May 2004 arXiv papers — page 5

A. Mangiarotti, P. R. Maurenzig, A. Olmi, S. Piantelli

Peripheral and semi-peripheral collisions have been studied in the system 93Nb+93Nb at 38 AMeV. The evaporative and midvelocity components of the light charged particle and intermediate mass fragment emissions have been carefully disentangled. In this way it was possible to obtain the average amount not only of charge and mass, but also of energy, pertaining

P. K. Saha, H. Noumi, D. Abe, S. Ajimura

In order to study the Sigma-nucleus optical potential, we measured inclusive (pi^-,K^+) spectra on medium-to-heavy nuclear targets: CH_2, Si, Ni, In and Bi. The CH_2 target was used to calibrate the excitation energy scale by using the elementary process p + pi^- -> K^+ + Sigma^-, where the C spectrum was also extracted. The calibration was done with +-0.1 M

Esteban Meca, Isabel Mercader, Oriol Batiste, Laureano Ramirez-Piscina

A global bifurcation of the blue sky catastrophe type has been found in a small Prandtl number binary mixture contained in a laterally heated cavity. The system has been studied numerically applying the tools of bifurcation theory. The catastrophe corresponds to the destruction of an orbit which, for a large range of Rayleigh numbers, is the only stable solu

Michael Baake, Bernd Sing

The diffraction spectra of lattice gas models on Z^d with finite-range ferromagnetic two-body interaction above T_c or with certain rates of decay of the potential are considered. We show that these diffraction spectra almost surely exist, are Z^d-periodic and consist of a pure point part and an absolutely continuous part with continuous density.

L. Chan, E. S. Cheb-Terrab

There exist sound literature and algorithms for computing Liouvillian solutions for the important problem of linear ODEs with rational coefficients. Taking as sample the 363 second order equations of that type found in Kamke's book, for instance, 51 % of them admit Liouvillian solutions and so are solvable using Kovacic's algorithm. On the other hand

Darrin Doud, Michael W. Moore

In this paper, we use a series of targeted Hunter searches to prove that the minimal prime conductor of an even icosahedral Galois representation is 1951. In addition, we give a complete list of all even icosahedral Galois representations of prime conductor less than 10,000.

Terrence Napier, Mohan Ramachandran

By a theorem of Greene and Wu, a noncompact connected Riemannian manifold admits a smooth strictly subharmonic exhaustion function. Demailly provided an elementary proof of this fact. A further simplification of Demailly's proof and some (mostly known) applications are described. Applications include the fact that the holomorphic line bundle associated t

Sean T. Paul, Gang Tian

In this note we identify the leading terms of the (reduced) K-energy map with a universal linear combination of the principal and subdominant coefficients of the weight of the $mth$ Hilbert point. This shows that the weight $F_{1}(λ;X)$ introduced by Donaldson in [SKD02] is just the weight of the CM-polarisation.The equivalence between the CM-(semi)stability

Mohamed Saidi

In this paper we study the semi-stable reduction of $p$ and $p^2$-cyclic covers of curves in equal characteristic $p>0$. The main tool we use is the classical Artin-Schreier-Witt theory for $p^n$-cyclic covers in characteristic $p$. Although the results of this paper concern only the cases of degree $p$ and $p^2$-cyclic cover we develop the techniques and th

Ted Stanford

We publish a table of primitive finite-type invariants of order less than or equal to six, for knots of ten or fewer crossings. We note certain mod-2 congruences, one of which leads to a chirality criterion in the Alexander polynomial. We state a computational result on mod-2 finite-type invariants of 2-strand string links.

Pieter Moree

For a fixed rational number g and integers a and d the sets N_g(a,d), respectively R_g(a,d), of primes p for which the order, respectively the index of g(mod p) is congruent to a(mod d), are considered. Under the Generalized Riemann Hypothesis (GRH), it was shown in part II that these sets have a natural density. Here it is shown that these densities can be

Henrik Holm, Peter Jorgensen

A semi-dualizing module over a commutative noetherian ring A is a finitely generated module C with RHom_A(C,C) \simeq A in the derived category D(A). We show how each such module gives rise to three new homological dimensions which we call C-Gorenstein projective, C-Gorenstein injective, and C-Gorenstein flat dimension, and investigate the properties of thes

Selahi Durusoy

We compute the Heegaard-Floer homology for the family Sigma(2,3,6n+1) of Brieskorn spheres using the algorithm by P. Ozsvath and Z. Szabo

Henrik Holm, Peter Jorgensen

We define three new homological dimensions - Cohen-Macaulay injective, projective, and flat dimension - which inhabit a theory similar to that of classical injective, projective, and flat dimension. Finiteness of the new dimensions characterizes Cohen-Macaulay rings with dualizing modules.

Hacene Djellout, Arnaud Guillin, Liming Wu

A moderate deviation principle for functionals, with at most quadratic growth, of moving average processes is established. The main assumptions on the moving average process are a Logarithmic Sobolev inequality for the driving random variables and the continuity, or weaker, of the spectral density of the moving average process. We also obtain the moderate de

Ivan Gentil, Arnaud Guillin, Laurent Miclo

We present a class of modified logarithmic Sobolev inequality, interpolating between Poincaré and logarithmic Sobolev inequalities, suitable for measures of the type $\exp(-|x|^\al)$ or more complex $\exp(-|x|^\al\log^β(2+|x|))$ ($\al\in]1,2[$ and $\be\in\dR$) which lead to new concentration inequalities. These modified inequalities share common properties w

Arash Rastegar

Let ${\mathbf F}_q$ denote a finite field of characteristic $p$ and let $n$ be an effective divisor on the affine line over ${\mathbf F}_q$ and let $v$ be a point on the affine line outside $n$. In this paper, we get congruences between ${\mathbb Q}_l$-valued weight two $v$-old Drinfeld modular forms and $v$-new Drinfeld modular forms of level $vn$. In order

Alexander Gorodnik, Hee Oh

Let X be a symmetric space of noncompact type and Γa lattice in the isometry group of X. We study the distribution of orbits of Γacting on the symmetric space X and its geometric boundary X(\infty). More precisely, for any y in X and b in X(\infty), we investigate the distribution of the set {(yγ,bγ^{-1}):γ\inΓ} in X\times X(\infty). It is proved, in particu

Tsuyoshi Kajiwara, Yasuo Watatani

In this paper, we study KMS states for the gauge actions on C${}^*$-algebras associated with self-similar sets whose branch points are finite. If the self-similar set does not contain any branch point, the Hutchinson measure gives the unique KMS state. But if the self-similar set dose contain a branch point, there sometimes appear other KMS states which come

Sofia Lambropoulou

In this paper we consider all possible generalizations of the B-type Hecke algebras, namely the cyclotomic and what we call 'generalized', and we construct Markov traces on each of them, so as to obtain all possible different levels of homfly-pt analogues in the solid torus related to the (Hecke) algebras of B-type.

Siddhartha Gadgil

This paper has been withdrawn due to an error in the proof. The paper implicitly assumed that every homotopically trivial knot is related to the unknot by negative crossings, which is false (as was pointed out to the author by Peter Ozsvath).

Wadim Zudilin

We present a brief survey of the methods used in deducing upper estimates for irrationality measures of the logarithm values. We particularly expose the best known estimates for $\log2$ (due to E. Rukhadze), $π$ (due to M. Hata) and $\log3$ (due to G. Rhin).

Wenchang Chu, Livia De Donno

The classical hypergeometric summation theorems are exploited to derive several striking identities on harmonic numbers including those discovered recently by Paule and Schneider (2003).

Francesco Vaccarino

Let R be a commutative ring and let n,m be two positive integers. Let be the polynomial ring in m x n commuting independent variables R. The symmetric group on n letters acts diagonally on A(n,m). We give generators and relations of the rings of invariants for this action.

Malika Ait Ben Haddou, El Hassan Saidi

Motivated by the study of duality cascades in supersymmetric quiver gauge theories beyond affine models, we develop in this paper the analysis of a class of simply laced hyperbolic Lie algebras. These are specific generalizations of affine ADE symmetries which form a particular subclass of the so-called Indefinite Lie algebras. Because of indefinite signatur

Riccardo Argurio

We show that the low-energy effective superpotential of an N=1 U(N) gauge theory with matter in the adjoint and arbitrary even tree-level superpotential has, in the classically unbroken case, the same functional form as the effective superpotential of a U(N) gauge theory with matter in the fundamental and the same tree-level interactions, up to some rescalin

Graciela Gelmini, Paolo Gondolo

We present two examples of velocity distributions for light dark matter particles that reconcile the annual modulation signal observed by DAMA with all other negative results from dark matter searches. They are: (1) a conventional Maxwellian distribution for particle masses of 6 to 9 GeV; (2) a dark matter stream coming from the general direction of Galactic

L. P. Csernai, A. Anderlik, Cs. Anderlik, V. K. Magas

Earlier fluid dynamical calculations with QGP show a softening of the directed flow while with hadronic matter this effect is absent. On the other hand, we indicated that a third flow component shows up in the reaction plane as an enhanced emission, which is orthogonal to the directed flow. This is not shadowed by the deflected projectile and target, and sho

J. Campbell, J. Huston

This note describes a theoretical study of Wbb and Wjj final states at the Tevatron using the NLO program MCFM. We extensively study the effect of NLO corrections with respect to variations of input parameters such as the minimum jet p_T and the choice of renormalization and factorization scales. In particular, we examine possible implications for the Method

K. Werner, F. M. Liu, T. Pierog

We try to understand recent data on proton-proton and deuteron-gold collisions at RHIC, employing a modified parton model approach.

Chun Liu

A supersymmetric model with gauge symmetry G_1 X G_2, where G_i=SU(3)_i X SU(2)_i X U(1)_i, is constructed within the framework of gauge mediated supersymmetry breaking. At the energy scale (10-100) TeV where the gauge symmetry breaks down to the Standard Model (SM), G_1 is strong and G_2 is weak. The observed gauge coupling constant unification of the SM is

Giulia Zanderighi

We present a novel treatment of resonant massive particles appearing as intermediate states in high energy collisions. The approach uses effective field theory methods to treat consistently the instability of the intermediate resonant state. As a result gauge invariance is respected in every step and calculations can in principle be extended to all orders in

Sharada Boinepalli, Waseem Kamleh, Derek B. Leinweber, Anthony G. Williams

The chiral properties of the fat-link irrelevant clover (FLIC) fermion action are examined. The improved chiral properties of fermion actions incorporating smoothed links are realized in the FLIC action where only the irrelevant operators of the fermion action are constructed with smoothed links. In particular, the histogram of the additive mass renormalizat

N. M. Agababyan, V. V. Ammosov, M. Atayan, N. Grigoryan

The influence of nuclear effects on the production of neutral strange particles ($V^{\circ}$) is investigated using the data obtained with SKAT propane-freon bubble chamber irradiated in the neutrino beam (with $E_ν$ = 3-30 GeV) at Serpukhov accelerator. The measured mean multiplicity of $V^{\circ}$ particles in nuclear interactions, ${<n_{V^{\circ}}>}_A$ =

A. L. Choudhury

We created a model of several dimensional physical universe. The extra dimensions associated with the four dimensional physical universe is assumed to have modified Gidding-Strominger wormhole core. This core is separated by a flexible wall, but it allows the adiabatic pressure generated in the wormhole to penetrate in the extra dimensions. We assume that th

Carlos Iván Chesñevar, Guillermo Ricardo Simari

In the last years, there has been an increasing demand of a variety of logical systems, prompted mostly by applications of logic in AI and other related areas. Labeled Deductive Systems (LDS) were developed as a flexible methodology to formalize such a kind of complex logical systems. Defeasible argumentation has proven to be a successful approach to formali

Carlos Iván Chesñevar, Guillermo Ricardo Simari, Alejandro Javier García

Defeasible argumentation has experienced a considerable growth in AI in the last decade. Theoretical results have been combined with development of practical applications in AI & Law, Case-Based Reasoning and various knowledge-based systems. However, the dialectical process associated with inference is computationally expensive. This paper focuses on speedin

Muhammad Nadeem, Javaid R. Laghari

The proposed election system lies in ensuring that it is transparent and impartial.Thus while the electoral system may vary from country to country, It has to take into account the peculiarities of every society while at the same time incorporating remedies to problems prevailing in the system. The Electoral process expressed serious concerns regarding the i

Yuguo He

Knowledge reduction, includes attribute reduction and value reduction, is an important topic in rough set literature. It is also closely relevant to other fields, such as machine learning and data mining. In this paper, an algorithm called TWI-SQUEEZE is proposed. It can find a reduct, or an irreducible attribute subset after two scans. Its soundness and com

R. S. Lazic, T. C. Newcomb, A. W. Roscoe

A system is data-independent with respect to a data type X iff the operations it can perform on values of type X are restricted to just equality testing. The system may also store, input and output values of type X. We study model checking of systems which are data-independent with respect to two distinct type variables X and Y, and may in addition use array

Francisco Javier Lopez-Fraguas, Jaime Sanchez-Hernandez

How to extract negative information from programs is an important issue in logic programming. Here we address the problem for functional logic programs, from a proof-theoretic perspective. The starting point of our work is CRWL (Constructor based ReWriting Logic), a well established theoretical framework for functional logic programming, whose fundamental no

Samir Genaim, Michael Codish, Jacob M. Howe

This note illustrates theoretical worst-case scenarios for groundness analyses obtained through abstract interpretation over the abstract domains of definite (Def) and positive (Pos) Boolean functions. For Def, an example is given for which any Def-based abstract interpretation for groundness analysis follows a chain which is exponential in the number of arg

Francois Fages, Emmanuel Coquery

We present a prescriptive type system with parametric polymorphism and subtyping for constraint logic programs. The aim of this type system is to detect programming errors statically. It introduces a type discipline for constraint logic programs and modules, while maintaining the capabilities of performing the usual coercions between constraint domains, and

Wang Liang, Guo YiPing, Fang Ming

Now no web search engine can cover more than 60 percent of all the pages on Internet. The update interval of most pages database is almost one month. This condition hasn&#39;t changed for many years. Converge and recency problems have become the bottleneck problem of current web search engine. To solve these problems, a new system, search engine based on DNS

D. Schmeltzer, A. Saxena, A. R. Bishop, D. L. Smith

We show that a spatially-dependent magnetic field can induce a persistent spin current in a spin-1/2 Heisenberg antiferromagnetic ring, proportional to the solid angle subtended by the magnetic field on a unit sphere. The result is a direct consequence of Berry &#34;parallel transport&#34; in space. The magnitude of the spin current is determined by the rati

G. M. Kavoulakis, A. D. Jackson, Gordon Baym

We examine the phase diagram of a Bose-Einstein condensate of atoms, interacting with an attractive pseudopotential, in a quadratic-plus-quartic potential trap rotating at a given rate. Investigating the behavior of the gas as a function of interaction strength and rotational frequency of the trap, we find that the phase diagram has three distinct phases, on

W. Maslana, P. Kossacki, P. Plochocka, A. Golnik

Microphotoluminescence mapping experiments were performed on a modulation doped (Cd,Mn)Te quantum well exhibiting carrier induced ferromagnetism. The zero field splitting that reveals the presence of a spontaneous magnetization in the low-temperature phase, is measured locally; its fluctuations are compared to those of the spin content and of the carrier den

F. G. Aliev, A. P. Levanyuk, R. Villar, E. M. Gonzalez

Superconducting films in perpendicular magnetic field are found to rectify alternating currents. The effect has been observed both in plain and nanostructured superconducting films (niobium and lead). The rectified voltage appears both along and transverse to alternating current and strongly depends on the magnetic field. Rectification phenomena is based on

Riccardo Capovilla, Jemal Guven

A covariant approach towards a theory of deformations is developed to examine both the first and second variation of the Helfrich-Canham Hamiltonian -- quadratic in the extrinsic curvature -- which describes fluid vesicles at mesoscopic scales. Deformations are decomposed into tangential and normal components; At first order, tangential deformations may alwa

Denis Dalidovich, Kun Yang

We study the phase transition between the normal and non-uniform (Fulde-Ferrell-Larkin-Ovchinnikov) superconducting state in quasi two-dimensional d-wave superconductors at finite temperature. We obtain an appropriate Ginzburg-Landau theory for this transition, in which the fluctuation spectrum of the order parameter has a set of minima at non-zero momenta.

O. Fruchart, J. C. Toussaint, P. O. Jubert, W. Wernsdorfer

We have measured the in-plane angular variation of nucleation and annihilation fields of a multi-domain magnetic single dot with a microsquid. The dots are Fe/Mo(110) self-assembled in UHV, with sub-micron size and a hexagonal shape. The angular variations were quantitatively reproduced by micromagnetic simulations. Discontinuities in the variations are obse

Sergei Fedotov, Stephanos Panayides

The purpose of this work is to explore the role that random arbitrage opportunities play in pricing financial derivatives. We use a non-equilibrium model to set up a stochastic portfolio, and for the random arbitrage return, we choose a stationary ergodic random process rapidly varying in time. We exploit the fact that option price and random arbitrage retur

V. S. Stepanyuk, L. Niebergall, A. N. Baranov, W. Hergert

Ab initio calculations of surface-state mediated interactions between Cu adatoms on transition metal surfaces are presented. We concentrate on Co/Cu(111) and Co(0001) substrates and compare results with our calculations for Cu(111). Our studies show that surface states of Co/Cu(111) and Co(0001) are spin-polarized. We reveal that long-range interactions betw

R. Khasanov, J. Karpinski, H. Keller

We report a study of the pressure effect (PE) on the in-plane magnetic field penetration depth lambda_{ab} in YBa_2Cu_4O_8 by means of Meissner fraction measurements. A pronounced PE on lambda_{ab}^{-2}(0) was observed with a maximum relative shift of Δλ^{-2}_{ab}/λ^{-2}_{ab}= 44(3)% at a pressure of 10.2 kbar. It arises from the pressure dependence of the e

Michael Biehl, Florian Much, Christian Vey

An off-lattice, continuous space Kinetic Monte Carlo (KMC) algorithm is discussed and applied in the investigation of strained heteroepitaxial crystal growth. As a starting point, we study a simplifying (1+1)-dimensional situation with inter-atomic interactions given by simple pair-potentials. The model exhibits the appearance of strain-induced misfit disloc

Yu. Kuzovlev, N. Mezin, G. Yarosh

The torque equation of nonlinear spin dynamics is considered in the magnetostatic approximation. In this framework, exact expressions for propagator of linear magnetostatic waves in ferromagnetic film between two antennas and corresponding mutual impedance of the antennas are derived, under conditions of uniform but arbitrarily oriented static magnetization

S. Rayaprol, Kausik Sengupta, E. V. Sampathkumaran, Y. Matsushita

Heat-capacity (C) and ac susceptibility measurements have been performed on the spin-chain compounds, Sr3ZnRhO6 and Ca3NiMnO6, to establish their magnetic behavior and to explore whether there are magnetic frustration effects due to antiferromagnetic coupling of the chains arranged in a triangular fashion. While the paramagnetic Curie temperatures have been

Kausik Sengupta, E. V. Sampathkumaran, T. Nakano, M. Hedo

The results of magnetic susceptibility, electrical resistivity ($ρ$), heat-capacity (C) and thermopower (S) measurements on CeCuAs2, forming in ZrCuSi2-type tetragonal structure, are reported. Our investigations reveal that Ce is trivalent and there is no clear evidence for long range magnetic ordering down to 45 mK. The $ρ$ behavior is notable in the sense

M. Nicklas, V. A. Sidorov, H. A. Borges, P. G. Pagliuso

Pressure studies of CeRh_1-xIr_xIn_5 indicate two superconducting phases as a function of x, one with T_c >= 2 K for x < 0.9 and the other with T_c < 1.2 K for x > 0.9. The higher T_c phase, phase-1, emerges in proximity to an antiferromagnetic quantum-critical point; whereas, Cooper pairing in the lower T_c phase-2 is inferred to arise from fluctuations of

C. F. Barenghi, N. G. Parker, N. P. Proukakis, C. S. Adams

It is thought that in a quantum fluid sound generation is the ultimate sink of turbulent kinetic energy in the absence of any other dissipation mechanism near absolute zero. We show that a suitably trapped Bose-Einstein condensate provides a model system to study the sound emitted by accelerating vortices in a controlled way.

Hiroaki Kusunose

We discuss influence of modulation of gap function and anisotropy of Fermi velocity to field angle dependences of upper critical field, $H_{c2}$, and specific heat, $C$, on the basis of the approximate analytic solution in the quasiclassical formalism. Using 4-fold modulation of the gap function and the Fermi velocity in the single-band model, we demonstrate

Palash Das, Jayanta K. Bhattacharjee

The frequency and shear dependent critical viscosity at a correlation length $ξ=κ^{-1}$, has the form $η=η_{0}κ^{-x_η}G(z_{1},z_{2})$, where $z_{1}$ and $z_{2}$ are the independent dimensionless numbers in the problem defined as $z_{1}=\frac{-iω}{2Γ_{0}κ^{3}}$ and $z_{2}=\frac{-iω}{2Γ_{0}κ_{c}^{3}}$. The decay rate of critical fluctuations of correlation len

A. Fouchet, W. Prellier, B. Mercey, L. Mechin

High quality ZnO thin films were gown using the pulsed laser deposition technique on (0001) Al$_2$O$_3$ substrates in an oxidizing atmosphere, using a Zn metallic target. We varied the growth conditions such as the deposition temperature and the oxygen pressure. First, using a battery of techniques such as x-rays diffraction, Rutherford Backscattering spectr

W. Wernsdorfer

In a recent paper, cond-mat/0405331 (Ref. 1), del Barco et al. reported experimental studies on a Ni4 molecular system. They used an experimental method (combining microwave spectroscopy with high sensitivity magnetic measurements) that we have introduced before, cond-mat/0404410 (see also Ref. 2 and 3). Among other things, our technique allows us to monitor

Karol Zyczkowski, Wojciech Slomczynski

The notion of the voting power is illustrated by examples of the systems of voting in the European Council according to the Treaty of Nice and the more recent proposition of the European Convent. We show that both systems are not representative, in a sense that citizens of different countries have not the same influence for the decision taken by the Council.

Yong-Jihn Kim

We introduce a new approach to the Josephson effect in SIS tunnel junctions. The Josephson coupling energy is calculated from the overlap of real space Cooper pair wavefunctions in two superconductors through an insulating barrier. It is shown that the Josephson tunneling is limited by the size of the Cooper pair and its shrinking during the tunneling. There

Shai Kaspi

Past X-ray observations by ASCA suggest that warm absorbers (O VII and O VIII edges) are apparently rare in high luminosity AGNs (quasars) while they are more common in low luminosity AGNs (Seyferts). However, this could be a selection effect if high luminosity AGNs have mostly narrow absorption lines (with no strong bound free edges), which escaped detectio

Roberto Cid Fernandes

The role of stars and starbursts in AGN has been a recurring issue for nearly as long as AGN have been recognized as hosts of interesting phenomena. The heated ``starburst X monster&#39;&#39; controversy of the 80&#39;s and 90&#39;s was gradually replaced by ``starburst plus monster&#39;&#39; studies, as observational work in the past decade has firmly estab

G. Pignata, F. Patat, R. Kotak, P. Meikle

We present preliminary results of the observational campaign on SN 2002er carried out by the European Supernova Collaboration (ESC). For this supernova the optical coverage from epochs -11 days to +50 days is excellent, both in imaging and spectroscopy. The extinction deduced from the photometry is E(B-V)=0.35, while Deltam15=1.31. In general SN 2002er behav

I. Yusifov, I. Kucuk

We study the Galactic distribution of normal pulsars with 1400 MHz luminosities greater than 0.1 mJy kpc^2 refining the shape and parameters of the radial distribution of pulsars. To estimate the distances to pulsars we used the new NE2001 Galactic electron density model. The maximum galactocentric distribution of pulsars is located at 3.2+/-0.4 kpc and the

L. A. Nolan, T. J. Ponman, A. M. Read, Francois Schweizer

Using the high sensitivity of XMM, we have studied the X-ray emission of the two proto-typical late-stage merger remnants, NGC 3921 and NGC 7252. In the case of NGC 7252, this is complemented by archival Chandra data. We investigate the nature of the discrete X-ray point source populations and the hot diffuse gas components in these two galaxies, and compare

Joseph D. Gelfand, T. Joseph W. Lazio, B. M. Gaensler

We present here the results of a 325 MHz radio survey of M31, conducted with the A-configuration of the Very Large Array. The survey covered an area of 7.6 deg$^2$, and a total of 405 radio sources between $\la$6\arcsec and 170\arcsec in extent were mapped with a resolution of 6\arcsec and a 1$σ$ sensitivity of $\sim$0.6 \mjyb. For each source, its morpholog

Bruce G. Elmegreen

The azimuthal power spectra of optical emission from star formation and dust in spiral galaxies resembles the azimuthal power spectra of HI emission from the LMC. These and other power spectra of whole galaxies all resemble that of velocity in incompressible Kolmogorov turbulence. The reasons for this are unknown but it could be simply that star and cloud fo

Bruce G. Elmegreen

There are at least 2 distinct mechanisms for the formation of young massive clusters (YMC), all of which require galactic-scale processes. One operates in harrassed fragile galaxies, in the dense cores of low mass galaxies, at the ends of spiral arms, or in galactic tidal shocks where transient and peculiar high pressures make massive clouds at high densitie

P. Tisserand, J. B. Marquette, J. P. Beaulieu, P. de Laverny

EROS 2 (Experience de Recherche d&#39;Objets Sombres) conducted a survey of the SMC between July 1996 and February 2003 in two EROS broad-band colours, V_E and R_E. The photometric data of 4.2 million stars have been searched for behaviour typical of R Coronae Borealis (RCB) candidates such as drastic changes in magnitude. Five objects have been found, four

Ruth A. Daly, S. G. Djorgovski

We describe a method to derive the expansion and acceleration rates directly from the data, without the need for the specification of a theory of gravity, and without adopting an a priori parameterization of the form or redshift evolution of the dark energy. If one also specifies a theory of gravity we can also determine the pressure, energy density, and equ

Hakala Pasi, Ramsay Gavin, Byckling Kristiina

RX J0806+15 shows a prominent intensity variation on a period of 321.5 sec. This has widely been interpreted as the binary orbital period, although this remains controversial. We have been monitoring the precise period of RX J0806+15 for a number of years. By measuring the rate of change we can help distinguish between competing physical models. New observat

H. Boehringer, P. Schuecker, L. Guzzo, C. A. Collins

We present the catalogue of the REFLEX Cluster Survey providing information on the X-ray properties, redshifts, and some identification details of the clusters in the REFLEX sample. The catalogue describes a statistically complete X-ray flux-limited sample of 447 galaxy clusters above an X-ray flux of 3 10(-12) erg /s/cm**2 (0.1 to 2.4 keV) in an area of 4.2

R. Vio, P. Ma, W. Zhong, J. Nagy

We consider the estimation of the regularization parameter for the simultaneous deblurring of multiple noisy images via Tikhonov regularization. We approach the problem in three ways. We first reduce the problem to a single-image deblurring for which the regularization parameter can be estimated through a classic generalized cross-validation (GCV) method. A

M. Liguori, S. Matarrese, M. Musso, A. Riotto

We generalize the treatment of inflationary perturbations to deal with the non-Markovian colored noise emerging from any realistic approach to stochastic inflation. We provide a calculation of the power-spectrum of the gauge-invariant comoving curvature perturbation to first order in the slow-roll parameters. Properly accounting for the constraint that our l

A. Mercurio, G. Busarello, P. Merluzzi, F. La Barbera

We analyse the properties of galaxy populations in the rich Abell cluster ABCG 209 at redshift z~0.21, on the basis of spectral classification of 102 member galaxies. We take advantage of available structural parameters to study separately the properties of bulge-dominated and disk-dominated galaxies. The star formation histories of the cluster galaxy popula

J. A. Bonet, I. Marquez, R. Muller, M. Sobotka

We investigate the dynamics of and the relations between small-scale penumbral and photospheric features near the outer penumbral boundary: penumbral grains (PGs), dark penumbral fibrils, granules, and photospheric G-band bright points. The analysis is based on a 2 h time sequence of a sunspot close to disc center, taken simultaneously in the G-band and in t

R. Tantalo, C. Chiosi

The bottom line of this study is (i) to check whether normal (quiescent) and interacting EGs have a different behavior in the popular diagnostic planes such as Hb vs. [MgFe] (and others); (ii) to seek whether the signature of mergers and/or interactions may mirror in some specific changes of the indices that could un-equivocally hint for burts of stellar act

D. A. N. Mueller, H. Peter, V. H. Hansteen

This work addresses the problem of plasma condensation and ``catastrophic cooling&#39;&#39; in solar coronal loops. We have carried out numerical calculations of coronal loops and find several classes of time-dependent solutions (static, periodic, irregular), depending on the spatial distribution of a temporally constant energy deposition in the loop. Dynami

C. A. Tremonti, T. M. Heckman, G. Kauffmann, J. Brinchmann

We utilize Sloan Digital Sky Survey imaging and spectroscopy of ~53,000 star-forming galaxies at z~0.1 to study the relation between stellar mass and gas-phase metallicity. We derive gas-phase oxygen abundances and stellar masses using new techniques which make use of the latest stellar evolutionary synthesis and photoionization models. We find a tight (+/-0

J. R. Shi, T. Gehren, G. Zhao

We present sodium abundances for a sample of nearby stars. All results have been derived from NLTE statistical equilibrium calculations. The influence of collisional interactions with electrons and hydrogen atoms is evaluated by comparison of the solar spectrum with very precise fits to the Na I line cores. The NLTE effects are more pronounced in metal-poor

R. T. Zavala, G. B. Taylor

Results from a survey of the parsec scale Faraday rotation measure properties for 40 quasars, radio galaxies and BL Lac objects are presented. Core rotation measures for quasars vary from approximately 500 to several thousand radians per meter squared. Quasar jets have rotation measures which are typically 500 radians per meter squared or less. The cores and

Andrei M. Beloborodov, Yuri levin

The traditional way of estimating the gravitational field from observed motions of test objects is based on the virial relation between their kinetic and potential energy. We find a more efficient method. It is based on the natural presumption that the objects are observed at a random moment of time and therefore have random orbital time phases. The proposed

E. Parizot, A. Marcowith, E. van der Swaluw, A. M. Bykov

Observations indicate that most massive stars in the Galaxy appear in groups, called OB associations, where their strong wind activity generates large structures known as superbubbles, inside which the subsequent supernovae (SNe) explode, in tight space and time correlation. Acknowledging this fact, we investigate four main questions: 1) does the clustering

W. H. Zurek

I show how probabilities arise in quantum physics by exploring implications of {\it environment - assisted invariance} or {\it envariance}, a recently discovered symmetry exhibited by entangled quantum systems. Envariance of perfectly entangled ``Bell-like&#39;&#39; states can be used to rigorously justify complete ignorance of the observer about the outcome

D. P. Marrone, J. Battat, F. Bensch, R. Blundell

The distribution of 12C16O J=9-8 (1.037 THz) emission has been mapped in OMC-1 at 35 points with 84&#34; resolution. This is the first map of this source in this transition and only the second velocity-resolved ground-based observation of a line in the terahertz frequency band. There is emission present at all points in the map, a region roughly 4&#39; by 6&

D. C. Latimer, D. J. Ernst

We derive a set of symmetry relations for the three-neutrino mixing angles, including the MSW matter effect. Though interesting in their own right, these relations are used to choose the physical region of the mixing angles such that oscillations are parameterized completely and uniquely. We propose that the preferred way of setting the bounds on the mixing

T. Ekedahl, N. I. Shepherd-Barron

We give a complete description of all classical Enriques surfaces with non-zero global vector fields. In particular we show that there are such surfaces. The obtained result also applies to supersingular Enriques surfaces fulfilling a rather special condition. During this classification we study some properties of genus 1-fibrations special to characteristic

M. Haghighat, M. M. Ettefaghi

We consider the Lorentz invariant non-commutative QED and complete the Feynman rules for the theory up to the order $θ^2$. In the Lorentz invariant version of the non-commutative QED the particles with fractional charges can be also considered. We show that in the parton model, even at the lowest order, the Bjorken scaling violates as $\simθ^2Q^4$.

Zheng Zheng

The three-point correlation function (3PCF) can now be measured in large galaxy redshift surveys, but in three dimensions its interpretation is complicated by the presence of redshift-space distortions. I investigate the projected 3PCF, where these distortions are eliminated by integrating over the redshift dimension, as is commonly done for the two-point co

R. Narayanan, H. Neuberger

We present numerical evidence for the hypothesis that, in the planar limit, four dimensional Euclidean Yang-Mills theory on a finite symmetrical four-torus breaks chiral symmetry spontaneously when the length of the sides l is larger than a critical value l_c with a bilinear condensate whose value is independent of l. Therefore spontaneous symmetry breaking

Keshav Dasgupta, Jonathan P. Hsu, Renata Kallosh, Andrei Linde

Among the inflationary models based on string theory, the D3/D7 model has the advantage that the flatness of the inflaton potential can be protected even with moduli stabilization. However, the Abrikosov-Nielsen-Olesen BPS cosmic strings produced at the end of original D3/D7 inflation lead to an additional contribution to the CMB anisotropy. To make this con

C. Wigger, W. Hajdas, K. Arzner, M. Güdel

Using the RHESSI satellite as a Compton polarimeter, a recent study claimed that the prompt emission of GRB021206 was almost fully linearly polarized. This was challenged by a subsequent reanalysis. We present an novel approach, applying our method to the same data. We identify Compton scattering candidates by carefully filtering events in energy, time, and

Spencer Chang, Can Kilic, Rakhi Mahbubani

In this paper we increase the MSSM tree level higgs mass bound to a value that is naturally larger than the LEP-II search constraint by adding to the superpotential a $λS H_{u}H_{d}$ term, as in the NMSSM, and UV completing with new strong dynamics {\it before} $λ$ becomes non-perturbative. Unlike other models of this type the higgs fields remain elementary,

Jamal Jalilian-Marian, Yuri V. Kovchegov

We calculate production cross sections of a forward quark-gluon pair and of two gluons at mid-rapidity in Deep Inelastic Scattering and in high energy proton-nucleus collisions. The calculation is performed in the framework of the Color Glass Condensate formalism. We first calculate the cross sections in the quasi-classical approximation, which includes mult