June 2009 arXiv papers — page 49

T. Appourchaux, R. Samadi, M. -A. Dupret

We emphasize that the mention of the significance level when rejecting the null hypothesis (H0) which assumes that what is observed is pure noise) can mislead one to think that the H0 hypothesis is unlikely to occur with that significance level. We show that the significance level has nothing to do with the posterior probability of H0 given the observed data

Cristina Ofelia Stanciu

This paper presents the main components of the decision assisting systems. Further on three types of architectures of these systems are described, analyzed, and respectively compared, namely: the network architecture, the centralized architecture and the hierarchical architecture.

Gregory Gutin, Daniel Karapetyan

The Multidimensional Assignment Problem (MAP or s-AP in the case of s dimensions) is an extension of the well-known assignment problem. The most studied case of MAP is 3-AP, though the problems with larger values of s have also a number of applications. In this paper we propose a memetic algorithm for MAP that is a combination of a genetic algorithm with a l

A. A. Shumeyko, S. L. Sotnik

The avalanche quantity of the information developed by mankind has led to concept of automation of knowledge extraction - Data Mining ([1]). This direction is connected with a wide spectrum of problems - from recognition of the fuzzy set to creation of search machines. Important component of Data Mining is processing of the text information. Such problems le

Emil Daniel Schwab

The paper examines a partial order on bipartite graphs (X1, X2, E) with n vertices, X1UX2={1,2,...,n}. This partial order is a natural partial order of subobjects of an object in a triangular category with bipartite graphs as morphisms.

Michael Kastner

Monte Carlo is a versatile and frequently used tool in statistical physics and beyond. Correspondingly, the number of algorithms and variants reported in the literature is vast, and an overview is not easy to achieve. In this pedagogical review, we start by presenting the probabilistic concepts which are at the basis of the Monte Carlo method. From these con

S. X. Nakamura, K. Sumiyoshi, T. Sato

We examine a potential role of the neutrino deuteron reactions in the mechanism of supernova explosion by evaluating the energy transfer cross section for the neutrino heating. We calculate the energy loss rate due to the neutrino absorptions through the charged-current process as well as the neutrino scattering through the neutral-current process. In so doi

Steven A. Balbus

The magnetohydrodynamical behavior (MHD) of accretion disks is reviewed. A detailed presentation of the fundamental MHD equations appropriate for protostellar disks is given. The combination of a weak (subthermal) magnetic field and Keplerian rotation is unstable to the magnetorotational instability (MRI), if the degree of ionization in the disk is sufficien

M. Thiele, W. -C. Müller

Navier-Stokes turbulence subject to solid-body rotation is studied by high-resolution direct numerical simulations (DNS) of freely decaying and stationary flows. Setups characterized by different Rossby numbers are considered. In agreement with experimental results strong rotation is found to lead to anisotropy of the direct nonlinear energy flux, which is a

A. de Souza Dutra, R. A. C. Correa

A class of oscillating Lorentz covariant configurations for the evolution of the domain walls in diverse dimensions are analytically obtained. It is shown that the oscillating solutions in the case of domain walls are responsible for structures which are larger than the usual kink-like configurations and, in the Lorentz covariant evolution case, lead to long

Vasiliy Saiko

The article describes the main problems concerned with using expert assessment method in consumer preference researches. The author proved the expediency of using a 3-point measurement scale. The author suggested an algorithm for controlling the judgments' consistency that includes analyzing and correcting the input estimates in real-time mode.

R. Hänninen

We study numerically some possible vortex configurations in a rotating cylinder that is tilted with respect to the rotation axis and where different numbers of vortices can be present at given rotation velocity. In a long cylinder at small tilt angles the vortices tend to align along the cylinder axis and not along the rotation axis. We also show that the ax

A. Zaccone, M. Soos, M. Lattuada, M. U. Baebler

Flow-induced aggregation of colloidal particles leads to aggregates with fairly high fractal dimension () which are directly responsible for the observed rheological properties of sheared dispersions. We address the problem of the decrease of aggregate size with increasing hydrodynamic stress, as a consequence of breakup, by means of a fracture-mechanics mod

Mohd Nazri Ismail

In this research, we propose an architectural solution to implement the voice over IP (VoIP) service in campus environment network. Voice over IP (VoIP) technology has become a discussion issue for this time being. Today, the deployment of this technology on an organization truly can give a great financial benefit over traditional telephony. Therefore, this

Shan He, Sheng Li, Hongru Ma

We propose a resource distribution strategy to reduce the average travel time in a transportation network given a fixed generation rate. Suppose that there are essential resources to avoid congestion in the network as well as some extra resources. The strategy distributes the essential resources by the average loads on the vertices and integrates the fluctua

Osvaldo Mendez, Nada al Hanna

We present an elementary Functional Analytic proof of the roughness of Exponential Dichotomy of Ordinary Differential Equations (with exponential growth) on an arbitrary Banach Space.

Christoph Studer, Helmut Bölcskei

Soft-input soft-output (SISO) detection algorithms form the basis for iterative decoding. The computational complexity of SISO detection often poses significant challenges for practical receiver implementations, in particular in the context of multiple-input multiple-output (MIMO) wireless communication systems. In this paper, we present a low-complexity SIS

T. K. Barik, P. Bandyopadhyay, A. Roy

In this article, we correlate the internal stress and the characteristics of a vibrational mode in wet foam. Using microscope images, we estimate the average size of the bubbles in wet foam, at specific time intervals, over a duration of twenty four hours. Raman spectra are also recorded at the same time intervals, over the same time frame. We show that the

Leonid Pestov, Victoria Bolgova, Oksana Kazarina

In this paper we develop numerical algorithm for solving inverse problem for the wave equation using Boundary Control method. The results of numerical experiments are represented.

Asaf Cohen, Eilon Solan

We study two-armed Levy bandits in continuous-time, which have one safe arm that yields a constant payoff s, and one risky arm that can be either of type High or Low; both types yield stochastic payoffs generated by a Levy process. The expectation of the Levy process when the arm is High is greater than s, and lower than s if the arm is Low. The decision mak

N. K. Das, R. K. Bhandari, P. Sen, B. Sinha

Anomalous temporal fluctuations of helium concentrations in spring emanations have been observed on a number of occasions prior to some major seismic events. Several recent studies have shown that a wide variety of natural systems display significant fluctuations that may be characterized by long-range power-law correlations. We have applied detrended fluctu

Nikos Bagis

The basis of the so-called Zenon effect in Quantum Mechanics, is the limiting behavior of the unitary solution of Schroedinger's equation, under repeated measurments. We examine the limit of a sequence of operators complosed by a usual operator and a projection operator.

Xueliang Li, Jianxi Liu

The energy $E$ of a graph is defined to be the sum of the absolute values of its eigenvalues. Nikiforov in {\it ``V. Nikiforov, The energy of $C_4$-free graphs of bounded degree, Lin. Algebra Appl. 428(2008), 2569--2573"} proposed two conjectures concerning the energy of trees with maximum degree $Δ\leq 3$. In this short note, we show that both conjectur

P. Chang, L. E. Strubbe, K. Menou, E. Quataert

Using a one-dimensional height integrated model, we calculate the evolution of an unequal mass binary black hole with a coplanar gas disk that contains a gap due to the presence of the secondary black hole. Viscous evolution of the outer circumbinary disk initially hardens the binary, while the inner disk drains onto the primary (central) black hole. As long

K. W. Kim, J. Y. Rhee, Y. V. Kudryavtsev, Y. H. Hyun

A giant diamagnetism in the Co$_{2}$CrAl compounds, in both bulk and thin film, below a certain temperature ($T_z$) was observed. Above $T_z$, the compound behaves as an ordinary ferromagnet. The diamagnetic alignment might be initiated by the Landau diamagnetism because of the half-metallic properties and the pinning of the diamagnetism is preserved by the

Yoshito Shimajiri, Satoko Takahashi, Shigehisa Takakuwa, Masao Saito

We have conducted millimeter interferometric observations of the Orion Molecular Cloud-2 (OMC-2) FIR 6 region at an angular resolution of $\sim$ 4$\arcsec$ - 7$\arcsec$ with the Nobeyama Millimeter Array (NMA). In the 3.3 mm continuum emission we detected dusty core counterparts of the previously identified FIR sources (FIR 6a, 6b, 6c, and 6d), and moreover,

Giovanni Landi, Alexander Pavlov

Analogues for Hilbert C*-modules of classical results of Fourier series theory in Hilbert spaces are considered. Relations between different properties of orthogonal and orthonormal systems for Hilbert C*-modules are studied with special attention paid on the differences with the well-known Hilbert space situation.

D. Allard, C. Alvarez, H. Asorey, H. Barros

In order to characterise the behaviour of Water Cherenkov Detectors (WCD) under a sudden increase of 1 GeV - 1 TeV background photons from a Gamma Ray Burst (GRB), simulations were conducted and compared to data acquired by the WCD of the Large Aperture GRB Observatory (LAGO). The LAGO operates arrays of WCD at high altitude to detect GRBs using the single p

Toru Misawa, Poshak Gandhi, Akira Hida, Toru Tamagawa

Large organic molecules and carbon clusters are basic building blocks of life, but their existence in the universe has not been confirmed beyond doubt. A number of unidentified absorption features (arising in the diffuse inter-stellar medium), usually called ``Diffuse Inter-stellar Bands (DIBs)'', are hypothesized to be produced by large molecules. A

Aakash Pushp, Colin V. Parker, Abhay. N. Pasupathy, Kenjiro K. Gomes

Understanding the mechanism by which d-wave superconductivity in the cuprates emerges and is optimized by doping the Mott insulator is one of the major outstanding problems in condensed matter physics. Our high-resolution scanning tunneling microscopy measurements of the high transition temperature (Tc) superconductor Bi2Sr2CaCu2O8+d show that samples with d

D. Allard, C. Alvarez, H. Asorey, H. Barros

The Large Aperture GRB Observatory (LAGO) is aiming at the detection of the high energy (around 100 GeV) component of Gamma Ray Bursts, using the single particle technique in arrays of Water Cherenkov Detectors (WCD) in high mountain sites (Chacaltaya, Bolivia, 5300 m a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m a.s.l). WCD at

Takashi Hotta

In an electron system coupled with anharmonic phonons, i.e., {\it rattling}, inverse isotope effect on the Kondo temperature $T_{\rm K}$ is found to occur by the numerical evaluation of the Sommerfeld constant $γ$ of the Anderson-Holstein model. For the anharmonic potential of an oscillator with mass $M$ in which large $γ$ has been found to be almost indepen

D. Allard, C. Alvarez, H. Asorey, H. Barros

Water Cherenkov Detectors (WCD) are efficient detectors for detecting GRBs in the 10 GeV - 1 TeV energy range using the single particle technique, given their sensitivity to low energy secondary photons produced by high energy photons when cascading in the atmosphere. The Large Aperture GRB Observatory (LAGO) operates arrays of WCD in high altitude sites (ab

Christos Lampropoulos, Stephen O. Hill, George Christou

The magnetization relaxation of Mn12 single-molecule magnets (SMMs) does not follow a simple Arrhenius law, even for data collected at low frequencies (5-1500 Hz) due to contributions from relaxation pathways via excited states with larger thermal barriers, but much faster attempt rates. A modified Arrhenius equation is presented as a means to overcome this

David P. Sanders

The exact mean time between encounters of a given particle in a system consisting of many particles undergoing random walks in discrete time is calculated, on both regular and complex networks. Analytical results are obtained both for independent walkers, where any number of walkers can occupy the same site, and for walkers with an exclusion interaction, whe

Burkard Polster

I often work on my laptop in bed. When needed, I park the laptop on the bedside table, where the computer has to share the small available space with a lamp, books, notes, and heaven knows what else. It often gets quite squeezy. Being regularly faced with this tricky situation, it finally occurred to me to determine once and for all how to place the laptop o

Manfred Paulini

The CDF and D0 experiments have produced a wealth of heavy flavour physics results since the beginning of Run II of the Fermilab Tevatron. We review recent measurements of B hadron states including excited B states (B^{**}, B_s^{**}) and the Bc+ meson. We also summarize the discoveries of the Sigma_b baryon states and the Xi_b baryon.

Yong Li, Z. D. Wang, C. P. Sun

We explore how to cool atomic collective excitations in an optically-driven three-level atomic ensemble, which may be described by a model of coupled two harmonic oscillators (HOs) with a time-dependent coupling. Moreover, the coupled two-HO model is further generalized to address other cooling issues, where the lower-frequency HO can be cooled whenever the

Masao Iwamatsu

The minimum free-energy path (MFEP) is the most probable route of the nucleation process on the multidimensional free-energy surface. In this study, the phase-field equation is used as a mathematical tool to deduce the minimum free-energy path (MFEP) of homogeneous nucleation. We use a simple square-gradient free-energy functional with a quartic local free-e

Valentino Lacquaniti, Giovanni Montani

In this paper we consider the Kaluza-Klein fields equations in presence of a generic 5D matter tensor which is governed by a conservation equation due to 5D Bianchi identities. Following a previous work, we provide a consistent approach to matter where the problem of huge massive modes is removed, without relaxing the compactification hypotheses; therefore w

Dan Pirjol, Carlos Schat

We discuss the application of the permutation group S_N to a few problems in hadron physics. A method is proposed for matching a quark model Hamiltonian onto the effective Hamiltonian of the 1/Nc expansion, which makes use of the transformation properties of the states and operators under S_N. This method is used to obtain information about the spin-flavor s

N. Canosa, R. Rossignoli

We evaluate the exact concurrence between any two spins in a cyclic XX chain of n spins placed in a uniform transverse magnetic field, both at zero and finite temperature, by means of the Jordan-Wigner transformation plus a number parity projected statistics. It is shown that while at T=0 there is always entanglement between any two spins in a narrow field i

Lixin Dai, Steven V. Fuerst, Roger Blandford

We present simulated results of quasi-periodic flares generated by the inelastic collisions of a star bound to a super-massive black hole (SMBH) and its attendant accretion disc. We show that the behavior of the quasi-periodicity is affected by the mass and spin of the black hole and the orbital elements of the stellar orbit. We also evaluate the possibility

Marc Krawitz

In this article, we study the Berglund--Hübsch transpose construction W^T for invertible quasihomogeneous potential W. We introduce the dual group G^T and establish the state space isomorphism between the Fan-Jarvis-Ruan-Witten A-model of W/G and the orbifold Milnor ring B-model of W^T/G^T. Furthermore, we prove a mirror symmetry theorem at the level of Frob

Andrej Vilfan

We present a model study of gliding assays in which actin filaments are moved by non-processive myosin motors. We show that even if the power stroke of the motor protein has no lateral component, the filaments will rotate around their axis while moving over the surface. Notably, the handedness of this twirling motion is opposite from that of the actin filame

A. Siria, A. Drezet, F. Marchi, F. Comin

We consider the problem of oscillation damping in air of a thermally actuated microlever as it is gradually approached towards an infinite wall in parallel geometry. As the gap is decreased from 20 nm down to 400 nm, we observe the increasing damping of the lever Brownian motion in the fluid laminar regime. This manifests itself as a linear decrease with dis

Kevin Heng, Bruce T. Draine

We present theoretical calculations of the X-ray scattering properties of porous grain aggregates with olivine monomers. The small and large angle scattering properties of these aggregates are governed by the global structure and substructure of the grain, respectively. We construct two diagnostics, R_X and T_X, based on the optical and X-ray properties of t

C. P. Moca, G. Zarand, M. Berciu

We construct a semi-microscopic theory, to describe the optical conductivity of GaMnAs in the dilute limit, x = 1%. We construct an effective Hamiltonian that captures inside-impurity band optical transitions as well as transitions between the valence band and the impurity band. All parameters of the Hamiltonian are computed from microscopic variational calc

Andreas Luscher, Andreas Laeuchli

We present a detailed study of the population imbalanced three-component Hubbard chain with attractive interactions. Such a system can be realized experimentally with three different hyperfine states of ultra cold $^6$Li atoms in an optical lattice. We find that there are different phases that compete with each other in this system: A molecular superfluid ph

Seungkyung Oh, Sungsoo S. Kim, Donald F. Figer

We estimate the enclosed mass profile in the central 10 pc of the Milky Way by analyzing the infrared photometry and the velocity observations of dynamically relaxed stellar population in the Galactic center. HST/NICMOS and Gemini Adaptive Optics images in the archive are used to obtain the number density profile, and proper motion and radial velocity data w

Jacques Distler, Daniel S. Freed, Gregory W. Moore

We give a precise and concise formulation of the orientifold construction in Type II superstring theory. Our results include anomaly cancellation on the worldsheet and a spacetime computation of the background Ramond-Ramond charge.

A. Settimi, S. Severini

The present paper proposes a comparison between the extinction theorem and the Sturm-Liouville theory approaches for calculating the e.m. field inside an optical cavity. We discuss for the first time to the best of our knowledge, in the framework of classical electrodynamics, a simple link between the Quasi Normal Modes (QNMs) and the Natural Modes (NMs) for

Roberto Artuso, Cesar Manchein

We claim that looking at probability distributions of \emph{finite time} largest Lyapunov exponents, and more precisely studying their large deviation properties, yields an extremely powerful technique to get quantitative estimates of polynomial decay rates of time correlations and Poincaré recurrences in the -quite delicate- case of dynamical systems with w

S. N. Ethier, Jiyeon Lee

The antique Mills Futurity slot machine has two unusual features. First, if a player loses 10 times in a row, the 10 lost coins are returned. Second, the payout distribution varies from coup to coup in a manner that is nonrandom and periodic with period 10. It follows that the machine is driven by a 100-state irreducible period-10 Markov chain. Here, we eval

Alexander Gutfraind

Complex socioeconomic networks such as information, finance and even terrorist networks need resilience to cascades - to prevent the failure of a single node from causing a far-reaching domino effect. We show that terrorist and guerrilla networks are uniquely cascade-resilient while maintaining high efficiency, but they become more vulnerable beyond a certai

S. Joseph, S. Majhi, B. F. L. Ward, S. A. Yost

We present Monte Carlo data showing the comparison between the parton shower generated by the standard DGLAP-CS kernels and that generated with the new IR-improved DGLAP-CS kernels recently developed by one of us(BFLW). We do this in the context of HERWIG6.5 by implementing the new kernels therein to generate a new MC, HERWIRI1.0, for hadron-hadron interacti

Rossen I. Ivanov

In this contribution we describe the role of several two-component integrable systems in the classical problem of shallow water waves. The starting point in our derivation is the Euler equation for an incompressible fluid, the equation of mass conservation, the simplest bottom and surface conditions and the constant vorticity condition. The approximate model

Benjamin P. Moster, Andrea V. Maccio', Rachel S. Somerville, Peter H. Johansson

We study the effect of dissipational gas physics on the vertical heating and thickening of disc galaxies during minor mergers. We produce a suite of minor merger simulations for Milky Way-like galaxies. This suite consists of collisionless simulations as well as hydrodynamical runs including a gaseous component in the galactic disc. We find that in dissipati

Andy Goulding, Dave Alexander

Using Spitzer-IRS spectroscopy, we investigate the ubiquity of Active Galactic Nuclei (AGN) in a complete (~94%), volume-limited sample of the most bolometrically-luminous galaxies (L_IR > (0.3-20) x 10^10 L_sun) to D < 15 Mpc. Our analyses are based on the detection of the high-excitation emission line [NeV](λ14.32 um; 97.1 eV) to unambiguously identify AGN

J. I. Read, T. Hayfield, O. Agertz

Standard formulations of smoothed particle hydrodynamics (SPH) are unable to resolve mixing at fluid boundaries. We use an error and stability analysis of the generalised SPH equations of motion to prove that this is due to two distinct problems. The first is a leading order error in the momentum equation. This should decrease with increasing neighbour numbe

Vasily Pestun

We localize the four-dimensional N=4 super Yang-Mills theory on a four-sphere to the two-dimensional constrained Hitchin/Higgs-Yang-Mills (cHYM) theory on a two-sphere S^2. We show that expectation values of certain 1/8 BPS supersymmetric Wilson loops on S^2 in the 4d N=4 SYM is captured by the 2d cHYM theory. We further argue that expectation values of Wils

I. M. Yurin, S. A. Trigger

Possibility for coexistence of a phonon and one-particle spectra in ${}^4He$ at all temperatures including temperatures below the $λ$ - point is shown. An approach developed to consider the problem of the weakly imperfect Bose gas results in the existence of a gap in the one-particle (one-atom) excitation spectrum below the transition point. Thus, the micros

Bernhard Keller, Dong Yang

We show that Derksen-Weyman-Zelevinsky&#39;s mutations of quivers with potential yield equivalences of suitable 3-Calabi-Yau triangulated categories. Our approach is related to that of Iyama-Reiten and Koszul dual to that of Kontsevich-Soibelman. It improves on previous work by Vitoria. In the appendix, the first-named author studies pseudo-compact derived c

Jonathan J. Heckman, Alireza Tavanfar, Cumrun Vafa

We show that in F-theory GUTs, a natural explanation of flavor hierarchies in the quark and lepton sector requires a single point of E_8 enhancement in the internal geometry, from which all Yukawa couplings originate. The monodromy group acting on the seven-brane configuration plays a key role in this analysis. Moreover, the E_8 structure automatically leads

A. G. R. Thomas

An algorithm for calculating the spectral intensity of radiation due to the coherent addition of many particles with arbitrary trajectories is described. Direct numerical integration of the Lienard-Wiechert potentials, in the far-field, for extremely high photon energies and many particles is made computationally feasible by a mixed analytic and numerical me

Charles Poli, Barbara Dietz, Olivier Legrand, Fabrice Mortessagne

We investigate a two-level model with a large number of open decay channels in order to describe avoided level crossing statistics in open chaotic billiards. This model allows us to describe the fundamental changes of the probability distribution of the avoided level crossings compared with the closed case. Explicit expressions are derived for systems with p

Lalitha Sankar, Xiaohu Shang, Elza Erkip, H. Vincent Poor

The sum-capacity for specific sub-classes of ergodic fading Gaussian two-user interference channels (IFCs) is developed under the assumption of perfect channel state information at all transmitters and receivers. For the sub-classes of uniformly strong (every fading state is strong) and ergodic very strong two-sided IFCs (a mix of strong and weak fading stat

Louis Paulot

We provide a general method to compute a Taylor expansion in time of implied volatility for stochastic volatility models, using a heat kernel expansion. Beyond the order 0 implied volatility which is already known, we compute the first order correction exactly at all strikes from the scalar coefficient of the heat kernel expansion. Furthermore, the first cor

Min Dai, Zuo Quan Xu, Xun Yu Zhou

A continuous-time Markowitz's mean-variance portfolio selection problem is studied in a market with one stock, one bond, and proportional transaction costs. This is a singular stochastic control problem,inherently in a finite time horizon. With a series of transformations, the problem is turned into a so-called double obstacle problem, a well studied problem

Min Dai, Zuo Quan Xu

A stock loan is a loan, secured by a stock, which gives the borrower the right to redeem the stock at any time before or on the loan maturity. The way of dividends distribution has a significant effect on the pricing of the stock loan and the optimal redeeming strategy adopted by the borrower. We present the pricing models sub ject to various ways of dividen

Andras Vasy

In this paper we prove the propagation of singularities for the wave equation on differential forms with natural (i.e. relative or absolute) boundary conditions on Lorentzian manifolds with corners, which in particular includes a formulation of Maxwell&#39;s equations. These results are analogous to those obtained by the author for the scalar wave equation a

Ki-Young Choi, Carlos E. Yaguna

The recent data from PAMELA and Fermi-LAT can be interpreted as evidence of new astrophysical sources of high energy positrons. In that case, such astrophysical positrons constitute an additional background against the positrons from dark matter annihilation. In this paper, we study the effect of that background on the prospects for the detection of a positr

Greg Hurst, Andrew Schultz

Let B_n denote the nth Bell number. We use well-known recursive expressions for B_n to give a generalizing recursion that can be used to prove Touchard&#39;s congruence.

Joerg Marks

After nine years of operation the BABAR experiment at the B factory PEPII (Standford Linear Accelerator Center) stopped data taking in April 2008. The last three month of data taking were devoted to e+e- collisions at center of mass energies of the Upsilon(2S), Upsilon(3S) and to an energy scan above the Upsilon(4S). Besides the observation of the bottomoniu

Jonathan M. Butterworth, John R. Ellis, Are R. Raklev, Gavin P. Salam

Recently there has been much interest in the use of single-jet mass and jet substructure to identify boosted particles decaying hadronically at the LHC. We develop these ideas to address the challenging case of a neutralino decaying to three quarks in models with baryonic violation of R-parity. These decays have previously been found to be swamped by QCD bac

Riccardo Argurio, Matteo Bertolini, Gabriele Ferretti, Alberto Mariotti

We consider semi-direct gauge mediation models of supersymmetry breaking where the messengers are composite fields and their supersymmetric mass is naturally generated through quartic superpotential couplings. We show that such composite messenger models can be easily embedded in quiver gauge theories arising from D-branes at Calabi-Yau singularities, and ar

A. Di Piazza, E. Lötstedt, A. I. Milstein, C. H. Keitel

Tunneling electron-positron pair production is studied in a new setup in which a strong low-frequency and a weak high-frequency laser field propagate in the same direction and collide head-on with a relativistic nucleus. The electron-positron pair production rate is calculated analytically in the limit in which in the nucleus rest frame the strong field is u

Marco G. Genoni, Carmen Invernizzi, Matteo G. A. Paris

We address quantum estimation of displacement and squeezing parameters by the class of probes made of Gaussian states undergoing Kerr interaction. If we fix the overall energy available to the probe, without posing any constraint on the available Gaussian squeezing, then Gaussian squeezing represents the optimal resource for parameter estimation. On the othe

J. X. Lu, Shan-Shan Xu

We explore various properties of interaction between D$_p$ and D$_{p&#39;}$ with each carrying a worldvolume flux and with the $p&#39;$-branes placed along $p&#39;$ spatial worldvolume directions of the p-branes at a separation when $p - p&#39; = 2$. Carefully analyzing the annulus amplitudes calculated via the boundary state approach, we find that many feat

Sven Erick Alm, Svante Janson, Svante Linusson

We study random graphs, both $G(n,p)$ and $G(n,m)$, with random orientations on the edges. For three fixed distinct vertices s,a,b we study the correlation, in the combined probability space, of the events a -> s and s -> b. For G(n,p), we prove that there is a p_c=1/2 such that for a fixed p<p_c the correlation is negative for large enough n and for p>p_c t

Vladimir V. Kornyak

Gauge invariance in discrete dynamical systems and its connection with quantization are considered. For a complete description of gauge symmetries of a system we construct explicitly a class of groups unifying in a natural way the space and internal symmetries. We describe the main features of the gauge principle relevant to the discrete and finite backgroun

J. L. van Velsen

A bias correction to Akaike&#39;s information criterion (AIC) is derived for seemingly unrelated regressions models. The correction is of particular use when the sample size is not much larger than the number of fitted parameters. A small-sample simulation study indicates that the bias-corrected AIC (AICc) provides better model choices than other model selec

Sarah J. MacLeod, Sergey Kafanov, Jukka P. Pekola

We present experiments on single Cooper-pair transistors made of two different superconducting materials. We chose Ti and Al to create an energy gap profile such that the island has a higher gap than the leads, thereby acting as a barrier to quasiparticle tunneling. Our transport measurements demonstrate that quasiparticle poisoning is suppressed in all our

William Guerin, Nicolas Mercadier, Franck Michaud, Davide Brivio

Atoms can scatter light and they can also amplify it by stimulated emission. From this simple starting point, we examine the possibility of realizing a random laser in a cloud of laser-cooled atoms. The answer is not obvious as both processes (elastic scattering and stimulated emission) seem to exclude one another: pumping atoms to make them behave as amplif

Arjen Stolk, K. Joost Batenburg

Discrete tomography is concerned with the reconstruction of images that are defined on a discrete set of lattice points from their projections in several directions. The range of values that can be assigned to each lattice point is typically a small discrete set. In this paper we present a framework for studying these problems from an algebraic perspective,

Marcin Dukalski, Stijn J. van Tongeren

We discuss fermionic reductions of type IIA superstrings on AdS4 x CP3 in relation to the conjectured AdS4/CFT3 duality. The superstring theory is described by means of a coset model construction, which is classically integrable. We discuss the global light-cone symmetries of the action and related kappa-symmetry gauge choices, and also present the complete

C. D. Westbrook, A. J. Illingworth, E. J. O&#39;Connor, R. J. Hogan

The properties of planar ice crystals settling horizontally have been investigated using a vertically-pointing Doppler lidar. Strong specular reflections were observed from their oriented basal facets, identified by comparison with a second lidar pointing 4deg from zenith. Analysis of 17 months of continuous high-resolution observations reveal that these pri

Alain Genestier, Sergey Lysenko

Let k be an algebraically closed field of characteristic two. Let R be the ring of Witt vectors of length two over k. We construct a group stack \hat G over k, the metaplectic extension of the Greenberg realization of Sp_{2n}(R). We also construct a geometric analog of the Weil representation of \hat G, this is a triangulated category on which \hat G acts by

Brijesh Kumar Rai, Bikash Kumar Dey

A directed acyclic network is considered where all the terminals need to recover the sum of the symbols generated at all the sources. We call such a network a sum-network. It is shown that there exists a solvably (and linear solvably) equivalent sum-network for any multiple-unicast network, and thus for any directed acyclic communication network. It is also

An-Ping Li, Hagen von Eitzen

In this paper, we will give an improvement on the lower bound for the counterfeit coins problem in the case that the number of false coins is unknown in advance

Javier R. Goicoechea, Mathieu Compiegne, Emilie Habart

We present the first detection of neutral atomic oxygen (3P_1-3P_2 fine structure line at ~63um) toward the Horsehead photodissociation region (PDR). The cloud has been mapped with the Spitzer Space Telescope at far-IR (FIR) wavelengths using MIPS in the spectral energy distribution (SED) mode. The [OI]63um line peaks at the illuminated edge of the cloud at

Chul-moon Yoo, Hideki Ishihara, Masashi Kimura, Sugure Tanzawa

We analyze momentarily static initial data sets of the gravitational field produced by two-point sources in five-dimensional Kaluza-Klein spacetimes. These initial data sets are characterized by the mass, the separation of sources and the size of a extra dimension. Using these initial data sets, we discuss the condition for black hole formation, and propose

Pekka Koskinen, Sami Malola, Hannu Häkkinen

The edges of nanoscopic objects determine most of their properties. For this reason the edges of honeycomb carbon--always considered either zigzag- or armchair-like--need special attention. In this report we provide experimental evidence confirming a previous unexpected prediction: zigzag is a metastable edge, as its planar reconstruction lowers energy and f

Olga Holtz, Noam Shomron

We survey classical and recent developments in numerical linear algebra, focusing on two issues: computational complexity, or arithmetic costs, and numerical stability, or performance under roundoff error. We present a brief account of the algebraic complexity theory as well as the general error analysis for matrix multiplication and related problems. We emp

Abhay Parvate, Seema Satin, A. D. Gangal

A new calculus on fractal curves, such as the von Koch curve, is formulated. We define a Riemann-like integral along a fractal curve F, called F-alpha-integral, where alpha is the dimension of F. A derivative along the fractal curve called F-alpha-derivative, is also defined. The mass function, a measure-like algorithmic quantity on the curves, plays a centr

JN Iyer, S. Müller-Stach

In this paper, we show the existence of a Chow--Kuenneth decomposition for the moduli stack of stable curves of genus g with r marked points, for low values of g,r. We also look at the moduli space R of double covers of genus 3 curves, branched along 4 distinct points. We obtain a birational model of the moduli space R as a group quotient of a product of two

Santo Fortunato

The modern science of networks has brought significant advances to our understanding of complex systems. One of the most relevant features of graphs representing real systems is community structure, or clustering, i. e. the organization of vertices in clusters, with many edges joining vertices of the same cluster and comparatively few edges joining vertices

A. A. Kochanov, T. S. Sinegovskaya, S. I. Sinegovsky

We study the influence of hadron interaction features on the high-energy atmospheric neutrino spectrum. The 1D calculation is performed with use of the known high-energy hadronic models, SIBYLL 2.1, QGSJET-II, Kimel and Mokhov, for the parameterizations of primary cosmic ray spectra issued from the measurement data. The results are compared with the Frejus d

Stefano Liberati, Luca Maccione

We review the main theoretical motivations and observational constraints on Planck scale suppressed violations of Lorentz invariance. After introducing the problems related to the phenomenological study of quantum gravitational effects, we discuss the main theoretical frameworks within which possible departures from Lorentz invariance can be described. In pa

Jian-Hua He, Bin Wang, Pengjie Zhang

Dark energy interacting with dark matter is a promising model to solve the cosmic coincidence problem. We study the signature of such interaction on large scale cosmic microwave background (CMB) temperature anisotropies. Based on the detail analysis in perturbation equations of dark energy and dark matter when they are in interaction, we find that the large