August 2005 arXiv papers — page 15

B. Vakili, H. R. Sepangi

We study the classical and quantum evolution of a universe in which the matter source is a massive Dirac spinor field and the universe is described by a Bianchi type I metric. We focus attention on those classical solutions that admit a degenerate metric in which the scale factors have smooth behavior in transition from a Euclidean to a Lorentzian domain and

Winfried Bruns, Tim Roemer

We show that the Ehrhart h-vector of an integer Gorenstein polytope with a regular unimodular triangulation satisfies McMullen's g-theorem; in particular, it is unimodal. This result generalizes a recent theorem of Athanasiadis (conjectured by Stanley) for compressed polytopes. It is derived from a more general theorem on Gorenstein affine normal monoids

Anirudh Pradhan, G. S. Khadekar, Vrishali Patki, Saeed Otarod

In this paper we have analyzed the Kaluza-Klein type Robertson Walker (RW) cosmological models by considering three different forms of variable $Λ$: $Λ\sim(\frac{\dot{a}}{a})^2$,$Λ\sim(\frac{\ddot{a}} {a})$ and $Λ\sim ρ$. It is found that, the connecting free parameters of the models with cosmic matter and vacuum energy density parameters are equivalent, in

J. A. Mendez-Bermudez, Tsampikos Kottos, Doron Cohen

We propose a random matrix modeling for the parametric evolution of eigenstates. The model is inspired by a large class of quantized chaotic systems. Its unique feature is having parametric invariance while still possessing the non-perturbative crossover that has been discussed by Wigner 50 years ago. Of particular interest is the emergence of an additional

Hiroaki Kadowaki, Yoshikazu Tabata, Masugu Sato, Naofumi Aso

A focus of recent experimental and theoretical studies on heavy fermion systems close to antiferromagnetic (AFM) quantum critical points (QCP) is directed toward revealing the nature of the fixed point, i.e., whether it is an itinerant antiferromagnet [spin density wave (SDW)] type or a locally-critical fixed point. The relevance of the local QCP was propose

Azhar Iqbal

An example of a quantum game is presented that explicitly shows the impact of entanglement on the game-theoretical concept of evolutionary stability.

T. Ambjoernsson, M. A. Lomholt, R. Metzler

We investigate the translocation of a stiff polymer consisting of M monomers through a nanopore in a membrane, in the presence of binding particles (chaperones) that bind onto the polymer, and partially prevent backsliding of the polymer through the pore. The process is characterized by the rates: k for the polymer to make a diffusive jump through the pore,

Ileana Stoica

Structure predictions of helical membrane proteins have been designed to take advantage of the structural autonomy of secondary structure elements, as postulated by the two-stage model of Engelman and Popot. In this context, we investigate structure calculation strategies for two membrane proteins with different functions, sizes, aminoacid compositions, and

S. M. Abrarov, Sh. U. Yuldashev, T. W. Kim, Y. H. Kwon

The temperature-dependent photoluminescence (PL) spectra of zinc oxide (ZnO) nanocrystals deposited inside the ultraviolet (UV) opal were studied. ZnO was grown in the voids between FCC packed silicon dioxide spheres using spray pyrolysis under ultrasonic vibration in the solution containing a zinc nitrate precursor. The ZnO nanoparticles inside opal matrix

Eduardo Cattani, Raymond Curran, Alicia Dickenstein

We present examples which show that in dimension higher than one or codimension higher than two, there exist toric ideals I_A such that no binomial ideal contained in I_A and of the same dimension is a complete intersection. This result has important implications in sparse elimination theory and in the study of the Horn system of partial differential equatio

Mark S. MacLean, Paul Terwilliger

We consider a bipartite distance-regular graph $G$ with diameter $D$ at least 4 and valency $k$ at least 3. We obtain upper and lower bounds for the local eigenvalues of $G$ in terms of the intersection numbers of $G$ and the eigenvalues of $G$. Fix a vertex of $G$ and let $T$ denote the corresponding subconstituent algebra. We give a detailed description of

Tatsuro Ito, Paul Terwilliger

Let $K$ denote an algebraically closed field with characteristic 0, and let $q$ denote a nonzero scalar in $K$ that is not a root of unity. Let $A_q$ denote the unital associative $K$-algebra defined by generators $x,y$ and relations x^3y-[3]_q x^2yx +[3]_q xyx^2 -yx^3=0, y^3x-[3]_q y^2xy +[3]_q yxy^2 -xy^3=0, where $[3]_q = (q^3-q^{-3})/(q-q^{-1})$. We clas

Benjamin V. Holt, Tyler J. Evans

Students having had a semester course in abstract algebra are exposed to the elegant way in which finite group theory leads to proofs of familiar facts in elementary number theory. In this note we offer two examples of such group theoretical proofs using the action of a group on a set. The first is Fermat's little theorem and the second concerns a well k

Kristopher Tapp

Examples of almost-positively and quasi-positively curved spaces of the form M=H((G,h)xF) were discovered recently. Here, h is a left-invariant metric on a compact Lie group G, F is a compact Riemannian manifold on which the subgroup H of G acts isometrically on the left, and M is the orbit space of the diagonal left action of H on (G,h)xF with the induced R

G. Y. Tsyaputa

Green's relations on the deformed finite inverse symmetric semigroup $\mathcal{IS}_n$ and the deformed finite symmetric semigroup $\mathcal{T}_n$ are described.

Ronald Brown, Neil Ghani, Anne Heyworth, Christopher D. Wensley

In this paper we show how string rewriting methods can be applied to give a new method of computing double cosets. Previous methods for double cosets were enumerative and thus restricted to finite examples. Our rewriting methods do not suffer this restriction and we present some examples of infinite double coset systems which can now easily be solved using o

Nariya Kawazumi

We study cohomology groups of the Lie algebra of vector fields on the complex line, $W_1$, with values in the tensor fields in several variables. From a generalization by Scheja of the second Riemann (Hartogs) continuation theorem, we deduce a cohomology exact sequence of the subalgebra of $W_1$ consisting of vectors having a zero at the origin. As applicati

Jie Qing, David Raske

In this note we study the conformal metrics of constant $Q$ curvature on closed locally conformally flat manifolds. We prove that for a closed locally conformally flat manifold of dimension $n\geq 5$ and with Poincarë exponent less than $\frac {n-4}2$, the set of conformal metrics of positive constant $Q$ and positive scalar curvature is compact in the $C^\i

Michael Larsen, Ayelet Lindenstrauss

A linear system of real quadratic forms defines a real projective variety. The real non-singular locus of this variety (more precisely of the underlying scheme) has a highly connected double cover as long as each non-zero form in the system has sufficiently high Witt index.

Jenia Tevelev

We study compactifications of subvarieties of algebraic tori defined by imposing a sufficiently fine polyhedral structure on their non-archimedean amoebas. These compactifications have many nice properties, for example any k boundary divisors intersect in codimension k. We consider some examples including $M_{0,n}\subset\bar M_{0,n}$ (and more generally log

Meng Chen

Let V be a smooth projective 3-fold of general type. Denote by $K^3$, a rational number, the self-intersection of the canonical sheaf of any minimal model of V. One defines $K^3$ as the canonical volume of $V$. Assume $p_g\ge 2$. We show that $K^3\ge {1/3}$, which is a sharp lower bound. Then we classify those V with small $K^3$ up to explicit tructure. We a

K. Ebrahimi-Fard, L. Guo

We formulate the Hopf algebraic approach of Connes and Kreimer to renormalization in perturbative quantum field theory using triangular matrix representation. We give a Rota-Baxter anti-homomorphism from general regularized functionals on the Feynman graph Hopf algebra to triangular matrices with entries in a Rota-Baxter algebra. For characters mapping to th

Walter Smilga

This paper analyzes, for a multi-particle system of spin-1/2 particles, the consequences of replacing the Poincare group as fundamental symmetry group by the de Sitter group SO(3,2). The flat-space approximation of the de Sitter group by the Poincare group defines a superselection rule, which correlates spin and momentum of particles. This correlation can be

Yakov Itin

Within the axiomatic premetric approach to classical electrodynamics, we derive under which covariant conditions the quartic Fresnel surface represents a unique light cone without birefringence in vacuum.

Jan Kalinowski

This report summarizes the progress in SUSY studies performed since the last International Linear Collider Workshop in Paris (LCWS04).

Dragos Trinca

Adaptive codes have been introduced in [Dragos Trinca, cs.DS/0505007] as a new class of non-standard variable-length codes. These codes associate variable-length codewords to symbols being encoded depending on the previous symbols in the input data string. A new data compression algorithm, called EAH, has been introduced in [Dragos Trinca, cs.DS/0505061], wh

Dragos Trinca

Adaptive codes associate variable-length codewords to symbols being encoded depending on the previous symbols in the input data string. This class of codes has been introduced in [Dragos Trinca, cs.DS/0505007] as a new class of non-standard variable-length codes. New algorithms for data compression, based on adaptive codes of order one, have been presented i

Dragos Trinca

Adaptive (variable-length) codes associate variable-length codewords to symbols being encoded depending on the previous symbols in the input data string. This class of codes has been presented in [Dragos Trinca, cs.DS/0505007] as a new class of non-standard variable-length codes. Generalized adaptive codes (GA codes, for short) have been also presented in [D

Dragos Trinca

The well-known Eulerian path problem can be solved in polynomial time (more exactly, there exists a linear time algorithm for this problem). In this paper, we model the problem using a string matching framework, and then initiate an algorithmic study on a variant of this problem, called the (2,1)-STRING-MATCH problem (which is actually a generalization of th

Dragos Trinca

In 1994, Burrows and Wheeler developed a data compression algorithm which performs significantly better than Lempel-Ziv based algorithms. Since then, a lot of work has been done in order to improve their algorithm, which is based on a reversible transformation of the input string, called BWT (the Burrows-Wheeler transformation). In this paper, we propose a c

R. Moessner, S. L. Sondhi, M. O. Goerbig

We study a large-N deformation of the S=1/2 pyrochlore Heisenberg antiferromagnet which leads to a soluble quantum dimer model at leading non-trivial order. In this limit, the ground state manifold -- while extensively degenerate -- breaks the inversion symmetry of the lattice, which implies a finite temperature Ising transition without translational symmetr

V. A. Brazhnyi, V. V. Konotop, Víctor M. Pérez-García

We present an approximate analytical theory and direct numerical computation of defect modes of a Bose-Einstein condensate loaded in an optical lattice and subject to an additional localized (defect) potential. Some of the modes are found to be remarkably stable and can be driven along the lattice by means of a defect moving following a step-like function de

Y. G. Shi, H. X. Yang, H. Huang, X. Liu

Two series of alpha and beta-NaxCoO2 materials have been prepared by means of Na deintercalation from the parent alpha-NaCoO2 and beta-Na0.6CoO2 phases, respectively. The alpha-NaxCoO2 materials undergo a clear phase transition from the hexagonal to the beta-phase like monoclinic structure along with Na deintercalation. Measur

Allan D. Boardman, Neil King, Larry Velasco

The concept of negative refraction is attracting a lot of attention. The initial ideas and the misconceptions that have arisen are discussed in sufficient detail to understand the conceptual structure that binds negative refraction to the existence of backward wave and forward wave phenomena. A presentation of the properties of isotropic media supporting bac

Yasuhiro Utsumi, Dmitri S. Golubev, Gerd Schön

We evaluate the current distribution for a single-electron transistor with intermediate strength tunnel conductance. Using the Schwinger-Keldysh approach and the drone (Majorana) fermion representation we account for the renormalization of system parameters. Nonequilibrium effects induce a lifetime broadening of the charge-state levels, which suppress large

Takashi Yoshidome, Akira Yoshimori, Takashi Odagaki

On the basis of the density functional theory, we give a clear definition of the free energy landscape. To show the usefulness of the definition, we construct the free energy landscape for rearrangement of atoms in an FCC crystal of hard spheres. In this description, the cooperatively rearranging region (CRR) is clealy related to the hard spheres involved in

Maria L. Ekiel-Jezewska, Eligiusz Wajnryb

A stationary stable solution of the Stokes equations for three identical heavy solid spheres falling in a vertical plane is found. It has no analog in the point-particle approximation. Three spheres aligned horizontally at equal distances evolve towards the equilibrium relative configuration while the point particles collapse onto a single point in a finite

Stefan Boettcher, Tomasz M. Kott

Using the discrete $\pm J$ bond distribution for the Sherrington-Kirkpatrick spin glass, all ground states for the entire ensemble of the bond disorder are enumerated. Although the combinatorial complexity of the enumeration severely restricts attainable system sizes, here $N\leq9$, some remarkably intricate patterns found in previous studies already emerge.

Dany Page, Andrew Cumming

Recent models of carbon ignition on accreting neutron stars predict superburst ignition depths that are an order of magnitude larger than observed. We explore a possible solution to this problem, that the compact stars in low mass X-ray binaries that have shown superbursts are in fact strange stars with a crust of normal matter. We calculate the properties o

Tohru Nagao, Kentaro Motohara, Roberto Maiolino, Alessandro Marconi

We present a very deep near-infrared spectroscopic observation of a strong Ly_alpha emitter at z=6.33, SDF J132440.6+273607, which we used to search for HeII 1640. This emission line is expected if the target hosts a significant number of population III stars. Even after 42 ksec of integration with the Subaru/OHS spectrograph, no emission-line features are d

D. Allard, E. Parizot, X. Bertou, J. Beatty

During the past ten years, gamma-ray bursts (GRB) have been extensively studied in the keV-MeV energy range but the high energy emission still remain mysterious. Ground based observatories have the possibility to investigate energy range around one GeV using the "single particle technique". The aim of the present study is to investigate the capabilit

J. R. Canvin, R. A. Laing, A. H. Bridle, W. D. Cotton

We apply our intrinsically symmetrical, decelerating relativistic jet model to deep VLA imaging of the inner 140 arcsec of the giant low-luminosity radio galaxy NGC 315. An optimized model accurately fits the data in both total intensity and linear polarization. We infer that the velocity, emissivity and field structure in NGC 315 are very similar to those o

B. H. C. Emonts, R. Morganti, T. A. Oosterloo, J. M. van der Hulst

We present results of an HI study of a complete sample of nearby radio galaxies. Our goal is to investigate whether merger or interaction events could be at the origin of the radio-AGN activity. Around five of our radio galaxies, hosted mainly by early-type galaxies, we detect extended HI in emission. In most cases this HI is distributed in large (up to 190

U. Kiziloglu, N. Kiziloglu, A. Baykal

CCD observations of stars in the young cluster IC 348 were obtained from 2004 August to 2005 January with a 0.45 m ROTSEIIId robotic reflecting telescope at the Turkish National Observatory site, Bakirlitepe, Turkey. The timing analysis of selected stars whose X-Ray counterpart were detected by Chandra X-Ray Observatory were studied. The time series of stars

Weike Xiao, Chang Peng, Xianfeng Ye, Heng Hao

Numerical simulation is an important tool to help us understand the process of structure formation in the universe. However many simulation results of cold dark matter (CDM) halos on small scale are inconsistent with observations: the central density profile is too cuspy and there are too many substructures. Here we point out that these two problems may be c

Qirong Yuan, Lifang Zhao, Yanbin Yang, Zhonglue Wen

The merging cluster of galaxies A2255 is covered by the Sloan Digital Sky Survey (SDSS) survey. In this paper we perform a morphological classification on the basis of the SDSS imaging and spectral data, and investigate the morphological dependence of the star formation rates (SFRs) for these member galaxies. As we expect, a tight correlation between the nor

Anne Thomas

Let X be a right-angled building. We show that the lattices in Aut(X) share many properties with tree lattices. For example, we characterise the set of covolumes of uniform and of nonuniform lattices in Aut(X), and show that the group Aut(X) admits an infinite ascending tower of uniform and of nonuniform lattices. These results are proved by constructing a f

D. M. Ghilencea, Hyun Min Lee

In orbifold compactifications on T^2/Z_2 with Scherk-Schwarz supersymmetry breaking, it is shown that (brane-localised) superpotential interactions and (bulk) gauge interactions generate at one-loop higher derivative counterterms to the mass of the brane (or zero-mode of the bulk) scalar field. These brane-localised operators are generated by integrating out

A. P. Balachandran, A. Pinzul, B. Qureshi

Poincaré-invariant quantum field theories can be formulated on non-commutative planes if the coproduct on the Poincaré group is suitably deformed \cite{Dimitrijevic:2004rf, Chaichian:2004za}.(See also especially Oeckl \cite{Oeckl:1999jun},\cite{Oeckl:2000mar} and Grosse et al.\cite{Grosse:2001mar}) As shown in \cite{Balachandran:2005eb}, this important resul

Darren E. Segall, Phillip C. Nelson, Rob Phillips

The tethered-particle method is a single-molecule technique that has been used to explore the dynamics of a variety of macromolecules of biological interest. We give a theoretical analysis of the particle motions in such experiments. Our analysis reveals that the proximity of the tethered bead to a nearby surface (the microscope slide) gives rise to a volume

Sorin Tanase-Nicola, Patrick B. Warren, Pieter Rein ten Wolde

Understanding cell function requires an accurate description of how noise is transmitted through biochemical networks. We present an analytical result for the power spectrum of the output signal of a biochemical network that takes into account the correlations between the noise in the input signal (the extrinsic noise) and the noise in the reactions that con

J. Wade Cherrington

We describe here some new results concerning the Lorentzian Barrett-Crane model, a well-known spin foam formulation of quantum gravity. Generalizing an existing finiteness result, we provide a concise proof of finiteness of the partition function associated to all non-degenerate triangulations of 4-manifolds and for a class of degenerate triangulations not p

Anirudh Pradhan, Vandana Rai, Saeed Otarod

Some bulk viscous general solutions are found for domain walls in Lyra geometry in the plane symmetric inhomogeneous spacetime. Expressions for the energy density and pressure of domain walls are derived in both cases of uniform and time varying displacement field $β$. The viscosity coefficient of bulk viscous fluid is assumed to be a power function of mass

Sourav Sur, Saurya Das, Soumitra SenGupta

We study generic Einstein-Maxwell-Kalb-Ramond-dilaton actions, and derive conditions under which they give rise to static, spherically symmetric black hole solutions. We obtain new asymptotically flat and non-flat black hole solutions which are in general electrically and magnetically charged. They have positive definite and finite quasi-local masses. Existi

M. Sadegh Movahed, G. R. Jafari, F. Ghasemi, Sohrab Rahvar

We use multifractal detrended fluctuation analysis (MF-DFA), to See query 1 study sunspot number fluctuations. The result of the MF-DFA shows that there are three crossover timescales in the fluctuation function. We discuss how the existence of the crossover timescales is related to a sinusoidal trend. Using Fourier detrended fluctuation analysis, the sinuso

C. W. J. Beenakker

I. Introduction (Preface, Exciton entanglers, Photon entanglers) II. Entanglement basics (Quantum versus classical correlations, Bell inequality, Entanglement measures for pure states, Entanglement measures for mixed states, Particle conservation, Phase reference) III. How to entangle free particles (Free bosons, Free fermions) IV. Spin versus orbital entang

Francisco Campanario, Antonio Pineda

We study the large order behaviour in perturbation theory of the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules. In particular, we consider their first infrared renormalons, for which we obtain their analytic structure with logarithmic accuracy and also an approximate determination of their normalization constant. Estimates of higher order terms of

P D Jarvis, S O Morgan

The Schrödinger-Robertson inequality for relativistic position and momentum operators X^μ, P_ν, μ, ν= 0,1,2,3, is interpreted in terms of Born reciprocity and `non-commutative' relativistic phase space geometry. For states which saturate the Schrödinger-Robertson inequality, a typology of semiclassical limits is pointed out, characterised by the orbit st

A. Cingoz, A. -T. Nguyen, D. Budker, S. K. Lamoreaux

We have studied collisional perturbations of radio-frequency (rf) electric-dipole (E1) transitions between the nearly degenerate opposite-parity levels in atomic dysprosium (Dy) in the presence of 10 to 80 $μ$Torr of H$_\text{2}$, N$_\text{2}$, He, Ar, Ne, Kr, and Xe. Collisional broadening and shift of the resonance, as well as the attenuation of the signal

Kang-Sin Choi, Jihn E. Kim

We study the transition between parallel and intersecting branes on a torus. Spontaneous symmetry breaking of nonabelian gauge symmetry is understood as brane separation, and a more general intermediate deformation is discussed. We argue that there exists supersymmetry preserving transition and we can always have parallel branes as a final state. The transit

Frank B. Estabrook

Ten conservation laws in useful polynomial form are derived from a Cartan form and Exterior Differential System (EDS) for the tetrad equations of vacuum relativity. The Noether construction of conservation laws for well posed EDS is introduced first, and an illustration given, deriving 15 conservation laws of the free field Maxwell Equations from symmetries

C. Figl, L. Longchambon, M. Jeppesen, M. Kruger

We present the first detector capable of recording high-bandwidth real time atom number density measurements of a Bose Einstein condensate. Based on a two-color Mach-Zehnder interferometer, our detector has a response time that is six orders of magnitude faster than current detectors based on CCD cameras while still operating at the shot-noise limit. With th

Juergen Appel, K. -P. Marzlin, A. I. Lvovsky

We analyze electromagnetically induced transparency and light storage in an ensemble of atoms with multiple excited levels (multi-Lambda configuration) which are coupled to one of the ground states by quantized signal fields and to the other one via classical control fields. We present a basis transformation of atomic and optical states which reduces the ana

Fernando G. Carvalhaes, Carla Goldman

We consider a nonlinear partial differential equation of conservation type to describe the dynamics of vesicular stomatitis virus observed in aliquots of fixed particle number taken from an evolving clone at periodic intervals of time \cite{novella 95}. The changes in time behavior of fitness function noticed in experimental data are related to a crossover e

Zhao Jianglin

In this paper, basing on a generalized Newtonian dynamics (GND) approach which has been proposed elsewhere we present a conjecture for turbulent flow. We firstly utilize the GND to reasonably unify the two phenomenological methods recently proposed of the water movement in unsaturated soils. Then in the same way a modified Euler equation (MEE) is yielded. Un

G. Y. Tsyaputa

All isolated, completely isolated, and nilpotent subsemigroups in the semigroup $\IS$ of all injective partial transformations of an $n$-element set, considered as a semigroup with a sandwich multiplication are described.

G. Y. Tsyaputa

Pairwise non-isomorphic semigroups obtained from the finite inverse symmetric semigroup $\mathcal{IS}_n ,$ finite symmetric semigroup $\mathcal{T}_n$ and bicyclic semigroup by the deformed multiplication proposed by Ljapin are classified.

Wlodzimierz Bryc, Jacek Wesolowski

We give an elementary construction of a time-invertible Markov process which is discrete except at one instance. The process is one of the quadratic harnesses studied in our previous papers and can be regarded as a random joint of two independent Poisson processes.

Aslak Bakke Buan, Henning Krause, Øyvind Solberg

We define support varieties in an axiomatic setting using the prime spectrum of a lattice of ideals. A key observation is the functoriality of the spectrum and that this functor admits an adjoint. We assign to each ideal its support and can classify ideals in terms of their support. Applications arise from studying abelian or triangulated tensor categories.

Taeyoung Lee, Melvin Leok, N. Harris McClamroch

We develop the equations of motion for full body models that describe the dynamics of rigid bodies, acting under their mutual gravity. The equations are derived using a variational approach where variations are defined on the Lie group of rigid body configurations. Both continuous equations of motion and variational integrators are developed in Lagrangian an

Mitya Boyarchenko

In this paper we prove an analogue of a recent result of Gordon and Stafford that relates the representation theory of certain noncommutative deformations of the coordinate ring of the n-th symmetric power of C^2 with the geometry of the Hilbert scheme of n points in C^2 through the formalism of Z-algebras. Our work produces, for every regular noncommutative

Anne Thomas

Let X be a polyhedral complex with finitely many isometry classes of links. We establish a restriction on the covolumes of uniform lattices acting on X. When X is two-dimensional and has all links isometric to either a complete bipartite graph or the building for a Chevalley group of rank 2 over a field of prime order, we obtain further restrictions on covol

Shyamoli Chaudhuri

CHL compactifications are supersymmetry preserving orbifolds of any perturbatively renormalizable and ultraviolet finite ground state of the perturbative string theories: heterotic, type I, or type II, preserving 32, 16, 12, 8, 4, (or zero) supersymmetries, and retaining the perturbative renormalizability and finiteness of the parent string vacuum. In this p

Alexander Belyaev, Jon Pumplin, Wu-Ki Tung, C. --P. Yuan

We study uncertainties of the predicted inclusive Higgs production cross section due to the uncertainties of parton distribution functions (PDF). Particular attention is given to bbH Yukawa coupling enhanced production mechanisms in beyond SM scenarios, such as MSSM. The PDF uncertainties are determined by the robust Lagrange Multiplier method within the CTE

Aiichi Iwazaki

We show a possibility that strong ``magnetic field'' $\sim 10^{15} $G is produced by color ferromagnetic quark matter in neutron stars. In the quark matter a color magnetic field is generated spontaneously owing to Savvidy mechanism and a gluon condensate arises for the stabilization of the field. Since the quark matter is electrically charged in the

H. E. Montgomery

This is a short paper summarising a presentation of the evolution of the Fermilab program for the next five to ten years. Emphasis is given to the Fermilab accelerator complex, but external collaboration is emphasised.

G. A. Monerat, E. V. Correa Silva, G. Oliveira-Neto, L. G. Ferreira Filho

We quantize three Friedmann-Robertson-Walker models in the presence of a negative cosmological constant and radiation. The models differ from each other by the constant curvature of the spatial sections, which may be positive, negative or zero. They give rise to Wheeler-DeWitt equations for the scale factor which have the form of the Schroedinger equation fo

Sugumi Kanno, Jiro Soda

We present a general formalism for black string perturbations in Randall-Sundrum 1 model (RS1). First, we derive the master equation for the electric part of the Weyl tensor $E_{μν}$. Solving the master equation using the gradient expansion method, we give the effective Teukolsky equation on the brane at low energy. It is useful to estimate gravitational wav

Jiro Soda, Sugumi Kanno

Homogeneous cosmology in the braneworld can be studied without solving bulk equations of motion explicitly. The reason is simply because the symmetry of the spacetime restricts possible corrections in the 4-dimensional effective equations of motion. It would be great if we could analyze cosmological perturbations without solving the bulk. For this purpose, w

F. Canfora

A suitable splitting of tachyon field equation is able to disclose non trivial properties of Born-Infeld (some known, some unexpected) and Polyakov actions; the tachyon equation also can be analyzed in some detail. The analysis displays an intriguing connection between sine-Gordon theory and some crucial issues such as the emergence of perturbative string st

Lorenzo Iorio

In this paper we explicitly work out the secular perturbations induced on all the Keplerian orbital elements of a test body to order O(e^2) in the eccentricity e by the weak-field long-range modifications of the usual Newton-Einstein gravity due to the Dvali-Gabadadze-Porrati (DGP) braneworld model. The Gauss perturbative scheme is used. It turns out that th

Moshe Schwartz, Paul H. Siegel, Alexander Vardy

We consider hard-decision iterative decoders for product codes over the erasure channel, which employ repeated rounds of decoding rows and columns alternatingly. We derive the exact asymptotic probability of decoding failure as a function of the error-correction capabilities of the row and column codes, the number of decoding rounds, and the channel erasure

Mikael Rechtsman, Frank Stillinger, Salvatore Torquato

We devise an inverse statistical-mechanical methodology to find optimized interaction potentials that lead spontaneously to a target many-particle configuration. Target structures can possess varying degrees of disorder, thus extending the traditional idea of self-assembly to incorporate both amorphous and crystalline structures as well as quasicrystals. For

A. Sarkar, K. Dasgupta, P. Barat, P. Mukherjee

Two sets of amorphous carbon materials prepared at different routes are irradiated with swift (145 MeV) heavy ion (Ne6+). The structural parameters like the size of ordered grains along c and a axis i.e. Lc & La, the average spacing of the crystallographic planes (002) i.e. d002 and the fraction of the amorphous phase of the unirradiated and the irradiated s

A. Ray, P. Barat, P. Mukherjee, A. Sarkar

Plastic flow behavior of low carbon steel has been studied at room temperature during tensile deformation by varying the initial strain rate of 3.3x10e-4 1/sec to the final strain rate ranging from 1.33x10e-3 1/sec to 2.0x10e-3 1/sec at a fixed engineering strain of 12%. Haasen plot revealed that the mobile dislocation density remained almost invariant at th

Tobias Ambjoernsson, Ralf Metzler

We use a master equation approach based on the Poland-Scheraga free energy for DNA denaturation to investigate the (un)zipping dynamics of a denaturation wedge in a stretch of DNA, that is clamped at one end. In particular, we quantify the blinking dynamics of a fluorophore-quencher pair mounted within the denaturation wedge. We also study the behavioural ch

Janos Polonyi, Franck Stauffer

The absence of fermionic, asymptotical one-particle states in the Luttinger model raises the suspicion that the interactions are actually strong at the vicinity of the Fermi points. The functional internal space renormalization group method, a systematical scheme for the computation of effective coupling strengths off the Fermi points, is applied to shed som

Ralf Metzler, Tobias Ambjoernsson

Based on modern single molecule techniques, we devise a number of possible experimental setups to probe local properties of DNA such as the presence of DNA-knots, loops or folds, or to obtain information on the DNA-sequence. Similarly, DNA may be used as a local sensor. Employing single molecule fluorescence methods, we propose to make use of the physics of

C. W. Luo, P. T. Shih, Y. -J. Chen, M. H. Chen

The spatially-resolved relaxation characteristics of photoinduced quasiparticles (QPs) in CuO$sub 2$ planes of underdoped YBCO are disclosed by polarized fs time-resolved spectroscopy. The relaxation time (tau) along b axis diverges at Tc, and appears to be governed by a temperature-dependent gap Delta(T) at T < Tc. Furthermore, for T > Tc, a monotonic incre

Melanie David, Tomoya Kishi, Masanori Kisaku, Hiroshi Nakanishi

We investigate the stable structures of Fe-filled single-walled carbon nanotubes (SWNTs) on Ni(111), using density functional theory calculations. We find stable geometries and electronic states for the nanotube on Ni(111). We propose the possibility that the C-C bonds of carbon nanotube are broken by Fe wire and Ni surface. That is, when Fe-filled SWNT(3, 3

Zuxin Ye, Qiang Li, W. D. Si, M. Suenaga

Magnetic flux front and induction contours in superconducting YBa2Cu3O7-d films with defect size s ~ l (superconducting coherence length) and s > l are studied by magneto-optical imaging. Robust self-affine spatial correlation was observed using scaling analysis in the small pinning-dominated (s ~ l) disorderd films. The roughness exponent was determined to

Eran Ginossar, Shimon Levit

We consider a semiconductor quantum-well placed in a wave guide microcavity and interacting with the broadband squeezed vacuum radiation, which fills one mode of the wave guide with a large average occupation. The wave guide modifies the optical density of states so that the quantum well interacts mostly with the squeezed vacuum. The vacuum is squeezed aroun

F. Combes

Polar ring galaxies, where matter is in equilibrium in perpendicular orbits around spiral galaxies, are ideal objects to probe the 3D shapes of dark matter halos. The conditions to constrain the halos are that the perpendicular system does not strongly perturb the host galaxy, or that it is possible to derive back its initial shape, knowing the formation sce

W. Brinkmann, I. E. Papadakis, C. Raeth, P. Mimica

We present the results of a detailed temporal analysis of the bright BL Lac object Mrk 421 using the three available long timing mode observations by the EPIC PN camera. This detector mode is characterized by its long life time and is largely free of photon pile-up problems. The source was found in different intensity and variability states differing by up t

Max Tegmark

How did it all begin? Although this question has undoubtedly lingered for as long as humans have walked the Earth, the answer still eludes us. Yet since my grandparents were born, scientists have been able to refine this question to a degree I find truly remarkable. In this brief essay, I describe some of my own past and ongoing work on this topic, centering

Akira Igarashi, Hiroaki S. Yamada

We numerically study influence of a polychromatic perturbation on wave acket dynamics in one-dimensional double-well potential. It is found that time-dependence of the tunneling probability shows two kinds of the motion typically, coherent oscillation and irregular fluctuation, depending on the perturbation parameters. The coherent motion changes the irregul

B. Blok, L. Frankfurt

We argue that at sufficiently small Bjorken $x$ where pQCD amplitude rapidly increases with energy and violates probability conservation the shadowing effects in the single-scale small $x$ hard QCD processes can be described by an effective quantum field theory of interacting quasiparticles. The quasiparticles are the perturbative QCD ladders. We find, withi

Emily Leeper, Kazuya Koyama, Roy Maartens

We demonstrate that a two brane system with a bulk scalar field driving power-law inflation on the branes has an instability in the radion. We solve for the resulting trajectory of the brane, and find that the instability can lead to collision. Brane quantities such as the scale factor are shown to be regular at this collision. In addition we describe the sy

Per Arne Rikvold

We compare and contrast the long-time dynamical properties of two individual-based models of biological coevolution. Selection occurs via multispecies, stochastic population dynamics with reproduction probabilities that depend nonlinearly on the population densities of all species resident in the community. New species are introduced through mutation. Both m

Brian C. Tiburzi

We determine the masses and magnetic moments of the octet baryons in chiral perturbation theory formulated for a mixed lattice action of Ginsparg-Wilson valence quarks and staggered sea quarks. Taste-symmetry breaking does not occur at next-to-leading order in the combined lattice-spacing and chiral expansion. Expressions derived for masses and magnetic mome