November 2007 arXiv papers — page 29

J. P. Beaulieu, S. Carey, I. Ribas, G. Tinetti

The hot Jupiter HD 189733b was observed during its primary transit using the Infrared Array Camera on the Spitzer Space Telescope. The transit depths were measured simultaneously at 3.6 and 5.8 microns. Our analysis yields values of 2.356 +- 0.019 % and 2.436 +- 0.020$ % at 3.6 and 5.8 microns respectively, for a uniform source. We estimated the contribution

L. Salasnich, N. Manini, F. Toigo

We study the macroscopic quantum tunneling of two weakly-linked superfluids made of interacting fermionic atoms. We derive atomic Josephson junction equations and find that zero-mode and pi-mode frequencies of coherent atomic oscillations depend on the tunneling coefficient and the sound velocity of the superfluid. By considering a superfluid of ^40K atoms,

David Kult, Johan Åberg, Erik Sjöqvist

A quantum holonomy reflects the curvature of some underlying structure of quantum mechanical systems, such as that associated with quantum states. Here, we extend the notion of holonomy to families of quantum channels, i.e., trace preserving completely positive maps. By the use of the Jamiołkowski isomorphism, we show that the proposed channel holonomy is re

J. Carr, D. Dornic, F. Jouvenot, G. Maurin

Theoretical predictions for neutrino fluxes indicate that km$^{3}$ scale detectors are needed to detect certain astrophysical sources. The three Mediterranean experiments, ANTARES, NEMO and NESTOR are working together on a design study, KM3NeT, for a large deep-sea neutrino telescope. A detector placed in the Mediterranean Sea will survey a large part of the

Michael Ruzhansky, James Smith

Dispersive and Strichartz estimates for solutions to general strictly hyperbolic partial differential equations with constant coefficients are considered. The global time decay estimates of $L^p-L^q$ norms of propagators are obtained, and it is shown how the time decay rates depend on the geometry of the problem. The frequency space is separated in several z

Gerasimos Dousmanis

Let $K$ be any finite extension of $Q_{p}$, $L$ any finite Galois extension of $K$ and $E$ any finite large enough coefficient field containing $L$. We classify two-dimensional, F-semistable $E$-representations of $G_{K}$, by listing the isomorphism classes of rank two weakly admissible filtered $(ϕ,N,L/K,E)$-modules.

Issaku Kanamori, Fumihiko Sugino, Hiroshi Suzuki

A strict positivity of the ground-state energy is a necessary and sufficient condition for spontaneous supersymmetry breaking. This ground-state energy may be directly determined from the expectation value of the Hamiltonian in the functional integral, defined with an \emph{antiperiodic} temporal boundary condition for all fermionic variables. We propose to

C. P. Moca, D. C. Marinescu

The Kubo formula is used to calculate the spin-Hall conductivity in a spin-polarized two-dimensional electron system with Rashba-type spin-orbit interaction. As in the case of the unpolarized electron system, spin Hall conductivity is entirely determined by states at the Fermi level, a property that persists in the presence of magnetic impurities. In the cle

K. Hamaya, M. Kitabatake, K. Shibata, M. Jung

Using a laterally-fabricated quantum-dot (QD) spin-valve device, we experimentally study the Kondo effect in the electron transport through a semiconductor QD with an odd number of electrons (N). In a parallel magnetic configuration of the ferromagnetic electrodes, the Kondo resonance at N = 3 splits clearly without external magnetic fields. With applying ma

R. Chingangbam, M. Sami, P. V. Tretyakov, A. V. Toporensky

In this paper, we analyze the viability of a vacuum Gauss-Bonnet cosmology by examining the dynamics of the homogeneous and anisotropic background in 4+1 dimensions. The trajectories of the system either originate from the standard singularity or from non-standard type, the later is characterized by the divergence of time derivative of the Hubble parameters

Alberica Toia

PHENIX has measured the dielectron continuum in sqrt(s_(NN))=200 GeV Au+Au and p+p collisions. In minimum bias Au+Au collisions the dielectron yield in the mass range between 150 and 750 MeV/c^2 is enhanced by a factor of 3.4 +/- 0.2(stat.) +/- 1.3(syst.) +/- 0.7(model) compared to the expectation from our model of hadron decays that well reproduces the mass

Rahul Basu, P. N. Pandita, Chandradew Sharma

We study the production of the lightest neutralinos in the radiative process $e^+e^- \to \tildeχ^0_1 \tildeχ^0_1γ$ in low energy supersymmetric models for the International Linear Collider energies. This includes the minimal supersymmetric standard model as well as its extension with an additional chiral Higgs singlet superfield, the nonminimal supersymmetri

Nicolas Verzelen, Fanny Villers

Let $(Y,(X_i)_{i\in\mathcal{I}})$ be a zero mean Gaussian vector and $V$ be a subset of $\mathcal{I}$. Suppose we are given $n$ i.i.d. replications of the vector $(Y,X)$. We propose a new test for testing that $Y$ is independent of $(X_i)_{i\in \mathcal{I}\backslash V}$ conditionally to $(X_i)_{i\in V}$ against the general alternative that it is not. This pr

Vasily E. Tarasov

A fractional generalization of variations is used to define a stability of non-integer order. Fractional variational derivatives are suggested to describe the properties of dynamical systems at fractional perturbations. We formulate stability with respect to motion changes at fractional changes of variables. Note that dynamical systems, which are unstable &#

Joseph H. Rhee, Inseok Song, B. Zuckerman

Only a few solar-type main sequence stars are known to be orbited by warm dust particles; the most extreme is the G0 field star BD+20 307 that emits ~4% of its energy at mid-infrared wavelengths. We report the identification of a similarly dusty star HD 23514, an F6-type member of the Pleiades cluster. A strong mid-IR silicate emission feature indicates the

Alakabha Datta, Yanyan Gao, Andrei V. Gritsan, David London

In this paper, we examine B -> VT decays (V is a vector and T is a tensor meson), whose final-state particles can have transverse or longitudinal polarization. Measurements have been made of B -> ϕK_2^*, and it is found that fT/fL is small, where fT (fL) is the fraction of transverse (longitudinal) decays. We find that the standard model (SM) naively predict

Arthur Cunha, Minh Do, Martin Vetterli

The {\it plenoptic function} (Adelson and Bergen, 91) describes the visual information available to an observer at any point in space and time. Samples of the plenoptic function (POF) are seen in video and in general visual content, and represent large amounts of information. In this paper we propose a stochastic model to study the compression limits of the

Issaku Kanamori, Fumihiko Sugino, Hiroshi Suzuki

The global supersymmetry is spontaneously broken if and only if the ground-state energy is strictly positive. We propose to use this fact to observe the spontaneous supersymmetry breaking in euclidean lattice simulations. For lattice formulations that possess a manifest fermionic symmetry, there exists a natural choice of a hamiltonian operator that is consi

Benjamin Monreal, Lorne A. Nelson, Joseph A. Formaggio

Although dark matter makes up 80% of the gravitational mass of our Galaxy, its composition is not known. One hypothesis is that dark matter consists of massive particles called WIMPs. WIMPs are expected to accumulate and coannihilate in the cores of stars, but the only signature of this accumulation has been thought to be hard- to-observe high-energy neutrin

E. G. Cavalcanti, M. D. Reid

We present a unified approach, based on the use of quantum uncertainty relations, for arriving at criteria for the demonstration of the EPR paradox and macroscopic superpositions. We suggest to view each criterion as a means to demonstrate an EPR-type paradox, where there is an inconsistency between the assumptions of a form of realism, either macroscopic re

Min Liu, Kevin E. Bassler

The effects of the finite size of the network on the evolutionary dynamics of a Boolean network are analyzed. In the model considered, Boolean networks evolve via a competition between nodes that punishes those in the majority. It is found that finite size networks evolve in a fundamentally different way than infinitely large networks do. The symmetry of the

V. P. Arkhipova, T. A. Lozinskaya, A. V. Moiseev, O. V. Egorov

Observations with the 6-m telescope of the Special Astrophysical Observatory obtained with the MPFS integral-field spectrograph and a longslit spectrograph with the SCORPIO focal reducer are used to analyze the emission spectrum of the ionized gas in a star-forming region in the BCD galaxy VII Zw 403. We present images of the galactic central region in the H

John Conway, Simon Kochen

We prove a no-triplets theorem for spin 1 particles, which implies a strengthened form of the no-cloning theorem.

Xavier Calmet, Stephen D. H. Hsu

We describe a model in which the fundamental scale M_\star of the theory which unifies gravity and quantum mechanics is in the TeV range, but without requiring additional spacetime dimensions. The weakness of gravity at low energies is due to a large vacuum expectation of a dilaton like field. The model requires a small dimensionless parameter (the self-coup

Y. Yang, H. Flores, F. Hammer, B. Neichel

(abbreviated) We present the first results of the ESO large program, ``IMAGES'' which aims at obtaining robust measurements of the kinematics of distant galaxies using the multi-IFU mode of GIRAFFE on the VLT. 3D spectroscopy is essential to robustly measure the often distorted kinematics of distant galaxies (e.g., Flores et al. 2006). We derive the

Xin Liu, Edwin L. Turner, Norio Narita, Yasushi Suto

We present a new technique for detecting scattered starlight from transiting, close-orbiting extrasolar giant planets (CEGPs) that has the virtues of simplicity, robustness, linearity, and model-independence. Given a series of stellar spectra obtained over various phases of the planetary orbit, the goal is to measure the strength of the component scattered b

Andres Jordan, Gregory R. Sivakoff, Dean E. McLaughlin, John P. Blakeslee

We present results of Hubble Space Telescope and Chandra X-ray Observatory observations of globular clusters (GCs) and low-mass X-ray binaries (LMXBs) in the central regions of Centaurus A. Out of 440 GC candidates we find that 41 host X-ray point sources that are most likely LMXBs. We fit King models to our GC candidates in order to measure their structural

David Kubiznak, Valeri P. Frolov

We demonstrate complete integrability of the Nambu-Goto equations for a stationary string in the general Kerr-NUT-(A)dS spacetime describing the higher-dimensional rotating black hole. The stationary string in D dimensions is generated by a 1-parameter family of Killing trajectories and the problem of finding a string configuration reduces to a problem of fi

Vesna Borka Jovanović

In this paper we perform a detailed study of the masses and mixing of the single charmed scalar tetraquarks: $c q \bar{q} \bar{q}$. We also give a systematic analysis of these tetraquark states by weight diagrams, quantum numbers and flavor wave functions. Tetraquark masses are calculated using four different fits. The following SU(3)$_\mathrm{F}$ representa

V. V. Nesvizhevsky, G. Pignol, K. V. Protasov

The available data on neutron scattering were analyzed to constrain a hypothetical new short-range interaction. We show that these constraints are several orders of magnitude better than those usually cited in the range between 1 pm and 5 nm. This distance range occupies an intermediate space between collider searches for strongly coupled heavy bosons and se

Martin Richarte, Claudio Simeone

We study spherically symmetric thin-shell wormholes in a string cloud background in (3+1)-dimensional spacetime. The amount of exotic matter required for the construction, the traversability and the stability under radial perturbations, are analyzed as functions of the parameters of the model. Besides, in the Appendices a non perturbative approach to the dyn

Victor G. Kac, Minoru Wakimoto

We study the problem of classification of triples ($\mathfrak{g}, f, k$), where $\mathfrak{g}$ is a simple Lie algebra, $f$ its nilpotent element and $k \in \CC$, for which the simple $W$-algebra $W_k (\mathfrak{g}, f)$ is rational.

D. S. Balsara, A. J. Bendinelli, D. A. Tilley, A. R. Massari

We present a large number of two and a half dimensional simulations of supernova remnants expanding into interstellar media having a range of densities, temperatures and magnetic field strengths. The volume of hot gas produced is strongly dependent on the inclusion of thermal conduction and magnetic fields. The four-volumes and three-areas of hot gas have be

Simon Portegies Zwart, Edward P. J. van den Heuvel

Supernova 2006gy in the galaxy NGC 1260 is the most luminous one recorded \cite{2006CBET..644....1Q, 2006CBET..647....1H, 2006CBET..648....1P, 2006CBET..695....1F}. Its progenitor might have been a very massive ($>100$ \msun) star \cite{2006astro.ph.12617S}, but that is incompatible with hydrogen in the spectrum of the supernova, because stars $>40$ \msun ar

Arbab I. Arbab

We consider a cosmological model with bulk viscosity ($η$) and variable cosmological $(Λ\propto ρ^{-α}, α=\rm const.$) and gravitational ($G$) constants. The model exhibits many interesting cosmological features. Inflation proceeds du to the presence of bulk viscosity and dark energy without requiring the equation of state $p=-ρ$. During the inflationary era

Brett Kotschwar, Lei Ni

In the first part of this paper, we prove local interior and boundary gradient estimates for p-harmonic functions on general Riemannian manifolds. With these estimates, following the strategy in recent work of R. Moser, we prove an existence theorem for weak solutions to the level set formulation of the 1/H (inverse mean curvature) flow for hypersurfaces in

Francisco M. Fernandez

Quantum--mechanical multiple--well oscillators exhibit curious complex eigenvalues that resemble resonances in models with continuum spectra. We discuss a method for the accurate calculation of their real and imaginary parts.

Pedro Lacerda

We show that candidate contact binary asteroids can be efficiently identified from sparsely sampled photometry taken at phase angles >60deg. At high phase angle, close/contact binary systems produce distinctive lightcurves that spend most of the time at maximum or minimum (typically >1mag apart) brightness with relatively fast transitions between the two. Th

Eric White, Qing He

Precision determination of the CKM angle $\gamma/\phi_3$ depends upon constraints on charm mixing amplitudes, measurements of doubly-Cabibbo suppressed amplitudes and relative phases, and studies of charm Dalitz plots tagged by flavor or CP eigenstates. In this note we describe the technique used at CLEO-c to constrain the $K_{S,L}\pi\pi$ model uncertainty,

Tobias Grafke, Holger Homann, Juergen Dreher, Rainer Grauer

The numerical simulation of the 3D incompressible Euler equation is analyzed with respect to different integration methods. The numerical schemes we considered include spectral methods with different strategies for dealiasing and two variants of finite difference methods. Based on this comparison, a Kida-Pelz like initial condition is integrated using adapti

Todor Stanev

We discuss the basic difficulties in understanding the origin of the highest energy particles in the Universe - the ultrahigh energy cosmic rays (UHECR). It is difficult to imagine the sources they are accelerated in. Because of the strong attenuation of UHECR on their propagation from the sources to us these sources should be at cosmologically short distanc

Peter Petreczky

I discuss lattice QCD calculations of the properties of strongly interacting matter at finite temperature, including the determination of the transition temperature Tc, equation of state, different static screening lengths and quarkonium spectral functions. The lattice data suggest that at temperatures above 2Tc many properties of the quark gluon plasma can

Valeri V. Dvoeglazov

On the basis of our recent modifications of the Dirac formalism we generalize the Bargmann-Wigner formalism for higher spins to be compatible with other formalisms for bosons. Relations with dual electrodynamics, with the Ogievetskii-Polubarinov notoph and the Weinberg 2(2J+1) theory are found. Next, we introduce the dual analogues of the Riemann tensor and

Ignacio Taboada, Michelangelo V. D'Agostino

It is standard in theoretical neutrino astrophysics to use a broken power law approximation, based on the Band function, to describe the average photon flux of the prompt emission of Gamma-Ray Bursts. We will show that this approximation overestimates the contribution of high energy gamma-rays (and underestimates low energy gamma-rays). As a consequence mode

Valeri V. Dvoeglazov

Amplitudes for fermion-fermion, boson-boson and fermion-boson interactions are calculated in the second order of perturbation theory in the Lobachevsky space. An essential ingredient of the model is the Weinberg's 2(2j+1)-component formalism for describing a particle of spin j. The boson-boson amplitude is then compared with the two-fermion amplitude obt

I. M. Suslov

A computer model of "a sense of humour" suggested previously [arXiv:0711.2058,0711.2061], relating the humorous effect with a specific malfunction in information processing, is given in somewhat different exposition. Psychological aspects of humour are elaborated more thoroughly. The mechanism of laughter is formulated on the more general level. Deta

Jessica L. DeGrado, Luke G. Rogers, Robert S. Strichartz

We use spectral decimation to provide formulae for computing the harmonic gradients of Laplacian eigenfunctions on the Sierpinski Gasket. These formulae are given in terms of special functions that are defined as infinite products.

L. A. Caffarelli, A. Mellet

We use a characterization of the fractional Laplacian as a Dirichlet to Neumann operator for an appropriate differential equation to study its obstacle problem in perforated domains.

S. -A. Yahiaoui, M. Bentaiba

The differential realization of the potential group SO(2,2) is used. The spectrum-generating algebra for a kind of exactly solvable potentials endowed with position-dependent mass is constructed.

I. Hunter, D. J. Lennon, P. L. Dufton, C. Trundle

We provide atmospheric parameters and rotational velocities of a large sample (~400) of O- and early B-type stars, analysed in a homogeneous and consistent manner, for use in constraining theoretical models. Comparison of the rotational velocities with evolutionary tracks suggest that the end of core hydrogen burning occurs later than currently predicted. We

B. M. Zwickl, W. E. Shanks, A. M. Jayich, C. Yang

We have measured the optical and mechanical loss of commercial silicon nitride membranes. We find that 50 nm-thick, 1 mm^2 membranes have mechanical Q > 10^6 at 293 K, and Q > 10^7 at 300 mK, well above what has been observed in devices with comparable dimensions. The near-IR optical loss at 293 K is less than 2E-4. This combination of properties make these

S. -A. Yahiaoui, M. Bentaiba

We extend the definition of eta-weak-pseudo-Hermiticity to the class of potentials endowed with position-dependent mass. The construction of non-Hermitian Hamiltonians through some generating function are obtained. Special cases of potentials are thus deduced.

Elio Conte

We discuss the Einstein, Podolsky, and Rosen paradox as it was formulated by Asher Peres in 1992 [4]. On this basis we realize an algebraic quantum like elaboration showing that in this formulation the paradox may be still interpreted and solved.

A. W. Thomas

Modern nuclear theory presents a fascinating study in contrasting approaches to the structure of hadrons and nuclei. Nowhere is this more apparent than in the treatment of the pion cloud. As this discussion really begins with Yukawa, it is entirely appropriate that this invited lecture at the Yukawa Institute in Kyoto should deal with the issue.

Wlodzimierz M. Tulczyjew

It is widely believed that statistical interpretation of quantum mechanics requires that density operators representing quantum states be normalized. We present a description of selective measurements in terms of density operators. The description is inspired by Schwinger's Algebra of Microscopic Measurements. Density operators used are not normalized. W

R. Khasanov, A. Shengelaya, D. Di Castro, E. Morenzoni

Oxygen isotope (^{16}O/^{18}O) effects (OIE's) on the superconducting transition (T_c), the spin-glass ordering (T_g), and the antiferromagnetic ordering (T_N) temperatures were studied for Y_1-xPr_xBa_2Cu_3O_7-δas a function of Pr content (0.0\leq x \leq 1.0). The OIE on T_c increases with increasing x up to x\approx0.55, where superconductivity disappe

The Pierre Auger Collaboration

Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above ~ 6x10^{19} electron volts and the positions of active galactic nuclei (AGN) lying within ~ 75 megaparsecs. We rejected the hypothesis of an isotropic distribution of these cosmic rays w

I. Abt, A. Caldwell, K. Kroeninger, J. Liu

The GERmanium Detector Array, GERDA, is designed for the search for ``neutrinoless double beta decay'' (0-nu-2-beta) with germanium detectors enriched in Ge76. An 18-fold segmented prototype detector for GERDA Phase II was exposed to an AmBe neutron source to improve the understanding of neutron induced backgrounds. Neutron interactions with the germ

M. V. Jouravlev

A derivation of the asymptotic expressions for the threshold intensity of laser induced thermal scattering in silica microresonator when illuminated with a plane wave is present. The calculation of anti-Stokes thermal combination frequencies are made for the spherical high Q-factor microresonators. The three modes regime of nonlinear interaction is considere

Sourendu Gupta, Kay Hubner, Olaf Kaczmarek

We present a renormalization procedure for Polyakov loops which explicitly implements the fact that the renormalization constant depends only on the ultraviolet cutoff. Using this we study the renormalized Polyakov loops in all representations upto the {\bf 27} of the gauge group SU(3). We find good evidence for Casimir scaling of the Polyakov loops and for

Jeffrey B. Weiss

Motivated by stochastic models of climate phenomena, the steady-state of a linear stochastic model with additive Gaussian white noise is studied. Fluctuation theorems for nonequilibrium steady-states provide a constraint on the character of these fluctuations. The properties of the fluctuations which are unconstrained by the fluctuation theorem are investiga

S. S. Larsen

CONTEXT: Until now, only one planetary nebula (PN) has been known in the Fornax dwarf spheroidal galaxy. AIMS: The discovery of a second PN candidate, associated with one of the 5 globular clusters in the Fornax dwarf, is reported. METHODS: Spectra of the globular cluster H5, obtained with the UVES echelle spectrograph on the ESO Very Large Telescope, show [

M. V. Jouravlev

Induced thermal scattering power thresholds have been calculated as a function of size and laser pump frequency. The thermal coupling coefficients of morphology dependent resonances were estimated by asymptotic methods. The resulting power threshold is comparable with experimental observations of thresholds of Raman lasing and thermal instability in spherica

Dmitri E. Nikonov, George I. Bourianoff, Paolo A. Gargini

Spintronics logic devices based on majority gates formed by atomic-level arrangements of spins in the crystal lattice is considered. The dynamics of switching is modeled by time-dependent solution of the density-matrix equation with relaxation. The devices are shown to satisfy requirements for logic. Switching speed and dissipated energy are calculated and c

M. E. Shirokov, A. S. Holevo

We develop an approximation approach to infinite dimensional quantum channels based on detailed investigation of the continuity properties of entropic characteristics of quantum channels and operations (trace-nonincreasing completely positive maps) as functions of a pair ``channel, input state''. The obtained results are then applied to the following

M. Mézard, M. Tarzia, C. Toninelli

The problem of Group Testing is to identify defective items out of a set of objects by means of pool queries of the form "Does the pool contain at least a defective?". The aim is of course to perform detection with the fewest possible queries, a problem which has relevant practical applications in different fields including molecular biology and comp

Guillaume Thomann, Jean Caelen, Morgan Verdier, Brigitte Meillon

Nowadays, more and more surgical interventions are carried out in Minimally Invasive Surgery, to make the post-operative constraints less painful for the patient. Actually, new surgical tools or medical products are designed after informal discussions between surgeons and designers. The user requirements documents are the main document used by the mechanical

Martin G. Gulbrandsen

We study the Fourier-Mukai functor D(Y) -> D(X) induced by the universal family on a fine moduli space Y for simple semihomogeneous vector bundles on an abelian variety X. The main result is that the Fourier-Mukai transform of a very negative line bundle on Y is ample if and only if the bundles parametrized by Y are nef.

N. Kaiser

Using SU(3) chiral perturbation theory we calculate the density-dependent complex-valued spin-orbit coupling strength $U_{Σls}(k_f)+ i W_{Σls}(k_f)$ of a $Σ$ hyperon in the nuclear medium. The leading long-range $ΣN$ interaction arises from iterated one-pion exchange with a $Λ$ or a $Σ$ hyperon in the intermediate state. We find from this unique long-range d

N. Kaiser

We calculate in chiral perturbation theory the parity-violating two-pion exchange nucleon-nucleon potentials at leading one-loop order. At a distance of $r= m_π^{-1} \simeq 1.4 $fm they amount to about $\pm 16%$ of the parity-violating $1π$-exchange potential. We evaluate also the parity-violating effects arising from $2π$-exchange with excitation of virtual

S. M. Iftiquar

We show two channel electromagnetically induced transparency (EIT) spectra at various optical power. The two channels are coupling field and probe field absorption. It is shown that EIT width and intensity increases linearly with pump power. A density matrix calculation is used to determine nature of EIT spectra induced by optical field. It has been observed

V. A. Okorokov, S. B. Nurushev

The differential cross-sections are calculated for proton-proton and proton-antiproton elastic scattering using the phenomenological model based on the analytic parameterizations for global scattering parameters (total cross-section and $ρ$ - parameter), crossing symmetry and derivative relations. We confront our model predictions with experimental data in w

Gianfausto Dell'Antonio, Rodolfo Figari, Alessandro Teta

We analyze a one dimensional quantum system consisting of a test particle interacting with two harmonic oscillators placed at the positions $a_1$, $a_2$, with $a_1 >0$, $|a_2|>a_1$, in the two possible situations: $a_2>0$ and $a_2 <0$. At time zero the harmonic oscillators are in their ground state and the test particle is in a superposition state of two wav

D. Takács, G. Stépán. S. J. Hogan

This study investigates a low degree-of-freedom (DoF) mechanical model of shimmying wheels. The model is studied using bifurcation theory and numerical continuation. Self-excited vibrations, that is, stable and unstable periodic motions of the wheel, are detected with the help of Hopf bifurcation calculations. These oscillations are then followed over a larg

Axel Hultman, Kathrin Vorwerk

We show that the principal order ideal below an element w in the Bruhat order on involutions in a symmetric group is a Boolean lattice if and only if w avoids the patterns 4321, 45312 and 456123. Similar criteria for signed permutations are also stated. Involutions with this property are enumerated with respect to natural statistics. In this context, a bijec

T. Zijlstra, C. F. J. Lodewijk, N. Vercruyssen, F. D. Tichelaar

High critical current-density (10 to 420 kA/cm^2) superconductor-insulator-superconductor tunnel junctions with aluminium nitride barriers have been realized using a remote nitrogen plasma from an inductively coupled plasma source operated in a pressure range of 10^{-3} to 10^{-1} mbar. We find a much better reproducibility and control compared to previous w

Francesco Sciortino

This article discusses recent attempts to provide a deeper understanding of the thermoreversible &#34;gel&#34; state of colloidal matter and to unravel the analogies between gels at the colloidal level and gels at the molecular level, commonly known as network-forming strong liquids. The connection between gel-forming patchy colloids and strong liquids is pr

T. Fabcic, J. Main, G. Wunner

The dynamics of quantum systems can be approximated by the time propagation of Gaussian wave packets. Applying a time dependent variational principle, the time evolution of the parameters of the coupled Gaussian wave packets can be calculated from a set of ordinary differential equations. Unfortunately, the set of equations is ill-behaved in most practical a

V. Ammosov

The HARP Collaboration recently published calibrations of their TPC and RPC detectors, and differential cross-sections of large-angle pion production in proton-nucleus collisions. We argue that these calibrations are biased and cross-sections based on them should not be trusted.

G. Y. Liang, G. Zhao

Different observation data for cool star--Procyon (Obs\_IDs of 63, 1461 and 1224) available from {\it Chandra Data Public Archive} were co-added and analyzed. Emissivities of emission lines of highly charged silicon ions (Si VII--Si XII) were calculated over temperatures by adopting the published data of Liang et al. (2007, {\it Atom. Data and Nucl. Data Tab

Mauricio Duque, Leonardo Castaneda, Carlos Duque

The purpose is to introduce in a clear and direct way the students of undergraduate courses in physics and/or astronomy to the subject of radiative transfer. A pedagogical revision is made in order to obtain the radiative transfer equation, its restrictions and the different types of interactions present between the radiation and the matter. Because in the c

Abhinav Singh, Dmitri Vainchtein, Howard Weiss

Thomas Schelling proposed an influential simple spatial model to illustrate how, even with relatively mild assumptions on each individual&#39;s nearest neighbor preferences, an integrated city would likely unravel to a segregated city, even if all individuals prefer integration. Aggregation relates to individuals coming together to form groups and global agg

Xiaoli Han, Jiayu Li

Let $M$ be a Kähler surface and $Σ$ be a closed symplectic surface which is smoothly immersed in $M$. Let $α$ be the Kähler angle of $Σ$ in $M$. We first deduce the Euler-Lagrange equation of the functional $L=\int_Σ\frac{1}{\cosα}dμ$ in the class of symplectic surfaces. It is $\cos^3αH=(J(J\nabla\cosα)^\top)^\bot$, where $H$ is the mean curvature vector of

D. Brown, M. Salaris, S. Cassisi, A. Pietrinferni

High precision photometry and spectroscopy of low-mass stars reveal a variety of properties standard stellar evolution cannot predict. Rotation, an essential ingredient of stellar evolution, is a step towards resolving the discrepancy between model predictions and observations. The first rotating stellar model, continuously tracing a low-mass star from the p

Alessandro Sergi, Francesco Petruccione

Thermal fluctuations in time-dependent quantum processes are treated by a constant-temperature generalization of Wigner&#39;s formulation of quantum mechanics in phase space. To this end, quantum Nosè-Hoover dynamics is defined by generalizing the Moyal bracket. Computational applications of the formalism, together with further theoretical developments, are

A. V. Kisselev

The Randall-Sundrum (RS) model with the small curvature is studied. In such a scheme the mass spectrum of Kaluza-Klein (KK) gravitons is similar to that in a model with one extra flat dimension. The gravity effects in the Bhabha scattering at the energy 1 TeV are estimated. The calculations are based on the analytical formula which describes virtual graviton

Alberto Ferrero, Hans-Christoph Grunau, Paschalis Karageorgis

The biharmonic supercritical equation $Δ^2u=|u|^{p-1}u$, where $n>4$ and $p>(n+4)/(n-4)$, is studied in the whole space $\mathbb{R}^n$ as well as in a modified form with $λ(1+u)^p$ as right-hand-side with an additional eigenvalue parameter $λ>0$ in the unit ball, in the latter case together with Dirichlet boundary conditions. As for entire regular radial sol

Kunji Nakayama

This paper deals with topos-theoretic truth-value valuations of quantum propositions. Concretely, a mathematical framework of a specific type of modal approach is extended to the topos theory, and further, structures of the obtained truth-value valuations are investigated. What is taken up is the modal approach based on a determinate lattice $\Dcal(e,R)$, wh

Stefano Ansoldi, Eduardo I. Guendelman, Idan Shilon

We present a review of selected topics concerning the creation and evolution of child universes, together with a concise account of some recent progress in the field.

Su-Chan Park, Hyunggyu Park

Systems with absorbing (trapped) states may exhibit a nonequilibrium phase transition from a noise-free inactive phase into an ever-lasting active phase. We briefly review the absorbing critical phenomena and universality classes, and discuss over the controversial issues on the pair contact process with diffusion (PCPD). Two different approaches are propose

J. Bartels, L. Motyka

The scattering of a baryon consisting of three massive quarks is investigated in the high energy limit of perturbative QCD. A model of a relativistic proton-like wave function, dependent on valence quark longitudinal and transverse momenta and on quark helicities, is proposed, and we derive the baryon impact factors for two, three and four t-channel gluons.

T. -S. H. Lee

The status of dynamical coupled-channel analysis at Excited Baryon Analysis Center (EBAC) of Jefferson Laboratory is reported.

F. Brauer, C. P. Dullemond, Th. Henning

The growth of solid particles towards meter sizes in protoplanetary disks has to circumvent at least two hurdles, namely the rapid loss of material due to radial drift and particle fragmentation due to destructive collisions. In this paper, we present the results of numerical simulations with more and more realistic physics involved. Step by step, we include

Adam Shwartz, Alan Weiss

We show global uniqueness of the solution to a class of constrained variational problems, using scaling properties. This is used to establish the essential uniqueness of solutions of a large deviations problem in multiple dimensions. The result is motivated by models of buffers, and in particular the probability of, and typical path to overflow in the limit

Andreas Thom

Motivated by the study of spectral properties of self-adjoint operators in the integral group ring of a sofic group, we define and study integer operators. We establish a relation with classical potential theory and in particular the circle of results obtained by M. Fekete and G. Szeg&#34;o. More concretely, we use results by R. Rumely on equidistribution of

Rami Atar, Adam Shwartz

We consider a queue with renewal arrivals and n exponential servers in the Halfin-Whitt heavy traffic regime, where n and the arrival rate increase without bound, so that a critical loading condition holds. Server k serves at rate $μ_k $, and the empirical distribution of the $μ_k $ is assumed to converge weakly. We show that very little information on the s

Arie Leizarowitz, Adam Shwartz

For a countable-state Markov decision process we introduce an embedding which produces a finite-state Markov decision process. The finite-state embedded process has the same optimal cost, and moreover, it has the same dynamics as the original process when restricting to the approximating set. The embedded process can be used as an approximation which, being

Miron Kaufman, H. T. Diep

We study a statistical mechanics model of a solid. Neighboring atoms are connected by Hookian springs. If the energy is larger than a threshold the &#34;spring&#34; is more likely to fail, while if the energy is lower than the threshold the spring is more likely to be alive. The phase diagram and thermodynamic quantities, such as free energy, numbers of bond

Paul D. Mitchener

In this article we use existing machinery to define connective $K$-theory spectra associated to topological ringoids. Algebraic $K$-theory of discrete ringoids, and the analytic $K$-theory of Banach categories are obtained as special cases. As an application, we show how the analytic assembly maps featuring in the Novikov and Baum-Connes conjectures can be f

Dean E. McLaughlin, Pauline Barmby, William E. Harris, Duncan A. Forbes

We present internal surface-brightness profiles, based on HST/ACS imaging in the F606W bandpass, for 131 globular cluster (GC) candidates with luminosities 10^4 - 3 x 10^6 solar, in the giant elliptical galaxy NGC 5128. Several structural models are fit to the profile of each cluster and combined with mass-to-light ratios from population-synthesis models, to