June 2006 arXiv papers — page 32

Itay Kaplan, Saharon Shelah

For a centerless group G, we can define its automorphism tower. We define G^{alpha} : G^0=G, G^{alpha +1}=Aut(G^alpha) and for limit ordinals G^delta=bigcup_{alpha < delta}G^alpha . Let tau_G be the ordinal when the sequence stabilizes. Thomas&#39; celebrated theorem says tau_G<2^{|G|})^{+} and more. If we consider Thomas&#39; proof too set theoretical, we h

L. Decreusefond, D. Nualart

We prove that solutions of stochastic differential equations driven by fractional Brownian motion for $H>1/2$ define flows of homeomorphisms on $\mathbb{R}^{d}$.

Xavier Yvonne

We show that the transition matrices between the standard and the canonical bases of infinitely many weight subspaces of the higher-level q-deformed Fock spaces are equal.

Atanas Iliev, Laurent Manivel

For a general K3 surface of genus g = 2,3,...,10, we prove that the intermediate jacobians of the family of prime Fano threefolds of genus g containing S as a hyperplane section, form generically an algebraic completely integrable system.

Jean-Marc Couveignes

This paper is concerned with the complexity and stability of arithmetic operations in the jacobian variety of curves over the field of complex numbers, as the genus grows to infinity. We focus on modular curves. Efficient and stable computation in the jacobian of modular curves is useful for computing coefficients of modular forms in deterministic polynomial

Jason P. Bell

Let $k$ be an uncountable algebraically closed field and let $A$ be a countably generated left Noetherian $k$-algebra. Then we show that $A \otimes_k K$ is left Noetherian for any field extension $K$ of $k$. We conclude that all subfields of the quotient division algebra of a countably generated left Noetherian domain over $k$ are finitely generated extensio

Andrea Surroca

We study the set of algebraic numbers of bounded height and bounded degree where an analytic transcendental function takes algebraic values.

Ivan Tyukin, Cees van Leeuwen

We propose a technique for the design and analysis of decentralized adaptation algorithms in interconnected dynamical systems. Our technique does not require Lyapunov stability of the target dynamics and allows nonlinearly parameterized uncertainties. We show that for the considered class of systems, conditions for reaching the control goals can be formulate

Zhenxin Liu, Shuguan Ji, Menglong Su

In the stability theory of dynamical systems, Lyapunov functions play a fundamental role. In this paper, we study the attractor-repeller pair decomposition and Morse decomposition for compact metric space in the random setting. In contrast to [8], by introducing slightly stronger definitions of random attractor and repeller, we characterize attractor-repelle

Eric M. Rains, Monica J. Vazirani

When one expands a Schur function in terms of the irreducible characters of the symplectic (or orthogonal) group, the coefficient of the trivial character is 0 unless the indexing partition has an appropriate form. A number of q-analogues of this fact were conjectured in math.QA/0112035; the present paper proves most of those conjectures, as well as some new

Jinpeng An, Zhengdong Wang

In this paper we prove some properties of the nonabelian cohomology $H^1(A,G)$ of a group $A$ with coefficients in a connected Lie group $G$. When $A$ is finite, we show that for every $A$-submodule $K$ of $G$ which is a maximal compact subgroup of $G$, the canonical map $H^1(A,K)\to H^1(A,G)$ is bijective. In this case we also show that $H^1(A,G)$ is always

Masao Ishikawa, Jiang Zeng

We show that the sum of the four parameter weights over all ordinary or strict partitions with parts each less than or equal to a given integer $N$ is expressed by the Al-Salam Chihara polynomials. This weight is a generalization of the Andrews-Stanley partition function. As a corollary we prove C. Boulet&#39;s results when the sum runs over all ordinary or

JongHae Keum

A fake projective plane is a compact complex manifold of dimension 2 which has the same Betti numbers as the complex projective plane, but not isomorphic to the complex projective plane. As was shown by D. Mumford, there exists at least one such surface. In this paper we prove the existence of a fake projective plane which is birational to a cyclic cover of

Jinpeng An, Zhengdong Wang

In this paper we generalize a result in [1], showing that an arbitrary Riemannian symmetric space can be realized as a closed submanifold of a covering group of the Lie group defining the symmetric space. Some properties of the subgroups of fixed points of involutions are also proved.

Alexandre Yu. Volkov

I prove Zamolodchikov&#39;s periodicity conjecture for type A with both ranks arbitrary.

Ulf Lindstrom, Martin Rocek

In this brief note we give a superspace description of the supersymmetric nonlocal Lorentz noninvariant actions recently proposed by Cohen and Freedman. This leads us to discover similar terms for gauge fields.

C. D. Fosco, F. D. Mazzitelli

We study quantum effects due to a Dirac field in 2+1 dimensions, confined to a spatial region with a non-trivial boundary, and minimally coupled to an Abelian gauge field. To that end, we apply a path-integral representation, which is applied to the evaluation of the Casimir energy and to the study of the contribution of the boundary modes to the effective a

Roman V. Buniy, Stephen D. H. Hsu, Brian M. Murray

We extend previous work showing that violation of the null energy condition implies instability in a broad class of models, including gauge theories with scalar and fermionic matter as well as any perfect fluid. Simple examples are given to illustrate these results. The role of causality in our results is discussed. Finally, we extend the fluid results to mo

Gautam Mandal, Nemani V. Suryanarayana

We count 1/8-BPS states in type IIB string theory on AdS_5 x S^5 background which carry three independent angular momenta on S^5. These states can be counted by considering configurations of multiple dual-giant gravitons up to N in number which share at least four supersymmetries. We map this counting problem to that of counting the energy eigen states of a

Tapobrata Sarkar, Gautam Sengupta, Bhupendra Nath Tiwari

We investigate the Ruppeiner geometry of the thermodynamic state space of a general class of BTZ black holes. It is shown that the thermodynamic geometry is flat for both the rotating BTZ and the BTZ Chern Simons black holes in the canonical ensemble. We further investigate the inclusion of thermal fluctuations to the canonical entropy of the BTZ Chern Simon

Anamaria Font, Jose Antonio Lopez

We study type IIB orientifolds on T^{2d}/Z_N with supersymmetry broken by the compactification. We determine tadpole cancellation conditions including anti-branes and considering different actions for the parity Omega. Using these conditions we then obtain the spectrum of tachyons and massless states. Various examples with N even correspond to type 0B orient

Ajay Patwardhan

A unified field theory in ten dimensions, of all interactions, can describe high energy processes occuring in the early universe. In such a theory transitions that give properties of the universe can occur due to the presence of algebraic and geometric structures. A correspondence between theory and observations of the universe is made, to obtain a new inter

Diego Julio Cirilo-Lombardo

In this work, we propose a new non-abelian generalization of the Born- Infeld lagrangian. It is based on a geometrical property of the abelian Born-Infeld lagrangian in its determinantal form. Our goal is to extend the abelian second type Born-Infeld action to the non-abelian form preserving this geometrical property, that permits to compute the generalized

Cheng-Wei Chiang, N. G. Deshpande, J. Jiang

Flavor-changing and CP-violating interactions of Z&#39; to fermions are generally present in models with extra U(1) gauge symmetry that are string-inspired or related to broken gauged family symmetry. We study the consequences of such couplings in fermion electric dipole moments, muon g-2, and K and B meson mixings. From experimental limits or measured value

Ayres Freitas, Peter Z Skands

Among the firm predictions of softly broken supersymmetry is the identity of gauge couplings and the corresponding Yukawa couplings between gauginos, sfermions and fermions. In the event that a SUSY-like spectrum of new particles is discovered at future colliders, a key follow-up will be to test these relations experimentally. In detailed studies it has been

R. Rapp, H. van Hees

We discuss recent developments in assessing heavy-quark interaction in the Quark-Gluon Plasma (QGP). While induced gluon radiation is expected to be the main energy-loss mechanism for fast-moving quarks, we focus on elastic scattering which prevails toward lower energies, evaluating both perturbative (gluon-exchange) and nonperturbative (resonance formation)

Eric Braaten, Meng Lu

The X(3872) seems to be a weakly-bound hadronic molecule whose constituents are two charm mesons. Its binding energy is much smaller than all the other energy scales in QCD. This separation of scales can be exploited through factorization formulas for production and decay rates of the X. In a low-energy effective field theory for the constituents of the X, t

Wei-Ning Zhang, Yan-Yu Ren, Cheuk-Yin Wong

In many simulations of high-energy heavy-ion collisions on an event-by-event analysis, it is known that the initial energy density distribution in the transverse plane is highly fluctuating. Subsequent longitudinal expansion will lead to many longitudinal tubes of quark-gluon plasma which have tendencies to break up into many spherical droplets because of sa

A. Blondel, A. Cervera-Villanueva, A. Donini, P. Huber

The recent discovery that neutrinos have masses opens a wide new field of experimentation. Accelerator-made neutrinos are essential in this program. Ideas for future facilities include high intensity muon neutrino beams from pion decay (`SuperBeam&#39;), electron neutrino beams from nuclei decays (`Beta Beam&#39;), or muon and electron neutrino beams from mu

Jacques Soffer

We recall how parton distributions are constructed in a statistical physical picture of the nucleon. The chiral properties of QCD lead to strong relations between quarks and antiquarks distributions and the importance of the Pauli exclusion principle is also emphasized. A global next-to-leading order QCD analysis of unpolarized and polarized deep-inelastic s

B. Borasoy, U. -G. Meißner, R. Nißler

The strong K^- p scattering length is extracted within chiral SU(3) unitary approaches from a very large variety of fits to low-energy K^- p scattering data. Very good overall agreement with available scattering data is obtained and the resulting scattering length is compared with the new accurate kaonic hydrogen data from DEAR. The pole structures of the ob

S. A. Abel, J. Jaeckel, V. V. Khoze, A. Ringwald

Restrictions imposed by gauge invariance in noncommutative spaces together with the effects of ultraviolet/infrared mixing lead to strong constraints on possible candidates for a noncommutative extension of the Standard Model. We study a general class of noncommutative models consistent with these restrictions. Specifically we consider models based upon a ga

G. F. Giudice, R. Rattazzi

We stress that the lack of direct evidence for supersymmetry forces the soft mass parameters to lie very close to the critical line separating the broken and unbroken phases of the electroweak gauge symmetry. We argue that the level of criticality, or fine-tuning, that is needed to escape the present collider bounds can be quantitatively accounted for by ass

Kiyotomo Kawagoe, Mihoko M. Nojiri

Discovery of supersymmetric (SUSY) particles at the Large Hadron Collider(LHC) has been studied for the models where squarks and gluino are much heavier than the lightest supersymetric particle (LSP). In this paper, we investigate the SUSY discovery in the models with degenerated mass spectrum up to m_LSP~0.7 m_sq. Such mass spectrum is predicted in certain

Mark Heinz

STAR has measured a variety of strange particle species in $p+p$ collisions at $\sqrt{s}$=200 GeV. These high statistics data are ideal for comparing to existing leading- and next-to-leading order perturbative QCD (pQCD) models. Leading-order (LO) models such as PYTHIA need to be tuned to describe identified strange particle data from STAR. We show that tune

Frank B. Estabrook

Two classic field theories of metric gravitation are given as constant-coefficient Exterior Differential Systems (EDS) on the flat orthonormal frame bundle over ten dimensional space. They are derivable by variation of Cartan 4-forms, and shown to be well-posed by calculation of their Cartan characteristic integers. Their solutions are embedded Riemannian 4-

Valery Dryuma

Some examples of ten-dimensional vacuum Einstein spaces made up on basis of four-dimensional Ricci-flat spaces and six-dimensional Ricci-flat spaces defined by solutions of the Sin-Gordon equation are constructed. The properties of geodesics for such type of the spaces are discussed

Edgard Casal de Rey Neto

We write out the geodesic deviations that take place in a $d\geq 4$ dimensional brane world subspace of a higher dimensional spacetime by splitting out the brane and the extra space dynamical quantities from a global metric spacetime of dimension $D\geq 5$. The higher dimensional dynamical quantities are projected onto two orthogonal subspaces, where one of

Tsutomu Kobayashi

The braneworld model of Dvali-Gabadadze-Porrati (DGP) provides an interesting alternative to a positive cosmological constant by modifying gravity at large distances. We investigate the asymptotic behavior of homogeneous and anisotropic cosmologies on the DGP brane. It is shown that all Bianchi models except type IX isotropize, as in general relativity, if t

Christian Artigues, Pierre Lopez, Pierre-Dimitri Ayache

We consider the job-shop problem with sequence-dependent setup times. We focus on the formal definition of schedule generation schemes (SGSs) based on the semi-active, active, and non-delay schedule categories. We study dominance properties of the sets of schedules obtainable with each SGS. We show how the proposed SGSs can be used within single-pass and mul

Laurent Hascoet, Mauricio Araya-Polo

This paper presents a new functionality of the Automatic Differentiation (AD) tool Tapenade. Tapenade generates adjoint codes which are widely used for optimization or inverse problems. Unfortunately, for large applications the adjoint code demands a great deal of memory, because it needs to store a large set of intermediates values. To cope with that proble

Ming-Zhe Chen

This paper contains some results of pentagons which can be determined by two X-rays. The results reveal this problem is more complicated.

V. V. Kryssanov, H. Tamaki, S. Kitamura

Although it has contributed to remarkable improvements in some specific areas, attempts to develop a universal design theory are generally characterized by failure. This paper sketches arguments for a new approach to engineering design based on Semiotics - the science about signs. The approach is to combine different design theories over all the product life

F. Schmitt, M. Hild, R. Roth

The zero temperature phase diagram of binary boson-fermion mixtures in two-colour superlattices is investigated. The eigenvalue problem associated with the Bose-Fermi-Hubbard Hamiltonian is solved using an exact numerical diagonalization technique, supplemented by an adaptive basis truncation scheme. The physically motivated basis truncation allows to access

M. Manosas, D. Collin, F. Ritort

We apply Kramers theory to investigate the dissociation of multiple bonds under mechanical force and interpret experimental results for the unfolding/refolding force distributions of an RNA hairpin pulled at different loading rates using laser tweezers. We identify two different kinetic regimes depending on the range of forces explored during the unfolding a

R. J. O. Mossanek, M. Abbate, A. Fujimori

We studied the electronic structure of the Ca1-xSrxVO3 series using a cluster model. Both the coherent and incoherent structures in photoemission correspond to well screened states. The coherent structure (3d1/u(C)) is mostly due to a non-local coherent screening, whereas the incoherent feature (3d1/u(L)) is mainly related to the ligand screening. The poorly

A. Wilson, J. Lawrence, E-C. Yang, M. Nakano

EPR studies of a Ni4 single-molecule magnet yield the zero-field-splitting (zfs) parameters, D, B40 and B44, based on a giant spin approximation (GSA) with S = 4. Experiments on an isostructural Ni-doped Zn4 crystal establish the Ni(II) ion zfs parameters. The 4th-order zfs parameters in the GSA arise from the interplay between the Heisenberg interaction, Js

M. D. Webb, I. L. Davis

We present a reduced-dimension, ballistic deposition, Monte Carlo particle packing algorithm and discuss its application to the analysis of the microstructure of hard-sphere systems with broad particle size distributions. We extend our earlier approach (the ``central string&#39;&#39; algorithm) to a reduced-dimension, quasi-3D approach. Our results for monom

V. Pancaldi, K. Christensen, P. R. King

In the context of flow in porous media, up-scaling is the coarsening of a geological model and it is at the core of water resources research and reservoir simulation. An ideal up-scaling procedure preserves heterogeneities at different length-scales but reduces the computational costs required by dynamic simulations. A number of up-scaling procedures have be

F. M. Zimmer, S. G. Magalhaes

The fermionic Ising spin glass models in a transverse field are investigated in a Grassmann path integral formalism. The Parisi&#39;s scheme of one-step replica symmetry breaking (RSB) is used within the static ansatz. This formalism has already been applied in a theory in which $m$ (Parisi&#39;s block-size parameter) is taken as a constant (PRB 72, 014447 (

Martin Zonda

A combination of small-cluster exact-diagonalization calculations and a well-controlled approximative method is used to examine the ground-state phase diagrams of the spin-one-half Falicov-Kimball model extended by the spin-dependent on-site interaction ($J$) between localized spins and itinerant ($d$) electrons, as well as by external magnetic field ($h$).

J. J. Prejean, E. Lhotel, A. Sulpice, F. Hippert

The quasicrystal Al-Pd-Mn is a model system for an experimental study of the competition between Ruderman-Kittel-Kasuya-Yoshida (RKKY) and Kondo interactions. First, specific of such alloys, only a few Mn atoms carry an effective spin and their concentration x is tunable over several orders of magnitude, even though the Mn amount is almost constant. Second,

Mikhail S. Kalenkov, Harald Kloos, Andrei D. Zaikin

We have evaluated a proximity-induced minigap in the density of states (DOS) of SNS junctions and SNS nanorings at an arbitrary concentration of non-magnetic impurities. We have demonstrated that an isotropic energy minigap in the electron spectrum opens up already at arbitrarily weak disorder, while angle resolved DOS at higher energies can remain strongly

Dmitry Pozdnyakov, Vadim Galenchik, Andrei Borzdov

In this paper the scattering rates of electrons in thin free standing GaAs quantum wires in the electric quantum limit are calculated self-consistently taking into account the collisional broadening caused by scattering processes. The following mechanisms of scattering are considered: one-dimensional acoustic and polar optical phonons, surface roughness and

A. Koitzsch, S. V. Borisenko, J. Geck, V. B. Zabolotnyy

We have investigated the low-energy electronic structure of the strongly correlated one-dimensional copper oxide chain compound SrCuO2 by angle resolved photoemission as a function of excitation energy. In addition to the prominent spinon-holon continuum we observe a peaklike and dispersive feature at the zone boundary. By fine-tuning the experimental parame

J. Servantie, P. Gaspard

We report a study of the rotational dynamics in double-walled nanotubes using molecular dynamics simulations and a simple analytical model reproducing very well the observations. We show that the dynamic friction is linear in the angular velocity for a wide range of values. The molecular dynamics simulations show that for large enough systems the relaxation

Malay Bandyopadhyay, Sushanta Dattagupta

The slow dynamics and concomitant memory (aging) effects seen in nanomagnetic systems are analyzed on the basis of two separate paradigms : superparamagnets and spinglasses. It is argued that in a large class of aging phenomena it suffices to invoke superparamagnetic relaxation of individual single domain particles but with a distribution of their sizes. Cas

P. Murugavel, W. Prellier

We have investigated the magnetotransport properties of La0.7Sr0.3MnO3/BaTiO3 superlattices, grown on SrTiO3 substrate by pulsed laser deposition technique, both with current-in-plane and current-perpendicular-to-the-plane directions. Several features indicate the presence of magnetic inhomogeneities at the interfaces which is independent of BaTiO3 layer thi

N. Kristoffel, P. Rubin

Isotope effects in a multiband superconductor with a leading interband pairing channel are investigated. A relatively small electron-phonon contribution into the pair-transfer interaction can cause effects of observed magnitude. A multiband model which interpolates the cuprate properties is used for illustrative calculations. Isotope exponents of the transit

J. Sugiyama, Y. Ikedo, K. Mukai, J. H. Brewer

The nature of the magnetic transition of the half-filled triangular antiferromagnet Ag$_{2}$NiO$_2$ with $T_{\rm N}$=56K was studied with positive muon-spin-rotation and relaxation ($μ^+$SR) spectroscopy. Zero field $μ^+$SR measurements indicate the existence of a static internal magnetic field at temperatures below $T_{\rm N}$. Two components with slightly

N. Ohba, K. Miwa, M. Aoki, T. Noritake

We report the results of the first-principles calculation on the intermediate compounds of LiBH$_4$. The stability of LiB$_3$H$_8$ and Li$_2$B$_n$H$_n (n=5-12)$ has been examined with the ultrasoft pseudopotential method based on the density functional theory. Theoretical prediction has suggested that monoclinic Li$_2$B$_{12}$H$_{12}$ is the most stable amon

Yutaka Okabe, Hiromi Otsuka

Using the Wang-Landau Monte Carlo method, we study the antiferromagnetic (AF) three-state Potts model with a staggered polarization field on the square lattice. We obtain two phase transitions; one belongs to the ferromagnetic three-state Potts universality class, and the other to the Ising universality class. The phase diagram obtained is quantitatively con

Olivier Gygi, Helmut G. Katzgraber, Matthias Troyer, Stefan Wessel

We report results of quantum Monte Carlo simulations in the canonical and the grand-canonical ensemble of the two- and three-dimensional Bose-Hubbard model with quadratic and quartic confining potentials. The quantum criticality of the superfluid-Mott insulator transition is investigated both on the boundary layer separating the two coexisting phases and at

Florian Baumann

I consider ageing behaviour in two exactly solvable reaction-diffusion systems. Ageing exponents and scaling functions are determined. I discuss in particular a case in which the equality of two critical exponents, known from systems with detailed balance, does not hold any more. Secondly it is shown that the form of the scaling functions can be understood b

W. Pietsch

The percolation threshold of the network model by Barabasi and Albert (BA-model) [Science 286, 509 (1999)] has thus far only been &#39;guessed&#39; based on simulations and comparison with other models. Due to the still uncertain influence of correlations, the reference to other models cannot be justified. In this paper, we explicitly derive the well-known v

S. Demers, P. Battinelli, E. Artigau

From a 2 x 2 degree survey of NGC 6822 we have previously established that this Local Group dwarf irregular galaxy possesses a huge spheroid having more than one degree in length. This spheroid is in rotation but its rotation curve is known only within ~15&#39; from the center. It is therefore critical to identify bright stars belonging to the spheroid to ch

Irena Stojimirović, Gopal Narayanan, Ronald L. Snell, John Bally

We present high sensitivity 12/13CO(1-0) molecular line maps covering the full extent of the parsec scale L1551 molecular outflow, including the redshifted east-west (EW) flow. We also present 12CO(3-2) data that extends over a good fraction of the area mapped in the 1-0 transition. We compare the molecular data to widefield, narrow-band optical emission in

James G. Bartlett

Galaxy clusters furnish extremely rich information on the contents and structure of our universe. The potential of galaxy cluster studies to constrain dark energy, for example, motivates a number of ambitious cluster surveys. Among these, surveys based on the Sunyaev-Zel&#39;dovich (SZ) effect are particularly powerful for their ability to cleanly select clu

Ana Paula Andrade, André Luís B. Ribeiro, Carlos Alexandre Wuensche

One possible way to investigate the nature of the primordial power spectrum fluctuations is by investigating the statistical properties of the local maximum in the density fluctuation fields. In this work we present a study of the mean correlation function, $ξ_r$, and the correlation function for high amplitude fluctuations (the peak-peak correlation) in a s

Martha L. Boyer, Charles E. Woodward, Jacco Th. van Loon, Karl D. Gordon

We present Spitzer Space Telescope IRAC and MIPS observations of the galactic globular cluster M15 (NGC 7078), one of the most metal-poor clusters with a [Fe/H] = -2.4. Our Spitzer images reveal a population of dusty red giants near the cluster center, a previously detected planetary nebula (PN) designated K648, and a possible detection of the intra-cluster

Andreas Kelz, Svend M. Bauer, Frank Grupp, Gary J. Hill

VIRUS is a planned integral-field instrument for the Hobby-Eberly Telescope (HET). In order to achieve a large field-of-view and high grasp at reasonable costs, the approach is to replicate integral-field units (IFU) and medium sized spectrographs many times. The Astrophysical Institute Potsdam (AIP) contributes to VIRUS with the development and testing of t

Anthony Meilland, Philippe Stee, Juan Zorec, Samer Kanaan

Aims. We report theoretical spectral energy distributions (SEDs), Br$γ$ line profiles and visibilities for two scenarios that can explain the disk dissipation of active hot stars an account for the transition from the Be to the B spectroscopic phase. Methods. We use the SIMECA code to investigate these two scenarios: the first one where the disk is formed by

David A. Neufeld, Gary J. Melnick, Paule Sonnentrucker, Edwin A. Bergin

We report the results of spectroscopic mapping observations carried out toward the Herbig-Haro objects HH7-11 and HH54 over the 5.2 - 37 micron region using the Infrared Spectrograph of the Spitzer Space Telescope. These observations have led to the detection and mapping of the S(0) - S(7) pure rotational lines of molecular hydrogen, together with emissions

Mei Zhang

We report in this letter our analysis of a large sample of photospheric vector magnetic field measurements. Our sample consists of 17200 vector magnetograms obtained from January 1997 to August 2004 by Huairou Solar Observing Station of the Chinese National Astronomical Observatory. Two physical quantities, $α$ and current helicity, are calculated and their

J. A. Aguilar, ANTARES Collaboration

In 2005, the ANTARES Collaboration deployed and operated at a depth of 2500 m a so-called Mini Instrumentation Line equipped with Optical Modules (MILOM) at the ANTARES site. The various data acquired during the continuous operation from April to December 2005 of the MILOM confirm the satisfactory performance of the Optical Modules, their front-end electroni

Laurence Perotto, Julien Lesgourgues, Steen Hannestad, Huitzu Tu

The Fisher matrix formalism has in recent times become the standard method for predicting the precision with which various cosmological parameters can be extracted from future data. This approach is fast, and generally returns accurate estimates for the parameter errors when the individual parameter likelihoods approximate a Gaussian distribution. However, w

D. Fargion

Future neutrino detector at Megaton mass might enlarge the neutrino telescope thresholds revealing cosmic supernova background and largest solar flares neutrino. Indeed the solar energetic flare particles while scattering among themselves on Solar corona atmosphere must produce prompt charged pions, whose chain decays are source of solar (electron-muon) neut

E. Schilbach, N. V. Kharchenko, A. E. Piskunov, S. Röser

Aims: Based on our well-determined sample of open clusters in the all-sky catalogue ASCC-2.5 we derive new linear sizes of some 600 clusters, and investigate the effect of mass segregation of stars in open clusters. Methods: Using statistical methods, we study the distribution of linear sizes as a function of spatial position and cluster age. We also examine

T. J. O&#39;Brien, M. F. Bode, R. W. Porcas, T. W. B. Muxlow

Nova outbursts take place in binary star systems comprising a white dwarf and either a low-mass Sun-like star or, as in the case of the recurrent nova RS Ophiuchi, a red giant. Although the cause of these outbursts is known to be thermonuclear explosion of matter transferred from the companion onto the surface of the white dwarf, models of the previous (1985

Francois Levrier, Edith Falgarone, Francois Viallefond

Most statistical tools used to characterize the complex structures of the interstellar medium can be related to the power spectrum, and therefore to the Fourier amplitudes of the observed fields. To tap into the vast amount of information contained in the Fourier phases, one may consider the probability distribution function (PDF) of phase increments, and th

S. Mikkola, P. Nurmi

We consider secular perturbations of nearly Keplerian two-body motion under a perturbing potential that can be approximated to sufficient accuracy by expanding it to second order in the coordinates. After averaging over time to obtain the secular Hamiltonian, we use angular momentum and eccentricity vectors as elements. The method of variation of constants t

Corinne Charbonnel, Nikos Prantzos

Galactic globular cluster stars exhibit abundance patterns which are not shared by their field counterparts. It is clear from recent spectroscopic observations of GC turnoff stars that these abundance anomalies were already present in the gas from which the observed stars formed. This provides undisputed support to the so-called self-enrichment scenario acco

P. Padovani, P. Giommi, P. Abraham, S. Csizmadia

The large majority of BL Lacertae objects belonging to the 1 Jy sample, the class prototype for radio-selected sources, are thought to emit most of their synchrotron power in the far IR band. Ironically, this spectral region is very sparsely sampled, with only a minority of the objects having IRAS data (most of them being upper limits or low-quality detectio

E. Zackrisson, N. Bergvall, G. Ostlin, G. Micheva

Optical and near-IR observations of the halos of disk galaxies and blue compact galaxies have revealed a very red spectral energy distribution, which cannot easily be reconciled with a normal, metal-poor stellar population like that in the stellar halo of the Milky Way. Here, spectral evolutionary models are used to explore the consequences of these observat

B. F. Liu, ; F. Meyer, E. Meyer-Hofmeister

Aims: The hard and soft spectral states of black hole accretion are understood as connected with ADAF accretion (truncated disk) and standard disk accretion, respectively. However, observations indicate the existence of cool gas in the inner region at times when the disk is already truncated outside. We try to shed light on these not yet understood intermedi

Garry W. Angus, Benoit Famaey, HongSheng Zhao

A proper test of Modified Newtonian Dynamics (MOND) in systems of non-trivial geometries depends on modelling subtle differences in several versions of its postulated theories. This is especially important for lensing and dynamics of barely virialised galaxy clusters with typical gravity of scale $\sim a_0 \sim 1Å{\rm s}^{-2}$. The original MOND formula, the

Soebur Razzaque, Peter Meszaros

Core collapse of massive stars and binary neutron stars or black hole-neutron star binary mergers are likely progenitors of long and short duration gamma-ray bursts respectively. Neutronized material in the former and neutron star material in the latter are ejected by the central engine implying a neutron-rich jet outflow. A free neutron, however, beta decay

Savvas M. Koushiappas

I discuss the prospects of detecting the smallest dark matter bound structures present in the Milky Way by searching for the proper motion of $γ$-ray sources in the upcoming GLAST all sky map. I show that for dark matter particle candidates that couple to photons the detection of at least one $γ$-ray microhalo source with proper motion places a constraint on

Lucas Goehring, Zhenquan Lin, Stephen W. Morris

Columnar jointing is a fracture pattern common in igneous rocks in which cracks self-organize into a roughly hexagonal arrangement, leaving behind an ordered colonnade. We report observations of columnar jointing in a laboratory analog system, desiccated corn starch slurries. Using measurements of moisture density, evaporation rates, and fracture advance rat

F. Febres Cordero, L. Reina, D. Wackeroth

We calculate the Next-to-Leading Order (NLO) QCD corrections to W-b-bbar production including full bottom-quark mass effects. We study the impact of NLO QCD corrections on the total cross section and invariant mass distribution of the bottom-quark jet pair at the Fermilab Tevatron p-pbar collider. We perform a detailed comparison with a calculation that cons

Manoj Kaplinghat, Arvind Rajaraman

Charged particles (X) decaying after primordial nucleosynthesis are constrained by the requirement that their decay products should not change the light element abundances drastically. If the decaying particle is negatively charged (X-) then it will bind to the nuclei. We consider the effects of the decay of X when bound to Helium-4 and show that this will m

Alexander Friedland, Cecilia Lunardini

The SuperKamiokande atmospheric neutrino measurements leave substantial room for nonstandard interactions (NSI) of neutrinos with matter in the nu_e- nu_tau sector. Large values of the NSI couplings are accommodated if the vacuum oscillation parameters are changed from their standard values. Short and medium baseline neutrino beams can break this degeneracy

Kenneth A. Dennison, Thomas W. Baumgarte, Harald P. Pfeiffer

We construct approximate analytical solutions to the constraint equations of general relativity for binary black holes of arbitrary mass ratio in quasicircular orbit. We adopt the puncture method to solve the constraint equations in the transverse-traceless decomposition and consider perturbations of Schwarzschild black holes caused by boosts and the presenc

Nathan Reading, David E Speyer

For a finite Coxeter group W and a Coxeter element c of W, the c-Cambrian fan is a coarsening of the fan defined by the reflecting hyperplanes of W. Its maximal cones are naturally indexed by the c-sortable elements of W. The main result of this paper is that the known bijection cl_c between c-sortable elements and c-clusters induces a combinatorial isomorph

Faouzi Chaabane, Hamdi Fathallah

In the present work, we consider a stable one-dimensional gaussian autoregressive model in continous time. Using the limit theorems with logarithmic averaging obtained for continous local martingales, we construct then an estimator of the noise covariance $σ^{2}$ and an estimator of $θ$ different of the one of the least squares estimator. By exploiting the w

David J. Lin, Alvin Bayliss, Ronald E. Taam

The Low Mach Number Approximation (LMNA) is applied to 2D hydrodynamical modeling of Type I X-ray bursts on a rectangular patch on the surface of a non-rotating neutron star. Because such phenomena involve decidedly subsonic flows, the timestep increase offered by the LMNA makes routine simulations of these deflagrations feasible in an environment where stro

Robert D. Schroll, Régis Wunenburger, Alexis Casner, Wendy W. Zhang

Using experiments and theory, we show that light scattering by inhomogeneities in the index of refraction of a fluid can drive a large-scale flow. The experiment uses a near-critical, phase-separated liquid, which experiences large fluctuations in its index of refraction. A laser beam traversing the liquid produces a large-scale deformation of the interface

Gary Steigman

Subsequent to the early Universe quark-hadron transition the universal baryon number is carried by nucleons: neutrons and protons. The total number of nucleons is preserved as the Universe expands, but as it cools lighter protons are favored over heavier neutrons reducing the average mass per baryon. During primordial nucleosynthesis free nucleons are transf

Andrej Bogdanov, Luca Trevisan

We survey the average-case complexity of problems in NP. We discuss various notions of good-on-average algorithms, and present completeness results due to Impagliazzo and Levin. Such completeness results establish the fact that if a certain specific (but somewhat artificial) NP problem is easy-on-average with respect to the uniform distribution, then all pro

Johannes Hirn, Veronica Sanz

We present a new class of 5D models, Holographic Technicolor, which fulfills the basic requirements for a candidate of comprehensible 4D strong dynamics at the electroweak scale. It is the first Technicolor-like model able to provide a vanishing or even negative tree-level S parameter, avoiding any no-go theorem on its sign. The model is described in the lar