November 2003 arXiv papers — page 10

Andrea Meucci, Carlotta Giusti, Franco Davide Pacati

A relativistic distorted wave impulse approximation model for electron-induced one proton knockout reactions and a Green's function approach to inclusive scattering are developed. Results for (e,e'p) and (e,e') reactions are presented in various kinematical conditions and compared (when possible) with nonrelativistic calculations.

Sofia Quaglioni, Nir Barnea, Victor D. Efros, Winfried Leidemann

The total cross sections of the processes 4He(gamma,p)3H and 4He(gamma,n)3He are calculated. For these exclusive reactions we investigate the question of the giant dipole peak height, but we also consider higher energies. The calculation includes full Final State Interaction (FSI) via the Lorentz Integral Transform (LIT) approach and employs the semi-realist

V. G. Nosov, A. M. Kamchatnov

A microscopic theory of the electromagnetic radiation emitted by a highly excited nucleus is developed on the basis of the Landau theory of a Fermi liquid. Closed formulae are obtained for the mean radiative width and its mean square fluctuation from level to level. The temperatures of many nuclei are found from the observed widths. The relaxation time is es

Toshiki Maruyama, Toshitaka Tatsumi, Dmitri N. Voskresensky, Tomonori Tanigawa

Non-uniform structures of nuclear matter are studied in a wide density-range. Using the density functional theory with a relativistic mean-field model, we examine non-uniform structures at sub-nuclear densities (nuclear ``pastas'') and at high densities, where kaon condensate is expected. We try to give a unified view about the change of the matter s

Feng Pan, V. G. Gueorguiev, J. P. Draayer

A Nilsson mean-field plus extended pairing interaction Hamiltonian with many-pair interaction terms is proposed. Eigenvalues of the extended pairing model are easy to obtain. Our investigation shows that one- and two-body interactions continue to dominate the dynamics for relatively small values of the pairing strength. As the strength of the pairing interac

M. Buescher

ANKE is a magnetic spectrometer and detection system at an internal target position of COSY-Juelich optimized for charged kaon detection. Recent results from ANKE on kaon production in pp and pD interactions are reported. From the pp data first absolutely normalized angular and invariant-mass spectra for the reaction pp -> dK+ K0-bar have been obtained. A pa

Maoke Chen, Tao He, Xing Li

A Mean-Field theory is presented and applied to a Cellular Automata model of distributed packet-switched networks. It is proved that, under a certain set of assumptions, the critical input traffic is inversely proportional to the free packet delay of the model. The applicability of Mean-Field theory in queue length estimation is also investigated. Results of

Gonzalo Alvarez, Fausto Montoya, Miguel Romera, Gerardo Pastor

This paper describes the security weakness of a recently proposed secure communication method based on discrete-time chaos synchronization. We show that the security is compromised even without precise knowledge of the chaotic system used. We also make many suggestions to improve its security in future versions.

J. H. P. Dawes, C. M. Postlethwaite, M. R. E. Proctor

Through multiple-scales and symmetry arguments we derive a model set of amplitude equations describing the interaction of two steady-state pattern-forming instabilities, in the case that the wavelengths of the instabilities are nearly in the ratio 1:2. In the case of exact 1:2 resonance the amplitude equations are ODEs; here they are PDEs. We discuss the sta

H. I. Ahmadov

In this paper we investigate distribution of zeros for once quasipolynom and obtain exactly lower-bound for their modulus.

Joan E. Hart, Kenneth Kunen

The compact Hausdorff space X has the Complex Stone-Weierstrass Property (CSWP) iff it satisfies the complex version of the Stone-Weierstrass Theorem. W. Rudin showed that all scattered spaces have the CSWP. We describe some techniques for proving that certain non-scattered spaces have the CSWP. In particular, if X is the product of a compact ordered space a

Anders Skovsted Buch, Frank Sottile, Alexander Yong

We give an explicit natural identification between the quiver coefficients of Buch and Fulton, decomposition coefficients for Schubert polynomials, and the Schubert structure constants for flag manifolds. This is also achieved in K-theory where we give a direct argument that the decomposition coefficients have alternating signs, based on a theorem of Brion,

J. M. Landsberg, Laurent Manivel

We establish basic techniques for studying the ideals of secant varieties of Segre varieties. We solve a conjecture of Garcia, Stillman and Sturmfels on the generators of the ideal of the first secant variety in the case of three factors and solve the conjecture set-theoretically for an arbitrary number of factors. We determine the low degree components of t

Harm Derksen

We construct error correcting nonlinear binary codes using a construction of Bose and Chowla in additive number theory. Our method extends a construction of Graham and Sloane for constant weight codes. The new codes improve 1028 of the 7168 best known h-error correcting codes of wordlength at most 512 and h at most 14. We give assymptotical comparisons to sh

Peter G. Casazza, Gitta Kutyniok

One approach to ease the construction of frames is to first construct local components and then build a global frame from these. In this paper we will show that the study of the relation between a frame and its local components leads to the definition of a frame of subspaces. We introduce this new notion and prove that it provides us with the link we need. I

D. Bulacu, S. Caenepeel, F. Panaite

We generalize various properties of Yetter-Drinfeld modules over Hopf algebras to quasi-Hopf algebras. The dual of a finite dimensional Yetter-Drinfeld module is again a Yetter-Drinfeld module. The algebra $H_0$ in the category of Yetter-Drinfeld modules that can be obtained by modifying the multiplication in a proper way is quantum commutative. We give a St

S. Caenepeel

We introduce Galois corings, and give a survey of properties that have been obtained so far. The Definition is motivated using descent theory, and we show that classical Galois theory, Hopf-Galois theory and coalgebra Galois theory can be obtained as a special case.

Gábor Elek

We introduce the notion of almost finite dimensionality of algebras and study its connection with the classical finiteness conditions.

Gábor Elek

We investigate the amenability of skew filed extensions of the complex numbers. We prove that all skew fields of finite Gelfand-Kirillov transcendence degree are amenable. However there are both amenable and non-amenable skew fields of infinite Gelfand-Kirillov transcendence degree. For example, the free field is non-amenable.

Aleksandar Ivić

We prove $\sum_{K-G}\le κ_j \le K+G}α_j H_j^3(1/2) \ll_εGK^{1+ε}$ for $K^ε\le G \le K$, where $α_j = |ρ_j(1)|^2(\cosh πκ_j)^{-1}$, and $ρ_j(1)$ is the first Fourier coefficient of the Maass wave form corresponding to the eigenvalue $λ_j = κ_j^2 + 1/4$ to which the Hecke series $H_j(s)$ is attached. This result yields the new bound $H_j(1/2) \ll_εκ_j^{1/3+ε}$

Joseph P. Previte, Eugene Z. Xia

Let $M$ be a four-holed sphere and $Γ$ the mapping class group of $M$ fixing the boundary $\partial M$. The group $Γ$ acts on $M_B(SL(2,C)) = Hom_B^+(pi_1(M),SL(2,C))/SL(2,C)$ which is the space of completely reducible $SL(2,C)$-gauge equivalence classes of flat $SL(2,C)$-connections on $M$ with fixed holonomy $B$ on $\partial M$. Let $B \in (-2,2)^4$ and $M

Jining Gao

In order to unify the methods which have been applied to various topics such as BRST theory of constraints, Poisson brackets of local functionals, and certain developments in deformation theory, we formulate a new concept which we call the {\it chain extension} of a $D$-algebra. We develop those aspects of this new idea which are central to applications to a

Christopher Tuffley

The kth finite subset space of a topological space X is the space exp_k X of non-empty finite subsets of X of size at most k, topologised as a quotient of X^k. The construction is a homotopy functor and may be regarded as a union of configuration spaces of distinct unordered points in X. We show that the finite subset spaces of a connected 2-complex admit &#

Grigori Olshanski

The aim of the present survey paper is to provide an accessible introduction to a new chapter of representation theory - harmonic analysis for noncommutative groups with infinite-dimensional dual space. I omitted detailed proofs but tried to explain the main ideas of the theory and its connections with other fields. The fact that irreducible representations

Frank Calegari, Matthew Emerton

Using the modularity technique of Wiles, we study the Hecke algebra of weight 2 and prime level N localized at the Eisenstein primes. On the way, we recover some results of Mazur ("Modular Curves and the Eisenstein Ideal") from a deformation theoretic point of view. Combining some of our results with a theorem of Merel, we obtain new information abou

Frank Calegari, Matthew Emerton

Let T_k denote the Hecke algebra acting on newforms of weight k and level N. We prove that the power of p dividing the index of T_k inside its normalisation grows at least linearly with k (for fixed N), answering a question of Serre. We also apply our method to give heuristic evidence towards recent conjectures of Buzzard and Mazur.

Frank Calegari

We prove that for N=6 and N=10, there do not exist any non-zero semistable abelian varieties over Q with good reduction outside primes dividing N. Our results are contingent on the GRH discriminant bounds of Odlyzko. Combined with recent results of Brumer--Kramer and of Schoof, this result is best possible: if N is squarefree, there exists a non-zero semista

Jonathan Kujawa

This paper provides results on the modular representation theory of the supergroup $GL(m|n).$ Working over a field of arbitrary characteristic, we prove that the explicit combinatorics of certain crystal graphs describe the representation theory of a modular analogue of the Bernstein-Gelfand-Gelfand category $\mathcal{O}$. In particular, we obtain a linkage

Mauricio D. Garay

We consider deformations of singular Lagrangian varieties in symplectic spaces. We show the coherence of the direct image sheaves of relative infinitesimal Lagrangian deformations. Using this result, we prove that, under some assumptions, a Lagrangian deformation is analytically rigid provided that this is the case infinitesimally. This gives generalisations

Bin Zhu, S. Caenepeel

$\nabla$-good filtration dimensions of modules and of algebras are introduced by Parker for quasi-hereditary algebras. These concepts are now generalized to the setting of standardly stratified algebras. Let $A$ be a standardly stratified algebra. The $\bar{\nabla}$-good filtration dimension of $A$ is proved to be the projective dimension of the characterist

Harm Derksen

Suppose that G is a linearly reductive group. We study the minimal free resolution of the invariant ring. If G is a finite linearly reductive group, then the ring of invariants is generated in degree at most |G|, the group order. We prove that the ideal of relations of a minimal set of generators of the invariant ring is generated in degree at most 2|G|.

Benjamin A. Burrington, James T. Liu

We examine the AdS Higgs phenomenon for spin-1 fields, and demonstrate that graviphotons pick up a dynamically generated mass in AdS_4, once matter boundary conditions are relaxed. We perform an explicit one-loop calculation of the graviphoton mass, and compare this result with the mass generated for the graviton in AdS. In this manner, we obtain a condition

D. Mamone

We derive an oscillator form for the Butterflies in terms of Sliver matrix S and its twisted version T as was already done for the Wedges in term of T. We write a General Squeezed state depending on a matrix U and we show in a compact way the interpolation between Identity state and the Sliver and between the Nothing state and the Sliver, growing in powers o

I. Drozdov

The ground state energy of a quantum field in the background of classical field configurations is considered. The subject of the ground state energy in framework of the quantum field theory is explained. The short review of calculation methods (generalized zeta function and heat kernel expansion) and their mathematical foundations is given. We use the zeta-f

Emilio Elizalde

A precise zeta-function calculation shows that the contribution of the vacuum energy to the observed value of the cosmological constant can possibly have the desired order of magnitude albeit the sign strongly depends on the topology of the universe. The non-renormalizable, infinite contributions which have been recently shown to occur when one physically im

D. Choudhury, N. G. Deshpande, D. K. Ghosh

The models of large extra compact dimensions, as suggested by Arkani-Hamed, Dimopoulos and Dvali, predict exciting phenomenological consequences with gravitational interactions becoming strong at the TeV scale. Such theories can be tested at the existing and future colliders. In this paper, we study the contribution of virtual Kaluza-Klein excitations in the

Nicole F. Bell

We review the consequences of neutrino mixing in the early universe. For both active-sterile mixing or mixing between three active neutrinos only, the consequences of oscillations depend crucially upon the size of the universe's lepton number (relic neutrino asymmetry.)

H. J. Pirner

We discuss the effects of gluon radiation by the struck quark and the subsequent absorption of the produced hadron in deep inelastic lepton-nucleus scattering. The theoretical picture is compared with HERMES results on multiplicity ratios.

Pedro Bicudo

The Weinberg theorem, the Adler self consistency zero, the Goldberger and Treiman relation and the Gell-Mann Oakes and Renner relation are proved analytically in full detail for Quark Models. These proofs are independent of the particular quark-quark interaction, and they are displayed with Feynman diagrams in a compact notation. I assume the ladder truncati

A. Gehrmann-De Ridder, T. Gehrmann, G. Heinrich

The inclusive four-particle phase space integral of any $1\to 4$ matrix element in massless QCD contains divergences due to the soft and collinear emission of up to two particles in the final state. We show that any term appearing in this phase space integral can be expressed as linear combination of only four master integrals. These four master integrals ar

V. Cuplov, A. Nehme

The charged $K_{\ell 4}$ decay, $K^+\toπ^+π^-\ell^+ν_{\ell}$ is studied in the framework of chiral perturbation theory based on the effective Lagrangian including mesons, photons, and leptons. We give analytic expressions for the two vectorial form factors, $f$ and $g$, calculated at one-loop level in the presence of Isospin breaking effects. These expressio

T. Gleisberg, F. Krauss, C. G. Papadopoulos, A. Schaelicke

In this paper total cross sections for signals and backgrounds of top- and Higgs-production channels in electron-positron collisions at a future linear collider are presented. All channels considered are characterized by the emergence of six-particle final states. The calculation takes into account the full set of tree-level amplitudes in each process. Two m

A. Ozpineci, S. B. Yakovlev, V. S. Zamiralov

New relations between QCD Borel sum rules for magnetic moments of Sigma^0 and Lambda hyperons are constructed. It is shown that starting from the sum rule for the Sigma^0 hyperon magnetic moment it is straightforward to obtain the corresponding sum rule for the Lambda hyperon magnetic moment et vice versa.

A. Schaelicke, T. Gleisberg, S. Hoeche, S. Schumann

Event generators are an indispensable tool for the preparation and analysis of particle-physics experiments. In this contribution, physics principles underlying the construction of such computer programs are discussed. Results, within and beyond the Standard Model of particle physics, obtained with a new event generator are presented. This generator is capab

Pasquale Migliozzi

In recent years great progress toward the understanding of the mixing in the leptonic sector has been made. Nonetheless, this field of research is just at the beginning. Further advance by accelerator based neutrino oscillation experiments requires new beams and detectors to reach the wanted physics goals. In this paper we review the next possible steps that

Yoshitaka Hatta, Kenji Fukushima

We argue that the chiral phase transition and the deconfinement phase transition in finite temperature QCD are just different limits of a single crossover phase transition driven by the lightest scalar field which is a mixture of the glueball and the sigma meson. The key mechanism, the level repulsion between the sigma and the glueball, gives not only a unif

K. R. S. Balaji, Robert H. Brandenberger, Damien A. Easson

The polarization of the cosmic microwave background radiation (CMBR) can serve as a probe for nonstandard parity violating interactions. Many such interactions are predicted in particle physics models arising from theories with extra dimensions such as superstring theory. These interactions produce an optical activity that depends on the space-time nature of

M. N. Chernodub, E. -M. Ilgenfritz, A. Schiller

We discuss the influence of closed Dirac strings on the photon propagator in the Landau gauge emerging from a study of the compact U(1) gauge model in 2+1 dimensions. This gauge also minimizes the total length of the Dirac strings. Closed Dirac strings are stable against local gauge-fixing algorithms only due to the torus boundary conditions of the lattice.

E. Bittner, W. Janke, H. Markum

The Regge Calculus is a powerful method to approximate a continuous manifold by a simplicial lattice, keeping the connectivities of the underlying lattice fixed and taking the edge lengths as degrees of freedom. The Discrete Regge Model limits the choice of the link lengths to a finite number. We examine the phase structure of Standard Regge Calculus in four

Fang-Yu Li, Zhang-Han Wu, Yi Zhang

According to electrodynamical equations in curved spacetime we consider the coupling of a linearized weak gravitational wave (GW) to a Gaussian beam passing through a static magnetic field. It is found that unlike the properties of the "left-circular" and "right-circular" waves of the tangential perturbative photon fluxes in the cylindrical p

S. Sivasubramanian, A. Widom, Y. N. Srivastava

We consider light waves propagating clockwise and other light waves propagating counterclockwise around a closed path in a plane (theoretically with the help of stationary mirrors). The time difference between the two light propagating path orientations constitutes the Sagnac effect. The general relativistic expression for the Sagnac effect is discussed. It

Louis J. Rubbo, Neil J. Cornish, Olivier Poujade

Planning is underway for several space-borne gravitational wave observatories to be built in the next ten to twenty years. Realistic and efficient forward modeling will play a key role in the design and operation of these observatories. Space-borne interferometric gravitational wave detectors operate very differently from their ground based counterparts. Com

Solomija N. Buk, Andrij A. Rovenchak

We use the rank-frequency analysis for the estimation of Kernel Vocabulary size within specific corpora of Ukrainian. The extrapolation of high-rank behaviour is utilized for estimation of the total vocabulary size.

Oleg Mazonka, Daniel B. Cristofani

In this paper we would like to present a very short (possibly the shortest) self-interpreter, based on a simplistic Turing-complete imperative language. This interpreter explicitly processes the statements of the language, which means the interpreter constitutes a description of the language inside that same language. The paper does not require any specific

J. Gerard Wolff

The SP theory of computing and cognition, described in previous publications, is an attractive model for intelligent databases because it provides a simple but versatile format for different kinds of knowledge, it has capabilities in artificial intelligence, and it can also function like established database models when that is required. This paper describes

Stephen Alstrup, Jacob Holm, Kristian de Lichtenberg, Mikkel Thorup

We introduce top trees as a design of a new simpler interface for data structures maintaining information in a fully-dynamic forest. We demonstrate how easy and versatile they are to use on a host of different applications. For example, we show how to maintain the diameter, center, and median of each tree in the forest. The forest can be updated by insertion

Y. Shin, M. Saba, A. Schirotzek, T. A. Pasquini

Bose-Einstein condensates of sodium atoms, prepared in an optical dipole trap, were distilled into a second empty dipole trap adjacent to the first one. The distillation was driven by thermal atoms spilling over the potential barrier separating the two wells and then forming a new condensate. This process serves as a model system for metastability in condens

Seung-Yeop Lee, Vito W. Scarola, J. K. Jain

Much of the present day qualitative phenomenology of the fractional quantum Hall effect can be understood by neglecting the interactions between composite fermions altogether. For example the fractional quantum Hall effect at $ν=n/(2pn\pm 1)$ corresponds to filled composite-fermion Landau levels,and the compressible state at $ν=1/2p$ to the Fermi sea of comp

I. S. Beloborodov, A. V. Lopatin, G. Schwiete, V. M. Vinokur

We investigate the effect of Coulomb interactions on the tunneling density of states (DOS) of granular metallic systems at the onset of Coulomb blockade regime in two and three dimensions. Using the renormalization group technique we derive the analytical expressions for the DOS as a function of temperature $T$ and energy $ε$. We show that samples with the b

B. Sapoval, A. Baldassarri, A. Gabrielli

Erosion of rocky coasts spontaneously creates irregular seashores. But the geometrical irregularity, in turn, damps the sea-waves, decreasing the average wave amplitude. There may then exist a mutual self-stabilisation of the waves amplitude together with the irregular morphology of the coast. A simple model of such stabilisation is studied. It leads, throug

David Chapot, Lyderic Bocquet, Emmanuel Trizac

In this paper we propose a framework allowing to compute the effective interactions between two anisotropic macromolecules, thereby generalizing the DLVO theory to non spherical finite size colloids. We show in particular that the effective interaction potential remains anisotropic at all distances and provide an expression for the anisotropy factor. We then

P. Giannozzi, F. De Angelis, R. Car

We present a plane-wave ultrasoft pseudopotential implementation of first-principle molecular dynamics, which is well suited to model large molecular systems containing transition metal centers. We describe an efficient strategy for parallelization that includes special features to deal with the augmented charge in the contest of Vanderbilt's ultrasoft p

D. K. Goswami, K. Bhattacharjee, B. Satpati, S. Roy

Growth and strain behavior of thin Ag films on Si substrate have been investigated by scanning tunneling microscopy, cross-sectional transmission electron microscopy and high resolution x-ray diffraction studies. Ag islands formed on Si at room temperature growth show strongly preferred heights and flat top. At low coverage, islands containing two atomic lay

Kostya Shundyak, René van Roij

We explore models of hard-rod fluids with a finite number of allowed orientations, and construct their bulk phase diagrams within Onsager's second virial theory. For a one-component fluid, we show that the discretization of the orientations leads to the existence of an artificial (almost) perfectly aligned nematic phase, which coexists with the (physical

S. V. Novikov, K. W. Edmonds, A. D. Giddings, K. Y. Wang

Cubic (zinc-blende) Ga1-xMnxN layers were grown by plasma-assisted molecular beam epitaxy on GaAs (001) substrates. Some of the structures also contained cubic AlN buffer layers. Auger Electron Spectroscopy and Secondary Ion Mass Spectroscopy studies clearly confirmed the incorporation of Mn into cubic GaN, the Mn being uniformly distributed through the laye

Anita Mehta, J. M. Luck

We explore the effect of shape -- jagged vs. regular -- in the jamming limit of very gently shaken packings. Our measure of shape $\eps$ is the void space occupied by a disordered grain; we show that depending on its number-theoretic nature, two generic behaviours are obtained. Thus, regularly shaped grains (rational $\eps$) have ground states of perfect pac

Y. Hou, C. Y. He, L. Liu, Z. X. Gao

We have proposed a systematic theoretic framework to calculate the trapped magnetic field and temperature distributions in a superconducting disk (SD) magnetized by a field-cooling process. Our calculations are based on the critical state model with temperature and field-dependent critical current density, and the heat conduction equation with account of the

Kikuo Cho, Jun Ushida, Motoaki Bamba

We give a general method to calculate photonic band structure in the form of wave number $k$ as a function of frequency $ω$, which is required whenever we want to calculate signal intensity related with photonic band structure. This method is based on the fact that the elements of the coefficient matrix for the plane wave expansion of the Maxwell equations c

P. Ao

With the excitement generated by this year's Nobel Prize in physics, here I give a brief critical review of current vortex dynamics research activity, using a recent book as the background material. Two directions in which major progresses can be expected are selected: the role of vortex-phonon interaction in low temperature superfluid turbulence and the

Aldemar Torres, Gabriel Tellez

It has been argued that for a finite two-dimensional classical Coulomb system of characteristic size $R$, in its conducting phase, as $R\to \infty $ the total free energy (times the inverse temperature $β$) admits an expansion of the form: $βF=AR^{2}+BR+{1/6}χ\ln R,$ where $χ$ is the Euler characteristic of the manifold where the system lives. The first two

Lina Merchan, Gabriel Tellez

Using a solvable model, the two-dimensional two-component plasma, we study a Coulomb gas confined in a disk and in an annulus with boundaries that can adsorb some of the negative particles of the system. We obtain explicit analytic expressions for the grand potential, the pressure and the density profiles of the system. By studying the behavior of the disjoi

S. W. Davis, O. M. Blaes, N. J. Turner, A. Socrates

Numerical calculations and linear theory of radiation magnetohydrodynamic flows indicate that the photon bubble and magnetorotational instability (MRI) may produce large density inhomogeneities in radiation pressure supported media. We study the effects of the photon bubble instability on accretion disk spectra using 2-D Monte Carlo (MC) and 1-D Feautrier ra

Asantha Cooray

The galaxy power spectrum is now a well-known tool of precision cosmology. In addition to the overall shape, baryon oscillations and the small-scale suppression of power by massive neutrinos capture complimentary information on cosmological parameters when compared to the angular power spectrum of cosmic microwave background anisotropies. We study both the r

V. Desai, J. J. Dalcanton, L. Mayer, D. Reed

We present galaxy circular velocity functions (GCVFs) for 34 low redshift (z < 0.15) clusters identified in the Sloan Digital Sky Survey (SDSS), for fifteen clusters drawn from dark matter simulations of hierarchical structure growth in a LambdaCDM cosmology, and for ~29,000 SDSS field galaxies. We find that the observed and simulated cluster GCVFs take the

Christopher Sneden, Robert P. Kraft, Puragra Guhathakurta, Ruth C. Peterson

We report new chemical abundances of 23 bright red giants of the globular cluster M3, based on high-resolution spectra obtained with the Keck I telescope. Combining these data with a previously-reported small sample of M3 giants obtained with the Lick 3m telescope, we compare [X/Fe] ratios for 28 M3 giants with 35 M13 giants, and with halo field stars. All t

Demosthenes Kazanas, Markos Georganopoulos, Apostolos Mastichiadis

The essence of the ``Supercritical Pile&#39;&#39; model is a process for converting the energy stored in the relativistic protons of a Relativistic Blast Wave (RBW) of Lorentz factor $Γ$ into electron -- positron pairs of similar Lorentz factor, while at the same time emitting most of the GRB luminosity at an energy $E_p \simeq 1$ MeV. This is achieved by sc

E. Koptelova, E. Shimanovskaya, B. Artamonov, V. Belokurov

This note addresses possible applications of the Tikhonov regularization to image reconstruction of gravitational lens systems. Several modifications of the regularization algorithm are discussed. Our illustrative example is the close quadruple gravitational lens QSO 2237+0305 (Einstein Cross). The restored image of the lens is decomposed into two parts - th

D. L. Harrison, F. van Leeuwen, M. Rowan-Robinson

This paper presents a method to reconstruct the position of the line of sight and orientation of the focal plane of the Planck satellite, which may be expressed by the parameters of the effective boresight and roll angles, respectively. The accuracy to which these parameters must be determined to avoid compromising the reconstruction of the C_{\ell} power sp

D. C. Gabuzda, E. Murray, P. Cronin

If the transverse jet B fields observed in BL Lac objects on parsec scales represent the toroidal component of the jet B fields, this should give rise to rotation-measure gradients across the jets, due to the systematic change in the line-of-sight component of the jet B field. We have found evidence for such rotation-measure gradients in one-third to one-hal

Rose A. Finn, Dennis Zaritsky, Donald W. McCarthy

We present H$α$-derived star-formation rates (SFRs) for the galaxy cluster CL J0023+0423B at $z = 0.845$. Our $3σ$ flux limits corresponds to a star-formation rate of 0.24 \smy, and our minimum reliable H$α$ + [N II] equivalent width is $> 10$ Å, demonstrating that near-infrared narrow-band imaging can sample the star-forming galaxy population in distant clu

Shigenobu Hirose, Julian H. Krolik, Jean-Pierre De Villiers, John F. Hawley

We present a detailed analysis of the magnetic field structure found in general relativistic 3D MHD simulations of accreting tori in the Kerr metric with different black hole spins. Among the properties analyzed are the field strength as a function of position and black hole spin, the shapes of field lines, the degree to which they connect different regions,

R. A. Laing, A. H. Bridle

We present a general approach to the modelling of the brightness and polarization structures of adiabatic, decelerating relativistic jets, based on the formalism of Matthews & Scheuer (1990). We compare the predictions of adiabatic jet models with deep, high-resolution observations of the radio jets in the FR I radio galaxy 3C 31. Adiabatic models require co

M. A. McLaughlin, J. M. Rankin

We discuss the discovery of `notch-like&#39; features in the mean pulse profile of the nearby, bright pulsar B0950+08. We compare these low-level features with those previously seen in the pulse profiles of pulsars J0437-4715 and B1929+10. While J0437-4715 is a binary millisecond pulsar and B0950+08 and B1929+10 are isolated, slow pulsars, all three pulsars

W. Boschin, M. Girardi, R. Barrena Delgado, A. Biviano

We present the results of the dynamical analysis of the rich, hot, and X-ray very luminous galaxy cluster A2219, containing a powerful diffuse radio-halo. Our analysis is based on new redshift data for 27 galaxies in the cluster region, measured from spectra obtained at the TNG, with the addition of other 105 galaxies recovered from reduction of CFHT archive

N. Menci, A. Cavaliere, A. Fontana, E. Giallongo

To address the problem concerning the early formation of stars in massive galaxies, we present the results of a semi-analytic model of galaxy formation which includes a physical description of starbursts triggered by galaxy interactions. These originate from the destabilization of cold galactic gas occurring in galaxy encounters, which in part feeds the accr

Rafael A. Araya-Gochez, Ethan Vishniac

A photon or neutrino gas--semi-contained by a baryonic species through scattering--comprises a rather peculiar MHD fluid where the magnetic field is truly frozen only to the co-moving volume associated with the mass density. Although radiative diffusion precludes an adiabatic treatment of compressive perturbations, we show that the energy equation may be cas

P. Wang, V. E. Lyubovitskij, Th. Gutsche, Amand Faessler

The phase transition of chiral symmetry restoration in strange hadronic matter is studied in the chiral SU(3) quark mean field model. When the baryon density is larger than a critical density $ρ_c$, the minimal energy density of the system occurs at the point where the effective masses of nucleon, $Λ$ or $Ξ$ drop to zero. The physical quantities change disco

Steen Hannestad

We propose an efficient and model independent method for reconstructing the primordial power spectrum from Cosmic Microwave Background (CMB) and large scale structure observations. The algorithm is based on a Monte Carlo principle and therefore very simple to incorporate into existing codes such as Markov Chain Monte Carlo. The algorithm has been used on pre

D. Guetta, T. Piran, E. Waxman

The realization that the total energy of GRBs is correlated with their jet break angles motivates the search for a similar relation between the peak luminosity, $L$, and the jet break angles, $L\proptoθ^{-2}$. Such a relation implies that the GRB luminosity function determines the angular distribution. We re-derive the GRB luminosity function using the BATSE

S. M. Koushiappas, J. S. Bullock, A. Dekel

(ABRIDGED) We present a model in which the seeds of supermassive black holes form from the lowest angular momentum gas in proto-galaxies at high redshift. We show that this leads to a correlation between black hole masses and spheroid properties, as observed today. We assume that gas in early-forming, rare halos has a distribution of specific angular momentu

Fumikazu Koyama, Yuji Tachikawa, Taizan Watari

The slow-roll inflation is a beautiful paradigm, yet the inflaton potential can hardly be sufficiently flat when unknown gravitational effects are taken into account. However, the hybrid inflation models constructed in D = 4 N = 1 supergravity can be consistent with N = 2 supersymmetry, and can be naturally embedded into string theory. This article discusses

R. Spurzem, P. Berczik, G. Hensler, Ch. Theis

First we present a recently developed 3D chemodynamical code for galaxy evolution from the K**2 collaboration. It follows the evolution of all components of a galaxy such as dark matter, stars, molecular clouds and diffuse interstellar matter (ISM). Dark matter and stars are treated as collisionless N-body systems. The ISM is numerically described by a smoot

Leopoldo A. Pando Zayas, Jacob Sonnenschein, Diana Vaman

We attempt to obtain realistic glueball Regge trajectories from the gauge/string correspondence. To this end we study closed spinning string configurations in two supergravity backgrounds: Klebanov-Strassler (KS) and Maldacena-Nunez (MN) which are dual to confining gauge theories. These backgrounds represent two embeddings of N=1 SYM, in the large rank limit

John Middleditch

Gamma-ray bursts can appear to be a hundred times as luminous as supernovae, but their underlying energy source(s) have remained a mystery. However, there has been evidence for some time now of an association of gamma-ray bursts with supernovae of Type Ib and Ic, a fact which has been exploited by a number of models, to explain the gamma-ray burst phenomenon

F. Epple, D. Lust

We review the worldsheet analysis for intersecting branes with focus on small and large angles. For small angles, we review the Yang-Mills fluctuation analysis in hep-th/0303204 and find an additional family of massless modes. They are the components of a Goldstone scalar corresponding to the spontaneously broken U(2)-gauge symmetry. For branes at large angl

Michael K. -H. Kiessling

The classical Maxwell--Born--Infeld field equations coupled with a Hamilton--Jacobi law of point charge motion are partially quantized by coupling the Hamilton-Jacobi phase function with an amplitude function, which combines with the phase function into a single complex wave function satisfying a relativistic Klein--Gordon equation self-consistently coupled

D. M. Ghilencea

Within an effective field theory framework we compute the most general structure of the one-loop corrections to the 4D gauge couplings in one- and two-dimensional orbifold compactifications with non-vanishing constant gauge background (Wilson lines). Although such models are non-renormalisable, we keep the analysis general by considering the one-loop correct

Ken Intriligator, Per Kraus, Anton V. Ryzhov, Masaki Shigemori

We consider N=1 supersymmetric U(N), SO(N), and Sp(N) gauge theories, with two-index tensor matter and added tree-level superpotential, for general breaking patterns of the gauge group. By considering the string theory realization and geometric transitions, we clarify when glueball superfields should be included and extremized, or rather set to zero; this is

Dmitri Burshtyn, Shmuel Elitzur, Yaakov Mandelbaum

The effect of NS 5 branes on an orientifold is studied. The orientifold is allowed to pass through a pile of k NS branes forming a regularized CHS geometry. Its effect on open strings in its vicinity is used to study the change in the orientifold charge induced by the NS branes.

Hannes Jung

The basic ideas of kt-factorization and CCFM parton evolution is discussed. The unintegrated gluon densities, obtained from CCFM fits to the proton structure function data at HERA are used to predict hadronic final state cross sections like jet production at HERA, but also comparisons with recent measurements of heavy quark production at the Tevatron are pre