September 2004 arXiv papers — page 11

Christopher J. Leininger

In a paper of Menasco and Reid, it is conjectured that there exist no hyperbolic knots in S^3 for which the complement contains a closed embedded totally geodesic surface. In this note, we show that one can get "as close as possible" to a counter-example. Specifically, we construct a sequence of hyperbolic knots {K_n} with complements containing clos

Shripad M. Garge

This thesis studies arithmetic of linear algebraic groups. It involves studying the properties of linear algebraic groups defined over global fields, local fields and finite fields, or more generally the study of the linear algebraic groups defined over the fields which admit arbitrary cyclic extensions.

Robert W. Baddeley, Cheryl E. Praeger, Csaba Schneider

The blow-up construction by L. G. Kovács has been a very useful tool to study embeddings of finite primitive permutation groups into wreath products in product action. In the present paper we extend the concept of a blow-up to finite quasiprimitive permutation groups, and use it to study embeddings of finite quasiprimitive groups into wreath products.

Steffen Froehlich

We investigate existence and stability of rotationally symmetric critical immersions of variational problems of higher order which were considered by Nitsche.

V. Danilov, G. Koshevoy

We give a simple bijective proof of associativity and commutativity of the Littlewood-Richardson coefficients or the hive ring. Specifically, we establish existence a polarized polymatroidal discretely concave functions on the tetrahedron with given boundary values at two adjoint faces.

M. J. Soto, José L. Vicente

We show that a convex pyramid in R^n with apex at 0 can be brought to the first quadrant by a finite sequence of monomial blowing-ups if and only if its intersection with the opposite of the first quadrant is 0. The proof is non-trivially derived from the theorem of Farkas-Minkowski. Then, we apply this theorem to show how the Newton diagrams of the roots of

anna melnikov

Let g be a semisimple complex Lie algebra. Let O be a nilpotent orbit in g. Fix a triangular decomposition g=n+h+n^-. An irreducible component of the intersection of O and n is called an orbital variety associated to O. It is a Lagrangian subvariety of O. In this note we discuss the closure of an orbital variety as a union of varieties. We show that if g con

Vladimir L. Popov, Evgueni A. Tevelev

We discover a class of projective self-dual algebraic varieties. Namely, we consider actions of isotropy groups of complex symmetric spaces on the projectivized nilpotent varieties of isotropy modules. For them, we classify all orbit closures $X$ such that $X=\check X$ where $\check X$ is the projective dual of $X$. We give algebraic criteria of projective s

Markus Schweighofer

We prove an extension of the classical Real Representation Theorem (going back to Krivine, Stone, Kadison, Dubois and Becker and often called Kadison-Dubois Theorem). It is a criterion for membership in subsemirings (sometimes called preprimes) of a commutative ring. Whereas the classical criterion is only applicable for functions which are positive on the r

T. Digernes, V. S. Varadarajan

In its most general formulation a quantum kinematical system is described by a Heisenberg group; the "configuration space" in this case corresponds to a maximal isotropic subgroup. We study irreducible models for Heisenberg groups based on compact maximal isotropic subgroups. It is shown that if the Heisenberg group is 2-regular, but the subgroup is

J. Brodzki, R. J. Plymen

Certain cocycles constructed by Connes are characters of $p$-summable Fredholm modules. In this article, we establish some consequences of the universal properties which these characters enjoy. Our main technical result is that the entire cyclic cohomology of the p-th Schatten ideal L^p (respectively, homology) is independent of p and isomorphic to the entir

Sanatan Rai

Consider $n$ points distributed uniformly in $[0,1]^d$. Form a graph by connecting two points if their mutual distance is no greater than $r(n)$. This gives a random geometric graph, $\gnrn$, which is connected for appropriate $r(n)$. We show that the spectral measure of the transition matrix of the simple random walk (\abbr{srw}) on $\gnrn$ is concentrated,

Gilles Carron

We obtain a topological interpretation for the space of $L^2$ harmonic forms for some complete Riemannian manifold : when the geometry at infinity is the geometry of a simply connected nilpotent Lie group, when the geometry at infinity is a symmetric space with non positive curvature and also when the geometry at infinity is parabolic.

M. Kleban, M. Porrati, R. Rabadan

We discuss two types of instabilities which may arise in string theory compactified to asymptotically AdS spaces: perturbative, due to discrete modes in the spectrum of the Laplacian, and non-perturbative, due to brane nucleation. In the case of three dimensional Einstein manifolds, we completely characterize the presence of these instabilities, and in highe

K. A. Milton

Quantum vacuum energy entered hadronic physics through the zero-point energy parameter introduced into the bag model. Estimates of this parameter led to apparent discordance with phenomenological fits. More serious were divergences which were omitted in an ad hoc manner. New developments in understanding Casimir self-stresses, and the nature of surface diver

Anton A. Gerasimov, Samson L. Shatashvili

The precise relation between Kodaira-Spencer path integral and a particular wave function in seven dimensional quadratic field theory is established. The special properties of three-forms in 6d, as well as Hitchin's action functional, play an important role. The latter defines a quantum field theory similar to Polyakov's formulation of 2d gravity; th

E. Ivanov, A. Sutulin

We describe four different types of the ${\cal N} = (4,4)$ twisted supermultiplets in two-dimensional ${\cal N} = (2,2)$ superspace ${\bf R}^{1,1|2,2}$. All these multiplets are presented by a pair of chiral and twisted chiral superfields and differ in the transformation properties under an extra hidden ${\cal N} = (2,2)$ supersymmetry. The sigma model ${\ca

Rajesh Gopakumar

An approach to systematically implement open-closed string duality for free large $N$ gauge theories is summarised. We show how the relevant closed string moduli space emerges from a reorganisation of the Feynman diagrams contributing to free field correlators. We also indicate why the resulting integrand on moduli space has the right features to be that of

Xun Su, Jun-Bao Wu

The fermionic extension of the CSW approach to perturbative gauge theory coupled with fermions is used to compute the six-quark QCD amplitudes. We find complete agreement with the results obtained by using the usual Feynman rules.

Martin Bojowald, Roy Maartens, Parampreet Singh

Loop quantum gravity introduces strong non-perturbative modifications to the dynamical equations in the semi-classical regime, which are responsible for various novel effects, including resolution of the classical singularity in a Friedman universe. Here we investigate the modifications for the case of a cyclic universe potential, assuming that we can apply

Stanley J. Brodsky, Ivan Schmidt, Jian-Jun Yang

The shadowing and antishadowing of nuclear structure functions in the Gribov-Glauber picture is due respectively to the destructive and constructive interference of amplitudes arising from the multiple-scattering of quarks in the nucleus. The effective quark-nucleon scattering amplitude includes Pomeron and Odderon contributions from multi-gluon exchange as

Bjorn O Lange

In this thesis we present an introduction to Soft-Collinear Effective Theory, which can be used to prove (or disprove) factorization theorems to all orders in the strong coupling constant for some B decays into light and energetic particles. Specifically, the factorizable amplitudes for inclusive B->X_u l nu and exclusive B->gamma l nu are calculated in reno

Lawrence J. Hall, Steven J. Oliver

We review the recent proposal that neutrinos are light because their masses are proportional to a low scale, f, of lepton flavor symmetry breaking. This mechanism is testable because the resulting pseudo-Goldstone bosons, of mass m_G, couple strongly with the neutrinos, affecting the acoustic oscillations during the eV era of the early universe that generate

T. M. Aliev, V. Bashiry, M. Savci

Double-lepton polarization asymmetries in (Lambda_b -> Lambda l^+ l^-) decay are calculated using a general, model independent form of the effective Hamiltonian. The sensitivities of these asymmetries to the new Wilson coefficients are studied in detail. Furthermore, the correlations between averaged double-lepton polarization asymmetry and branching ratio a

Dan Hooper

In this talk, we discuss the potential for the indirect detection of Kaluza-Klein dark matter using neutrino telescopes and cosmic positron experiments. We find that future kilometer-scale neutrino telescopes, such as IceCube, as well as future experiments capable of measuring the cosmic positron spectrum, such as PAMELA and AMS-02, will be quite sensitive t

Ulrich D. Jentschura

Processes mediated by two virtual low-energy photons contribute quite significantly to the energy of hydrogenic S states. The corresponding level shift is of the order of (alpha/pi)^2 (Zalpha)^6 m_e c^2 and may be ascribed to a two-loop generalization of the Bethe logarithm. For 1S and 2S states, the correction has recently been evaluated by Pachucki and Jen

A. Peshier

The gluon and quark collisional widths in hot QCD plasmas are discussed with emphasis on temperatures near Tc, where the coupling is large. Considering the effect on the entropy, which is known from lattice calculations, it is argued that the width of the partons, which in the perturbative limit is given by gamma ~ g^2 ln(1/g) T, should be sizeable at interm

Amol Dighe

I shall review some of the recent results concerning the astrophysics of a core collapse supernova (SN) and neutrino oscillations. Neutrinos play an important role in the SN explosion, and they also carry most of the energy of the collapse. The energy spectra of neutrinos and antineutrinos arriving at the Earth incorporate information on the primary neutrino

Herbert Neuberger

An example of interpolation by means of local field theories between the case of normal Kogut-Susskind fermions and the case of keeping just the fourth root of the Kogut-Susskind determinant is given. For the fourth root trick to be a valid approximation certain limits need to be smooth. The question about the validity of the fourth root trick is not resolve

L. Levkova, R. Mawhinney

The DWF formulation becomes increasingly problematic at gauge couplings for which $a^{-1}<2$ GeV, where the roughness of the gauge field leads to increased explicit chiral symmetry breaking ($\mres$). This problem becomes especially severe for sufficiently strong coupling where the underlying 4-dimensional Wilson theory is in the Aoki phase. We review our at

I. Wetzorke, K. Jansen, F. Palombi, A. Shindler

We report on recent results for the pion and nucleon matrix element of the twist-2 operator corresponding to the average momentum of non-singlet quark densities. We discuss finite size effects for the nucleon matrix element and present first preliminary results for the non-perturbative renormalisation from full dynamical simulations.

I. Mikulec

The most recent progress and future prospects in kaon physics are reviewed. Main results are the first observation of the rare decays KS->pi0ee and KS->pi0mumu by NA48, new K+->pinunu event observed by E949 and new precision measurements of K0->pienu decays by KTeV, KLOE and NA48 made in an effort to resolve the slight deviation from the unitarity in the CKM

Thomas A. Roman

This essay reviews some of the recent progress in the area of energy conditions and wormholes. Most of the discussion centers on the subject of ``quantum inequality&#39;&#39; restrictions on negative energy. These are bounds on the magnitude and duration of negative energy which put rather severe constraints on its possible macroscopic effects. Such effects

T. Padmanabhan

There is a general belief, reinforced by statements in standard textbooks, that: (i) one can obtain the full non-linear Einstein&#39;s theory of gravity by coupling a massless, spin-2 field $h_{ab}$ self-consistently to the total energy momentum tensor, including its own; (ii) this procedure is unique and leads to Einstein-Hilbert action and (iii) it only us

Harry Fitié

An application is a logical image of the world on a computer. A scalable application is an application that allows one to update that logical image at run time. To put it in operational terms: an application is scalable if a client can change between time T1 and time T2 - the logic of the application as expressed by language L; - the structure and volume of

Vita Hinze-Hoare

A Survey of the principal literature on Human Centred Design reveals the four most referenced principles. These are discussed with reference to the application of a particular website, and a user survey is constructed based upon the four principles.

Constantino Tsallis

The cornerstones of Boltzmann-Gibbs and nonextensive statistical mechanics respectively are the entropies $S_{BG} \equiv -k \sum_{i=1}^W p_i \ln p_i $ and $S_{q}\equiv k (1-\sum_{i=1}^Wp_i^{q})/(q-1) (q\in{\mathbb R} ; S_1=S_{BG})$. Through them we revisit the concept of additivity, and illustrate the (not always clearly perceived) fact that (thermodynamical

Onuttom Narayan, Harsh Mathur

For a quantum double well system interacting with a mesoscopic bath, it is shown that a single particle in the bath is sufficient to substantially reduce tunneling between the two wells. This is demonstrated by considering an ammonia molecule in the center of a ring; in addition to halving the maser line frequency, there is an increase in intensity by four o

Duane C. Wallace, Eric D. Chisolm, Brad E. Clements

A transit is the motion of a system from one many-particle potential energy valley to another. We report the observation of transits in molecular dynamics (MD) calculations of supercooled liquid argon and sodium. Each transit is a correlated simultaneous shift in the equilibrium positions of a small local group of particles, as revealed in the fluctuating gr

F. D. Klironomos, A. T. Dorsey

We calculate the tunneling current in a quantum Hall bilayer system in the strong magnetic field limit. We model the bilayer electron system as two Wigner crystals coupled through interlayer Coulomb interactions, treated in the continuum limit. We generalized the Johansson and Kinaret (JK) model and were able to study the effect of the low energy out-of-phas

V. A. Sidorov, E. A. Ekimov, S. M. Stishov, E. D. Bauer

We report measurements of the specific heat, Hall effect, upper critical field and resistivity on bulk, B-doped diamond prepared by reacting amorphous B and graphite under high-pressure/high-temperature conditions. These experiments establish unambiguous evidence for bulk superconductivity and provide a consistent set of materials parameters that favor a con

O. Braun, U. Seifert

Mechanical single molecule experiments probe the energy profile of biomolecules. We show that in the case of a profile with two minima (like folded/unfolded) periodic driving leads to a stochastic resonance-like phenomenon. We demonstrate that the analysis of such data can be used to extract four basic parameters of such a transition and discuss the statisti

A. Agliolo Gallitto, G. Giunchi, Li Vigni, G. Vaglica

We report on transient effects in the microwave second-order response of different type of superconductors in the mixed state. The samples have contemporarily been exposed to a dc magnetic field, varying with a constant rate of 60 Oe/s, and a pulsed microwave magnetic field. The time evolution of the signal radiated at the second-harmonic frequency of the dr

G. M. Falco, H. T. C. Stoof

We derive the atom-molecule theory for an atomic gas near a broad Feshbach resonance, where the energy dependence of the atom-molecule coupling becomes crucial for understanding experimental results. We show how our many-body theory incorporates the two-atom physics exactly. In particular, we calculate the magnetic moment of a two-component gas of ^{6}Li ato

Claudio J. Tessone, Raul Toral

We study a model for opinion formation which incorporates three basic ingredients for the evolution of the opinion held by an individual: imitation, influence of fashion and randomness. We show that in the absence of fashion, the model behaves as a bistable system with random jumps between the two stable states with a distribution of times following Kramer&#

Lydie Staron, Jean-Pierre Vilotte, Farhang Radjai

By means of contact dynamics simulations, we analyze the stress state in a granular bed slowly tilted towards its angle of repose. An increasingly large number of grains are overloaded in the sense that they are found to carry a stress ratio above the Coulomb yield threshold of the whole packing. Using this property, we introduce a coarse-graining length sca

G. Schoenherr

One-dimensional hard rod gases are explicitly constructed as the limits of discrete systems: exclusion processes involving particles of arbitrary length. Those continuum many-body systems in general do not exhibit the same hydrodynamic properties as the underlying discrete models. Considering as examples a hard rod gas with additional long-range interaction

R. González-Cinca, L. Ramírez-Piscina

We present a numerical study of sidebranching of a solidifying dendrite by means of a phase--field model. Special attention is paid to the regions far from the tip of the dendrite, where linear theories are no longer valid. Two regions have been distinguished outside the linear region: a first one in which sidebranching is in a competition process and a seco

N. Andrei, C. J. Bolech

In this talk we will present the solution of the two-channel Anderson impurity model, proposed in the context of the heavy fermion compound UBe13, and discuss briefly the more general multi-channel case. We will show results for the thermodynamics in the full range of temperature and fields and make the connection with the current experimental situation.

G. Kaniadakis, M. Lissia

Editorial of the International Conference (NEXT 2003): News and expectations in Thermostatistics, Sardinia 21-28 Sept. 2003

Arjun R. Acharya

In this thesis we examine methodologies for determining free energy differences (FEDs) of phases via Monte Carlo simulation. We identify and address three generic issues that arise in FED calculations; the choice of representation, the choice of estimator, and the choice of sampling strategy. In addition we discuss how the classical framework may be extended

Pavel Exner, Valentin A. Zagrebnov

We show that Bose-Einstein condensate can be created in quasi-one-dimensional systems in a purely geometrical way, namely by bending or other suitable deformation of a tube.

Pasqualantonio Pingue, Paolo Baschieri, Cesare Ascoli, Michel Dayez

A home made DSP-controlled scanning probe microscope (SPM) system has been developed and its utilization as a tool for lithography on nanometer scale is reported. User-friendly graphic interface allows to directly perform nanolithography importing a bitmap pattern on previously-imaged sample region, otherwise moving in real time the probe using an ordinary m

Tsviki Y. Hirsh, David A. Kessler

We study Mode I crack propagation in amorphous material via a molecular dynamics simulation of a binary alloy with pairwise central-force interactions. We find that when the system is subjected to constant displacement after introduction of a seed crack, the crack does not propagate. This was found to be true both for the modified Lennard-Jones potential of

M. Banobre-Lopez, F. Rivadulla, R. Caudillo, M. A. Lopez-Quintela

We report a complete analysis of the formal oxidation state of Co in NaxCoO2, in the interval 0.31<x<0.67. Iodometric titration and thermoelectric power confirm that a direct relationship between the Na content and the amount of Co 3 + cannot be established in this system. Creation of a significant amount of oxygen vacancies accompanies Na-ion deintercalatio

H. Harimochi, J. Kitagawa, M. Ishizaka, Y. Kadoya

We have performed terahertz time-domain spectroscopy of carrier-doped nanoporous crystal 12CaO7Al2O3 showing the Mott variable range hopping at room temperature. The real part of the dielectric constant clearly demonstrates the nature of localized carriers. The frequency dependence of both the real and imaginary parts of the dielectric constant can be simply

Andrey L. Pankratov, Bernardo Spagnolo

The influence of fluctuations and periodical driving on temporal characteristics of short overdamped Josephson junction is analyzed. We obtain the standard deviation of the switching time in the presence of a dichotomous driving force for arbitrary noise intensity and in the frequency range of practical interest. For sinusoidal driving the resonant activatio

Mehmet Burcin Unlu, Hong-Liang Cui

We develop a Wigner function representation of the quantum transport theory of the conduction band electrons in Rashba effect resonant tunneling structures with a phonon bath. In narrow band gap heterostructures, spin splitting occurs mainly as a result of inversion asymmetry in the spatial dependence of the potential or as a result of external electric fiel

L. Y. Wang, C. S. Tang, C. S. Chu

We propose and demonstrate theoretically that resonant inelastic scattering (RIS) can play an important role in dc spin current generation. The RIS makes it possible to generate dc spin current via a simple gate configuration: a single finger-gate that locates atop and orients transversely to a quantum channel in the presence of Rashba spin-orbit interaction

M. W. Haverkort, Z. Hu, A. Tanaka, G. Ghiringhelli

Utilizing a sum-rule in a spin-resolved photoelectron spectroscopic experiment with circularly polarized light, we show that the orbital moment in LaTiO$_3$ is strongly reduced both below and above the Néel temperature. Using Ti $L_{2,3}$ x-ray absorption spectroscopy as a local probe, we found that the crystal field splitting in the $t_{2g}$ subshell is abo

Naoki Masuda, Norio Konno

Random walks are used for modeling various dynamics in, for example, physical, biological, and social contexts. Furthermore, their characteristics provide us with useful information on the phase transition and critical phenomena of even broader classes of related stochastic models. Abundant results are obtained for random walk on simple graphs such as the re

Stanley P. Owocki, Kenneth G. Gayley, Nir J. Shaviv

We examine radiatively driven mass loss from stars near and above the Eddington limit (Ledd). We begin by reviewing the instabilities that are expected to form extensive structure near Ledd. We investigate how this &#34;porosity&#34; can reduce the effective coupling between the matter and radiation. Introducing a new &#34;porosity-length&#39;&#39; formalism

M. Bernardi, R. K. Sheth, R. C. Nichol, D. P. Schneider

We present an analysis of the color-magnitude-velocity dispersion relation for a sample of 39320 early-type galaxies within the Sloan Digital Sky Survey. We demonstrate that the color-magnitude relation is entirely a consequence of the fact that both the luminosities and colors of these galaxies are correlated with stellar velocity dispersions. Previous stud

J. L. Donley, L. Staveley-Smith, R. C. Kraan-Korteweg, J. M. Islas-Islas

We present the results of the northern extension of the HI Parkes Zone of Avoidance Survey, a blind HI survey utilizing the multibeam receiver on the Parkes 64-m telescope. In the two regions studied here, l=36 to 52 deg. and l=196 to 212 deg., |b|<5 deg., we have detected 77 HI galaxies, twenty of which have been previously detected in HI. The survey has a

Roberto Soria, Mark Cropper, Manfred Pakull, Richard Mushotzky

We have studied the candidate optical counterparts and the stellar population in the star-forming complex around a bright ULX in NGC4559, using HST/WFPC2, XMM-Newton/OM, and ground-based data. We find that the ULX is located near a small group of OB stars. The brightest point source in the Chandra error circle is consistent with a single blue supergiant of m

C. Cacciari, T. M. Corwin, B. W. Carney

We have performed a detailed study of the pulsational and evolutionary characteristics of 133 RR Lyrae stars in the globular cluster NGC5272 (M3) using highly accurate BVI data taken on 5 separate epochs. M3 seems to contain no less than ~32% of Blazhko stars, and the occurrence and characteristics of the Blazhko effect have been analyzed in detail. We have

H. L. Marshall, D. A. Schwartz, J. E. J. Lovell, D. W. Murphy

We present results from Chandra X-ray imaging and spectroscopy of a flux-limited sample of flat spectrum radio-emitting quasars with jet-like extended structure. Twelve of twenty quasar jets are detected in 5 ks ACIS-S exposures. The quasars without X-ray jets are not significantly different from those in the sample with detected jets except that the extende

J. I. Read, G. Gilmore

Dwarf spheroidal galaxies have shallow central dark matter density profiles, low angular momentum and approximately exponential surface brightness distributions. Through N-body simulations and analytic calculations we investigate the extent to which these properties can be generated from ``typical&#39;&#39; $Λ$CDM galaxies, which differ in all of these prope

J. -B. Melin, J. G. Bartlett, J. Delabrouille

We study the nature of cluster selection in Sunyaev-Zel&#39;dovich (SZ) surveys, focusing on single frequency observations and using Monte Carlo simulations incorporating instrumental effects, primary cosmic microwave background (CMB) anisotropies and extragalactic point sources. Clusters are extracted from simulated maps with an optimal, multi-scale matched

Dominik Elsaesser, Karl Mannheim

The 17m Imaging Air shower Cherenkov Telescope MAGIC (Roque de los Muchachos Observatory, La Palma, Canary Islands) has recently entered its commissioning phase. One of the main goals of the MAGIC telescope project is to provide an unprecedented sensitivity for the detection of gamma rays with energies as low as 30 GeV. A dedicated search for the gamma rays

K. Galsgaard, C. Parnell

In this paper, we investigate a simple model where two, initially unconnected, flux systems are forced to interact in response to the imposed boundary driving by solving the non-ideal 3D MHD equations numerically. The reconnection rate of the dynamical process is determined and compared with the corresponding rate for the potential evolution of the magnetic

J. Rodriguez, D. C. Hannikainen, S. E. Shaw, C. Cabanac

We report here the first results of the spectral and timing analysis of our simultaneous INTEGRAL/RXTE observations of GRS 1915+105. The first observation ever performed with INTEGRAL revealed a new class of variability, where changes of luminosity seem driven by changes in the Comptonising medium. The spectro-temporal study of our data taken later, in the s

D. Watson, J. Hjorth, P. Jakobsson, K. Pedersen

The hard X-ray (2-10keV) luminosity of a star-forming galaxy tracks its population of high mass X-ray binaries and is essentially unobscured. It is therefore a practically unbiased measure of star-formation in the host galaxies of gamma-ray bursts (GRBs). Using recent and archival observations of GRBs with the XMM-Newton and Chandra X-ray observatories, limi

Padeli P. Papadopoulos, Thomas R. Greve

We present new sensitive wide-band measurements of the fine structure line 3^P_1 -> 3^P_0 (J=1-0, 492GHz) of neutral atomic carbon (CI) in the two typical Ultra Luminous Infrared Galaxies NGC6240 and Arp220. We then use them along with several other CI measurements in similar objects found in the literature to estimate their global molecular gas content unde

Tomislav Prokopec

We argue that the dynamics of photons canonically coupled to scalars in de Sitter inflation gets modified by a photon mass term. This might have lead to generation of potentially observable magnetic field correlated over cosmological scales today.

H. J. Deeg, R. Alonso, J. A. Belmonte, Keith Horne

A prototype system for the Permanent All Sky Survey (PASS) project is presented. PASS is a continuous photometric survey of the entire celestial sphere with a high temporal resolution. Its major objectives are the detection of all giant-planet transits (with periods up to some weeks) across stars up to mag 10.5, and to deliver continuously photometry that is

D. Tsiklauri, V. M. Nakariakov, T. D. Arber, M. J. Aschwanden

In the recent work of Nakariakov et al. (2004), it has been shown that the time dependences of density and velocity in a flaring loop contain pronounced quasi-harmonic oscillations associated with the 2nd harmonic of a standing slow magnetoacoustic wave. That model used a symmetric heating function (heat deposition was strictly at the apex). This left outsta

Michael Scholz

Model-predicted and observed properties of the brightness distribution on M-type Mira disks are discussed. Fundamental issues of limb-darkening and diameter definition, of assigning observational data to diameter-type quantities and of interpreting such quantities in terms of model diameters are outlined. The influence of model properties upon interpretation

D. J. Radburn-Smith, J. R. Lucey, M. J. Hudson

We compare the measured peculiar velocities of 98 local (<150/h Mpc) type Ia supernovae with predictions derived from the PSCz survey. There is excellent agreement between the two datasets with a best fit beta_I (=Omega_m^0.6/b_I) of 0.55+-0.06. Subsets of the supernovae dataset are further analysed and the above result is found to be robust with respect to

J. S. Dowker

The hybrid spectral problem where the field satisfies Dirichlet conditions (D) on part of the boundary of the relevant domain and Neumann (N) on the remainder is discussed in simple terms. A conjecture for the C_1 coefficient is presented and the conformal determinant on a 2-disc, where the D and N regions are semi-circles, is derived. Comments on higher coe

M. J. Bhaseen, A. M. Tsvelik

We briefly review some examples of confinement which arise in condensed matter physics. We focus on two instructive cases: the off-critical Ising model in a magnetic field, and an array of weakly coupled (extended) Hubbard chains in the Wigner crystal phase. In the appropriate regime, the elementary excitations in these 1+1 and quasi-one-dimensional systems

Jin Wang, H. M. Wiseman, G. J. Milburn

For two two-level atoms coupled to a single-mode cavity field that is driven and heavily damped, the steady-state can be entangled by shining an un-modulated driving laser on the system [S.Schneider, G. J. Milburn Phys. Rev A 65, 042107, 2002]. We present a scheme to significantly increase the steady-state entanglement by using homodyne-mediated feedback, in

Elizabeth Denne, John M Sullivan

The distortion of a curve measures the maximum arc/chord length ratio. Gromov showed any closed curve has distortion at least pi/2 and asked about the distortion of knots. Here, we prove that any nontrivial tame knot has distortion at least 5pi/3; examples show that distortion under 7.16 suffices to build a trefoil knot. Our argument uses the existence of a

R. D. Gill, J. M. Robins

We extend Robins&#39; theory of causal inference for complex longitudinal data to the case of continuously varying as opposed to discrete covariates and treatments. In particular we establish versions of the key results of the discrete theory: the g-computation formula and a collection of powerful characterizations of the g-null hypothesis of no treatment ef

Roshan Foadi, Shrihari Gopalakrishna, Carl Schmidt

Extra-dimensional Higgsless models with electroweak symmetry breaking through boundary conditions generically have difficulties with electroweak precision constraints, when the fermions are localized to the ``branes&#39;&#39; in the fifth dimension. In this paper we show that these constraints can be relaxed by allowing the light fermions to have a finite ex

Preston Jones, Lucas Wanex

The coordinate conditions for three exact solutions for the metric components of a coordinate system with constant acceleration or of a static plane symmetric gravitational field are presented. First, the coordinate condition that the acceleration of light is constant is applied to the field equations to derive the metric of a coordinate system of constant a

A. Ferrando, M. Zacares, P. Andres, P. Fernandez de Cordoba

We present a new type of soliton solutions in nonlinear photonic systems with discrete point-symmetry. These solitons have their origin in a novel mechanism of breaking of discrete symmetry by the presence of nonlinearities. These so-called nodal solitons are characterized by nodal lines determined by the discrete symmetry of the system. Our physical realiza

Luca Amendola

Scalar field models with non-standard kinetic terms have been proposed in the context of k-inflation, of Born-Infeld lagrangians, of phantom energy and, more in general, of low-energy string theory. In general, scalar fields are expected to couple to matter inducing a new interaction. In this paper I derive the cosmological perturbation equations and the Yuk

Huijun Fan, Tyler J. Jarvis, Yongbin Ruan

We introduce W-spin structures on a Riemann surface and give a precise definition to the corresponding W-spin equations for any quasi-homogeneous polynomial W. Then, we construct examples of nonzero solutions of spin equations in the presence of Ramond marked points. The main result of the paper is a compactness theorem for the moduli space of the solutions

Mark Dijkstra, Zoltan Haiman, Caleb Scharf

We explore the possibility of resolving an image of a damped Lyman alpha (DLA) system in absorption against an extended, diffuse background X-ray source. Typical columns of neutral hydrogen in DLAs are high enough to block out up to ~30% of the soft X-ray flux at an observed photon energy of 0.5 keV, and we find that ~ 1% of the area of extended X-ray source

N. Matagne, Fl. Stancu

Using the $1/N_c$ expansion of QCD we analyze the spectrum of positive parity resonances with strangeness $S = 0, -1, -2$ and -3 in the 2-3 GeV mass region, supposed to belong to the $[\textbf{56},4^+]$ multiplet. The mass operator is similar to that of $[\textbf{56},2^+]$, previously studied in the literature. The analysis of the latter is revisited. In the

Andrey Katz, Yael Shadmi

The logarithmic energy dependence of gauge couplings in AdS_5 emerges almost automatically when the theory is deconstructed on a coarse lattice. Here we study the theory away from the coarse-lattice limit. While we cannot analytically calculate individual KK masses for a fine lattice, we can calculate the product of all non-zero masses. This allows us to wri

A. Kabakcioglu, A. L. Stella

We show that the collapsed globular phase of a polymer accommodates a scale-free incompatibility graph of its contacts. The degree distribution of this network is found to decay with the exponent $γ= 1/(2-c)$ up to a cut-off degree $d_c \propto L^{2-c}$, where $c$ is the loop exponent for dense polymers ($c=11/8$ in two dimensions) and $L$ is the length of t

E. O. Kamenetskii, A. K. Saha, I. Awai

We discuss the problem of magnetic-dipolar oscillations combined with microwave resonators. The energy density of magnetic-dipolar or magnetostatic (MS) oscillations in ferrite resonators is not the electromagnetic-wave density of the energy and not the exchange energy density as well. This fact reveals very special behaviors of the geometrical effects. Comp

Adam Miranowicz, Andrzej Grudka

The problem of ordering of two-qubit states imposed by relative entropy of entanglement (E) in comparison to concurrence (C) and negativity (N) is studied. Analytical examples of states consistently and inconsistently ordered by the entanglement measures are given. In particular, the states for which any of the three measures imposes order opposite to that g

Roberto Frezzotti

I review the main theoretical properties and some recent analytical and numerical investigations of the formulations of lattice QCD with chirally twisted Wilson quarks (also known as twisted mass lattice QCD).

Asaf Pe&#39;er, Eli Waxman

We describe a numerical model constructed for the study of the emission of radiation from relativistic plasma under conditions characteristic, e.g., to gamma-ray bursts (GRB&#39;s) and active galactic nuclei (AGN&#39;s). The model solves self consistently the kinetic equations for e^\pm and photons, describing cyclo-synchrotron emission, direct Compton and i

Franz Hinterleitner

For a certain example of a &#34;doubly special relativity theory&#34; the modified space-time Lorentz transformations are obtained from momentum space transformations by using canonical methods. In the sequel an energy-momentum dependent space-time metric is constructed, which is essentially invariant under the modified Lorentz transformations. By associatin

Romuald A. Janik

In this paper we study the description of saturation in Balitsky, Jalilian-Marian, Iancu, McLerran, Weigert, Leonidov and Kovner (B-JIMWLK) picture when restricted to observables made up only from dipole operators. We derive a functional form of the evolution equation for the dipole probability distribution and find a one-parameter family of exact solutions

Hylke Koers

We consider the rate of fermion-antifermion pair creation by an external field. We derive a rate formula that is valid for a coupling with arbitrary vector and axial vector components to first order in perturbation theory. This is then applied to study the creation of neutrinos by nuclear matter, a problem with astrophysical relevance. We present an estimate