in each of the buffers, the busy periods, and the idle periods. To investigate these fluid networks, we relate the above three quantities to fluctuations of the input Levy process by solving a multidimen

A. Opitz, M. Scherge, S. I. -U. Ahmed, J. A. Schaefer

The reliable operation of micro and nanomechanical devices necessitates a thorough knowledge of the water film thickness present on the surfaces of these devices with an accuracy in the nm range. In this work, the thickness of an ultra-thin water layer was measured by distance tunnelling spectroscopy and distance dynamic force spectroscopy during desorption

Reinaldo J. Gleiser, Metin Gurses, Atalay Karasu, Ozgur Sarioglu

It is shown explicitly that when the characteristic vector field that defines a Godel-type metric is also a Killing vector, there always exist closed timelike or null curves in spacetimes described by such a metric. For these geometries, the geodesic curves are also shown to be characterized by a lower dimensional Lorentz force equation for a charged point p

Vyacheslav M. Abramov

A large dam model is an object of study of this paper. The parameters $L^{lower}$ and $L^{upper}$ are its lower and upper levels, $L=L^{upper}-L^{lower}$ is large, and if a current level of water is between these bounds, then the dam is assumed to be in normal state. Passage one or other bound leads to damage. Let $J_1$ $(J_2)$ denote the damage cost of cros

Mira Bernstein, Christopher Tuffley

Let W -> A^2 be the universal Weierstrass family of cubic curves over C. For each N >= 2, we construct surfaces parametrizing the three standard kinds of level N structures on the smooth fibers of W. We then complete these surfaces to finite covers of A^2. Since W -> A^2 is the versal deformation space of a cusp singularity, these surfaces convey information

C. J. Wellard, L. C. L. Hollenberg, S. Das Sarma

We present a theoretical analysis of a microwave spectroscopy experiment on a charge qubit defined by a P$_2^+$ donor pair in silicon, for which we calculate Hamiltonian parameters using the effective-mass theory of shallow donors. We solve the master equation of the driven system in a dissipative environment to predict experimental outcomes. We describe how

Alexander Barg, Dmitry Nogin

We give new proofs of asymptotic upper bounds of coding theory obtained within the frame of Delsarte's linear programming method. The proofs rely on the analysis of eigenvectors of some finite-dimensional operators related to orthogonal polynomials. The examples of the method considered in the paper include binary codes, binary constant-weight codes, spheric

Alexander Barg, Dmitry Nogin

We give a new asymptotic upper bound on the size of a code in the Grassmannian space. The bound is better than the upper bounds known previously in the entire range of distances except very large values.

Gopal Prasad, Sai-Kee Yeung

A fake projective plane is a smooth complex surface which is not the complex projective plane but has the same Betti numbers as the complex projective plane. The first example of such a surface was constructed by David Mumford in 1979 using p-adic uniformization. Two more examples were found by Ishida and Kato by related method. Keum has recently given an ex

Jen-Tsung Hsiang, Da-Shin Lee

The influence of electromagnetic vacuum fluctuations in the presence of the perfectly conducting plate on electrons is studied with an interference experiment. The evolution of the reduced density matrix of the electron is derived by the method of influence functional. We find that the plate boundary anisotropically modifies vacuum fluctuations that in turn

Tomi Koivisto, David F. Mota

We investigate the consequences of an imperfect dark energy component on the large scale structure. A phenomenological three parameter fluid description is used to study the effect of dark energy on the cosmic microwave background radiation (CMBR) and matter power spectrum. In addition to the equation of state and the sound speed, we allow a nonzero viscosit

Anthony Aguirre, Matthew C. Johnson

We investigate the formation via tunneling of inflating (false-vacuum) bubbles in a true-vacuum background, and the reverse process. Using effective potentials from the junction condition formalism, all true- and false-vacuum bubble solutions with positive interior and exterior cosmological constant, and arbitrary mass are catalogued. We find that tunneling

Ken Williams

The nondistributivity of compound quantum mechanical propositions leads to a theorem that rules out the possibility of microscopic deterministic hidden variables, the Logical No-Go Theorem. We observe that there appear in fact two distinct nondistributivity relations in the derivation: one with a semantics governed by an empirical conjunctive syntax, the oth

Ken Williams

Compatibility between the realist tenants of value-definiteness and causality is called into question by several realism impossibility proofs in which their formal elements are shown to conflict. We review how this comes about in the Kochen-Specker and von Neumann proofs and point out a connection between their key assumptions: a constraint on realist causal

Hwayean Lee, Jongin Lim, HyungJin Yang

We propose two Quantum Direct Communication (QDC) protocols with user authentication. Users can identify each other by checking the correlation of Greenberger-Horne-Zeilinger (GHZ) states. Alice can directly send a secret message to Bob using the remaining GHZ states after authentication. Our second QDC protocol can be used even though there is no quantum li

C. Quesne, B. Bagchi, A. Banerjee, V. M. Tkachuk

A new method for generating exactly solvable Schrödinger equations with a position-dependent mass is proposed. It is based on a relation with some deformed Schrödinger equations, which can be dealt with by using a supersymmetric quantum mechanical approach combined with a deformed shape-invariance condition. The solvability of the latter is shown to impose t

Carsten Henkel

We review the current status of the field of atom-surface interactions, with an emphasis on the regimes specific to atom chips. Recent developments in theory and experiment are highlighted. In particular, atom-surface interactions define physical limits for miniaturization and coherent operation. This implies constraints for applications in quantum informati

S. A. Moiseev, B. S. Ham

We propose the dynamic control of two-color stationary light in a double-lambda four-level system using electromagnetically induced transparency. We demonstrate the complete localization of two-color quantum fields inside a medium using coherence moving gratings resulting from slow-light based atom-field interactions in backward nondegenerate four-wave mixin

Stein Olav Skrøvseth

We present a technique to resolve a Gaussian density matrix and its time evolution through known expectation values in position and momentum. Further we find the full spectrum of this density matrix and apply the technique to a chain of harmonic oscillators to find agreement with conformal field theory in this domain. We also observe that a non-conformal sta

Elad Schneidman, Michael J. Berry, Ronen Segev, William Bialek

Biological networks have so many possible states that exhaustive sampling is impossible. Successful analysis thus depends on simplifying hypotheses, but experiments on many systems hint that complicated, higher order interactions among large groups of elements play an important role. In the vertebrate retina, we show that weak correlations between pairs of n

R. B. Govindan, J. Raethjen, K. Arning, F. Kopper

Recently it has been demonstrated by Albo that partial coherence analysis is sensitive to signal to noise ratio (SNR) and that it will always identify the signal with the highest SNR among the three signals as the main (driving) influence. We propose to use time delay analysis in parallel to partial coherence analysis to identify the connectivities between t

N P Basse

We have in earlier work (Basse N P 2005, Phys. Lett. A vol. 340 p. 456) reported on intriguing similarities between density fluctuation power versus wavenumber on small (mm) and large (Mpc) scales. In this paper we expand upon our previous studies of small and large scale measurements made in fusion plasmas and using cosmological data, respectively. The meas

V. I. Telnov

At Snowmass2005 the Global Group 6 (Physics Options) considered the requirements and configurational issues related to possiblealternatives to the baseline e+e- collisions, including gamma-gamma, gamma-electron, electron-electron, GigaZ and fixed target experiments, and identified the potential performance parameters.

Evangelos Chaliasos

At first, a review of our knowledge on the distribution of galaxies at large-scale, leading to a foam-like large-scale structure of the Universe, is presented in the Introduction. Then, it is shown how, according to the present theory for the formation of superclusters, wave scalar perturbations of the same frequency traveling in opposite directions give ris

A. Baronchelli, L. Dall&#39;Asta, A. Barrat, V. Loreto

We investigate how very large populations are able to reach a global consensus, out of local &#34;microscopic&#34; interaction rules, in the framework of a recently introduced class of models of semiotic dynamics, the so-called Naming Game. We compare in particular the convergence mechanism for interacting agents embedded in a low-dimensional lattice with re

Hana Hromčíková, Pavel Kundrát, Miloš Lokajíček

Published survival data for Chinese hamster ovarian cells CHO-K1 and their radiosensitive mutant xrs5 after irradiation by carbon ions of energies from 2.4 to 266.4 MeV/u have been analyzed using the probabilistic two-stage radiobiological model, which enables to represent the interplay of damage induction and repair processes. The results give support for t

Arkady Vilenkin, Baruch Meerson

We develop a numerical method for solving a free boundary problem which describes shape relaxation, by surface tension, of a long and thin bubble of an inviscid fluid trapped inside a viscous fluid in a Hele-Shaw cell. The method of solution of the exterior Dirichlet problem employs a classical boundary integral formulation. Our version of the numerical meth

Marcel G. Clerc, Artem Petrossian, Stefania Residori

Experimental evidence of bouncing localized structures in a nonlinear optical system is reported.

Guillaume Labeyrie, Franck Michaud, Robin Kaiser

We have observed self-sustained radial oscillations in a large magneto-optical trap (MOT), containing up to $10^{10}$ Rb$^{85}$ atoms. This instability is due to the competition between the confining force of the MOT and the repulsive interaction associated with multiple scattering of light inside the cold atomic cloud. A simple analytical model allows us to

Matthew Borselli, Thomas J. Johnson, Oskar Painter

The silicon/silicon dioxide (Si/SiO2) interface plays a crucial role in the performance, cost, and reliability of most modern microelectronic devices, from the basic transistor to flash memory, digital cameras, and solar cells. Today the gate oxide thickness of modern transistors is roughly 5 atomic layers, with 8 metal wire layers required to transport all

Lennur Ya. Arifov

It is offered another method how to describe contemporary stage of the Universe evolution. The method is based upon classical Einstein equations without a dark energy and other hypothetical fields.

Yukio Hayashi

The scale-free (SF) structure that commonly appears in many complex networks is one of the hot topics related to social, biological, and information sciences. The self-organized generation mechanisms are expected to be useful for efficient communication or robust connectivity in socio-technological infrastructures. This paper is the first review of geographi

Marc Joyeux, Sahin Buyukdagli

We present a nonlinear dynamical model for DNA thermal denaturation, which is based on the finite stacking enthalpies used in thermodynamical nearest-neighbour calculations. Within this model, the finiteness of stacking enthalpies is shown to be responsible for the sharpness of calculated melting curves. Transfer-integral and molecular dynamics calculations

Gentaro Watanabe, Hidetaka Sonoda

In cores of supernovae and crusts of neutron stars, nuclei can adopt interesting shapes, such as rods or slabs, etc., which are referred to as nuclear &#34;pasta.&#34; Recently, we have been studying the pasta phases focusing on their dynamical aspects with quantum molecular dynamic (QMD) approach. We review our findings on the following topics: dynamical fo

D. Lenis, Dennis Bonatsos

An analytic, parameter-free (up to overall scale factors) solution of the Bohr Hamiltonian involving axially symmetric quadrupole and octupole deformations, as well as an infinite well potential, is obtained, after separating variables in a way reminiscent of the Variable Moment of Inertia (VMI) concept. Normalized spectra and B(EL) ratios are found to agree

P. Descouvemont, E. M. Tursunov, D. Baye

Three-body continuum states are investigated with the hyperspherical method on a Lagrange mesh. The $R$-matrix theory is used to treat the asymptotic behaviour of scattering wave functions. The formalism is developed for neutral as well as for charged systems. We point out some specificities of continuum states in the hyperspherical method. The collision mat

Vasily E. Tarasov, George M. Zaslavsky

We consider one-dimensional chain of coupled linear and nonlinear oscillators with long-range power-wise interaction. The corresponding term in dynamical equations is proportional to $1/|n-m|^{α+1}$. It is shown that the equation of motion in the infrared limit can be transformed into the medium equation with the Riesz fractional derivative of order $α$, whe

Sibusiso Moyo, P. G. L. Leach

We study the symmetry properties of autonomous integrating factors from an algebraic point of view. The symmetries are delineated for the resulting integrals treated as equations and symmetries of the integrals treated as functions or configurational invariants. The succession of terms (pattern) is noted. The general pattern for the solution symmetries for e

Paul K. Buah-Bassuah, René Rojas, Stefania Residori, Fortunato Tito Arecchi

We report a new type of drop instability, where the density difference between the drop and the solvent is negative. We show that the drop falls inside the solvent down to a minimum height, then fragmentation takes place and secondary droplets rise up to the surface. We have developed a theoretical model that captures the essential of the phenomenon and pred

N. Crampe, C. A. S. Young

We prove, using the coordinate Bethe ansatz, the exact solvability of a model of three particles whose point-like interactions are determined by the root system of g_2. The statistics of the wavefunction are left unspecified. Using the properties of the Weyl group, we are also able to find Bethe equations. It is notable that the method relies on a certain ge

P. J. Forrester, N. S. Witte

In a previous work a random matrix average for the Laguerre unitary ensemble, generalising the generating function for the probability that an interval $ (0,s) $ at the hard edge contains $ k $ eigenvalues, was evaluated in terms of a Painlevé V transcendent in $ σ$-form. However the boundary conditions for the corresponding differential equation were not sp

Ph. Barbe, W. P. McCormick

We establish some asymptotic expansions for infinite weighted convolutions of distributions having light subexponential tails. Examples are presented, some showing that in order to obtain an expansion with two significant terms, one needs to have a general way to calculate higher order expansions, due to possible cancellations of terms. An algebraic methodol

Vladimir Shpilrain, Alexander Ushakov

In this paper we present a new key establishment protocol based on the decomposition problem in non-commutative groups which is: given two elements $w, w_1$ of the platform group $G$ and two subgroups $A, B \subseteq G$ (not necessarily distinct), find elements $a \in A, b \in B$ such that $w_1 = a w b$. Here we introduce two new ideas that improve the secur

Patricia A. Carey, Anant P. Godbole

The classical Erd\H os-Ko-Rado theorem states that if $k\le\floor{n/2}$ then the largest family of pairwise intersecting $k$-subsets of $[n]=\{0,1,...,n\}$ is of size ${{n-1}\choose{k-1}}$. A family of $k$ subsets satisfying this pairwise intersecting property is called an EKR family. We generalize the EKR property and provide asymptotic lower bounds on the

G. Ehrman, A. Gurpinar, M. Thibault, D. N. Yetter

This paper summarizes substantive new results derived by a student team (the first three authors) under the direction of the fourth author at the 2005 session of the KSU REU ``Brainstorming and Barnstorming&#39;&#39;. The main results are a decomposition theorem for quandles in terms of an operation of `semidisjoint union&#39; showing that all finite quandle

Axel Werner

We consider unimodality and related properties of f-vectors of polytopes in various dimensions. By a result of Kalai (1988), f-vectors of 5-polytopes are unimodal. In higher dimensions much less can be said; we give an overview on current results and present a potentially interesting construction as well as a conjecture arising from this.