December 2007 arXiv papers — page 30

Tatsuo Azeyanagi, Andreas Karch, Tadashi Takayanagi, Ethan G. Thompson

We use the holographic proposal for calculating entanglement entropies to determine the boundary entropy of defects in strongly coupled two-dimensional conformal field theories. We study several examples including the Janus solution and show that the boundary entropy extracted from the entanglement entropy as well as its more conventional definition via the

E. L. Koschmieder

We determine the strength of the weak nuclear force which holds the lattices of the elementary particles together. We also determine the strength of the strong nuclear force which emanates from the sides of the nuclear lattices. The strong force is the sum of the unsaturated weak forces at the surface of the nuclear lattices. The strong force is then about t

Alexei Borodin, Jeffrey Kuan

We study a two-dimensional family of probability measures on infinite Gelfand-Tsetlin schemes induced by a distinguished family of extreme characters of the infinite-dimensional unitary group. These measures are unitary group analogs of the well-known Plancherel measures for symmetric groups. We show that any measure from our family defines a determinantal p

R. Fittipaldi, A. Vecchione, R. Ciancio, S. Pace

Superconducting behavior has been observed in the Sr2RuO4-Sr3Ru2O7 eutectic system as grown by the flux-feeding floating zone technique. A supercurrent flows across a single interface between Sr2RuO4 and Sr3Ru2O7 areas at distances that are far beyond those expected in a conventional proximity scenario. The current-voltage characteristics within the Sr3Ru2O7

Craig J. Fennie, Ram Seshadri, Karin M. Rabe

The oxide pyrochlore Bi$_2$Ti$_2$O$_7$ is in some ways analogous to perovskite PbTiO$_3$, in that Bi$_2$Ti$_2$O$_7$ has two cations, Bi$^{3+}$ and Ti$^{4+}$ in oxidation states that are normally associated with a propensity to off-center. However, unlike PbTiO$_3$, Bi$_2$Ti$_2$O$_7$ is experimentally observed to remain cubic down to 2 K, while the only obser

Gastao S. F. Frederico, Delfim F. M. Torres

The study of fractional variational problems with derivatives in the sense of Caputo is a recent subject, the main results being Agrawal's necessary optimality conditions of Euler-Lagrange and respective transversality conditions. Using Agrawal's Euler-Lagrange equation and the Lagrange multiplier technique, we obtain here a Noether-like theorem for

Jan Staff, Brian Niebergal, Rachid Ouyed

We describe a model within the ``Quark-nova'' scenario to interpret the recent observations of early X-ray afterglows of long Gamma-Ray Bursts (GRB) with the Swift satellite. This is a three-stage model within the context of a core-collapse supernova. STAGE 1 is an accreting (proto-) neutron star leading to a possible delay between the core collapse

Adrian Vasiu

We present a general and comprehensive overview of recent developments in the theory of integral models of Shimura varieties of Hodge type. The paper covers the following topics: construction of integral models, their possible moduli interpretations, their uniqueness, their smoothness, their properness, and basic stratifications of their special fibres.

I. V. Khalzov, A. I. Smolyakov, V. I. Ilgisonis

Analytical expression for energy of eigen-modes in magnetohydrodynamic flows of ideal fluids is obtained. It is shown that the energy of unstable modes is zero, while the energy of stable oscillatory modes (waves) can assume both positive and negative values. Negative energy waves always correspond to non-symmetric eigen-modes -- modes that have a component

J Cuevas, G James, P G Kevrekidis, B A Malomed

We study four different approximations for finding the profile of discrete solitons in the one-dimensional Discrete Nonlinear Schrödinger (DNLS) Equation. Three of them are discrete approximations (namely, a variational approach, an approximation to homoclinic orbits and a Green-function approach), and the other one is a quasi-continuum approximation. All th

K. Kieling, J. Eisert

This article is a draft of a book chapter of the book entitled "Quantum Percolation and Breakdown", to appear 2008.

Carlos E. Kenig, Frank Merle

We show that if a solution of the defocusing cubic NLS in 3d remains bounded in the homogeneous Sobolev norm of order 1/2 in its maximal interval of existence, then the interval is infinite and the solution scatters. No radial assumption is made.

G. E. Romero, M. Orellana, A. T. Okazaki, S. P. Owocki

LS I +61 303 is a puzzling object detected from radio up to high-energy gamma-rays. Variability has recently been observed in its high-energy emission. The object is a binary system, with a compact object and a Be star as primary. The nature of the secondary and the origin of the gamma-ray emission are not clearly established at present. Recent VLBA radio da

Robert R. Gibson, W. N. Brandt, Donald P. Schneider, S. C. Gallagher

We use quantitative metrics to characterize the variation of CIV 1549 A broad absorption lines (BALs) over 3--6 (rest-frame) years in a sample of 13 quasars at 1.7 <= z <= 2.8 and compare the results to previous studies of BAL variability on shorter time scales. The strong BALs in our study change in complex ways over 3--6 yr. Variation occurs in discrete re

B. Groves, M. Dopita, R. Sutherland, L. Kewley

We combine the the stellar spectral synthesis code Starburst99, the nebular modelling code MAPPINGSIII, and a 1-D dynamical evolution model of HII regions around massive clusters of young stars to generate improved models of the spectral energy distribution (SED) of starburst galaxies. We introduce a compactness parameter, C, which characterizes the specific

M. J. Calderon, Belita Koiller, S. Das Sarma

We analyze the effects of valley interference on the quantum control and manipulation of an electron bound to a donor close to a Si/SiO2 interface as a function of the valley-orbit coupling at the interface. We find that, for finite valley-orbit coupling, the tunneling times involved in shuttling the electron between the donor and the interface oscillate wit

W. A. Al-Saidi, E. J. Walter, A. M. Rappe

We report Hartree-Fock (HF) based pseudopotentials suitable for plane-wave calculations. Unlike typical effective core potentials, the present pseudopotentials are finite at the origin and exhibit rapid convergence in a plane-wave basis; the optimized pseudopotential method [A. M. Rappe et. al, Phys. Rev. B 41 1227--30 (1990)] improves plane-wave convergence

Steffen Mieske, Pavel Kroupa

A new type of compact stellar systems, labelled ``ultra-compact dwarf galaxies&#39;&#39; (UCDs), was discovered in the last decade. Recent studies show that their dynamical mass-to-light ratios (M/L) tend to be too high to be explained by canonical stellar populations, being on average about twice as large as those of Galactic globular clusters of comparable

D. E. Chang, V. Gritsev, G. Morigi, V. Vuletic

Understanding strongly correlated quantum systems is a central problem in many areas of physics. The collective behavior of interacting particles gives rise to diverse fundamental phenomena such as confinement in quantum chromodynamics, phase transitions, and electron fractionalization in the quantum Hall regime. While such systems typically involve massive

G. Gentile, H. S. Zhao, B. Famaey

We present the analysis of 23 published rotation curves of disk galaxies belonging to the Ursa Major group of galaxies, with kinematics free of irregularities. The rotation curves are analysed in the context of MOND (Modified Newtonian Dynamics). We add an extra component to the rotation curve fits, in addition to the stellar and gaseous disks: a speculative

Rafel Escribano

A phenomenological analysis of radiative $V\to Pγ$ and $P\to Vγ$ decays is performed in order to determine the gluonic content of the $η^\prime$ wave function. Our result shows that there is no evidence for such a gluonium contribution, $Z_{η^\prime}^2=0.04\pm 0.09$. In terms of a mixing angle description this corresponds to $ϕ_P=(41.4\pm 1.3)^\circ$ and $|ϕ

J. Leon-Tavares, A. P. Lobanov, V. H. Chavushyan, T. G. Arshakian

We aim to test the model proposed to explain the correlation between the flux density at 15 GHz of a stationary component in the parsec-scale jet and the optical continuum emission in the radio galaxy 3C~390.3. In the model, the double-peaked emission from 3C~390.3 is likely to be generated both near the disk and in a rotating subrelativistic outflow surroun

J. A. McLaughlin, A. W. Hood

The nature of fast magnetoacoustic and Alfvén waves is investigated in a zero $β$ plasma in the neighbourhood of a pair of two-dimensional null points. This gives an indication of wave propagation in the low $β$ solar corona, for a more complicated magnetic configuration than that looked at by McLaughlin & Hood (2004). It is found that the fast wave is attra

Daniel Nagaj, Edward Farhi, Jeffrey Goldstone, Peter Shor

We give a generalization to an infinite tree geometry of Vidal&#39;s infinite time-evolving block decimation (iTEBD) algorithm for simulating an infinite line of quantum spins. We numerically investigate the quantum Ising model in a transverse field on the Bethe lattice using the Matrix Product State ansatz. We observe a second order phase transition, with c

Christian Bonatti, Boris Kolev

Let f be an orientation-preserving homeomorphism of the plane such that f-Id is contracting. Under these hypotheses, we establish the existence, for every periodic orbit, of a fixed point which has nonzero linking number with this periodic orbit.

C. González-Fernández, A. Cabrera-Lavers, P. L. Hammersley, F. Garzón

In this paper, we present low resolution (R=500) near-infrared spectra for selected and serendipitous sources in six inner in-plane Galactic fields, with the aim of analysing the stellar content present. From the equivalent widths of the main features of the K band spectra (the NaI, CaI and CO bandheads) we have derived the metallicities of the sources by me

Sébastien George, Cécile Bothorel

In a distance learning context, providing usual communication tools (forum, chat, ...) is not always enough to create efficient interactions between learners and to favour collective knowledge building. A solution consists in setting-up collective activities which encourage learners to communicate. But, even in that case, tools can sometimes become a barrier

A. Mondragón, M. Mondragón, E. Peinado

A variety of lepton flavour violating effects related to the recent discovery of neutrino oscillations and mixings is here systematically discussed in terms of an S_3-flavour permutational symmetry. After a brief review of some relevant results on lepton masses and mixings, that had been derived in the framework of a Minimal S_3-Invariant Extension of the St

Ivan Calvo, Raul Sanchez, Benjamin A. Carreras, Boudewijn Ph. van Milligen

In the study of transport in inhomogeneous systems it is common to construct transport equations invoking the inhomogeneous Fick law. The validity of this approach requires that at least two ingredients be present in the system. First, finite characteristic length and time scales associated to the dominant transport process must exist. Secondly, the transpor

Michael J. Williams

We show that lens space surgeries on knots in $S^3$ which arise from the primitive/Seifert type construction also arise from the primitive/primitive construction. This is the first step of a three step program to prove the Berge conjecture for tunnel number one knots.

Nikolas Akerblom, Ralph Blumenhagen, Dieter Lust, Maximilian Schmidt-Sommerfeld

We review some aspects of D-instantons in intersecting D-brane models. In particular, we present applications of the recently proposed instanton calculus to computations of charged matter superpotential couplings and corrections to the gauge kinetic function in the low energy effective action of type IIA orientifolds. As an interesting byway, we also discuss

J. A. McLaughlin, A. W. Hood

The nature of fast magnetoacoustic and Alfvén waves is investigated in a zero $β$ plasma. This gives an indication of wave propagation in the low $β$ solar corona. It is found that for a two-dimensional null point, the fast wave is attracted to that point and the front of the wave slows down as it approaches the null point, causing the current density to acc

R. M. Abrarov, E. Ya. Sherman, J. E. Sipe

We use a hydrodynamic model to describe the relaxation of optically injected currents in quantum wells on a picosecond time scale, numerically solving the continuity and velocity evolution equations with the Hermite-Gaussian functions employed as a basis. The interplay of the long-range Coulomb forces and nonlinearity in the equations of motion leads to rath

M. Bridges, J. D. McEwen, M. Cruz, M. P. Hobson

We have returned to our previous Bianchi VII_h analysis in light of the Cruz et al. 2007 suggestion that the cold spot observed near the southern Galactic pole may be a remnant temperature perturbation of a cosmic texture. In Bridges et al. 2006b we found two favoured left handed Bianchi VII_h templates with restricted prior probabilities so that the templat

M. Lavagnini, A. Sacchetti, L. Degiorgi, E. Arcangeletti

We report the pressure dependence of the optical response of LaTe$_2$, which is deep in the charge-density-wave (CDW) ground state even at 300 K. The reflectivity spectrum is collected in the mid-infrared spectral range at room temperature and at pressures between 0 and 7 GPa. We extract the energy scale due to the single particle excitation across the CDW g

Karim A. Malik, David Seery, Kishore N. Ananda

We derive the Klein--Gordon equation for a single scalar field coupled to gravity at second order in perturbation theory and leading order in slow-roll. This is done in two ways: we derive the Klein--Gordon equation first using the Einstein field equations, and then directly from the action after integrating out the constraint equations. We also point out an

J. A. McLaughlin, A. W. Hood

This paper is the third in a series of investigations by the authors. The nature of fast magnetoacoustic and Alfvén waves is investigated in a 2D $β=0$ plasma in the neighbourhood of two dipoles. We use both numerical simulations (two-step Lax-Wendroff scheme) and analytical techniques (WKB approximation). It is found that the propagation of the linear fast

Qinghui Zhang, Alex Pevsner, Agung Hertanto, Yu-Chi Hu

Modeling of respiratory motion is important for a more accurate understanding and accounting of its effect on dose to cancers in the thorax and abdomen by radiotherapy. We have developed a model of respiration-induced organ motion in the thorax, without the commonly adopted assumption of repeatable breath cycles. The model describes the motion of a volume of

Bjorn Poonen

Fix a number field k. We prove that if there is an algorithm for deciding whether a smooth projective geometrically integral k-variety has a k-point, then there is an algorithm for deciding whether an arbitrary k-variety has a k-point and also an algorithm for computing X(k) for any k-variety X for which X(k) is finite. The proof involves the construction of

J. Alexandre, K. Farakos, N. E. Mavromatos, P. Pasipoularides

We study decoherence models for flavour oscillations in four-dimensional stochastically fluctuating space times and discuss briefly the sensitivity of current neutrino experiments to such models. We pay emphasis on demonstrating the model dependence of the associated decoherence-induced damping coefficients in front of the oscillatory terms in the respective

Aram Mekjian

A fundamental symmetry of nuclear and particle physics is isospin whose third component is the Gell-Mann/Nishijima expression I(z)=Q-(B+S)/2 . The role of isospin symmetry in relativistic heavy ion collisions is studied. An isospin I(z), strangeness S correlation is shown to be a direct and simple measure of flavor correlations, vanishing in a Qg phase of un

Peng Gao

We study finite sections of weighted Hardy&#39;s inequality following the approach of De Bruijn. Similar to the unweighted case, we obtain an asymptotic expression for the optimal constant.

Rachit Agarwal

We obtain a technique to reduce the computational complexity associated with decoding of Hermitian codes. In particular, we propose a method to compute the error locations and values using an uni-variate error locator and an uni-variate error evaluator polynomial. To achieve this, we introduce the notion of Semi-Erasure Decoding of Hermitian codes and prove

J. Javaloyes, M. Perrin, A. Politi

We consider here a model previously introduced to describe the collective behavior of an ensemble of cold atoms interacting with a coherent electromagnetic field. The atomic motion along the self-generated spatially-periodic force field can be interpreted as the rotation of a phase oscillator. This suggests a relationship with synchronization transitions occ

Sébastien George, Alain Derycke

Educative platforms are at the heart of the development of online education. They can not only be reduced to technological aspects. Underlying models impact teaching and learning from the preparing of lessons to the learning sessions. Research related to these platforms are numerous and their stakes are important. For these reasons, we launched a call to a s

Guillaume Jourdan, Astrid Lambrecht, Fabio Comin, Joël Chevrier

We show that the Casimir force gradient can be quantitatively measured with no contact involved. Results of the Casimir force measurement with systematic uncertainty of 3% are presented for the distance range of 100-600 nm. The statistical uncertainty is shown to be due to the thermal fluctuations of the force probe. The corresponding signal to noise ratio e

Marguerite Virotte-Ducharme

In this paper we prove that $2^{20+1}.U_6(2)$, known as the centralizer of an involution in the group $2E_6(2)$ is a quotient of a Coxeter group. We obtain a presentation of $2^{20+1}.U_6(2)$ as a $Q_{222}$-group, which now resolve a long pending question.

S. Piatek, C. Pryor, E. W. Olszewski

Kallivayalil et al. have used the \textit{Hubble Space Telescope} to measure proper motions of the LMC and SMC using images in 21 and five fields, respectively, all centered on known QSOs. These results are more precise than previous measurements, but have surprising and important physical implications: for example, the LMC and SMC may be approaching the Mil

M. Guedel

(abridged) The Sun&#39;s magnetic activity has steadily declined during its main-sequence life. While the solar photospheric luminosity was about 30% lower 4.6 Gyr ago when the Sun arrived on the main sequence compared to present-day levels, its faster rotation generated enhanced magnetic activity; magnetic heating processes in the chromosphere, the transiti

Frederic Jouhet, Elie Mosaki

In this paper, we focus on a q-analogue of the Riemann zeta function at positive integers, which can be written for s\in\N^* by ζ_q(s)=\sum_{k\geq 1}q^k\sum_{d|k}d^{s-1}. We give a new lower bound for the dimension of the vector space over \Q spanned, for 1/q\in\Z\setminus\{-1;1\} and an even integer A, by 1,ζ_q(3),ζ_q(5),...,ζ_q(A-1). This improves a recent

Yue Zou, Israel Klich, Gil Refael

We investigate the influence of inhomogeneity in the pairing coupling constant $U(\vec r)$ on dirty BCS superconductors, focusing on $T_c$, the order parameter $Δ(\vec r)$, and the energy gap $E_g(\vec r)$. Within mean-field theory, we find that when the length-scale of the inhomogeneity is comparable to, or larger than the coherence length, the ratio $2E_g/

Madeth May, Sébastien George, Patrick Prévôt

Tracking data of user&#39;s activities resulting from Computer Mediated Communication (CMC) tools (forum, chat, etc.) is often carried out in an ad-hoc manner, which either confines the reusability of data in different purposes or makes data exploitation difficult. Our research works are biased toward methodological challenges involved in designing and devel

D. Gamermann, E. Oset

We analyze two recent reactions of Belle, producing $D\bar D$ and $D\bar D^*$ states that have an enhancement of the invariant $D\bar D$, $D\bar D^*$ mass distribution close to threshold, from the point of view that they might be indicative of the existence of a hidden charm scalar and an axial vector meson states below $D\bar D$ or $D\bar D^*$ thresholds, r

M. T. Beltran, R. Estalella, J. M. Girart, P. T. P. Ho

Context. This is the third of a series of papers devoted to study in detail and with high-angular resolution intermediate-mass molecular outflows and their powering sources. Aims. The aim of this paper is to study the intermediate-mass YSO IRAS 20050+2720 and its molecular outflow, and put the results of this and the previous studied sources in the context o

Anisse Kasraoui, Jiang Zeng

We study statistics on ordered set partitions whose generating functions are related to $p,q$-Stirling numbers of the second kind. The main purpose of this paper is to provide bijective proofs of all the conjectures of \stein (Arxiv:math.CO/0605670). Our basic idea is to encode ordered partitions by a kind of path diagrams and explore the rich combinatorial

Pierre-Henri Chavanis, Giovanni De Ninno, Duccio Fanelli, Stefano Ruffo

Systems with long-range interactions display a short-time relaxation towards Quasi-Stationary States (QSSs), whose lifetime increases with system size. With reference to the Hamiltonian Mean Field (HMF) model, we here review Lynden-Bell&#39;s theory of ``violent relaxation&#39;&#39;. The latter results in a maximum entropy scheme for a water-bag initial prof

Joni Tammi

If taken into account, the transmission of the particle-scattering turbulence --in addition to just the particles-- through the shock front can change the effective compression ratio felt by the accelerating particles significantly from the compression of the underlying plasma. This can lead to significantly harder energy spectra than what are traditionally

S. F. King

This is a review article about the most recent developments on the field of neutrino mass. The first part of the review introduces the idea of neutrino masses and mixing angles, summarizes the most recent experimental data then discusses the experimental prospects and challenges in this area. The second part of the review discusses the implications of these

Joni Tammi, Paul Dempsey

We present both numerical and semi-analytical results on test-particle acceleration in multiple parallel shocks. We apply a kinetic Monte Carlo code and an eigenfunction expansion method to calculate the distribution functions for electron populations accelerated in subsequent parallel shocks with speeds ranging from non- to fully-relativistic. We examine th

M. B. N. Kouwenhoven, R. de Grijs

The total mass of distant star clusters is often derived from the virial theorem, using line-of-sight velocity dispersion measurements and half-light radii. Although most stars form in binary systems, this is mostly ignored when interpreting the observations. The components of binary stars exhibit orbital motion, which may increase the measured velocity disp

C. Toher, S. Sanvito

In transport calculations for molecular junctions based on density functional theory the choice of exchange and correlation functional may dramatically affect the results. In particular local and semi-local functionals tend to over-delocalize the molecular levels thus artificially increasing their broadening. In addition the same molecular levels are usually

E. Alecian, C. Catala, G. A. Wade, J. -F. Donati

After our recent discovery of four magnetic Herbig stars, we have decided to study in detail one of them, HD 200775, to determine if its magnetic topology is similar to that of the main sequence magnetic stars. With this aim, we monitored this star in Stokes I and V over more than two years, using the new spectropolarimeters ESPaDOnS at CFHT, and Narval at T

Michele Sciacca, David Jou, Maria Stella Mongioví

We propose a phenomenological equation for the vortex line density in rotating Bose-Einstein condensates as a function of the angular speed. This equation provides a simple description of the gross features of the increase in vortex number from the appearance of the first vortex to the theoretical rigid-body result for high vortex density, and allows one to

Joerg Fischera, Michael A. Dopita

We derive the spectral energy distribution (SED) of dusty, isothermal, self gravitating, stable and spherical clouds externally heated by the ambient interstellar radiation field. For a given radiation field and dust properties, the radiative transfer problem is determined by the pressure of the surrounding medium and the cloud mass expressed as a fraction o

J. Silvester, G. A. Wade, O. Kochukhov, J. D. Landstreet

Historically, the magnetic field geometries of the chemically peculiar Ap stars were modelled in the context of a simple dipole field. However, with the acquisition of increasingly sophisticated diagnostic data, it has become clear that the large-scale field topologies exhibit important departures from this simple model. Recently, new high-resolution circula

J. L. Jaramillo, N. Vasset, M. Ansorg

Our current picture of black hole gravitational collapse relies on two assumptions: i) the resulting singularity is hidden behind an event horizon -- weak cosmic censorship conjecture -- and ii) spacetime eventually settles down to a stationarity state. In this setting, it follows that the minimal area containing an apparent horizon is bound by the square of

Sang-Hyuk Lee, Yohai Roichman, Gi-Ra Yi, Shin-Hyun Kim

We use digital holographic microscopy and Mie scattering theory to simultaneously characterize and track individual colloidal particles. Each holographic snapshot provides enough information to measure a colloidal sphere&#39;s radius and refractive index to within 1%, and simultaneously to measure its three-dimensional position with nanometer in-plane precis

S. Bednarek, K. Lis, B. Szafran

We present a self-consistent Schroedinger-Poisson scheme for simulation of electrostatic quantum dots defined in gated two-dimensional electron gas formed at n-AlGaAs/GaAs heterojunction. The computational method is applied to a quantitative description of transport properties studied experimentally by Elzermann et al. [Appl. Phys. Lett. {\bf 84}, 4617 (2004

Sampsa Riikonen, Daniel Sanchez-Portal

We present here a comprehensive search for the structure of the Si(553)-Au reconstruction. More than two hundred different trial structures have been studied using first-principles density-functional calculations with the SIESTA code. An iterative procedure, with a step-by-step increase of the accuracy and computational cost of the calculations, was used to

J. A. McLaughlin, J. S. L. Ferguson, A. W. Hood

This paper is a demonstration of how the WKB approximation can be used to help solve the linearised 3D MHD equations. Using Charpit&#39;s Method and a Runge-Kutta numerical scheme, we have demonstrated this technique for a potential 3D magnetic null point, ${\bf{B}}=(x,εy -(ε+1)z)$. Under our cold plasma assumption, we have considered two types of wave propa

I. Beslic, L. Vranjes Markic, J. Boronat

We have investigated the stability limits of small spin-polarized clusters consisting of up to ten spin-polarized tritium T$\downarrow$ atoms and the mixtures of T$\downarrow$ with spin-polarized deuterium D$\downarrow$ and hydrogen H$\downarrow$ atoms. All of our calculations have been performed using the variational and diffusion Monte Carlo methods. For c

Tadafumi Ohsaku

The dynamical symmetry breaking in a quasi-(1+1)-dimensional relativistic model is investigated. The motions of particles in intrachain are described as a relativistic electron-hole gas, while the interchain hopping term is introduced as a 0th-component of vector in (1+1)-dimensions, a kind of chemical potential of the system. The gauge symmetry of the model

Boris S. Kerner

Spatiotemporal features and physics of vehicular traffic congestion occurring due to heavy freeway bottlenecks caused by bad weather conditions or accidents are found based on simulations in the framework of three-phase traffic theory. A model of a heavy bottleneck is presented. Under a continuous non-limited increase in bottleneck strength, i.e., when the a

Sergey V. Sushkov, Yuan-Zhong Zhang

We construct exact nonstatic nonhomogeneous spherically symmetric solutions in the theory of gravity with a scalar field possessing the exponential potential. The solution of particular interest corresponds to the scalar field with negative kinetic energy, i.e. a ghost, and represents two asymptotically homogeneous spatially flat universes connected by a thr

M. Mudrich, G. Droppelmann, P. Claas, C. P. Schulz

Femtosecond multiphoton pump-probe photoionization is applied to helium nanodroplets doped with rubidium (Rb). The yield of Rb+ ions features pronounced quantum interference (QI) fringes demonstrating the coherence of a superposition of electronic states on a time scale of tens of picoseconds. Furthermore, we observe QI in the yield of formed RbHe exciplex m

K. Kowalski, J. Rembielinski

The coherent states for the quantum mechanics on a torus and their basic properties are discussed.

C. Bedogné, A. P. Masucci, G. J. Rodgers

We introduce a new class of deterministic networks by associating networks with Diophantine equations, thus relating network topology to algebraic properties. The network is formed by representing integers as vertices and by drawing cliques between M vertices every time that M distinct integers satisfy the equation. We analyse the network generated by the Py

G. Conner, M. Meilstrup, D. Repovš, A. Zastrow

Two natural questions are answered in the negative: (1) If a space has the property that small nulhomotopic loops bound small nulhomotopies, then are loops which are limits of nulhomotopic loops themselves nulhomotopic? (2) Can adding arcs to a space cause an essential curve to become nulhomotopic? The answer to the first question clarifies the relationship

S. Burciu

The notion of double coset for semisimple finite dimensional Hopf algebras is introduced. This is done by considering an equivalence relation on the set of irreducible characters of the dual Hopf algebra. As an application formulae for the restriction of the irreducible characters to normal Hopf subalgebras are given.

C. Malyshev

A translational gauge approach of the Einstein type is proposed for obtaining the stresses that are due to non-singular screw dislocation. The stress distribution of second order around the screw dislocation is classically known for the hollow circular cylinder with traction-free external and internal boundaries. The inner boundary surrounds the dislocation&

Dinh-V-Trung, Jeremy Lim

We report high angular-resolution VLA observations of cyanopolyyne molecules HC$_3$N and HC$_5$N from the carbon rich circumstellar envelope of IRC+10216. The observed low-lying rotational transitions trace a much more extended emitting region than seen in previous observations at higher frequency transitions. We resolve the hollow quasi-spherical distributi

Grigoris Panotopoulos

An inflationary single field model with a non-trivial kinetic term for the inflaton is discussed. It is shown that it is possible to have large primordial non-gaussianities and large tensor-to-scalar ratio in a simple concrete model with just a scalar field and a generalized kinetic term for the inflaton field. This is potentially interesting in the prospect

Alexey Glutsyuk, Christophe Sabot

In this work we compute the Stokes matrices of the ordinary differential equation satisfied by the hypergeometric integrals associated to an arrangement of hyperplanes in generic position. This generalizes the computation done by Ramis and Duval for confluent hypergeometric functions, which correspond to the arrangement of two points on the line. The proof i

Esmerindo Bernardes

In this article, we present an analytical direct method, based on a Numerov three-point scheme, which is sixth order accurate and has a linear execution time on the grid dimension, to solve the discrete one-dimensional Poisson equation with Dirichlet boundary conditions. Our results should improve numerical codes used mainly in self-consistent calculations i

V. V. Bel&#39;kov, P. Olbrich, S. A. Tarasenko, D. Schuh

Symmetry and spin dephasing of in (110)-grown GaAs quantum wells (QWs) are investigated applying magnetic field induced photogalvanic effect (MPGE) and time-resolved Kerr rotation. We show that MPGE provides a tool to probe the symmetry of (110)-grown quantum wells. The photocurrent is only observed for asymmetric structures but vanishes for symmetric QWs. A

Michael Carley

A method of deriving quadrature rules has been developed which gives nodes and weights for a Gaussian-type rule which integrates functions of the form: f(x,y,t) = a(x,y,t)/((x-t)^2+y^2) + b(x,y,t)/([(x-t)^2+y^2]^{1/2}) + c(x,y,t)\log[(x-t)^2+y^2]^{1/2} + d(x,y,t), without having to explicitly analyze the singularities of $f(x,y,t)$ or separate it into its co

I. M. Brandão, M. S. Cunha, J. F. Gameiro

For the first time, the bolometric correction of $α$ Cir was determined. Two values, both based on an estimation of the total integrated flux, were obtained. For that purpose spectroscopic and photometric data of $α$ Cir available in the literature was used. The values derived were then used to place $α$ Cir in the HR diagram.

Michael Carley

An arithmetically simple method has been developed for the evaluation of Biot--Savart integrals on tetrahedralized distributions of vorticity. In place of the usual approach of analytical formulae for the velocity induced by a linear distribution of vorticity on a tetrahedron, the integration is performed using Gaussian quadrature and a ray tracing technique

Ad Polosa

There are several reasons to believe that some of the new particles observed at B-factories have no ordinary quark composition. We briefly illustrate the diquark-antidiquark model and the recent experimental discoveries which confirm some of its most striking predictions.

Hannu Reittu, Ilkka Norros

We consider a variant of so called power-law random graph. A sequence of expected degrees corresponds to a power-law degree distribution with finite mean and infinite variance. In previous works the asymptotic picture with number of nodes limiting to infinity has been considered. It was found that an interesting structure appears. It has resemblance with suc

Hermine Landt, Paolo Padovani, Paolo Giommi, Matteo Perri

This paper presents XMM-Newton and Chandra X-ray spectroscopy of ten flat-spectrum radio quasars (FSRQ) which are candidates to have an X-ray spectrum dominated by jet synchrotron emission. In all these FSRQ, which are less strongly relativistically beamed than blazars, a considerable contribution from a power-law component similar to that present in radio-q

E. Mikheeva, A. Doroshkevich, V. Lukash

We propose a solution of the cusp problem in framework of the standard $Λ$CDM cosmology. To do this we describe the linear and nonlinear periods of halo formation by the entropy function of dark matter particles. This approach allows us to take into account together the impact of both the processes of nonlinear relaxation of compressed matter and the small s

Luc Devroye, Gábor Lugosi

It is shown that functions defined on $\{0,1,...,r-1\}^n$ satisfying certain conditions of bounded differences that guarantee sub-Gaussian tail behavior also satisfy a much stronger ``local&#39;&#39; sub-Gaussian property. For self-bounding and configuration functions we derive analogous locally subexponential behavior. The key tool is Talagrand&#39;s [Ann.

Kai Matzutt

This article describes, in elementary terms, a generic approach to produce discrete random tilings and similar random structures by using point process theory. The standard Voronoi and Delone tilings can be constructed in this way. For this purpose, convex polytopes are replaced by their vertex sets. Three explicit constructions are given to illustrate the c

Daniel Duque, Pedro Tarazona, Enrique Chacón

Recently, the intrinsic sampling method has been developed in order to obtain, from molecular simulations, the intrinsic structure of the liquid-vapor interface that is presupposed in the classical capillary wave theory. Our purpose here is to study dynamical processes at the liquid-vapor interface, since this method allows tracking down and analyzing the mo

Vladimir Gol&#39;dshtein, Stanislav Dubrovskiy

We show that every closed L_infty,loc - form on R^n is exact. Differential is understood in the sense of currents. The proof does not use any explicit geometric constructions. De Rham theorem follows.

Rémi Carles, Satoshi Masaki

We justify WKB analysis for Hartree equation in space dimension at least three, in a regime which is supercritical as far as semiclassical analysis is concerned. The main technical remark is that the nonlinear Hartree term can be considered as a semilinear perturbation. This is in contrast with the case of the nonlinear Schrodinger equation with a local nonl

Franco Ferrari, Jaroslaw Paturej, Thomas A. Vilgis

In this work we discuss the dynamics of a three dimensional chain which is described by generalized nonlinear sigma model The formula of the probability distribution of two topologically entangled chain is provided. The interesting case of a chain which can form only discrete angles with respect to the $z-$axis is also presented.

Radja Boughezal

Recent developements in the calculation of the NNLO QCD corrections to the charm quark mass dependent matrix elements in B -> X_s gamma are reported. Special emphasis is put on the new results of the virtual O(alpha_s^2) fermionic contribution to these matrix elements [1].

A. Kwasniowski, J. Adamowski

Exchange interaction has been studied for electrons in coupled quantum dots (QD&#39;s) by a configuration interaction method using confinement potentials with different profiles. The confinement potential has been parametrized by a two-centre power-exponential function, which allows us to investigate various types of QD&#39;s described by either soft or hard