April 2010 arXiv papers — page 14

Kenton Born

Current best practices heavily control user permissions on network systems. This effectively mitigates many insider threats regarding the collection and exfiltration of data. Many methods of covert communication involve crafting custom packets, typically requiring both the necessary software and elevated privileges on the system. By exploiting the functional

Gautam S. Thakur, Mukul Sharma, Ahmed Helmy

School and College campuses face a perceived threat of violent crimes and require a realistic plan against unpredictable emergencies and disasters. Existing emergency systems (e.g., 911, campus-wide alerts) are quite useful, but provide delayed response (often tens of minutes) and do not utilize proximity or locality. There is a need to augment such systems

Andrew J. Millis, Darrell G. Schlom

Appropriately designed transition metal oxide heterostructures involving small band gap Mott insulators are argued to support spatially separated electron and hole gasses at equilibrium. Spatial separations and carrier densities favoring the formation of excitonic states are achievable. The excitonic states may exhibit potentially novel properties. Energetic

X. Zotos

By the Bethe ansatz method we study the energy dispersion of a particle interacting by a local interaction with fermions (or hard core bosons) of equal mass in a one dimensional lattice. We focus on the period of the Bloch oscillations which turns out to be related to the Fermi wavevector of the Fermi sea and in particular on how this dispersion emerges as a

Mostafa Annabestani, Seyed Javad Akhtarshenas, Mohamad Reza Abolhassani

In this article we investigate the effects of shifting position decoherence, arisen from the tunneling effect in the experimental realization of the quantum walk, on the one-dimensional discreet time quantum walk. We show that in the regime of this type of noise the quantum behavior of the walker does not fade, in contrary to the coin decoherence for which t

Song Li, Yongge Ma

The cosmological model of dark energy interacting with cold dark matter without coupling to the baryonic matter, is studied in the background of both classical Einstein and loop quantum cosmology. We consider two types of interacting models. In the former model, the interaction is a linear combination of the densities of two dark sectors, while in the latter

Artur Avila

We show that SL(2,R) cocycles with a positive Lyapunov exponent are dense in all regularity classes and for all non-periodic dynamical systems. For Schrödinger cocycles, we show prevalence of potentials for which the Lyapunov exponent is positive for a dense set of energies.

Guillem Rigaill, Emilie Lebarbier, Stéphane Robin

In segmentation problems, inference on change-point position and model selection are two difficult issues due to the discrete nature of change-points. In a Bayesian context, we derive exact, non-asymptotic, explicit and tractable formulae for the posterior distribution of variables such as the number of change-points or their positions. We also derive a new

Alejandro M. Lobos, Thierry Giamarchi

We study the screening of the Coulomb interaction in a quasi one-dimensional superconductor given by the presence of either a one- or a two-dimensional non-interacting electron gas. To that end, we derive an effective low-energy phase-only action, which amounts to treating the Coulomb and superconducting correlations in the random-phase approximation. We con

A. Kappes

Even 100 years after the discovery of cosmic rays their origin remains a mystery. In recent years, TeV gamma-ray detectors have discovered and investigated many Galactic sources where particles are accelerated up to energies of 100 TeV. However, it has not been possible up to now to identify these sites unambiguously as sources of hadronic acceleration. The

J. Palacci, C. Cottin-Bizonne, C. Ybert, L. Bocquet

In this paper, we investigate experimentally the non-equilibrium steady state of an active colloidal suspension under gravity field. The active particles are made of chemically powered colloids, showing self propulsion in the presence of an added fuel, here hydrogen peroxide. The active suspension is studied in a dedicated microfluidic device, made of permea

Svatopluk Krýsl

Let $(M,ω)$ be a symplectic manifold admitting a metaplectic structure (a symplectic analogue of the Riemannian spin structure) and a torsion-free symplectic connection $\nabla.$ Symplectic Killing spinor fields for this structure are sections of the symplectic spinor bundle satisfying a certain first order partial differential equation and they are the main

G. H. Zhong, Y. C. Liang, F. Hammer, X. Y. Chen

We study the star formation histories (SFH) and stellar populations of 213 red and 226 blue nearly face-on low surface brightness disk galaxies (LSBGs), which are selected from the main galaxy sample of Sloan Digital Sky Survey (SDSS) Data Release Seven (DR7). We also want to compare the stellar populations and SFH between the two groups. The sample of both

Rosario E. V. Profumo, Marco Polini, Reza Asgari, Rosario Fazio

Multi-layer graphene on the carbon face of silicon carbide is an intriguing electronic system which typically consists of a stack of ten or more layers. Rotational stacking faults in this system dramatically reduce inter-layer coherence. In this article we report on the influence of inter-layer interactions, which remain strong even when coherence is negligi

Hadi Ahmadi, Reihaneh Safavi-Naini

The problem of Secret Key Establishment (SKE) over a pair of independent Discrete Memoryless Broadcast Channels (DMBCs) has already been studied in \cite{Ah10}, where we provided lower and upper bounds on the secret-key capacity. In this paper, we study the above setup under each of the following two cases: (1) the DMBCs have secrecy potential, and (2) the D

Xiao Jianhua

In modern science, the thermo mechanics motion can be traced back to quantum motion in micro viewpoint. On the other hand, the thermo mechanics is definitely related with geometrical configuration motion (phase) in macro viewpoint. On this sense, the thermomechanics should be formulated by two kinds of motion: quantum motion and configuration motion. Its pri

M. Chaichian, A. Tureanu, A. A. Zheltukhin

Recently N. Berkovits, motivated by the supertwistor description of ${\cal N}=4 D=4$ super Yang-Mills, considered the generalization of the ${\cal N}=1 D=4$ $θ$-twistor construction to D=10 and applied it for a compact covariant description of ${\cal N}=1 D=10$ super Yang-Mills. This supports the relevance of the $θ$-twistor as a supersymmetric twistor alter

Begum Umme Jamil

Deep Inelastic Scattering (DIS) experiments have provided important information on the structure of hadrons and ultimately the structure of matter and on the nature of interactions between leptons and hadrons, since the discovery of partons. Various high energy deep inelastic interactions lead to different evolution equations from which we obtain various str

Joseph Shtok, Michael Elad

Finding the sparsest solution $α$ for an under-determined linear system of equations $Dα=s$ is of interest in many applications. This problem is known to be NP-hard. Recent work studied conditions on the support size of $α$ that allow its recovery using L1-minimization, via the Basis Pursuit algorithm. These conditions are often relying on a scalar property

Udayan Kumar, Gautam Thakur, Ahmed Helmy

Many interactions between network users rely on trust, which is becoming particularly important given the security breaches in the Internet today. These problems are further exacerbated by the dynamics in wireless mobile networks. In this paper we address the issue of trust advisory and establishment in mobile networks, with application to ad hoc networks, i

Vassily Olegovich Manturov

Based on a recently introduced by the author notion of {\em parity}, in the present paper we construct a sequence of invariants (indexed by natural numbers $m$) of long virtual knots, valued in certain simply-defined group ${\tilde G}_{m}$ (the Cayley graphs of these groups are represented by grids in the $(m+1)$-space); the conjugacy classes of elements of

L. DiCarlo, M. D. Reed, L. Sun, B. R. Johnson

Traditionally, quantum entanglement has played a central role in foundational discussions of quantum mechanics. The measurement of correlations between entangled particles can exhibit results at odds with classical behavior. These discrepancies increase exponentially with the number of entangled particles. When entanglement is extended from just two quantum

Lester Ingber, Paul L. Nunez

The dynamic behavior of scalp potentials (EEG) is apparently due to some combination of global and local processes with important top-down and bottom-up interactions across spatial scales. In treating global mechanisms, we stress the importance of myelinated axon propagation delays and periodic boundary conditions in the cortical-white matter system, which i

Xiang-Feng Zhou, Xiao Dong, Guang-Rui Qian, Lixin Zhang

The physical mechanisms behind the reduction of the bulk modulus of a high-pressure cubic TiO2 phase are confirmed by first-principles calculations. An unusual and abrupt change occurs in the dependence of energy on pressure at 43 GPa, indicating a pressure-induced phase transition from columbite TiO2 to a newly-identified modified fluorite TiO2 with a Pca21

MohammadHossein Bateni, MohammadTaghi Hajiaghayi, Nicole Immorlica, Hamid Mahini

We study bargaining games between suppliers and manufacturers in a network context. Agents wish to enter into contracts in order to generate surplus which then must be divided among the participants. Potential contracts and their surplus are represented by weighted edges in our bipartite network. Each agent in the market is additionally limited by a capacity

Y. Chen, F. L. Zhang, J. L. Chen

We generalize Maxwell equations which describe the vacuum of quantum electrodynamics into the quantum form. This nontraditional approach is different from the widely used theory|-Quantum Electrodynamics. From another viewpoint, it could be a direction for interpreting quantum theories properly.

María V. Fasano, Ricardo A. Maronna, Mariela Sued, Víctor J. Yohai

This paper deals with the Fisher-consistency, weak continuity and differentiability of estimating functionals corresponding to a class of both linear and nonlinear regression high breakdown M estimates, which includes S and MM estimates. A restricted type of differentiability, called weak differentiability, is defined, which suffices to prove the asymptotic

Y. Saidi, R. Burston, H. Moradi, L. Gizon

A data and computation center for helioseismology has been set up at the Max Planck Institute for Solar System Research in Germany to prepare for the SDO mission. Here we present the system infrastructure and the scientific aims of this project, which is funded through grants from the German Aerospace Center and the European Research Council.

David Parlongue

We will give in this paper the proof of an integral breakdown criterion for Einstein vacuum equations. In a recent article of S.Klainerman and I.Rodnianski a new breakdown criterion was proved as a result of a sequence of articles involving new techniques. However, in this article, the authors mentioned that it was likely possible to prove a sharper result i

Theo Johnson-Freyd

Given an arbitrary Lagrangian function on \RR^d and a choice of classical path, one can try to define Feynman's path integral supported near the classical path as a formal power series parameterized by "Feynman diagrams," although these diagrams may diverge. We compute this expansion and show that it is (formally, if there are ultraviolet divergences) invari

Lenny Taelman

We state and prove a formula for a certain value of the Goss L-function of a Drinfeld module. This gives characteristic-p-valued function field analogues of the class number formula and of the Birch and Swinnerton-Dyer conjecture. The formula and its proof are presented in an entirely self-contained fashion.

Wei Cui, Zairong Xi, Yu Pan

There has long been interest to control the transfer of population between specified quantum states. Recent work has optimized the control law for closed system population transfer by using a gradient ascent pulse engineer- ing algorithm [1]. Here, a spin-boson model consisting of two-level atoms which interact with the dissipative environment, is investigat

Tomi S. Koivisto

Nonsingular cosmologies are investigated in the framework of f(R) gravity within the first order formalism. General conditions for bounces in isotropic and homogeneous cosmology are presented. It is shown that only a quadratic curvature correction is needed to predict a bounce in a flat or to describe cyclic evolution in a curved dust-filled universe. Formal

Steve Butler

In this short note we look at the problem of counting juggling patterns with one ball or two balls with a throw at every occurrence. We will do this for both traditional juggling and for spherical juggling. In the latter case we will show a connection to the "associated Mersenne numbers" (A001350) and so as a result will be able to recover a proof th

Ralf Meyer, Maarten Solleveld

We prove that the Jacquet restriction functor for a parabolic subgroup of a reductive group over a non-Archimedean local field is right adjoint to the parabolic induction functor for the opposite parabolic subgroup, in the generality of smooth group representations on R-modules for any unital ring R in which the residue field characteristic is invertible. Co

Javier Fernandez, Cora Tori, Marcela Zuccalli

In this paper we propose a process of lagrangian reduction and reconstruction for nonholonomic discrete mechanical systems where the action of a continuous symmetry group makes the configuration space a principal bundle. The result of the reduction process is a discrete dynamical system that we call the discrete reduced system. We illustrate the techniques b

Hichem Hajaiej, Luc Molinet, Tohru Ozawa, Baoxiang Wang

Sufficient and necessary conditions for the generalized Gagliardo-Nirenberg (GN) inequality in Besov spaces and Triebel-Lizorkin spaces are obtained. Applying the GN inequality, we show that the finite-time blowup solutions have concentration phenomena in critical Lebesgue space L^3. Moreover, we consider the minimizer for a class of variational problem by a

Tomáš Brázdil, Javier Esparza, Stefan Kiefer, Michael Luttenberger

We study the problem of scheduling tasks for execution by a processor when the tasks can stochastically generate new tasks. Tasks can be of different types, and each type has a fixed, known probability of generating other tasks. We present results on the random variable S^sigma modeling the maximal space needed by the processor to store the currently active

V. Bardek, J. Feinberg, S. Meljanac

The collective field formulation of the Calogero model supports periodic density waves. An important set of such density waves is a two-parameter family of BPS solutions of the equations of motion of the collective field theory. One of these parameters is essentially the average particle density, which determines the period, while the other parameter determi

Jakub Jȩdrak, Jozef Spałek

Using an advanced version of the renormalized mean-field theory (RMFT) for the t-J model, we examine spin-singlet superconducting (SC) state of $d_{x^2 - y^2}$-symmetry. Overall doping dependence of the SC gap magnitude is in good agreement with experimental results for $\text{Bi}_{2}\text{Sr}_{2}\text{Ca} \text{Cu}_2 \text{O}_{8 + δ}$ (BSCCO) and $\text{La}

Edward W. J. Wallace

Given a discrete stochastic process, for example a chemical reaction system or a birth and death process, we often want to find a continuous stochastic approximation so that the techniques of stochastic differential equations may be brought to bear. One powerful and useful way to do this is the system size expansion of van Kampen to express a trajectory as a

Teng Wang, Tianbo Liu, Da-Xin Zhang, Bo-Qiang Ma

We investigate the rare decays $B_c \rightarrow D_s(1968) \ell \bar{\ell}$ and $B_c\rightarrow D_s^*(2317) \ell \bar{\ell}$ in the framework of the light-cone quark model (LCQM). The transition form factors are calculated in the space-like region and then analytically continued to the time-like region via exponential parametrization. The branching ratios and

Abolfazl Jafari

We are going to show that new star product was found by Mebaraki for noncommutative curved space time has some properties when $\triangle$ (it has appeared in new multiplication) is a constant.

M. Hafez, S. A. Jafari

We use Perturbative Continuous Unitary Transformations (PCUT) to study the one dimensional Extended Ionic Hubbard Model (EIHM) at half-filling in the band insulator region. The extended ionic Hubbard model, in addition to the usual ionic Hubbard model, includes an inter-site nearest-neighbor (n.n.) repulsion, $V$. We consider the ionic potential as unperturb

Mouchira Zaiter

Let g be a semisimple Lie algebra of finite dimension. The nullcone N of g is the set of (x, y) in g\timesg such that x and y are nilpotents and are in the same Borel subalgebra. The main result of this paper is that N is a closed and irreducible subvariety of g \times g whose normalization has rational singularities and such that the normalization morphism

Toshimitsu Takaesu

In this paper the Hamiltonian for the system of semi-relativistic particles interacting with a scalar bose field is investigated. A scaled total Hamiltonian of the system is defined and its scaling limit is considered. Then the semi-relativistic Schrodinger operator with an effective potential is derived.

Gauhar Abbas, B. Ananthanarayan, I. Caprini, I. Sentitemsu Imsong

We present a general formalism for deriving bounds on the shape parameters of the weak and electromagnetic form factors using as input correlators calculated from perturbative QCD, and exploiting analyticity and unitarity. The values resulting from the symmetries of QCD at low energies or from lattice calculations at special points inside the analyticity dom

Aaron Abrams, Noel Brady, Pallavi Dani, Moon Duchin

We construct "pushing maps" on the cube complexes that model right-angled Artin groups (RAAGs) in order to study filling problems in certain subsets of these cube complexes. We use radial pushing to obtain upper bounds on higher divergence functions, finding that the k-dimensional divergence of a RAAG is bounded by r^{2k+2}. These divergence function

Stephen Simons

In this paper, we show how the Brezis-Browder theorem for maximally monotone multifunctions with a linear graph on a reflexive Banach space, and a consequence of it due to Yao, can be generalized to SSDB spaces.

Qingshuo Song, Richard Stockbridge, Chao Zhu

This paper investigates the optimal harvesting strategy for a single species living in random environments whose growth is given by a regime-switching diffusion. Harvesting acts as a (stochastic) control on the size of the population. The objective is to find a harvesting strategy which maximizes the expected total discounted income from harvesting {\em up t

Charles D. Dermer, Soebur Razzaque

Fermi Gamma ray Space Telescope measurements of spectra, variability time scale, and maximum photon energy give lower limits to the apparent jet powers and, through gammagamma opacity arguments, the bulk Lorentz factors of relativistic jets. The maximum cosmic-ray particle energy is limited by these two quantities in Fermi acceleration scenarios. Recent data

E. Mukhin, V. Tarasov, A. Varchenko

We introduce families of maximal commutative subalgebras, called Bethe subalgebras, of the group algebra of the symmetric group. Bethe subalgebras are deformations of the Gelfand-Zetlin subalgebra. We describe various properties of Bethe subalgebras.

M. Neeley, R. C. Bialczak, M. Lenander, E. Lucero

Entanglement is one of the key resources required for quantum computation, so experimentally creating and measuring entangled states is of crucial importance in the various physical implementations of a quantum computer. In superconducting qubits, two-qubit entangled states have been demonstrated and used to show violations of Bell's Inequality and to im

Shaoyu Yin, Bin Wang, Robert Mann, Chong Oh Lee

We investigate the stability of a new warped black string with nontrivial topologies in five-dimensional Anti-de Sitter spacetime. After studying the linear gravitational perturbation, we find that this black string is unstable when the Kaluza-Klein mass falls in a certain range and the instability exists for all topological spacetimes.

Anatoly Khitrin, Michael Michalski, Jae-Seung Lee

We present experimental NMR demonstration of a scheme of reversible projective measurement, which allows extracting information on outcomes and probabilities of a projective measurement in a non-destructive way, with a minimal net effect on the quantum state of an ensemble. The scheme uses reversible dynamics and weak measurement of the intermediate state. T

Richard Evan Schwartz, Serge Tabachnikov

The pentagram map is a natural iteration on projective equivalence classes of (twisted) n-gons in the projective plane. It was recently proved ([OST]) that the pentagram map is completely integrable, with the complete set of Poisson commuting integrals given by the polynomials O1,...,O[n/2],On and E1,...,E[n/2],En, previously constructed in [S3]. These polyn

Alan R. Denton

Thermodynamic properties of charge-stabilised colloidal suspensions are commonly modeled by implementing the mean-field Poisson-Boltzmann (PB) theory within a cell model. This approach models a bulk system by a single macroion, together with counterions and salt ions, confined to a symmetrically shaped, electroneutral cell. While easing solution of the nonli

Omid Taheri, Sergiy A. Vorobyov

A new segmented compressed sampling method for analog-to-information conversion (AIC) is proposed. An analog signal measured by a number of parallel branches of mixers and integrators (BMIs), each characterized by a specific random sampling waveform, is first segmented in time into $M$ segments. Then the sub-samples collected on different segments and differ

Kenny De Commer

In a previous paper, we showed how one can obtain from the action of a locally compact quantum group on a type I-factor a possibly new locally compact quantum group. In another paper, we applied this construction method to the action of quantum SU(2) on the standard Podles sphere to obtain Woronowicz' quantum E(2). In this paper, we will apply this techn

F. S. Tabatabaei, E. M. Berkhuijsen

We derive distributions of dust temperature and dust opacity across M31 at 45" resolution using the Spitzer data. With the opacity map and a standard dust model we de-redden the Ha emission yielding the first de-reddened Ha map of M31. We compare the emissions from dust, Ha, HI and H2 by means of radial distributions, pixel-to-pixel correlations and wave

Wei Cui, Zairong Xi, Yu Pan

We theoretically analyze the entanglement generation and dynamics by coupled Josephson junction qubits. Considering a current-biased Josephson junction (CBJJ), we generate maximally entangled states. In particular, the entanglement dynamics is considered as a function of the decoherence parameters, such as the temperature, the ratio $r\equivω_c/ω_0$ between

Slavik Jablan, Ljiljana Radovic, Radmila Sazdanovic

This article contains general formulas for Tutte and Jones polynomials for families of knots and links given in Conway notation and "portraits of families"-- plots of zeroes of their corresponding Jones polynomials.

Sai-Yun Ye, Zhen-Biao Yang, Shi-Biao Zheng, Alessio Serafini

The coherent evolution of two atomic qubits mediated by a set of bosonic field modes is investigated. By assuming a specific encoding of the quantum states in the internal levels of the two atoms we show that entangling quantum gates can be realised, with high fidelity, even when a large number of mediating modes is involved. The effect of losses and imperfe

Viveck R. Cadambe, Syed A. Jafar, Hamed Maleki

We consider a set up where a file of size M is stored in n distributed storage nodes, using an (n,k) minimum storage regenerating (MSR) code, i.e., a maximum distance separable (MDS) code that also allows efficient exact-repair of any failed node. The problem of interest in this paper is to minimize the repair bandwidth B for exact regeneration of a single f

Pengkai Zhao Babak Daneshrad

Multiple-Input Multiple-Output (MIMO) based Medium Access Control (MAC) protocols have received a good deal of attention as researchers look to enhance overall performance of Ad Hoc networks by leveraging multi antenna enabled nodes. To date such MAC protocols have been evaluated through comparative simulation based studies that report on the number of concu

Charles L. Cartledge, Michael L. Nelson

We investigate the use of autonomically created small-world graphs as a framework for the long term storage of digital objects on the Web in a potentially hostile environment. We attack the classic Erdos - Renyi random, Barab'asi and Albert power law, Watts - Strogatz small world and our Unsupervised Small-World (USW) graphs using different attacker stra

E. A. Demekhin, E. N. Kalaidin, A. S. Selin

The paper continues a series of publications devoted to the 3D nonlinear localized coherent structures on the surface of vertically falling liquid films. The work is primarily focussed on experimental investigations. We study: (i) instabilities and transitions leading to 3D coherent structures; (ii) characteristics of these structures. Some nonstationary eff

Peter Collins, Gregory S. Ezra, Stephen Wiggins

We investigate the phase space structure and dynamics of a Hamiltonian isokinetic thermostat, for which ergodic thermostat trajectories at fixed (zero) energy generate a canonical distribution in configuration space. Model potentials studied consist of a single bistable mode plus transverse harmonic modes. Interpreting the bistable mode as a reaction (isomer

H. Knuepfer, C. B. Muratov

We investigate the ground state of a uniaxial ferromagnetic plate with perpendicular easy axis and subject to an applied magnetic field normal to the plate. Our interest is the asymptotic behavior of the energy in macroscopically large samples near the saturation field. We establish the scaling of the critical value of the applied field strength below satura

Numan Akdogan, Bulat Rameev, Sumeyra Guler, Osman Ozturk

Magnetic anisotropies of Co-implanted ZnO (0001) films grown on single-crystalline Al2O3 (11-20) substrates have been studied by ferromagnetic resonance (FMR) technique for different cobalt implantation doses. The FMR data show that the easy and hard axes have a periodicity of 60 degrees in the film plane, in agreement with the hexagonal structure of the ZnO

N. A. Poklonski, E. F. Kislyakov, S. A. Vyrko, N. N. Hieu

Structural and energy characteristics of the smallest magnetic endofullerene Fe@C20 have been calculated using the density functional theory approach. The ground state of Fe@C20 is found to be a septet state, and the magnetic moment of Fe@C20 is estimated to be 8 Bohr magnetons. Characteristics of an (8,8) carbon nanotube with a single Fe@C20 inside are stud

C. McNeile, C. T. H. Davies, E. Follana, K. Hornbostel

We extend our earlier lattice-QCD analysis of heavy-quark correlators to smaller lattice spacings and larger masses to obtain new values for the c mass and QCD coupling, and, for the first time, values for the b mass: m_c(3GeV,n_f=4)=0.986(6)GeV, alpha_msb(M_Z,n_f=5)=0.1183(7), and m_b(10GeV,n_f=5)=3.617(25)GeV. These are among the most accurate determinatio

Anthony G. A. Brown, Simon F. Portegies Zwart, Jennifer Bean

We describe the results of a search for the remnants of the Sun's birth cluster among stars in the Hipparcos Catalogue. This search is based on the predicted phase space distribution of the Sun's siblings from simple simulations of the orbits of the cluster stars in a smooth Galactic potential. For stars within 100 pc the simulations show that it is

Ratnesh Pandey, Kalpana Awasthi, R. S. Tiwari, O. N. Srivastava

The functionalized graphene sheets (FGS)-polyacrylamide (PAM) composite films have been prepared by solution cast technique. The FGS have been synthesized by thermal exfoliation of graphite oxide. Several composites with different weight % (between 0 to 25 wt %) of FGS loading in PAM have been prepared and characterized by XRD, SEM, TEM and FTIR spectroscopy

R. D. Ekers

Technology leads discovery in astronomy, as in all other areas of science, so growth in technology leads to the continual stream of new discoveries which makes our field so fascinating. Derek de Solla Price had analysed the discovery process in science in the 1960s and he introduced the terms 'Little Science' and 'Big Science' as part of his

N. B. Melnikov, B. I. Reser, V. I. Grebennikov

A characteristic feature of the Gaussian approximation in the functional-integral approach to the spin-fluctuation theory is the jump phase transition to the paramagnetic state. We eliminate the jump and obtain a continuous second-order phase transition by taking into account high-order terms in the expansion of the free energy in powers of the fluctuating e

Xuan-Chao Huang, Jay Cheng

One of the main problems in all-optical packet-switched networks is the lack of optical buffers, and one feasible technology for the constructions of optical buffers is to use optical crossbar Switches and fiber Delay Lines (SDL). In this two-part paper, we consider SDL constructions of optical queues with a limited number of recirculations through the optic

D. K. Singh, M. T. Tuominen

The interplay of magnetic energies in a Kondo lattice is the underlying physics of a heavy fermion system. Creating an artificial Kondo lattice system by localizing the moments in an ordered metallic array provides a prototype system to tune and study the energetic interplay while avoiding the complications introduced by random alloying of the material. In t

Irina Semenova

The article describes the prospects of model base management system design automation for decision support systems and suggests the toolbox scheme for design automation based on intelligent technologies.

William Y. C. Chen, Doris D. M. Sang, Diane Y. H. Shi

We find involutions for three Rogers-Ramanujan-Gordon type identities obtained by Andrews on the generating functions for partitions with part difference and parity restrictions.

Ester Pantaleo, Michele Tumminello, Fabrizio Lillo, Rosario N. Mantegna

The use of improved covariance matrix estimators as an alternative to the sample estimator is considered an important approach for enhancing portfolio optimization. Here we empirically compare the performance of 9 improved covariance estimation procedures by using daily returns of 90 highly capitalized US stocks for the period 1997-2007. We find that the use

Rustum Choksi, Mark A. Peletier

We present the second of two articles on the small volume fraction limit of a nonlocal Cahn-Hilliard functional introduced to model microphase separation of diblock copolymers. After having established the results for the sharp-interface version of the functional (arXiv:0907.2224), we consider here the full diffuse-interface functional and address the limit

Nikolay G. Moshchevitin

We give a simplified exposition of the easiest case of a breakthrough result by D.Badziahin, A.Pollington and S.Velani related to W.M.Schmidt's conjecture.

Renaud Lambiotte

We focus on the detection of communities in multi-scale networks, namely networks made of different levels of organization and in which modules exist at different scales. It is first shown that methods based on modularity are not appropriate to uncover modules in empirical networks, mainly because modularity optimization has an intrinsic bias towards partiti

Gi-Ren Liu, Narn-Rueih Shieh

Let ${\bf{w}}(t,x):=(u,v)(t,x),\ t>0,\ x\in \mathbb{R}^{n},$ be the $\mathbb{R}^2$-valued spatial-temporal random field ${\bf{w}}=(u, v)$ arising from a certain two-equation system of fractional kinetic equations of reaction-diffusion type, with given random initial data $u(0,x)$ and $v(0,x).$ The space-fractional derivative is characterized by the compositi

David Martinez-Martin, Miriam Jaafar, Ruben Perez, Julio Gomez-Herrero

Cervenka et al. have recently reported ferromagnetism along graphite steps. We present Magnetic Force microscopy (MFM) data showing that the signal along the steps is independent of an external magnetic field. Moreover, by combining Kelvin Probe Force Microscopy (KPFM) and MFM, we are able to separate the electrostatic and magnetic interactions along the ste

M. R. Rozinas

We consider finite irreducible Markov chains. It was shown that mean hitting time from one state to another satisfies the triangle inequality. Hence, sum of mean hitting time between couple of states in both directions is a metric on the space of states.

Illes Horvath, Balint Toth, Balint Veto

The myopic (or `true') self-avoiding walk model (MSAW) was introduced in the physics literature by Amit, Parisi and Peliti (1983). It is a random motion in Z^d pushed towards domains less visited in the past by a kind of negative gradient of the occupation time measure. We investigate the asymptotic behaviour of MSAW in the non-recurrent dimensions. For

Hans Schoutens

We propose a suitable substitute for the classical Grothendieck ring of an algebraically closed field, in which any quasi-projective scheme is represented, while maintaining its non-reduced structure. This yields a more subtle invariant, called the schemic Grothendieck ring, in which we can formulate a form of integration resembling Kontsevich's motivic

Kyoko Watanabe, Sam Krucker, Hugh Hudson, Toshifumi Shimizu

We report on G-band emission observed by the Solar Optical Telescope onboard the Hinode satellite in association with the X1.5-class flare on 2006 December 14. The G-band enhancements originate from the footpoints of flaring coronal magnetic loops, coinciding with non-thermal hard X-ray bremsstrahlung sources observed by the Reuven Ramaty High Energy Solar S

Shaul K. Bar-Lev, Gerard Letac

Hazard rates play an important role in various areas, e.g., reliability theory, survival analysis, biostatistics, queueing theory and actuarial studies. Mixtures of distributions are also of a great preeminence in such areas as most populations of components are indeed heterogeneous. In this study we present a sufficient condition for mixtures of two element

B. C. Paul, P. Thakur, S. Ghose

We study a composition of normal and exotic matter which is required for a flat Emergent Universe scenario permitted by the equation of state (EOS)($p=Aρ-Bρ^{1/2}$) and predict the range of the permissible values for the parameters $A$ and $B$ to explore a physically viable cosmological model. The permitted values of the parameters are determined taking into

Marian Ioan Munteanu, Ana Irina Nistor

In the present paper we classify all surfaces in $\E^3$ with a canonical principal direction. Examples of these type of surfaces are constructed. We prove that the only minimal surface with a canonical principal direction in the Euclidean space ${\mathbb{E}}^3$ is the catenoid.

Woo Seok Choi, K. Taniguchi, S. J. Moon, S. S. A. Seo

We investigated the electronic structure and lattice dynamics of multiferroic MnWO4 by optical spectroscopy. With variation of polarization, temperature, and magnetic field, we obtained optical responses over a wide range of photon energies. The electronic structure of MnWO4 near to the Fermi level was examined, with inter-band transitions identified in opti

Joel D. Hartman

Recently Knutson et al. (2010) have demonstrated a correlation between the presence of temperature inversions in the atmospheres of hot Jupiters, and the chromospheric activity levels of the host stars. Here we show that there is also a correlation, with greater than 99.5% confidence, between the surface gravity of hot Jupiters and the activity levels of the

Wolfram von Oertzen

The formation of alpha-clusters in nuclei close to the decay thresholds is discussed. These states can be considered to be boson-condensates, which are formed in a second order phase transition in a mixture of nucleons and alpha-particles. The de Broglie wavelength of the alpha-particles is larger than the nuclear diameter, therefore the coherent properties

Bryan M. Wong, Alfredo M. Morales

We present photocurrent power-enhancement calculations of a carbon nanotube p-n junction electromagnetically coupled to a highly-efficient photonic structure. Particular attention is paid to a GaAs photonic structure specifically modified to increase the intensity of infrared light onto the nanotube region for effective energy conversion. Using finite-differ

Bryan M. Wong

Stimulated by the recent observation of π-π interactions between C60 and corannulene subunits in a molecular tweezer arrangement (J. Am. Chem. Soc. 2007, 129, 3842), a density functional theory study was performed to analyze the electronic structure and properties of various noncovalent corannulene complexes. The theoretical approach is first applied to cora

Bryan M. Wong, Joseph G. Cordaro

The excited-state properties in a series of coumarin solar cell dyes are investigated with a long-range-corrected (LC) functional which asymptotically incorporates Hartree-Fock exchange. Using time-dependent density functional theory (TDDFT), we calculate excitation energies, oscillator strengths, and excited-state dipole moments in each of the dyes as a fun

Shabnam Sodagari, Peyman Hesami, Alireza Nasiri Avanaki

We propose a novel error concealment algorithm to be used at the receiver side of a lossy image transmission system. Our algorithm involves hiding the edge map of the original image at the transmitter within itself using a robust watermarking scheme. At the receiver, wherever a lost block is detected, the extracted edge information is used as border constrai