December 2006 arXiv papers — page 28

M. E. Zhitomirsky, H. Tsunetsugu

Quantum Heisenberg antiferromagnets on pyrochlore and checkerboard lattices in a strong external magnetic field are mapped onto hard-core lattice gases with an extended exclusion region. The effective models are studied by the exchange Monte Carlo simulations and by the transfer matrix method. The transition point and the critical exponents are obtained nume

E. V. Votyakov, Yu. Kolesnikov, O. Andreev, E. Zienicke

We use a combination of numerical simulations and experiments to elucidate the structure of the flow of an electrically conducting fluid past a localized magnetic field, called magnetic obstacle. We demonstrate that the stationary flow pattern is considerably more complex than in the wake behind an ordinary body. The steady flow is shown to undergo two bifur

Oleg Derzhko, Johannes Richter, Andreas Honecker, Heinz-Jürgen Schmidt

The purpose of the present paper is two-fold. On the one hand, we review some recent studies on the low-temperature strong-field thermodynamic properties of frustrated quantum spin antiferromagnets which admit the so-called localized-magnon eigenstates. One the other hand, we provide some complementary new results. We focus on the linear independence of the

T. M. Aliev, M. Savci

Scalar form factor of the nucleon is calculated in the framework of light cone QCD sum rules, using the most general form of the baryon current. Using the result on scalar form factor of the nucleon, the nucleon-scalar "sigma" and "a_0" meson coupling constants are estimated. Our results on these couplings are in good agreement with the predi

Stephen Lack

Bicat is the tricategory of bicategories, homomorphisms, pseudonatural transformations, and modifications. Gray is the subtricategory of 2-categories, 2-functors, pseudonatural transformations, and modifications. We show that these two tricategories are not triequivalent.

Zihua Weng

Based on Maxwellian quaternionic electromagnetic theory, the electromagnetic interaction, gravitational interaction and their coupling influence with the dark matter field in octonionic space are discussed. The research results disclose the close relationships of dark matter field with electromagnetic and gravitational interactions. In the electromagnetic in

Cristopher Moore, Alexander Russell, Piotr Sniady

It is known that any quantum algorithm for Graph Isomorphism that works within the framework of the hidden subgroup problem (HSP) must perform highly entangled measurements across Ω(n \log n) coset states. One of the only known models for how such a measurement could be carried out efficiently is Kuperberg's algorithm for the HSP in the dihedral group, i

Tom Jeltes, John M. McNamara, Wim Hogervorst, Wim Vassen

Fifty years ago, Hanbury Brown and Twiss (HBT) discovered photon bunching in light emitted by a chaotic source, highlighting the importance of two-photon correlations and stimulating the development of modern quantum optics . The quantum interpretation of bunching relies upon the constructive interference between amplitudes involving two indistinguishable ph

Pierdomenico Paolino, Ludovic Bellon

We present an application of a quadrature phase interferometer to the measurement of the angular position of a parallel laser beam with interferometric precision. In our experimental realization we reach a resolution of 6.8e-10 rad (1.4e-4 arcsec) for 1 kHz bandwidth in a 2e-2 rad (1 deg) range. This alternative to the optical lever technique features absolu

Yun-Juan Bao, Shun-Qing Shen

Electric response of spin polarization in two-dimensional electron gas with structural inversion asymmetry subjected to a magnetic field was studied by means of the linear and non-linear theory and numerical simulation with the disorder effect. It was found by Kubo linear reponse theory that an electric resonant response of spin polarization occurs when the

N. Scoville, A. Benson, A. W. Blain, D. Calzetti

The Cosmic Evolution Survey (COSMOS) was initiated with an extensive allocation (590 orbits in Cycles 12-13) using the Hubble Space Telescope (HST) for high resolution imaging. Here we review the characteristics of the HST imaging with the Advanced Camera for Surveys (ACS) and parallel observations with NICMOS and WFPC2. A square field (1.8$\sq$°) has been i

Margarita Safonova, C. S. Stalin

Globular clusters have been alternatively predicted to host intermediate-mass black holes (IMBHs) or nearly impossible to form and retain them in their centres. Over the last decade enough theoretical and observational evidence have accumulated to believe that many galactic globular clusters may host IMBHs in the centres, just like galaxies do. The well-esta

A. V. Tsiganov

We introduce a family of compatible Poisson brackets on the space of $2\times 2$ polynomial matrices, which contains the Sklyanin bracket, and use it to derive a multi-Hamiltonian structure for a set of integrable systems that includes $XXX$ Heisenberg magnet, the open and periodic Toda lattices, the discrete self-trapping model and the Goryachev-Chaplygin g

Ajay C. Ramadoss

Given a vector bundle $\mathcal E$ on a connected compact complex manifold $X$, [FLS] use a notion of completed Hochschild homology $\hat{\text{HH}}$ of $\text{Diff}(\mathcal E)$ such that $\hat{\text{HH}}_0(\text{Diff}(\mathcal E))$ is isomorphic to $\text{H}^{2n}(X, \mathbb C)$. On the other hand, they construct a trace on $\hat{\text{HH}}_0(\text{Diff}(\m

Garud Iyengar, Anuj Kumar

We present a simple dynamic equilibrium model for an online exchange where both buyers and sellers arrive according to a exogenously defined stochastic process. The structure of this exchange is motivated by the limit order book mechanism used in stock markets. Both buyers and sellers are elastic in the price-quantity space; however, only the sellers are ass

Gen Tatara, Hiroshi Kohno, Junya Shibata, Yann Lemaho

Non-adiabatic correction to spin transfer torque arising from fast-varying spin texture is calculated treating conduction electron fully quantum mechanically. The torque is non-local in space, and is shown to equivalent to a force (due to momentum transfer) acting on the center of mass of the texture. Another kind of force exists in the adiabatic regime, and

Ian Ellwood

The standard notion of NS-NS 3-form flux is lifted to Hitchin's generalized geometry. This generalized flux is given in terms of an integral of a modified Nijenhuis operator over a generalized 3-cycle. Explicitly evaluating the generalized flux in a number of familiar examples, we show that it can compute three-form flux, geometric flux and non-geometric

Robert Archbold, Astrid an Huef

We consider separable $C^*$-dynamical systems $(A,G,α)$ for which the induced action of the group $G$ on the spectrum $\hat A$ of the $C^*$-algebra $A$ is free. We study how the representation theory of the associated crossed-product $C^*$-algebra $A\rtimes_αG$ depends on the representation theory of $A$ and the properties of the action of $G$ on $\hat A$. O

Yuri Borissov, Moon Ho Lee

The average conditional entropy of the key given the message and its corresponding cryptogram, H(K|M,C), which is reffer as a key appearance equivocation, was proposed as a theoretical measure of the strength of the cipher system under a known-plaintext attack by Dunham in 1980. In the same work (among other things), lower and upper bounds for H(S}_{M}|M^L,C

Chuan-Hung Chen, Chao-Qiang Geng

If the HyperCP three events for the decay of $Σ^+\to pμ^+μ^-$ are explained by a new pseudoscalar (axial-vector) boson $X_{P(A)}$ with a mass of 214.3 MeV, we study the constraints on the couplings between $X_{P(A)}$ and fermions from the experimental data in $K$ and $B$ processes. Some implications of the new particle on flavor changing $B$ and $τ$ decays a

Jeffrey H. Shapiro, Mohsen Razavi

The weak nonlinear Kerr interaction between single photons and intense laser fields has been recently proposed as a basis for distributed optics-based solutions to few-qubit applications in quantum communication and computation. Here, we analyze the above Kerr interaction by employing a continuous-time multi-mode model for the input/output fields to/from the

John Learned, Steve Dye, Sandip Pakvasa, Robert Svoboda

We describe a method for determining the hierarchy of the neutrino mass spectrum and theta_13 through remote detection of antineutrinos from a nuclear reactor. This method utilizing a single, 10-kt scintillating liquid detector at a distance of 50-64 kilometers from the reactor complex measures mass-squared differences involving nu_3 with a one (ten) year ex

Dongsu Bak, Nobuyoshi Ohta, Paul K. Townsend

We present new supersymmetric solutions of the Dirac-Born-Infeld equations for time-independent D2-branes, including a 1/2 supersymmetric `dyonic' D2-brane and various 1/4 supersymmetric configurations that include `twisted' supertubes, superfunnels with arbitrary planar cross-section, asymptotically planar D2-branes, and non-singular intersections o

Casey R. Myers, Marcus Silva, Kae Nemoto, William J. Munro

In this paper we investigate stabilizer quantum error correction codes using controlled phase rotations of strong coherent probe states. We explicitly describe two methods to measure the Pauli operators which generate the stabilizer group of a quantum code. First, we show how to measure a Pauli operator acting on physical qubits using a single coherent state

Robert A. Van Wesep

There is a natural equivalence relation on representations of the states of a given quantum system in a Hilbert space, two representations being equivalent iff they are related by a unitary transformation. There are two equivalence classes, with members of opposite classes being related by a conjugate-unitary (anti-unitary) transformation. These two conjugac

C. Quesne

An exactly solvable position-dependent mass Schrödinger equation in two dimensions, depicting a particle moving in a semi-infinite layer, is re-examined in the light of recent theories describing superintegrable two-dimensional systems with integrals of motion that are quadratic functions of the momenta. To get the energy spectrum a quadratic algebra approac

C. Quesne, V. M. Tkachuk

The $D$-dimensional two-parameter deformed algebra with minimal length introduced by Kempf is generalized to a Lorentz-covariant algebra describing a ($D+1$)-dimensional quantized space-time. For D=3, it includes Snyder algebra as a special case. The deformed Poincaré transformations leaving the algebra invariant are identified. Uncertainty relations are stu

Marco G. Genoni, Matteo G. A. Paris

We address the trade-off between information gain and state disturbance in measurement performed on qudit systems and devise a class of optimal measurement schemes that saturate the ultimate bound imposed by quantum mechanics to estimation and transmission fidelities. The schemes are minimal, i.e. they involve a single additional probe qudit, and optimal, i.

Katarzyna Bolonek, Piotr Kosinski

We consider two simple models of higher-derivative and nonlocal quantu systems.It is shown that, contrary to some claims found in literature, they can be made unitary.

Jie Liu, Li-Bin Fu

Adiabatic approximation for quantum evolution is investigated quantitatively with addressing its dependence on the Berry connections. We find that, in the adiabatic limit, the adiabatic fidelity may uniformly converge to unit or diverge manifesting the breakdown of adiabatic approximation, depending on the type of the singularity of the Berry connections as

Xiaolong Su, Jietai Jing, Qing Pan, Changde Xie

We proposed a scheme of continuous-variable quantum key distribution, in which the bright Einstein-Podolsky-Rosen entangled optical beams are utilized. The source of the entangled beams is placed inside the receiving station, where half of the entangled beams are transmitted with round trip and the other half are retained by the receiver. The amplitude and p

Refael Abta, Nadav M. Shnerb

The linear instability of Lotka-Volterra orbits in the homogenous manifold of a two-patch system is analyzed. The origin of these orbits instability in the absence of prey migration is revealed to be the dependence of the angular velocity on the azimuthal angle; in particular, the system desynchronizes at the exit from the slow part of the trajectory. Using

F. Pontiggia, G. Colombo, C. Micheletti, H. Orland

The near-native free energy landscape of protein G is investigated through 0.4 microseconds-long atomistic molecular dynamics simulations in explicit solvent. A theoretical and computational framework is used to assess the time-dependence of salient thermodynamical features. While the quasi-harmonic character of the free energy is found to degrade in a few n

Igor L. Iosilevski, Alexander Yu. Chigvintsev

The properties of the first-order phase transition in a set of plasma models with common feature - absence of individual correlations between charges of op-posite sign, have been studied. Predicted discontinuities in equilibrium non-uniform charge profiles have been calculated for the case of electron distribution in atomic cell and some other similar situat

L. S. Yao, S. Ghosh Moulic

The nonlinear development of finite amplitude disturbances in mixed convection flow in a heated vertical annulus is studied by direct numerical simulation. The unsteady Navier Stokes equations are solved numerically by a spectral method for different initial conditions. The results indicate that the equilibrium state of the flow is not unique, but depends on

Murray W. McCutcheon, Georg W. Rieger, Jeff F. Young, Dan Dalacu

Second-harmonic and sum-frequency mixing phenomena associated with 3D-localized photonic modes are studied in InP-based planar photonic crystal microcavities excited by short-pulse radiation near 1550 nm. Three-missing-hole microcavities that support two closely-spaced modes exhibit rich second-order scattering spectra that reflect intra- and inter-mode mixi

K. Szymaniec, W. Chalupczak, E. Tiesinga, C. J. Williams

We have observed that the collisional frequency shift in primary caesium fountain clocks varies with the clock state population composition and, in particular, is zero for a given fraction of the |F = 4, mF = 0> atoms, depending on the initial cloud parameters. We present a theoretical model explaining our observations. The possibility of the collisional shi

John W. Norbury

A set of examples is provided that illustrate the use of work as applied to simple machines. The ramp, pulley, lever and hydraulic press are common experiences in the life of a student and their theoretical analysis therefore makes the abstract concept of work more real. The mechanical advantage of each of these systems is also discussed so that students can

L. I. Ognev

By computer numerical simulation of heating of a dust conducting particle in homogeneous plasma it was shown that depending on initial temperature of a particle both heating and cooling were possible with formation of two different quasi-stable conditions - temperature bistability. The "hot" condition corresponds to positive charge of the particle an

B. Roth, J. Koelemeij, S. Schiller, L. Hilico

We describe the current status of high-precision ab initio calculations of the spectra of molecular hydrogen ions (H_2^+ and HD^+) and of two experiments for vibrational spectroscopy. The perspectives for a comparison between theory and experiment at a level of 1 ppb are considered.

Edoardo Milotti

In a recent paper I have introduced a package for the exact simulation of power-law noises and other colored noises (E. Milotti, Comput. Phys. Commun. {\bf 175} (2006) 212): in particular the algorithm generates $1/f^α$ noises with $0 < α\leq 2$. Here I extend the algorithm to generate $1/f^α$ noises with $2 < α\leq 4$ (black noises). The method is exact in

Yong Sun

In this work, the Z-average, effective, apparent diffusion coefficients and their poly-dispersity indexes were investigated for dilute poly-disperse homogeneous spherical particles in dispersion where the Rayleigh-Gans-Debye approximation is valid. The results reveal that the values of the apparent and effective diffusion coefficients at a scattering angle i

A. S. Botvina, I. N. Mishustin, W. Trautmann

During the collapse of massive stars, and the supernova type-II explosions, stellar matter reaches densities and temperatures which are similar to the ones obtained in intermediate-energy nucleus-nucleus collisions. The nuclear multifragmentation reactions can be used for determination of properties of nuclear matter at subnuclear densities, in the region of

John W. Norbury

Modern cosmic ray transport codes, that are capable of use for a variety of applications, need to include all significant atomic, nuclear and particle reactions at a variety of energies. Lepton pair production from nucleus-nucleus collisions has not been included in transport codes to date. Using the methods of Baur, Bertulani and Baron, the present paper pr

T. Melde, W. Plessas, B. Sengl

We report on a study of pi and eta decays of strange baryon resonances within relativistic constituent-quark models based on one-gluon-exchange and Goldstone-boson-exchange dynamics. The investigations are performed in the point form of Poincare-invariant relativistic quantum mechanics with a spectator-model decay operator. The covariant predictions of the c

Ru Peng, Xiao-Ming Xu, Dai-Cui Zhou

We predict that initially produced chi_cJ mesons at low transverse momentum in the central rapidity region are almost dissociated by nucleons and antinucleons in hadronic matter produced in central Au+Au collisions at RHIC energies sqrt {s_{NN}}= 130 and 200 GeV. In calculations the nucleon and antinucleon distributions in hadronic matter are results of evol

A. Parravano, H. Rivera-Ramirez, M. G. Cosenza

We study the consequences of introducing individual nonconformity in social interactions, based on Axelrod&#39;s model for the dissemination of culture. A constraint on the number of situations in which interaction may take place is introduced in order to lift the unavoidable ho mogeneity present in the final configurations arising in Axelrod&#39;s related m

Eric J. Hildebrand, Michael A. Buice, Carson C. Chow

We present an approach for the description of fluctuations that are due to finite system size induced correlations in the Kuramoto model of coupled oscillators. We construct a hierarchy for the moments of the density of oscillators that is analogous to the BBGKY hierarchy in the kinetic theory of plasmas and gases. To calculate the lowest order system size e

Dmitry Levko

The method of solving of nonlinear Schrödinger equation is considered. Some examples of its applications are demonstrated.

Bruno Cessac, Jacques-Alexandre Sepulchre

We consider simple examples illustrating some new features of the linear response theory developed by Ruelle for dissipative and chaotic systems [{\em J. of Stat. Phys.} {\bf 95} (1999) 393]. In this theory the concepts of linear response, susceptibility and resonance, which are familiar to physicists, have been revisited due to the dynamical contraction of

Harold Fellermann, Steen Rasmussen, Hans-Joachim Ziock, Ricard V. Sole

Cross-reactions and other systematic issues generated by the coupling of functional chemical subsystems pose the largest challenge for assembling a viable protocell in the laboratory. Our current work seeks to identify and clarify such key issues as we represent and analyze in simulation a full implementation of a minimal protocell. Using a 3D dissipative pa

Ihor Lubashevsky, Rudolf Friedrich, Reinhard Mahnke, Andrey Ushakov

The boundary conditions for the Fokker-Planck equations, forward and backward ones are directly derived from the Chapman-Kolmogorov equation for M-dimensional region with boundaries. The boundaries are assumed, in addition, to be able to absorb wandering particles or to give rise to fast surface transport. It is demonstrated that the boundaries break down th

T. Miyao, H. Spohn

The bipolaron are two electrons coupled to the elastic deformations of an ionic crystal. We study this system in the Fröhlich approximation. If the Coulomb repulsion dominates, the lowest energy states are two well separated polarons. Otherwise the electrons form a bound pair. We prove the validity of the Pekar-Tomasevich energy functional in the strong coup

Hongyun Wang

In this manuscript, we consider the case where a Brownian particle is subject to a static periodic potential and is driven by a constant force. We derive analytic formulas for the average velocity and the effective diffusion.

Pierre Guillot

We study a collection of operations on the cohomotopy of any space, with which it becomes a &#34;beta-ring&#34;, an algebraic structure analogous to a lambda-ring. In particular, this ring possesses Adams operations, represented by maps on the infinite loop space of the sphere spectrum. We compute their effect in homotopy on the image of J, and in mod 2 coho

John B. Bell, Alejandro L. Garcia, Sarah A. Williams

The Landau-Lifshitz Navier-Stokes (LLNS) equations incorporate thermal fluctuations into macroscopic hydrodynamics by using stochastic fluxes. This paper examines explicit Eulerian discretizations of the full LLNS equations. Several CFD approaches are considered (including MacCormack&#39;s two-step Lax-Wendroff scheme and the Piecewise Parabolic Method) and

Olga Plamenevskaya

In this short note, we observe that the Heegaard Floer contact invariant is combinatorial by applying the algorithm of Sarkar--Wang to the description of the contact invariant due to Honda--Kazez--Matic. We include an example of this combinatorial calculation.

Milena Stanislavova, Atanas Stefanov

We show that the viscous Camassa-Holm equation subject to an external force, and where the viscosity term is given by second order differential operator in divergence form has a global attractors in the energy space $H^1$. Moreover, we establish an asymptotic smoothing effect.

G. Lusztig

Let G be a special orthogonal group over an algebraically closed field of characteristic exponent p. In this paper we extend certain aspects of the Dynkin-Kostant theory of unipotent elements in G (when p=1) to the general case (including p=2).

Marissa Condon, Rossen I. Ivanov

Explicit expressions are presented that describe the input-output behaviour of a nonlinear system in both the frequency and the time domain. The expressions are based on a set of coefficients that do not depend on the input to the system and are universal for a given system. The anharmonic oscillator is chosen as an example and is discussed for different cho

Gabor Wiese, Niko Naumann

In this article we consider mod p modular Galois representations which are unramified at p such that the Frobenius element at p acts through a scalar matrix. The principal result states that the multiplicity of any such representation is bigger than 1.

L. J. P. Kilford, Gabor Wiese

In this article we report on extensive calculations concerning the Gorenstein defect for Hecke algebras of spaces of modular forms of prime weight p at maximal ideals of residue characteristic p such that the attached mod p Galois representation is unramified at p and the Frobenius at p acts by scalars. The results lead us to the ask the question whether the

Andreas Kollross, Evangelia Samiou

We classify all simply connected Riemannian manifolds whose isotropy groups act with cohomogeneity less than or equal to two.

J. Creutzig, T. Mueller-Gronbach, K. Ritter

We study optimal approximation of stochastic processes by polynomial splines with free knots. The number of free knots is either a priori fixed or may depend on the particular trajectory. For the $s$-fold integrated Wiener process as well as for scalar diffusion processes we determine the asymptotic behavior of the average $L_p$-distance to the splines space

Vincent Bansaye

We consider a generalized version in continuous time of the parking problem of Knuth. Files arrive following a Poisson point process and are stored on a hardware identified with the real line, at the right of their arrival point. We study here the evolution of the extremities of the data block straddling 0, which is empty at time 0 and is equal to $\RRR$ at

Gert-Martin Greuel, Christoph Lossen, Eugenii Shustin

In this survey, we report on progress concerning families of projective curves with fixed number and fixed (topological or analytic) types of singularities. We are, in particular, interested in numerical, universal and asymptotically proper sufficient conditions to guarantee the nonemptyness, T-smoothness and irreducibility of the variety of all projective c

Sergei Sergeev

This paper presents two universal algorithms for generalized Bellman equations with symmetric Toeplitz matrix. The algorithms are semiring extensions of two well-known methods solving Toeplitz systems in the ordinary linear algebra.

Iasson Karafyllis, Costas Kravaris

In this paper it is showed that if a time-varying uncertain system is robustly completely detectable then there exists an estimator for this system, i.e. we can estimate asymptotically the state vector of the system. Moreover, if a time-varying uncertain system is robustly completely observable then there exists an estimator for this system that guarantees c

R Haydon, A Molto, J Orihuela

Let $Γ$ be a Polish space and let $K$ be a separable and pointwise compact set of real-valued functions on $Γ$. It is shown that if each function in $K$ has only countably many discontinuities then $C(K)$ may be equipped with a $T_p$-lower semicontinuous and locally uniformly convex norm, equivalent to the supremum norm.

Marc Peigné, Wolfgang Woess

Let $(Y_n)$ be a sequence of i.i.d. real valued random variables. Reflected random walk $(X_n)$ is defined recursively by $X_0=x \ge 0$, $X_{n+1} = |X_n - Y_{n+1}|$. In this note, we study recurrence of this process, extending a previous criterion. This is obtained by determining an invariant measure of the embedded process of reflections.

Yves Benoist, Hee Oh

Let G be the group of k-points of a connected reductive k-group and H a symmetric subgroup associated to an involution s of G. We prove a polar decomposition G=KAH for the symmetric space G/H over any local field k of characteristic not 2. Here K is a compact subset of G and A is a finite union of the groups of k-points of maximal (k,s)-split tori, one for e

Ilka Agricola, Thomas Friedrich, Mario Kassuba

Assume that the compact Riemannian spin manifold $(M^n,g)$ admits a $G$-structure with characteristic connection $\nabla$ and parallel characteristic torsion ($\nabla T=0$), and consider the Dirac operator $D^{1/3}$ corresponding to the torsion $T/3$. This operator plays an eminent role in the investigation of such manifolds and includes as special cases Kos

Boris Tsirelson

Motions of the plane (shifts and rotations) correspond to automorphisms of the type I Arveson system of white noise. I prove that automorphisms corresponding to rotations cannot be extended to the type II Arveson system of Warren&#39;s noise.

Nicolas Monod

We establish the vanishing for non-trivial unitary representations of the bounded cohomology of SL_d up to the rank. It holds more generally for uniformly bounded representations on superreflexive spaces. The same results are obtained for lattices. We also prove that the real bounded cohomology of any lattice is invariant in the same range.

Marco D&#39;Anna, Marco Fontana

After recalling briefly the main properties of the amalgamated duplication of a ring $R$ along an ideal $I$, denoted by $R\JoinI$, we restrict our attention to the study of the properties of $R\JoinI$, when $I$ is a multiplicative canonical ideal of $R$ \cite{hhp}. In particular, we study when every regular fractional ideal of $R\Join I$ is divisorial.

Polona Oblak

In this paper we completely characterize all possible pairs of Jordan canonical forms for mutually annihilating nilpotent pairs, i.e. pairs $(A,B)$ of nilpotent matrices such that $AB=BA=0$.

YanYan Li, Lei Zhang

For a sequence of blow up solutions of the Yamabe equation on non-locally confonformally flat compact Riemannian manifolds of dimension 10 or 11, we establish sharp estimates on its asymptotic profile near blow up points as well as sharp decay estimates of the Weyl tensor and its covariant derivatives at blow up points. If the Positive Mass Theorem held in d

Cheng K. Lee, Jenq-Daw Lee

A survival model is derived from the exponential function using the concept of fractional differentiation. The hazard function of the proposed model generates various shapes of curves including increasing, increasing-constant-increasing, increasing-decreasing-increasing, and so-called bathtub hazard curve. The model also contains a parameter that is the maxi

Zongxia Liang, Tusheng Zhang

In this paper, we establish the existence of the solutions $ (X, L)$ of reflected stochastic differential equations with possible anticipating initial random variables. The key is to obtain some substitution formula for Stratonovich integrals via a uniform convergence of the corresponding Riemann sums.

Jeff Cheeger, Bruce Kleiner

This is one of a series of papers examining the interplay between differentiation theory for Lipschitz maps, X-->V, and bi-Lipschitz nonembeddability, where X is a metric measure space and V is a Banach space. Here, we consider the case V=L^1 where differentiability fails. We establish another kind of differentiability for certain X, including R^n and H, the

Jan R. Strooker

Of the many interesting insights in the Auslander-Bridger Memoir of 1969, the theory of Gorenstein dimension has most often been taken up by commutative algebraists. Over a local ring, it deals with resolutions by modules which are totally reflexive with regard to free modules. For some years now, one has been trying to replace frees by semidualizing modules

Xavier Yvonne

We derive a straightening-free algorithm that computes the canonical bases of any higher-level q-deformed Fock space.

Claudia Pinzari, John E. Roberts

The spectral functor of an ergodic action of a compact quantum group G on a unital C*-algebra is quasitensor, in the sense that the tensor product of two spectral subspaces is isometrically contained in the spectral subspace of the tensor product representation, and the inclusion maps satisfy natural properties. We show that any quasitensor *-functor from Re

Graham Smith

Let $(M,Q)$ be a compact, three dimensional manifold of strictly negative sectional curvature. Let $(Σ,P)$ be a compact, orientable surface of hyperbolic type (i.e. of genus at least two). Let $θ:π_1(Σ,P)\toπ_1(M,Q)$ be a homomorphism. Generalising a recent result of Gallo, Kapovich and Marden concerning necessary and sufficient conditions for the existence

Santanu Dey, Rolf Gohm

Motivated by a result on weak Markov dilations, we define a notion of characteristic function for ergodic and coisometric row contractions with a one-dimensional invariant subspace for the adjoints. This extends a definition given by G. Popescu. We prove that our characteristic function is a complete unitary invariant for such tuples and show how it can be c

Marisa Fernández, Vicente Muñoz

This paper expands some of the issues of the paper math.SG/0506449. We introduce a new technique to produce symplectic manifolds, by taking a symplectic non-free action of a finite group on a symplectic manifold and resolving symplectically the singularities of the quotient. We also introduce a new type of Massey product to detect non-formality. This allows

William J. Cook, Haisheng Li, Kailash C. Misra

Using certain results for the vertex operator algebras associated with affine Lie algebras we obtain recurrence relations for the characters of integrable highest weight irreducible modules for an affine Lie algebra. As an application we show that in the simply-laced level 1 case, these recurrence relations give the known characters, whose principal speciali

Peter Watson, Hugo Reinhardt

Coulomb gauge Yang-Mills theory within the first order formalism is considered with a view to deriving the propagator Dyson-Schwinger equations. The first order formalism is studied with special emphasis on the BRS invariance and it is found that there exists two forms of invariance - invariance under the standard BRS transform and under a second, non-standa

M. Chaichian, M. Mnatsakanova, A. Tureanu, Yu. Vernov

Classical results of the axiomatic quantum field theory - Reeh and Schlieder&#39;s theorems, irreducibility of the set of field operators and generalized Haag&#39;s theorem are proven in SO(1,1) invariant quantum field theory, of which an important example is noncommutative quantum field theory. In SO(1,3) invariant theory new consequences of generalized Haa

Marcel Kossow

In this article an energy correction is calculated in the time independent perturbation setup using a regularised ultraviolet finite Hamiltonian on the noncommutative Minkowski space. The correction to the energy is invariant under rotation and translation but is not Lorentz covariant and this leads to a distortion of the dispersion relation. In the limit wh

Pietro Menotti, Erik Tonni

We develop a general technique for solving the Riemann-Hilbert problem in presence of a number of heavy charges and a small one thus providing the exact Green functions of Liouville theory for various non trivial backgrounds. The non invariant regularization suggested by Zamolodchikov and Zamolodchikov gives the correct quantum dimensions; this is shown to o

Tomasz R. Taylor

In this contribution to the Festschrift celebrating Gabriele Veneziano on his 65th birthday, I discuss the threshold effects of extra dimensions and their applications to physics beyond the standard model, focusing on superstring theory.

Massimo Giovannini

Warped configurations admitting pairs of gravitating defects are analyzed. After devising a general method for the construction of multidefects, specific examples are presented in the case of higher-dimensional Einstein-Hilbert gravity. The obtained profiles describe diverse physical situations such as (topological) kink-antikink systems, pairs of non-topolo

M. H. Dehghani, N. Bostani

We obtain two new classes of magnetic brane solutions in third order Lovelock gravity. The first class of solutions yields an $(n+1)$-dimensional spacetime with a longitudinal magnetic field generated by a static source. We generalize this class of solutions to the case of spinning magnetic branes with one or more rotation parameters. These solutions have no

I. Ya. Aref&#39;eva, I. V. Volovich

Field theories which violate the null energy condition (NEC) are of interest for the solution of the cosmological singularity problem and for models of cosmological dark energy with the equation of state parameter $w<-1$. We discuss the consistency of two recently proposed models that violate the NEC. The ghost condensate model requires higher-order derivati

Nicolas Garron

In this short review, I present a summary of various methods used to simulate heavy quarks on the lattice. I mainly focus on effectives theories, and give some physical results.

Elvira Gamiz, Matthias Jamin, Antonio Pich, Joaquim Prades

Recent progress in the determination of |V_us| employing strange hadronic tau-decay data are reported. This includes using the recent OPAL update of the strange spectral function, as well as augmenting the dimension-two perturbative contribution with the recently calculated order alpha_s^3 term on the theory side. These updates result in |V_us| = 0.2220 +- 0

C. Royon

In these lectures, we present and discuss the most recent results on inclusive diffraction from the HERA and Tevatron colliders and give the prospects for the future at the LHC. Of special interest is the exclusive production of Higgs boson and heavy objects ($W$, top, stop pairs) which will require a better understanding of diffractive events and the link b

Helmut Satz

The QCD counterpart of Hawking radiation from black holes leads to thermal hadron production in high energy collisions, from $e^+e^-$ annihilation to heavy ion interactions. This hadronic radiation is formed by tunnelling through the event horizon of colour confinement and is emitted at a universal temperature $T_H \simeq (σ/2 π)^{1/2}$, where $σ$ denotes th

Moskov Amarian, Dmitri Diakonov, Maxim V. Polyakov

Since all couplings of the exotic $Θ^+$ baryon to normal hadrons seem to be small it is hard to reveal it in standard resonance searching. We suggest to look for the $Θ^+$ production in interference with a known resonance yielding the same final state but having a high production rate. The interference process is linear in the $Θ^+$ couplings whereas the non