February 2009 arXiv papers — page 12

Walter R. Innes

Fourier transform analysis of the calorimeter noise problem gives quantitative results on a) the time-height correlation, b) the effect of background on optimal shaping and on the ENC, c) sampling frequency requirements, and d) the relation between sampling frequency and the required quantization error.

Michael E. Crenshaw

We show that the material dependencies of macroscopically quantized fields in linear media are not consistent with the classical electromagnetic boundary conditions. We then phenomenologically construct macroscopic quantized fields that satisfy quantum--classical correspondence with the result indicating that the canonical momentum in a linear medium is modi

L. Binette, N. Flores-Fajardo, A. C. Raga, L. Drissen

It is generally believed that O stars, confined near the galactic midplane, are somehow able to photoionize a significant fraction of what is termed the "diffuse ionized gas" (DIG) of spiral galaxies, which can extend up to 1-2 kpc above the galactic midplane. The heating of the DIG remains poorly understood, however, as simple photoionization models

Pavel Stransky, Petr Hruska, Pavel Cejnar

Spectra of the geometric collective model of atomic nuclei are analyzed to identify chaotic correlations among nonrotational states. The model has been previously shown to exhibit a high degree of variability of regular and chaotic classical features with energy and control parameters. Corresponding signatures are now verified also on the quantum level for d

Jeremy D. Schnittman, Julian H. Krolik

We present new calculations of X-ray polarization from black hole (BH) accretion disks in the thermally-dominated state, using a Monte-Carlo ray-tracing code in full general relativity. In contrast to many previously published studies, our approach allows us to include returning radiation that is deflected by the strong-field gravity of the BH and scatters o

Lucianne M. Walkowicz, Andrew C. Becker, Scott F. Anderson, Joshua S. Bloom

The next decade of survey astronomy has the potential to transform our knowledge of variable stars. Stellar variability underpins our knowledge of the cosmological distance ladder, and provides direct tests of stellar formation and evolution theory. Variable stars can also be used to probe the fundamental physics of gravity and degenerate material in ways th

Anastasios Giovanidis, Gerhard Wunder, Joerg Buehler

A single queue incorporating a retransmission protocol is investigated, assuming that the sequence of per effort success probabilities in the Automatic Retransmission reQuest (ARQ) chain is a priori defined and no channel state information at the transmitter is available. A Markov Decision Problem with an average cost criterion is formulated where the possib

Bogdan Cichocki, Maria L. Ekiel-Jezewska

Self-diffusion of a sphere in a network of rods is analyzed theoretically. Hydrodynamic interactions are taken into account according to the model of Dhont et al., under the assumption that $\ka << 1$ and $\bar{a}/L<<1$, where $1/κ$ is the network hydrodynamic screening length, $\bar{a}=a+D/2$, and $a$ is the sphere radius, while $D$ and $L$ are the diameter

Patricia Goncalves

We prove a Central Limit Theorem for the empirical measure in the one-dimensional Totally Asymmetric Zero-Range Process in the hyperbolic scaling $N$, starting from the equilibrium measure $ν_ρ$. We also show that when taking the direction of the characteristics, the limit density fluctuation field does not evolve in time until $N^{4/3}$, which implies the c

Tomomi Ishikawa

We discuss the perturbative $O(α_s a)$ matching in the static heavy and domain-wall light quark system. The gluon action is the Iwasaki action and the link smearing is performed in the static heavy action. The chiral symmetry of the light quark realized by using the domain-wall fermion formulation does not prohibit the mixing of the operators at $O(a)$. The

K. D. Sen, Jacob Katriel

Position and momentum information measures are evaluated for the ground state of the \emph{relativistic} hydrogen-like atoms. Consequences of the fact that the radial momentum operator is not self-adjoint are explicitly studied, exhibiting fundamental shortcomings of the conventional uncertainty measures in terms of the radial position and momentum variances

R. Nath, L. Santos

Faraday patterns can be induced in Bose-Einstein condensates by a periodic modulation of the system nonlinearity. We show that these patterns are remarkably different in dipolar gases with a roton-maxon excitation spectrum. Whereas for non-dipolar gases the pattern size decreases monotonously with the driving frequency, patterns in dipolar gases present, eve

Stere Ianus, Mihai Visinescu, Gabriel Eduard Vilcu

We show the existence of conformal Killing-Yano tensors on a manifold endowed with a mixed 3-Sasakian structure.

Carl McBride, Carlos Vega, Eduardo Sanz, Luis G. MacDowell

A number of crystal structures of water have been `superheated&#39; in Monte Carlo simulations. Two well known models for water were considered; namely the TIP4P model and the SPC/E model. By comparing the fluid-solid coexistence temperature to the temperature at which the solid becomes mechanically unstable and melts it is possible to determine the typical

F. J. Lockman, J. Ott

Studies of nearby galaxies including the Milky Way have provided fundamental information on the evolution of structure in the Universe, the existence and nature of dark matter, the origin and evolution of galaxies, and the global features of star formation. Yet despite decades of work, many of the most basic aspects of galaxies and their environments remain

E. Shchukin W. Vogel

We derive a Bell-type inequality for observables with arbitrary spectra. For the case of continuous variable systems we propose a possible experimental violation of this inequality, by using squeezed light and homodyne detection together with methods of quantum-state reconstruction. It is shown that the violation is also possible for realistic detection effi

P. Elebert, P. J. Callanan, M. A. P. Torres, M. R. Garcia

We present phase resolved optical spectroscopy and Doppler tomography of V1341 Cygni, the optical counterpart to the neutron star low mass X-ray binary Cygnus X-2. We derive a radial velocity curve for the secondary star, finding a projected radial velocity semi-amplitude of K2 = 79 +/- 3 km/s, leading to a mass function of 0.51 +/- 0.06 Msun, ~30% lower tha

Aurelien Alvarez

We prove a analog of Kurosh theorem for countable Borel equivalence relations giving the structure of sub-relations in free products.

P. Xenitidis

We consider the partial difference equations of the Adler-Bobenko-Suris classification, which are characterized as multidimensionally consistent. The latter property leads naturally to the construction of auto-B{ä}cklund transformations and Lax pairs for all the equations in this class. Their symmetry analysis is presented and infinite hierarchies of general

Misha Marie Gregersen, Mathias B. Andersen, Gaurav Soni, Carl Meinhart

For a microchamber filled with a binary electrolyte and containing a flat un-biased center electrode at one wall, we employ three numerical models to study the strength of the resulting induced-charge electro-osmotic (ICEO) flow rolls: (i) a full nonlinear continuum model resolving the double layer, (ii) a linear slip-velocity model not resolving the double

Minas Tsoukalas

In this talk we discuss black hole solutions in six-dimensional gravity with a Gauss- Bonnet term in the bulk and an induced gravity term on a thin 3-brane of codimension-2. It is shown that these black holes can be localized on the 3-brane, and they can further be extended into the bulk by a warp function. These solutions have regular horizons and no other

Oleg Safronov

We study the distribution of eigenvalues of the Schrödinger operator with a complex valued potential $V$. We prove that if $|V|$ decays faster than the Coulomb potential, then all eigenvalues are in a disc of a finite radius.

Dr. Henry Makowitz, Ph. D

Arguments are presented based on particle phenomenology and the requirement for Unitarity for a complex valued postulated four generation CKM Matrix (VCKM ) based on a Sequential Fourth Generation Model (sometimes named SM4). A modified four generation QCD Standard Model Lagrangian is utilized per SM4. A four generation neutrino mass mixing MNS Matrix, (VMNS

Pedro Jiménez Delgado

A new generation of (unpolarized) dynamical parton distribution functions of the nucleon is determined. After introducing basic elements of perturbative QCD, the dynamical model is discussed and compared with the approach to parton distributions used by most other groups (&#34;standard&#34;). Parton distributions sets (with uncertainties) at different orders

B. M. Pazderska, M. P. Gawronski, R. Feiler, M. Birkinshaw

We report the results of a survey of 442 planetary nebulae at 30 GHz. The purpose of the survey is to develop a list of planetary nebulae as calibration sources which could be used for high frequency calibration in future. For 41 PNe with sufficient data, we test the emission mechanisms in order to evaluate whether or not spinning dust plays an important rol

Peter Hokayem, Debasish Chatterjee, John Lygeros

This paper is concerned with the problem of Model Predictive Control and Rolling Horizon Control of discrete-time systems subject to possibly unbounded random noise inputs, while satisfying hard bounds on the control inputs. We use a nonlinear feedback policy with respect to noise measurements and show that the resulting mathematical program has a tractable

A. Ibarra, E. Kuulkers, J. P. Osborne, K. Page

Classical novae are phenomena caused by explosive hydrogen burning on an accreting white dwarf. So far, only one classical nova has been identified in X-rays before the actual optical outburst occurred (V2487 Oph). The recently discovered nova, V2491 Cyg, is one of the fastest (He/N) novae observed so far. Using archival ROSAT, XMM-Newton and Swift data, we

Christian Gnodtke, Ulf Saalmann, Jan M. Rost

A general scenario for electronic charge migration in finite samples illuminated by an intense laser pulse is given. Microscopic calculations for neon clusters under strong short pulses as produced by X-ray free-electron laser sources confirm this scenario and point to the prominent role of field ionization by strong internal fields. The latter leads to the

A. Lecavelier des Etangs

Here we describe the observations and the resulting constraints on the upper atmosphere (thermosphere and exosphere) of the &#34;Hot-Jupiters&#34;. In particular, observations and theoretical modeling of Hot-Jupiter evaporation are described. The observations allowed the discovery that the planet orbiting HD209458 has an extended atmosphere of escaping hydro

J. Fresnais, J. -F. Berret, L. Qi, J. -P. Chapel

Water-soluble clusters made from 7 nm inorganic nanoparticles have been investigated by small-angle neutron scattering. The internal structure factor of the clusters was derived and exhibited a universal behavior as evidenced by a correlation hole at intermediate wave-vectors. Reverse Monte-Carlo calculations were performed to adjust the data and provided an

L. Yaroslavsky

Discrete sampling theorem is formulated that refers to discrete signals specified by a finite number of their samples and band-limited in a domain of a certain orthogonal transform. Conditions of the recoverability of such signals from their sparse samples are discussed for different transforms and applications are illustrated by examples of image super-reso

Michael Boshernitzan, Eli Glasner

We review some aspects of recurrence in topological dynamics and focus on two open problems. The first is an old one concerning the relation between Poincare and Birkhoff recurrence; the second, due to Boshernitzan, is about moving recurrence. We provide a partial answer to a topological version of the moving recurrence problem.

Andrei Derevianko, Sergey G. Porsev, James F. Babb

The electric dipole polarizabilities evaluated at imaginary frequencies for hydrogen, the alkali-metal atoms, the alkaline earth atoms, and the inert gases are tabulated along with the resulting values of the atomic static polarizabilities, the atom-surface interaction constants, and the dispersion (or van der Waals) constants for the homonuclear and the het

Domenico Giulini

Wheeler&#39;s Superspace is the arena in which Geometrodynamics takes place. I review some aspects of its geometrical and topological structure that Wheeler urged us to take seriously in the context of canonical quantum gravity.

Anders K. H. Bengtsson

Returning to an old idea of a certain two-particle relativistic harmonic oscillator as an underlying mechanical model for higher spin gauge fields, various space-time pictures are discussed for the propagation and the interactions.

Fabien Cheynis, Helge Haas, Thierry Fournier, Laurent Ranno

We report on a new approach, entirely based on electron-beam lithography technique, to contact electrically, in a four-probe scheme, single nanostructures obtained by self-assembly. In our procedure, nanostructures of interest are localised and contacted in the same fabrication step. This technique has been developed to study the field-induced reversal of an

Brent Everitt

This is the first installment of a book on combinatorial and geometric group theory from the topological point of view. This is a classical subject. The installment contains Chapters 1, 3 and 4, and there are nine chapters in total: 1. Combinatorial Complexes 2. Topological Invariants 3. Coverings 4. Galois Theory 5. Generators and Relations 6. The Topologic

Brendon J. Brewer, Dennis Stello

The measured properties of stellar oscillations can provide powerful constraints on the internal structure and composition of stars. To begin this process, oscillation frequencies must be extracted from the observational data, typically time series of the star&#39;s brightness or radial velocity. In this paper, a probabilistic model is introduced for inferri

K. Schonning, Chr. Bargholtz, M. Bashkanov, M. Berlowski

The production of $\omega$ mesons in the $pd \to{}^3$He$ \omega$ reaction has been studied at two energies near the kinematic threshold, $T_p=1450$ MeV and $T_p=1360$ MeV. The differential cross section was measured as a function of the $\omega$ cm angle at both energies over the whole angular range. Whereas the results at 1360 MeV are consistent with isotro

Seoktae Koh

We have investigated if the vector field can give rise to an accelerating phase in the early universe. We consider a timelike vector field with a general quadratic kinetic term in order to preserve an isotropic background spacetime. The vector field potential is required to satisfy the three minimal conditions for successful inflation: i) $ρ>0$, ii) $ρ+3P <

Adrian Sabin Popescu

In the last years the Space Science community was confronted to a continuous increasing interest in Martian missions, extra-solar planet search and multi-satellite missions. The presented T.I.P.O. mission is a proposal for a research program dedicated to study, by space borne interferometric methods, the radio emissions generated in the atmospheres and magne

Tsunehiro Kobayashi

A tachyon field having a negative squared-mass $-m_t^2$ can be described in terms of massless fields degenerating infinitely with respect to the helicity. The degeneracy leads symmetry breakings of space-time. This picture for the tachyon does not contradict causality. The tachyon vector-field is quenched from the interactions with matter fields, and the eff

Josef Ludescher, Ralf Hofmann

We re-evaluate the build-up of a horizon-sized temperature profile of amplitude $δT/T \sim 10^{-3}$ at $z\sim 1$ in light of an improved determination of the black-body anomaly, based on a pure SU(2) Yang-Mills theory, and the correction of a mistake in deriving the evolution equation for $δT$. Our present results for the temperature profiles hardly are dist

ETM Collaboration, C. McNeile, C. Michael, C. Urbach

We compare flavour singlet and non-singlet vector mesons from first principles using lattice QCD. With N_f=2 flavours of light quark, this addresses the omega-rho mass difference. Using maximally twisted-mass lattice QCD, we are able for the first time to determine this mass difference precisely and we compare with experiment. We also discuss omega-rho mixin

J. Klaja, P. Moskal, J. Zdebik

The measurement of the quasi-free production of the eta prime meson has been carried out at the COSY-11 detection setup using a proton beam and a deuteron cluster target. The energy dependence of the cross section is extracted using a fixed proton beam momentum of p_beam=3.35 GeV/c and exploiting the Fermi momenta of nucleons inside deuterons. The data cover

R. Schoedel, D. Merritt, A. Eckart

Nuclear star clusters (NSCs) are located at the photometric and dynamical centers of the majority of galaxies. They are among the densest star clusters in the Universe. The NSC in the Milky Way is the only object of this class that can be resolved into individual stars. We measured the proper motions of more than 6000 stars within ~1.0 pc of the supermassive

Jukka Kiukas, Pekka Lahti, Jussi Schultz

We illustrate the use of the statistical method of moments for determining the position and momentum distributions of a quantum object from the statistics of a single measurement. The method is used for three different, though related, models; the sequential measurement model, the Arthurs-Kelly model and the eight-port homodyne detection model. In each case,

J. Okolowicz, M. Ploszajczak

We demonstrate existence of exceptional points in many-body scattering continuum of atomic nucleus and discuss their salient effects on the example of one-nucleon spectroscopic factors.

L. Hartmann, M. Spreafico

We compute the analytic torsion of a cone over a sphere of dimension 1, 2, and 3, and we conjecture a general formula for the cone over an odd dimensional sphere.

Marius Dadarlat, Mikael Rordam

It is shown that a strongly self-absorbing C*-algebra is of real rank zero and absorbs the Jiang-Su algebra if it contains a nontrivial projection. We also consider cases where the UCT is automatic for strongly self-absorbing C*-algebras, and K-theoretical ways of characterizing when Kirchberg algebras are strongly self-absorbing.

Gerard van der Geer

We construct curves with many points over finite fields using the class group

Geoffrey L. Sewell

We resolve the long standing question of temperature dependence of uniformly moving bodies by means of a quantum statistical treatment centred on the zeroth law of thermodynamics. The key to our treatment is the result, established by Kossakowski et al, that a macroscopic body behaves as a thermal reservoir with well-defined temperature, in the sense of the

Michele Campisi, Peter Talkner, Peter Hänggi

Based on the observation that the thermodynamic equilibrium free energy of an open quantum system in contact with a thermal environment can be understood as the difference between the free energy of the total system and that of the bare environment, the validity of the Crooks theorem and of the Jarzynski equality is extended to open quantum systems. No restr

E. Heinsalu, M. Patriarca, I. Goychuk, P. Hanggi

The fractional Fokker-Planck equation for subdiffusion in time-dependent force fields is derived from the underlying continuous time random walk. Its limitations are discussed and it is then applied to the study of subdiffusion under the influence of a time-periodic rectangular force. As a main result, we show that such a force does not affect the universal

Gerard van der Geer, Alexis Kouvidakis

We study the Picard variety of the Fano surface of nodal and mildly cuspidal cubic threefolds in arbitrary characteristic by relating divisors on the Fano surface to divisors on the symmetric product of a curve of genus 4.

Haihui Luo, Xuan Qian, Xuezhong Ruan, Yang Ji

We report on time-resolved Kerr rotation measurements of spin coherence of electrons in the first excited subband of a high-mobility low-density two-dimensional electron system in a GaAs/Al0.35Ga0.65As heterostructure. While the transverse spin lifetime (T2*) of electrons decreases monotonically with increasing magnetic field, it has a non-monotonic dependen

Agnes Sambale, Dirk-Gunnar Welsch, Stefan Yoshi Buhmann, Ho Trung Dung

Based on a unified approach to macroscopic QED that allows for the inclusion of amplification in a limited space and frequency range, we study the Casimir force as a Lorentz force on an arbitrary partially amplifying system of linearly locally responding (isotropic) magnetoelectric bodies. We demonstrate that the force on a weakly polarisable/magnetisable am

Adrien Dubouloz, David R. Finston, Parag Deepak Mehta

The affine cancellation problem, which asks whether complex affine varieties with isomorphic cylinders are themselves isomorphic, has a positive solution for two dimensional varieties whose coordinate rings are unique factorization domains, in particular for the affine plane, but counterexamples are found within normal surfaces Danielewski surfaces and facto

N. L. Tsitsas, N. Rompotis, I. Kourakis, P. G. Kevrekidis

Starting from Maxwell&#39;s equations, we use the reductive perturbation method to derive a second-order and a third-order nonlinear Schroedinger equation, describing ultra-short solitons in nonlinear left-handed metamaterials. We find necessary conditions and derive exact bright and dark soliton solutions of these equations for the electric and magnetic fie

A. D. Chernin, P. Teerikorpi, M. J. Valtonen, G. G. Byrd

Dark energy must be taken into account to estimate more reliably the amount of dark matter and how it is distributed in the local universe. For systems several Mpc across like the Local Group, we introduce three self-consistent independent mass estimators. These account for the antigravity effect of dark energy treated as Einstein&#39;s cosmological constant

S. A. Petrova

The induced Compton scattering of radio emission off the particles of the ultrarelativistic electron-positron plasma in the open field line tube of a pulsar is considered. We examine the scattering of a bright narrow radio beam into the background over a wide solid angle and specifically study the scattering in the transverse regime, which holds in a moderat

Mehmet Tekkoyun

This study introduces standard Cliffordian Kaehler analogue of Hamiltonian mechanic systems. In the end, the some results related to standard Cliffordian Kaehler dynamical systems are also discussed.

J. Moldon, M. Ribo, J. M. Paredes, J. Marti

LS 5039 is one of the four TeV emitting X-ray binaries detected up to now. The powering source of its multi-wavelength emission can be accretion in a microquasar scenario or wind interaction in a young non-accreting pulsar scenario. These two scenarios predict different morphologic and peak position changes along the orbital cycle of 3.9 days, which can be t

Eric Jaeger, Thérèse Hardin

We present Bicoq3, a deep embedding of the B system in Coq, focusing on the technical aspects of the development. The main subjects discussed are related to the representation of sets and maps, the use of induction principles, and the introduction of a new de Bruijn notation providing solutions to various problems related to the mechanisation of languages an

Chuan Wang, Rong-Zhen Jiao, Hai-Qiang Ma, Yong Zhang

Recently, Briegel et al. present a quantum repeaters protocol using nest entanglement purification for long distance quantum communication(Physical Review Letters \textbf{81},5932). In this paper we present a modified scheme for constructing an optimal quantum repeater using doubly entangled photon pairs that overcomes the limitations of quantum communicatio

Eric Jaeger, Thérèse Hardin

Formal methods provide remarkable tools allowing for high levels of confidence in the correctness of developments. Their use is therefore encouraged, when not required, for the development of systems in which safety or security is mandatory. But effectively specifying a secure system or deriving a secure implementation can be tricky. We propose a review of s

Jack H. Koolen, Jongyook Park

A Shilla distance-regular graph G (say with valency k) is a distance-regular graph with diameter 3 such that its second largest eigenvalue equals to a3. We will show that a3 divides k for a Shilla distance-regular graph G, and for G we define b=b(G):=k/a3. In this paper we will show that there are finitely many Shilla distance-regular graphs G with fixed b(G

Eric Jaeger, Catherine Dubois

The use of formal methods provides confidence in the correctness of developments. Yet one may argue about the actual level of confidence obtained when the method itself -- or its implementation -- is not formally checked. We address this question for the B, a widely used formal method that allows for the derivation of correct programs from specifications. Th

Maria K. Koleva

A complex interplay between the academic issue about generalization of the thermodynamics and the practical matter about setting standards for a sustainable evolution of both tailored devices and natural systems is considered. It is established that the measure for a sustainable evolution in an ever-changing environment appears as a Boltzmann-Gibbs weight. A

K. -I. Izawa, Fuminobu Takahashi, T. T. Yanagida, Kazuya Yonekura

Supersymmetric SU(N_C) gauge theories possess runaway-type superpotentials for N_F < N_C, where N_F is the flavor number of massless quarks. We show that the runaway behavior can be stabilized for N_F nearly equal to N_C by introducing singlets with the aid of perturbative corrections to the Kahler potential, generating (local) minima of supersymmetry breaki

Lucian Covaci, Mona Berciu

We study the effects of the Rashba spin-orbit coupling on the polaron formation, using a suitable generalization of the Momentum Average approximation. Contrary to previous investigations of this problem, we find that the spin-orbit interaction decreases the effective electron-phonon coupling. It is thus possible to lower the effective mass of the polaron by

Philip M. Hinz, Scott Kenyon, Michael R. Meyer, Alan Boss

The detection of lower mass planets now being reported via radial velocity and microlensing surveys suggests that they may be ubiquitous. If missions such as Kepler are able to confirm this, the detection and study of rocky planets via direct imaging with ground-based telescopes of apertures > 20 m is feasible in the thermal infrared. We discuss two cases fo

Lincoln Chayes, Maria del Mar Gonzalez, Maria Pia Gualdani, Inwon Kim

We study a model due to J.M. Lasry and P.L. Lions, describing the evolution of a scalar price which is realized as a free boundary in a 1-D diffusion equation with dynamically evolving, non-standard sources. We establish global existence and uniqueness.

Lian-Ao Wu, Stephen S. Wu, Dvira Segal

We study generic aspects of bubble dynamics in DNA under time dependent perturbations, for example temperature change, by mapping the associated Fokker-Planck equation to a quantum time-dependent Schroedinger equation with imaginary time. In the static case we show that the eigenequation is exactly the same as that of the $β$-deformed nuclear liquid drop mod

Zhiyuan Li, Q. Daniel Wang, Bart P. Wakker

We present a multiwavelength investigation of the circumnuclear environment of M31. Based on Chandra/ACIS data, we tightly constrain the X-ray luminosity of M31*, the central supermassive black hole of the galaxy, to be L (0.3-7 keV)<= 1.2x10^{36}erg/s, approximately 10^{-10} of the Eddington luminosity. From the diffuse X-ray emission, we characterize the c

Amit Singer, Mihai Cucuringu

The problem of completing a low-rank matrix from a subset of its entries is often encountered in the analysis of incomplete data sets exhibiting an underlying factor model with applications in collaborative filtering, computer vision and control. Most recent work had been focused on constructing efficient algorithms for exact or approximate recovery of the m

Zekeriya Uykan

It&#39;s well-known that in a traditional discrete-time autonomous linear systems, the eigenvalues of the weigth (system) matrix solely determine the stability of the system. If the spectral radius of the system matrix is larger than 1, then the system is unstable. In this paper, we examine the linear systems with symmetric weight matrix whose spectral radiu

A. M. Ermolaev, G. I. Rashba

The effective mass approximation is used to consider plasma and magnetoplasma waves in an electron system on the surface of the semiconductor cylindrical nanotube. The electron-electron coupling is taken into account in the random phase approach. In the case of a degenerate electron gas the spectral windows on the wavevector-frequency plane and the spectra o

Samuel E. Vazquez

We study a class of heterogeneous agent-based models which are based on a basic set of principles, and the most fundamental operations of an economic system: trade and product transformations. A basic guiding principle is scale invariance, which means that the dynamics of the economy should not depend on the units used to measure the different products. We d

Agung Budiyono, Ken Umeno

We consider spatially two dimensional Madelung fluid whose irrotational motion reduces into the Schrödinger equation for a single free particle. In this respect, we regard the former as a direct generalization of the latter, allowing a rotational quantum flow. We then ask for the most likely wave function possessing a given average energy by maximizing the S

Cheoljun Eom, Jongwon Park, Woo-Sung Jung, Taisei Kaizoji

In this study, we have investigated empirically the effects of market properties on the degree of diversification of investment weights among stocks in a portfolio. The weights of stocks within a portfolio were determined on the basis of Markowitz&#39;s portfolio theory. We identified that there was a negative relationship between the influence of market pro

Christian Riedweg, Daniel Schäppi

We compare the homology groups $H_n ^{IC}(X)$ of the chain complex of integral currents with compact support of a metric space $X$ with the singular Lipschitz homology $H^L_n (X)$ and with ordinary singular homology. If $X$ satisfies certain cone inequalities all these homology theories coincide. On the other hand, for the Hawaiian Earring the homology of in

Paolo Aschieri, Leonardo Castellani

We present a noncommutative extension of Einstein-Hilbert gravity in the context of twist-deformed space-time, with a $\star$-product associated to a quite general triangular Drinfeld twist. In particular the $\star$-product can be chosen to be the usual Groenewald-Moyal product. The action is geometric, invariant under diffeomorphisms and centrally extended

V. Lakshmibai, K. N. Raghavan, P. Sankaran

Two classical rings of invariants are shown to be Frobenius split: for the special linear group acting on the direct sum of several copies of the defining representation and several copies of the dual of the defining representation; and for the special orthogonal group acting on several copies of the defining representation.

Elmar Wagner

A fibre product construction is used to give a description of quantum line bundles over the generic Podles spheres by gluing two quantum discs along their boundaries. Representatives of the corresponding $K_0$-classes are given in terms of 1-dimensional projections belonging to the C*-algebra, and in terms of analogues of the classical Bott projections. The

Kristina Frantzen

In this dissertation classification problems for K3-surfaces with finite group actions are considered. Special emphasis is put on K3-surfaces with antisymplectic involutions and compatible actions of symplectic transformations. Given a finite group $G$ it is investigated if it can act in a compatible fashion on a K3-surfaces $X$ with antisymplectic involutio

Benjamin Nabet, Naomi Ehrich Leonard

Using dynamic models of tensegrity structures, we derive provable, distributed control laws for stabilizing and changing the shape of a formation of vehicles in the plane. Tensegrity models define the desired, controlled, multi-vehicle system dynamics, where each node in the tensegrity structure maps to a vehicle and each interconnecting strut or cable in th

Igor Iosilevskiy

Limiting structure of thermodynamic functions of gaseous plasmas is under consideration in the limit of low temperature and density. The remarkable tendency, that was claimed previously [High Temp. 19, 799 (1981)], is carried to extreme. In the limit discussed, when temperature and density tend to zero at constant value of electron chemical potential, both e

B. Vršnak, G. Poletto, E. Vujić, A. Vourlidas

Eruption of a coronal mass ejection (CME) drags and &#34;opens&#34; the coronal magnetic field, presumably leading to the formation of a large-scale current sheet and the field relaxation by magnetic reconnection. We analyze physical characteristics of ray-like coronal features formed in the aftermath of CMEs, to check if the interpretation of this phenomeno

Jean-Baptiste Le Bouquin, Sylvestre Lacour, Stephanie Renard, Eric Thiebaut

Diffuse envelopes around Mira variables are among the most important sources influencing the chemical evolution of galaxies. However they represent an observational challenge because of their complex spectral features and their rapid temporal variability. We constrained the exact brightness distribution of the Mira star TLep with a model-independent analysis

Umberto Marini Bettolo Marconi, Simone Melchionna

Using methods of kinetic theory and liquid state theory we propose a description of the non-equilibrium behavior of molecular fluids which takes into account their microscopic structure and thermodynamic properties. The present work represents an alternative to the recent dynamic density functional theory which can only deal with colloidal fluids and is not

Alain Chenciner, François Laudenbach

A section in the 2-jet space of Morse functions is not always homotopic to a holonomic section. We give a necessary condition for being the case and we discuss the sufficiency.

Eric N. Zimanyi, Robert J. Silbey

The connection between work and changes in the Hamiltonian for a system with a time-dependent Hamiltonian has recently been called into question, casting doubt on the usefulness of the Jarzynski equality for calculating free energy changes. In this paper, we discuss the relationship between two possible definitions of free energy and show how some recent dis

Klaus Lichtenegger, Wilhelm Schappacher

We present results on a stochastic forest fire model, where the influence of the neighbour trees is treated in a more realistic way than usual and the definition of neighbourhood can be tuned by an additional parameter. This model exhibits a surprisingly sharp phase transition which can be shifted by redefinition of neighbourhood. The results can also be int

Alicia M. Soderberg, Jonathan E. Grindlay, Joshua S. Bloom, Suvi Gezari

Over the next decade, we can expect time domain astronomy to flourish at optical and radio wavelengths. In parallel with these efforts, a dedicated transient &#34;machine&#34; operating at higher energies (X-ray band through soft gamma-rays) is required to reveal the unique subset of events with variable emission predominantly visible above 100 eV. Here we f

David Merritt

Tests for the intrinsic shape of the luminosity distribution in elliptical galaxies are discussed, with an emphasis on the uncertainties. Recent determinations of the ellipticity frequency function imply a paucity of nearly spherical galaxies, and may be inconsistent with the oblate hypothesis. Statistical tests based on the correlation of surface brightness

Viktor P. Zastavnyi, Emilio Porcu

We characterize completely the Gneiting class of space-time covariance functions and give more relaxed conditions on the involved functions. We then show necessary conditions for the construction of compactly supported functions of the Gneiting type. These conditions are very general since they do not depend on the Euclidean norm. Finally, we discuss a gener

S. J. Gates, J. Gonzales, B. MacGregor, J. Parker

Presented in this paper the nature of the supersymmetrical representation theory behind 4D, N = 1 theories, as described by component fields, is investigated using the tools of Adinkras and Garden Algebras. A survey of familiar matter multiplets using these techniques reveals they are described by two fundamental valise Adinkras that are given the names of t

Guy Blaylock

Most physicists agree that the Einstein-Podolsky-Rosen-Bell paradox exemplifies much of the strange behavior of quantum mechanics, but argument persists about what assumptions underlie the paradox. To clarify what the debate is about, we employ a simple and well-known thought experiment involving two correlated photons to help us focus on the logical assumpt

Saibal Mitra

Assuming the validity of the Many Worlds Interpretation (MWI) of quantum mechanics, we show that memory erasure can cause one to end up in a different sector of the multiverse where the contents of the erased memory is different.