December 2006 arXiv papers — page 33

Yoshihisa Kitazawa, Shun'ya Mizoguchi, Osamu Saito

We report on progress in determining the complete form of vertex operators for the IIB matrix model. The exact expressions are obtained for those emitting massless IIB supergravity fields up to sixth order in the light-cone superfield, in which the conjugate gravitino and conjugate two-form vertex operators are newly determined. We also provide a consistency

R. de Lima Rodrigues, A. F. de Lima, E. R. Bezerra de Mello, V. B. Bezera

We investigate the linear classical stability of Bogomol'nyi-Prasad-Sommerfield (BPS) on three domain wall solutions in a system of three coupled real scalar fields, for a general positive potential with a square form. From a field theoretic superpotential evaluated on the domain states, the connection between the supersymmetric quantum mechanics involvi

A. A. Pankov, N. Paver, A. V. Tsytrinov

Contactlike nonstandard effective interactions can be revealed through deviations of observables from the Standard Model predictions. If such deviations were observed, the relevant source should be identified among the possible models that could explain them. We estimate the expected discrimination reach on the ADD model of gravity in large compactified extr

M. Hashemi

In this report the CMS potential for the light charged Higgs boson discovery in the Minimal Supersymmetric Standard Model is presented. First the latest results of the Tevatron and LEP experiments on the light charged Higgs search are reminded. In the rest of the report the perspectives of CMS for the light charged Higgs search are presented with description

S. Abachi, C. Buchanan, A. Chien, S. Chun

From the studies of rates and distributions of heavy quark mesons we have developed additional evidence that hadron formation is dominantly controlled by a Space-Time Area Law, an approach suggested by both non-perturbative QCD and Relativistic String Models.

CDF Collaboration

We present a new measurement of the $B^+$ meson differential cross section $dσ/d p_T$ at $\sqrt{s}=1960$ GeV. The data correspond to an integrated luminosity of 739pb$^{-1}$ collected with the upgraded CDF detector (CDF II) at the Fermilab Tevatron collider. $B^+$ candidates are reconstructed through the decay $B^+ \to J/ψK^+$, with $J/ψ\to μ^+ μ^-$. The int

Puxun Wu, Hongwei Yu

We examine observational constraints on the generalized Chaplygin gas (GCG) model for dark energy from the 9 Hubble parameter data points, the 115 SNLS Sne Ia data and the size of baryonic acoustic oscillation peak at redshift, $z=0.35$. At a 95.4% confidence level, a combination of three data sets gives $0.67\leq A_s\leq 0.83$ and $-0.21\leq α\leq 0.42$, wh

U. Gayathree

This is the second part of a paper on Conscious Intelligent Systems. We use the understanding gained in the first part (Conscious Intelligent Systems Part 1: IXI (arxiv id cs.AI/0612056)) to look at understanding. We see how the presence of mind affects understanding and intelligent systems; we see that the presence of mind necessitates language. The rise of

U. Gayathree

Did natural consciousness and intelligent systems arise out of a path that was co-evolutionary to evolution? Can we explain human self-consciousness as having risen out of such an evolutionary path? If so how could it have been? In this first part of a two-part paper (titled IXI), we take a learning system perspective to the problem of consciousness and inte

Paul Vitanyi

The information in an individual finite object (like a binary string) is commonly measured by its Kolmogorov complexity. One can divide that information into two parts: the information accounting for the useful regularity present in the object and the information accounting for the remaining accidental information. There can be several ways (model classes) i

D. B. Gutman

Quantum hydrodynamics of interacting electrons with a parabolic single particle spectrum is studied using the Calogero-Sutherland model. The effective action and modulation equations, describing evolution of periodic excitations in the fluid, are derived. Applications to the problem of a single electron tunneling into the FQHE edge state are discussed.

Mauricio Girardi, Aline L. Balladares, Vera B. Henriques, Marcia C. Barbosa

We investigate the phase diagram of a three-dimensional associating gas $(ALG)$ model. This model combines orientational ice-like interactions and ``van der Waals'' that might be repulsive, representing, in this case, a penalty for distortion of hydrogen bonds. These interactions can be interpreted as two competing distances making the connection bet

O. Kapikranian, B. Berche, Yu. Holovatch

We make a short overview of the recent analytic and numerical studies of the classical two-dimensional XY and Heisenberg models at low temperatures. Special attention is being paid to an influence of finite system size L on the peculiarities of the low-temperature phase. In accordance with the Mermin-Wagner-Hohenberg theorem, spontaneous magnetisation does n

M. H. Wu, Q. C. Li, J. M. Liu

By using Monte Carlo simulation on a ferromagnetic core/antiferromagnetic shell nanoparticle, we investigate in details the exchange bias of the magnetic hysteresis as a function of both core radius and shell thickness, at low temperature. It is found that the exchange bias is very sensitive to the core radius and a small variation of the radius may lead to

C. Peter Sebastian, Sudhindra Rayaprol, Rolf-Dieter Hoffmann, Ute Ch. Rodewald

Two modifications of CeCuSn were prepared from the elements: the high-temperature (beta) modification crystallizes directly from the quenched sample, while the low-temperature (alpha) modification forms after annealing at 700 deg C for one month. Both modifications were investigated by X-ray powder and single crystal diffraction. We find for alpha-CeCuSn a s

P. H. Frampton

Dark energy in a brane world reconciles an infinitely cyclic cosmology with the second law of thermodynamics. At turnaround one causal patch with no matter and vanishing entropy is retained for the contraction.

Amaya Moro-Martín, John M. Carpenter, Michael R. Meyer, Lynne A. Hillenbrand

Using data from the Spitzer Space Telescope Legacy Science Program ``Formation and Evolution of Planetary Systems'' (FEPS), we have searched for debris disks around 9 FGK stars (2-10 Gyr), known from radial velocity (RV) studies to have one or more massive planets. Only one of the sources, HD 38529, has excess emission above the stellar photosphere;

Guenter Sigl

We give a brief (and highly incomplete) overview of the current experimental and theoretical status of high energy cosmic rays and their secondary gamma-rays and neutrinos. We focus on the role of large scale magnetic fields and on multi-messenger aspects linking these three channels. We also recall that the flavor composition of neutrino fluxes from astroph

Wolter Siemons, Gertjan Koster, Hideki Yamamoto, Walter A. Harrison

As discovered by Ohtomo et al., a large sheet charge density with high mobility exists at the interface between SrTiO3 and LaAlO3. Based on transport, spectroscopic and oxygen-annealing experiments, we conclude that extrinsic defects in the form of oxygen vacancies introduced by the pulsed laser deposition process used by all researchers to date to make thes

Marni Mishna

Using an algorithm for computing the symmetric function Kronecker product of D-finite symmetric functions we find some new Kronecker product identities. The identities give closed form formulas for trace-like values of the Kronecker product.

Andrew G. Cohen, Tuhin S. Roy, Martin Schmaltz

Running of gauge couplings in the MSSM from a unified value at high energies leads to a successful prediction of the weak mixing angle. Supersymmetric models at the TeV scale may contain further hints of high scale physics, such as the pattern of superpartner masses when evolved from the TeV scale to a high scale using the renormalization group. This running

Larsen Louder

This is the third paper in a sequence on Krull dimension for limit groups, answering a question of Z. Sela. We give generalizations of the well known fact that a nontrivial commutator in a free group is not a proper power to both graphs of free groups over cyclic subgroups and freely decomposable groups. None of the paper is specifically about limit groups.

Julio M. Hoff da Silva, Roldao da Rocha

We investigate the particle production in a toroidal compactified spacetime due to the expansion of a Friedmann cosmological model in R3 x S1 outside a U(1) local cosmic string. The case of a Friedmann spacetime is also investigated when torsion is incorporated in the connection. We present a generalization to toroidal compactification of p extra dimensions,

J. E. Herald, L. Bianchi

We observed five central stars of planetary nebulae (CSPN) in the Large Magellanic Cloud (LMC) and three in the Small Magellanic Cloud (SMC) with the Far Ultraviolet Spectroscopic Explorer (FUSE), in the range 905-1187 Ang. We performed a model-based analysis of these spectra in conjunction with Hubble Space Telescope (HST) spectra in the UV and optical rang

C. O. Heinke, P. G. Jonker, R. Wijnands, R. E. Taam

Thermal X-ray radiation from neutron star soft X-ray transients in quiescence provides the strongest constraints on the cooling rates of neutron stars, and thus on the interior composition and properties of matter in the cores of neutron stars. We analyze new (2006) and archival (2001) XMM-Newton observations of the accreting millisecond pulsar SAX J1808.4-3

I. Cabrera-Carnero, L. Alejandro Correa-Borbonet, G. C. S. Valadares

By means of the Ehrenfest's Theorem inside the context of a noncommutative Quantum Mechanics it is obtained the Newton's Second Law in noncommutative space. Considering discrete systems with infinite degrees of freedom whose dynamical evolutions are governed by the noncommutative Newton's Second Law we have constructed some alternative noncommuta

Andrea Antoniazzi, Francesco Califano, Duccio Fanelli, Stefano Ruffo

We here discuss the emergence of Quasi Stationary States (QSS), a universal feature of systems with long-range interactions. With reference to the Hamiltonian Mean Field (HMF) model, numerical simulations are performed based on both the original $N$-body setting and the continuum Vlasov model which is supposed to hold in the thermodynamic limit. A detailed c

T. S. Evans, A. D. K. Plato

We consider the rewiring of a bipartite graph using a mixture of random and preferential attachment. The full mean field equations for the degree distribution and its generating function are given. The exact solution of these equations for all finite parameter values at any time is found in terms of standard functions. It is demonstrated that these solutions

Marc S. Seigar, Aaron J. Barth, James S. Bullock

We present an updated mass model for M31 that makes use of a Spitzer 3.6 $μ$m image, a mass-to-light ratio gradient based on the galaxy's B-R colour profile, and observed rotation curve data from a variety of sources. We examine cases where the dark matter follows a pure NFW profile and where an initial NFW halo contracts adiabatically in response to the

Colin Ingalls, Hugh Thomas

We situate the noncrossing partitions associated to a finite Coxeter group within the context of the representation theory of quivers. We describe Reading's bijection between noncrossing partitions and clusters in this context, and show that it extends to the extended Dynkin case. Our setup also yields a new proof that the noncrossing partitions associat

Marc S. Seigar, Alister W. Graham, Helmut Jerjen

We have analysed deep R-band images, down to a limiting surface brightness of 26.5 R-mag arcsec$^{-2}$ (equivalent to ~28 B-mag arcsec$^{-2}$), of 5 cD galaxies to determine the shape of the surface brightness profiles of their extended stellar envelopes. Both de Vaucouleurs R^{1/4} model and Sersic's R^{1/n} model, on their own, provide a poor descripti

Sergei Gukov, Edward Witten

In the gauge theory approach to the geometric Langlands program, ramification can be described in terms of ``surface operators,'' which are supported on two-dimensional surfaces somewhat as Wilson or 't Hooft operators are supported on curves. We describe the relevant surface operators in N=4 super Yang-Mills theory, and the parameters they depen

Yu. F. Pirogov

The minimal metagravity theory, explicitly violating the general covariance but preserving the unimodular one, is applied to study the evolution of the isotropic homogeneous Universe. The massive scalar graviton, contained in the theory in addition to the massless tensor one, is treated as a source of the dark matter and/or dark energy. The modified Friedman

Victor S. L'vov, Sergei V. Nazarenko, Oleksii Rudenko

We consider superfluid turbulence near absolute zero of temperature generated by classical means, e.g. towed grid or rotation but not by counterflow. We argue that such turbulence consists of a {\em polarized} tangle of mutually interacting vortex filaments with quantized vorticity. For this system we predict and describe a bottleneck accumulation of the ene

J. Gil, G. I. Melikidze, B. Zhang

We consider the problem of the thermal X-ray radiation from the hot polar cap of radio pulsars showing evidence of \EB subpulse drift in radio band. In our recent Paper I, using the partially screened gap (PSG) model of inner acceleration region we derived a simple relationship between the drift rate of subpulses observed in a radio-band and the thermal X-ra

Edmundo Castillo, Rafael Diaz

We construct membrane homology groups $\h(M)$ associated with each compact connected oriented smooth manifold, and show that $\h(M)$ is matrix graded algebra.

G. Davatz, M. Dittmar, F. Pauss

The potential to discover a Standard-Model-like Higgs boson at the LHC in the mass range from 150-180 GeV, decaying into a pair of W bosons with subsequent leptonic decays, has been established during the last 10 years. Assuming that such a signal will eventually be observed, the analysis described in this paper investigates how accurate the signal cross sec

Joshua N. Winn, Matthew J. Holman, Gregory W. Henry, Anna Roussanova

We present photometry of HD 189733 during eight transits of its close-in giant planet, and out-of-transit photometry spanning two years. Using the transit photometry, we determine the stellar and planetary radii and the photometric ephemeris. Outside of transits, there are quasiperiodic flux variations with a 13.4 day period that we attribute to stellar rota

Simon Catterall

We study a discretization of ${\cal N}=2$ super Yang-Mills theory which possesses a single exact supersymmetry at non-zero lattice spacing. This supersymmetry arises after a reformulation of the theory in terms of {\it twisted} fields. In this paper we derive the action of the other twisted supersymmetries on the component fields and study, using Monte Carlo

Maximilien Gadouleau, Zhiyuan Yan

In this paper, we first introduce the concept of elementary linear subspace, which has similar properties to those of a set of coordinates. We then use elementary linear subspaces to derive properties of maximum rank distance (MRD) codes that parallel those of maximum distance separable codes. Using these properties, we show that, for MRD codes with error co

Marie-Noëlle Célérier

Since its decovery during the late 90's, the dimming of distant SN Ia apparent luminosity has been mostly ascribed to the influence of a mysterious dark energy component. Based upon the cosmological "principle" hypothesis, this interpretation has given rise to the "concordance" model, developed in the context of a Friedmann-Lemaitre cosmo

Ruiming Zhang

In this work we study the Plancherel-Rotach type asymptotics for selected $q$-series and $q$-orthogonal polynomials with complex scalings. The $q$-series we cover are Euler's $q$-exponential, Ramanujan function, Jackson's $q$-Bessel function of second kind, Ismail-Masson orthogonal polynomials, Stieltjes-Wigert polynomials and $q$-Laguerre polynomial

Mylene Pischella, Jean-Claude Belfiore

This paper has been withdrawn by the author.

Laurent Busé, Bernard Mourrain

In this paper, the result of applying iterative univariate resultant constructions to multivariate polynomials is analyzed. We consider the input polynomials as generic polynomials of a given degree and exhibit explicit decompositions into irreducible factors of several constructions involving two times iterated univariate resultants and discriminants over t

NA49 Collaboration

The centrality and system size dependence of multiplicity fluctuations of charged particles produced in nuclear collisions at $158 A$ GeV was studied by the NA49 collaboration. Centrality selected Pb+Pb collisions, semi-central C+C and Si+Si collisions as well as inelastic p+p interactions were analyzed. The number of projectile participants determined on an

Guillaume Rond

We investigate some properties of regularity of homomorphisms of local algebras over positive characteristic fields. We state a result of monomialization of such a homomorphism between algebras of analytic or algebraic power series. From this we deduce some extensions in positive characteristic of results due to S. Izumi and A. Gabrielov.

S. Bonazzola, L. Villain, M. Bejger

A flexible spectral code for the study of general relativistic magnetohydrodynamics is presented. Aiming at investigating the physics of slowly rotating magnetized compact stars, this new code makes use of various physically motivated approximations. Among them, the relativistic anelastic approximation is a key ingredient of the current version of the code.

M. Bejger, P. Haensel, J. L. Zdunik

Recent observations of XTE J1739-285 suggest that it contains a neutron star rotating at 1122 Hz. Such rotation imposes bounds on the structure of neutron star in XTE J1739-285. These bounds may be used to constrain poorly known equation of state of dense matter. One-parameter families of stationary configurations rotating rigidly at 1122 Hz are constructed,

C. G. Doudoulakis

A numerical search for bosonic superconducting static vortex rings in a $U(1)_{A}\times U(1)_{W}$ model is presented. The fate of these rings without current, is to shrink due to their tension until extinction. The superconductivity of the loop does not seem to prevent shrinking. Current quenching takes place before stabilization.

Minghui Zhang, Qing Wei, Xia Shen, Yongfeng Liu

We report, for the first time, the observation of sub-wavelength coherent image of a pure phase object with thermal light,which represents an accurate Fourier transform. We demonstrate that ghost-imaging scheme (GI) retrieves amplitude transmittance knowledge of objects rather than the transmitted intensities as the HBT-type imaging scheme does.

B. Pasquini, M. Pincetti, S. Boffi

The unpolarized, helicity and transversity distributions of quarks in the proton are calculated in the overlap representation of light-cone wavefunctions truncated to the lowest order Fock-space components with three valence quarks. The three distributions at the hadronic scale satisfy an interesting relation consistent with the Soffer inequality. Results ar

Andre Beineke, Thomas Brüstle, Lutz Hille

Acyclic cluster algebras have an interpretation in terms of tilting objects in a Calabi-Yau category defined by some hereditary algebra. For a given quiver $Q$ it is thus desirable to decide if the cluster algebra defined by $Q$ is acyclic. We call $Q$ cluster-acyclic in this case, otherwise cluster-cyclic. In this note we classify the cluster-cyclic quivers

Charles Tahan

Manufacturing materials and systems with components thousands of times smaller than the width of a human hair promises vast and sometimes unimaginable advances in technology. Yet the term nanotechnology has formed as much from people's expectations as from scientific reality. Understanding the creation and context of this social construction can help us

Heidi Forster, Peter Samuelsson, Markus Buttiker

We investigate correlations of current at contacts and voltage fluctuations at voltage probes coupled to interferometers. The results are compared with correlations of current and occupation number fluctuations at dephasing probes. We use a quantum Langevin approach for the average quantities and their fluctuations. For higher order correlations we develop a

Nobuhito Maru, Norisuke Sakai, Nobuhiro Uekusa

A warped space model with a constant boundary superpotential has been an efficient model both to break supersymmetry and to stabilize the radius, when hypermultiplet, compensator and radion multiplet are taken into account. In such a model of the radius stabilization, the radion and moduli masses, the gravitino mass and the induced soft masses are studied. W

Ling-Yan Hung

A candidate supergravity solution of intersecting D7-branes with a five-dimensional intersecting domain (an I5-brane) is presented. This displays an enhanced Poincare symmetry and supersymmetry away from the brane cores. We also explore the possibility of a relation between the intersection region of D7-branes and conifolds through F-theory.

Ranjan Chaudhury, Samir K. Paul

Physical configurations corresponding to topological excitations present in the XY limit of a quantum spin 1/2 Heisenberg ferromagnet, are investigated on a two dimensional square lattice. Quantum vortices(anti-vortices) are constructed in terms of terms of coherent spin field components and the crucial role of the associated Wess-Zumino term is highlighted.

H. Khachatryan, G. V. Vereshchagin, G. Yegorian

Analysis of cosmological solutions of GX dark energy models shows the presence of a separatrix in the phase space of solutions which divides them into two classes: Friedmannian-like with initial singularity and non-Friedmannian solutions. The invariants are found, that reveal the intrinsic symmetry in GX models.

V. Sanglard

The EDELWEISS experiment is dedicated to the WIMPs direct search using heat-and-ionization Ge cryogenic detectors. We present the final results obtained by the first stage of the experiment, EDELWEISS-I which used three 320 g bolometers, corresponding to 62 kg.d. We describe EDELWEISS-II which commissioning runs have already started. This second stage of the

Chao-Yang Pang

Vector is the general format of input data of most algorithms. Designing unitary operation to load all information of vector into quantum registers of quantum CPU from classical memory is called quantum loading scheme (QLS). QLS assembles classical memory and quantum CPU as a whole computer, which will be important for further quantum computation. We present

Hisao Taira, Hiroyuki Shima

The curvature effect on the electronic states of a deformed cylindrical conducting surface of variable diameter is theoretically investigated. The quantum confinement of electrons normal to the curved surface results in an effective potential energy that affects the electronic structures of the system at low energies. This suggests the possibility that balli

Leiming Chen, John Toner

We present a theory of the elasticity and fluctuations of the Smectic A and C phases in uniaxial, anisotropic disordered environments, e.g., stretched aerogel. We find that, bizarrely, the low-temperature, lower-symmetry Smectic $C$ phase is less translationally ordered than the high-temperature, higher-symmetry Smectic $A$ phase, with short-ranged "$m=1

A. I. Molev

We give a new version of the fusion procedure for the symmetric group which originated in the work of Jucys and was developed by Cherednik. We derive it from the Jucys-Murphy formulas for the diagonal matrix units for the symmetric group.

T. Amano, M. Hoshino

Electron injection process at high Mach number collisionless quasi-perpendicular shock waves is investigated by means of one-dimensional electromagnetic particle-in-cell simulations. We find that energetic electrons are generated through the following two steps: (1) electrons are accelerated nearly perpendicular to the local magnetic field by shock surfing a

Pierre Andreoletti

We consider Sinai's random walk in random environment. We prove that the logarithm of the local time is a good estimator of the random potential associated to the random environment. We give a constructive method allowing us to built the random environment from a single trajectory of the random walk.

Vyjayanthi Chari, Jacob Greenstein

We study the category of graded finite-dimensional representations of the polynomial current algebra associated to a simple Lie algebra. We prove that the category has enough injectives and compute the graded character of the injective envelopes of the simple objects as well as extensions between simple objects. The simple objects in the category are paramet

Charlene Ahn, Kevin Birnbaum

The $αη$ protocol given by Barbosa \emph{et al.}, PRL 90, 227901 (2003) claims to be a secure way of encrypting messages using mesoscopic coherent states. We show that transmission under $αη$ exposes information about the secret key to an eavesdropper, and we estimate the rate at which an eavesdropper can learn about the key. We also consider the consequence

James Allen Fill, David B. Wilson

We analyze the two-player game of Knock 'em Down, asymptotically as the number of tokens to be knocked down becomes large. Optimal play requires mixed strategies with deviations of order sqrt(n) from the naive law-of-large numbers allocation. Upon rescaling by sqrt(n) and sending n to infinity, we show that optimal play's random deviations always hav

Alex Kumjian, David Pask, Aidan Sims

A covering of k-graphs (in the sense of Pask-Quigg-Raeburn) induces an embedding of universal C*-algebras. We show how to build a (k+1)-graph whose universal algebra encodes this embedding. More generally we show how to realise a direct limit of k-graph algebras under embeddings induced from coverings as the universal algebra of a (k+1)-graph. Our main focus

Robert B. Griffiths

Many of the conceptual problems students have in understanding quantum mechanics arise from the way probabilities are introduced in standard (textbook) quantum theory through the use of measurements. Introducing consistent microscopic probabilities in quantum theory requires setting up appropriate sample spaces taking proper account of quantum incompatibilit

Roland Hildebrand

Let L_n be the n-dimensional Lorentz cone. A linear map M from R^m to R^n is called Lorentz-positive if M[L_m] is contained in L_n. We extend the notion of concurrence, which was initially introduced to quantify the entanglement of bipartite density matrices, to Lorentz-positive maps and provide an explicite formula for it. This allows us to obtain formulae

Julia Kempe, Thomas Vidick

We show that the value of a general two-prover quantum game cannot be computed by a semi-definite program ofvpolynomial size (unless P=NP), a method that has been successful in more restricted quantum games. More precisely, we show that proof of membership in the NP-complete problem GAP-3D-Matching can be obtained by a 2-prover, 1-round quantum interactive p

Jochen Gemmer, Mathias Michel

We consider discrete quantum systems coupled to finite environments which may possibly consist of only one particle in contrast to the standard baths which usually consist of continua of oscillators, spins, etc. We find that such finite environments may, nevertheless, act as thermostats, i.e., equilibrate the system though not necessarily in the way predicte

Rajesh R. Parwani

I begin by reviewing the arguments leading to a nonlinear generalisation of Schrodinger's equation within the context of the maximum uncertainty principle. Some exact and perturbative properties of that equation are then summarised: those results depend on a free regulating/interpolation parameter $η$. I discuss here how one may fix that parameter using

Ali Ahanj, Pramod Joag

In this paper we present a new approach for testing QM against the realism aspect of hidden variable theory (HVT). We consider successive measurements of non-commuting operators on a input spin $s$ state. The key point is that, although these operators are non-commuting, they act on different states so that the joint probabilities for the outputs of successi

Jerome K Vanclay

An analysis of data from 212 permanent sample plots provided no evidence of any decline in rainforest productivity after three cycles of selection logging in the tropical rainforests of north Queensland. Relative productivity was determined as the difference between observed diameter increments and increments predicted from a diameter increment function whic

A. Akindinov, V. Ammosov, V. Gapienko, Yu. Grishuk

Usage of electrodes made of glass with low bulk resistivity seems to be a promising way to adapt the Resistive Plate Chambers (RPC) to the high-rate environment of the upcoming CBM experiment. A pilot four-gap RPC sample with electrodes made of phosphate glass, which has bulk resistivity in the order of 10^10 Ohm cm, has been studied with MIP beam for TOF ap

H. Schmitz, R. Grauer

A standard starting point for the simulation of collisionless reconnection is the Harris equilibrium which is made up of a current sheet that separates two regions of opposing magnetic field. Magnetohydrodynamic simulations of collisionless reconnection usually include a homogeneous background density for reasons of numerical stability. While, in some cases,

J. Astrom, P. C. F. Di Stefano, F. Probst, L. Stodolsky

We note the striking similarity between earthquake and CRESST microfracture data for waiting times.

Alexander Mishev

The existing and in development devices at Basic Environmental Observatory (BEO) Moussala are presented, precisely the experiments connected with space weather and astroparticle studies. The recent results of the secondary cosmic ray measurements using atmospheric Cherenkov light telescope are presented precisely the possibility to study the atmospheric tran

Taras Plakhotnik

The ultimate sensitivity of optical detection is limited by the signal-to-noise ratio (SNR). The first part of the paper shows that coherence plays an important role in the noise analysis. Although interference between an auxiliary wave and a signal wave makes the photo detector response to the signal stronger, the coherent noise also enhances. This makes in

Gianluca Geloni, Evgeni Saldin, Evgeni Schneidmiller, Mikhail Yurkov

Electron accelerators with higher and higher longitudinal field gradients are desirable, as they allow for the production of high energy beams by means of compact and cheap setups. The new laser-plasma acceleration technique appears to constitute the more promising breakthrough in this direction, delivering unprecedent field gradients up to TV/m. In this art

V. V. Nesterenko, A. Feoli, G. Lambiase, G. Scarpetta

The frequency band used by cellular telephones includes the eigenfrequencies of a dielectric sphere with physical characteristics close to those of a human head. Proceeding from the spatial features of the natural modes of such a sphere we propose an independent and clear evident accuracy test for the complicated numerical calculations which are conducted wh

C. Y. Wang, L. Diehl, A. Gordon, C. Jirauschek

We report the observation of a coherent multimode instability in quantum cascade lasers (QCLs), which is driven by the same fundamental mechanism of Rabi oscillations as the elusive Risken-Nummedal-Graham-Haken (RNGH) instability predicted 40 years ago for ring lasers. The threshold of the observed instability is significantly lower than in the original RNGH

Gabriele U. Varieschi

In this paper we describe a simple conceptual problem, regarding the actual position of the Sun at sunset or sunrise. Although this problem can be easily explained in terms of rotating frames of references and standard Coriolis Effect, it is sometimes misunderstood by students and even by some physics textbooks. We also present a simple experimental activity

John W. Norbury, Khin Maung Maung

Relativistic nucleus-nucleus reactions occur mainly through the Strong or Electromagnetic (EM) interactions. Transport codes often neglect the latter. This work shows the importance of including EM interactions for space radiation applications.

D. Zschiesche, L. Portugal

The decoupling surface in relativistic heavy-ion collisions may not be homogeneous. Rather, inhomogeneities should form when a rapid transition from high to low entropy density occurs. We analyze the hadron "chemistry" from high-energy heavy-ion reactions for the presence of such density inhomogeneities. We show that due to the non-linear dependence

NA50 Collaboration

psi' production is studied in Pb-Pb collisions at 158 GeV/c per nucleon incident momentum. Absolute cross-sections are measured and production rates are investigated as a function of the centrality of the collision. The results are compared with those obtained for lighter colliding systems and also for the J/psi meson produced under identical conditions.

NA50 Collaboration

We report a new measurement of J/psi, psi&#39; and Drell-Yan cross-sections, in the kinematical domain $-0.425<y_{\rm cm}<0.575$ and $-0.5<\cosθ_{\rm CS}<0.5$, performed at the CERN-SPS using 400 GeV/c incident protons on Be, Al, Cu, Ag, W and Pb targets. The dependence of the charmonia production cross-sections on the size of the target nucleus allows to qu

C. Vaman, C. Andreoiu, D. Bazin, A. Becerril

Rare isotope beams of neutron-deficient $^{106,108,110}$Sn nuclei from the fragmentation of $^{124}$Xe were employed in an intermediate-energy Coulomb excitation experiment yielding $B(E2, 0^+_1 \to 2^+_1)$ transition strengths. The results indicate that these $B(E2,0^+_1 \to 2^+_1)$ values are much larger than predicted by current state-of-the-art shell mod

J. Smyrski, H. -H. Adam, A. Budzanowski, E. Czerwinski

We have measured excitation functions for the d+p->3He+X, (X=pi0, eta) channels near the eta production threshold. The data were taken during a slow ramping of the COSY internal deuteron beam scattered on a proton target. The excitation function for the reaction d+p->3He+pi0 does not show any structure which could originate from the decay of 3He-eta bound st

Ren Guo

In \cite{rigidity}, Luo introduced a $ψ_λ$ edge invariant which turns out to be a coordinate of the Teichmüller space of a surface with boundary. And he proved that for $λ\geq 0$, the image of the Teichmüller space under $ψ_λ$ edge invariant coordinate is an open cell. In this paper we verify his conjecture that for $λ<0$, the image of the Teichmüller space

Arvind Singh

We consider a diffusion process $X$ in a random potential $\V$ of the form $\V_x = §_x -δx$ where $δ$ is a positive drift and $§$ is a strictly stable process of index $α\in (1,2)$ with positive jumps. Then the diffusion is transient and $X_t / \log^αt$ converges in law towards an exponential distribution. This behaviour contrasts with the case where $\V$ is

Sergiu Moroianu

We give an analytic proof of the fact that the index of an elliptic operator on the boundary of a compact manifold vanishes when the principal symbol comes from the restriction of a $K$-theory class from the interior. The proof uses noncommutative residues inside the calculus of cusp pseudodifferential operators of Melrose.

Gert Almkvist

The Calabi-Yau differential equations of degree 2 and 3 are listed. The idea is to bring some order into the &#34;big table&#34; into the &#34;big table&#34; (math. AG/0507430). The author has benefitted from an unpublished result by Yifan Yang, which reduces the degree of many equations. Also difference equations (giving rise to Calabi-Yau differential equa

Jakša Cvitanić, Robert Liptser, Boris Rozovskii

This paper is concerned with nonlinear filtering of the coefficients in asset price models with stochastic volatility. More specifically, we assume that the asset price process $S=(S_{t})_{t\geq0}$ is given by \[ dS_{t}=m(θ_{t})S_{t} dt+v(θ_{t})S_{t} dB_{t}, \] where $B=(B_{t})_{t\geq0}$ is a Brownian motion, $v$ is a positive function and $θ=(θ_{t})_{t\geq0

Iasson Karafyllis, Pierdomenico Pepe, Zhong-Ping Jiang

In this work characterizations of notions of output stability for uncertain time-varying systems described by retarded functional differential equations are provided. Particularly, characterizations by means of Lyapunov and Razumikhin functions of uniform and non-uniform in time Robust Global Asymptotic Output Stability and Input-to-Output Stability are give

Iasson Karafyllis, Zhong-Ping Jiang

A Small-Gain Theorem, which can be applied to a wide class of systems that includes systems satisfying the weak semigroup property, is presented in the present work. The result generalizes all existing results in the literature and exploits notions of weighted, uniform and non-uniform Input-to-Output Stability (IOS) property. Applications to partial state fe

James L. Ulrich

Motivated by a desire to test the security of the pubic key exchange protocol of I. Anshel, M. Anshel, and D. Goldfeld, (``An Algebraic Method for Public-Key Cryptography&#39;&#39;, Mathematical Research Letters, vol. 6, pp. 1-5, 1999), we study algorithmic approaches to the simple commutator decision and promise problems (SCDP/SCPP) for the braid groups B_n

Andrei Radulescu-Banu

For a cofibrantly generated Quillen model category, we show that the cofibrant replacement functor constructed using the small object argument admits a cotriple structure. If all acyclic cofibrations are monomorphisms, the fibrant replacement functor constructed using the small object argument admits a triple structure. For a triple in the base category, the