March 2010 arXiv papers — page 15

Carlo Giocoli, Matthias Bartelmann, Ravi K. Sheth, Marcello Cacciato

Accurate knowledge of the non-linear dark-matter power spectrum is important for understanding the large-scale structure of the Universe, the statistics of dark-matter haloes and their evolution, and cosmological gravitational lensing. We analytically model the dark-matter power spectrum and its cross-power spectrum with dark-matter haloes. Our model extends

Shirley Ho, Edwin L. Turner

Radial velocity (RV) observations of an exoplanet system giving a value of M_T sin(i) condition (i.e. give information about) not only the planet's true mass M_T but also the value of sin(i) (where i is the orbital inclination angle). Thus the value of sin(i) for a system with any particular observed value of M_T sin(i) cannot be assumed to be drawn rand

Kedron Silsbee, Yacine Ali-Haimoud, Christopher M. Hirata

We investigate the rotational emission from dust grains that rotate around non- principal axes. We argue that in many phases of the interstellar medium, the smallest grains, which dominate spinning dust emission, are likely to have their nutation state (orientation of principal axes relative to the angular momentum vector) randomized during each thermal spik

S. Das Sarma, Shaffique Adam, E. H. Hwang, Enrico Rossi

We provide a broad review of fundamental electronic properties of two-dimensional graphene with the emphasis on density and temperature dependent carrier transport in doped or gated graphene structures. A salient feature of our review is a critical comparison between carrier transport in graphene and in two-dimensional semiconductor systems (e.g. heterostruc

Daniele S. M. Alves, Siavosh R. Behbahani, Philip Schuster, Jay G. Wacker

Composite dark matter is a natural setting for implementing inelastic dark matter - the O(100 keV) mass splitting arises from spin-spin interactions of constituent fermions. In models where the constituents are charged under an axial U(1) gauge symmetry that also couples to the Standard Model quarks, dark matter scatters inelastically off Standard Model nucl

Anders Claesson, Svante Linusson

We show that there are $n!$ matchings on $2n$ points without, so called, left (neighbor) nestings. We also define a set of naturally labeled $(2+2)$-free posets, and show that there are $n!$ such posets on $n$ elements. Our work was inspired by Bousquet-Mélou, Claesson, Dukes and Kitaev [J. Combin. Theory Ser. A. 117 (2010) 884--909]. They gave bijections be

J. I. Katz

In order to test theories of fission cross-sections, it is desirable to measure the (n,f) cross-sections of both an isomeric state and the ground state of the same isotope of the same element. This would test the ability to calculate effects that depend only on spin and parity without the confusion of effects that depend on (Z,A). At present there is no isot

Dmytro Volin

In this thesis a general procedure to represent the integral Bethe Ansatz equations in the form of the Reimann-Hilbert problem is given. This allows us to study in simple way integrable spin chains in the thermodynamic limit. Based on the functional equations we give the procedure that allows finding the subleading orders in the solution of various integral

Colin D. Reid

Let G be a finite non-nilpotent group such that every Sylow subgroup of G is generated by at most d elements, and such that p is the largest prime dividing |G|. We show that G has a non-nilpotent image G/N, such that N is characteristic and of index bounded by a function of d and p. This result will be used to prove that the index of the Frattini subgroup of

Daniel Coutand, Steve Shkoller

We prove well-posedness for the 3-D compressible Euler equations with moving physical vacuum boundary, with an equation of state given by the so-called gamma gas-law for gamma > 1. The physical vacuum singularity requires the sound speed c to go to zero as the square-root of the distance to the moving boundary, and thus creates a degenerate and characteristi

Giorgi Japaridze

"Clarithmetic" is a generic name for formal number theories similar to Peano arithmetic, but based on computability logic (see http://www.cis.upenn.edu/~giorgi/cl.html) instead of the more traditional classical or intuitionistic logics. Formulas of clarithmetical theories represent interactive computational problems, and their "truth" is unde

V. N. Velizhanin

The result for the six-loop anomalous dimension of twist-three operators in the planar N=4 SYM theory is presented. The calculations were performed along the paper arXiv:0912.1624. This result provides a new data for testing the proposed spectral equations for planar AdS/CFT correspondence.

J. D. Biggins

This paper gives conditions for the rightmost particle in the $n$th generation of a multitype branching random walk to have a speed, in the sense that its location divided by n converges to a constant as n goes to infinity. Furthermore, a formula for the speed is obtained in terms of the reproduction laws. The case where the collection of types is irreducibl

Alan Barros de Oliveira, Andrea Fortini, Sergey V. Buldyrev, David Srolovitz

We study the dynamics of the contact between a pair of surfaces (with properties designed to mimic ruthenium) via molecular dynamics simulations. In particular, we study the contact between a ruthenium surface with a single nanoasperity and a flat ruthenium surface. The results of such simulations suggest that contact behavior is highly variable. The goal of

I. V. Tanatarov, I. N. Adamenko, K. E. Nemchenko, A. F. G. Wyatt

We analyse the dispersion relation of ripplons, on the surface of superfluid helium, using the dispersive hydrodynamics approach and find a new ripplon branch. We obtain analytical equation for the dispersion relation and analytic expressions for the limiting cases. We discuss where ripplons can exist in the energy-wavenumber plane. A numerical solution for

Masato Arai, Katri Huitu, Santosh Kumar Rai, Kumar Rao

We study the production of a single charged slepton in association with a top quark in a R-parity violating supersymmetric model with lepton number violating interactions at the Large Hadron Collider. We find that the longitudinal polarization asymmetry of the top quark in such a production mode is significantly different from that in the production of a sin

P. Abolmasov, O. Maryeva, A. N. Burenkov

We present new spectral (FPI and long-slit) data on the Eastern optical filament of the well known radionebula W50 associated with SS433. We find that on sub-parsec scales different emission lines are emitted by different regions with evidently different physical conditions. Kinematical properties of the ionized gas show evidence for moderately high (V ~ 100

L. Baracco

We give positive answer to a conjecture by Agranovsky. A continuous function on the sphere which has separate holomorphic extension along the set of complex lines passing through three non aligned interior points, is the trace of a holomorphic function in the ball.

Jean-Baptiste Gramain

In this paper, we prove that a refinement of the Alperin-McKay Conjecture for $p$-blocks of finite groups, formulated by I. M. Isaacs and G. Navarro in 2002, holds for all covering groups of the symmetric and alternating groups, whenever $p$ is an odd prime.

Rupert L. Frank, Barry Simon

We prove bounds of the form $\sum_{e\in I\cap\sigma_\di (H)} \dist (e,\sigma_\e (H))^{1/2} \leq L^1$-norm of a perturbation, where $I$ is a gap. Included are gaps in continuum one-dimensional periodic Schr\"odinger operators and finite gap Jacobi matrices where we get a generalized Nevai conjecture about an $L^1$ condition implying a Szeg\H{o} condition. One

Michael Shao, Joseph Catanzarite, Xiaopei Pan

The holy grail of exoplanet searches is an exo-Earth, an Earth mass planet in the habitable zone around a nearby star. Mass is the most important parameter of a planet and can only be measured by observing the motion of the star around the planet-star center of mass. A single image of a planet, however, does not provide evidence that the planet is Earth mass

Simone Speziale

We study a modification of the Plebanski action for general relativity, which leads to a modified theory of gravity with eight degrees of freedom. We show how the action can be recasted as a bi-metric theory of gravity, and expanding around a bi-flat background we identify the six extra degrees of freedom with a second, massive graviton and a scalar mode.

Michael Drmota, Éric Fusy, Mihyun Kang, Veronika Kraus

We present a unified general method for the asymptotic study of graphs from the so-called "subcritical"$ $ graph classes, which include the classes of cacti graphs, outerplanar graphs, and series-parallel graphs. This general method works both in the labelled and unlabelled framework. The main results concern the asymptotic enumeration and the limit laws of

Matsuo Sato

We show that an action of a supermembrane in an eleven-dimensional spacetime with a semi-light-cone gauge can be written only with Nambu-Poisson bracket and an invariant symmetric bilinear form under an approximation. Thus, the action under the conditions is manifestly covariant under volume preserving diffeomorphism even when the world-volume metric is flat

A. E. Dorokhov

Recently, the BABAR collaboration published (arXiv:0905.4778) data for the photon-pion transition form factor $F_{πγγ^{\ast}}(Q^{2})$, which are in strong contradiction to the predictions of the standard factorization approach to perturbative QCD. Immediately afterwards, two mechanisms were suggested (A.E. Dorokhov, arXiv:0905.4577; A.V. Radyushkin, arXiv:09

Lun Zhang, Pablo Román

We study the asymptotic zero distribution of type II multiple orthogonal polynomials associated with two Macdonald functions (modified Bessel functions of the second kind). Based on the four-term recurrence relation, it is shown that, after proper scaling, the sequence of normalized zero counting measures converges weakly to the first component of a vector o

R. Salimov, E. Sevostyanov

We study the so--called ring $(p,Q)$--mappings which are the natural generalization of quasiregular and quasi isometric mappings. It is proved that open discrete ring $(p,Q)$--mappings are differentiable a.e. and belong to the class $ACL$ in ${\Bbb R}^n$, $n\ge 2$, furthermore, $f\in W_{loc}^{1,1}$ provided that $Q\in L^{1}_{loc}$ and $p>n-1$

Pavel Etingof, Giovanni Felder, Xiaoguang Ma, Alexander Veselov

To every irreducible finite crystallographic reflection group (i.e., an irreducible finite reflection group G acting faithfully on an abelian variety X), we attach a family of classical and quantum integrable systems on X (with meromorphic coefficients). These families are parametrized by G-invariant functions of pairs (T,s), where T is a hypertorus in X (of

M. Reibelt, S. Weyeneth, A. Erb, A. Schilling

We have investigated the magnetic phase diagram of a fully oxygenated detwinned YBa2Cu3O7 single crystal by means of magneto-caloric and magnetization measurements, and found thermodynamic evidence for a temperature dependent first-order phase-transition line deep within the vortex-solid region. The associated discontinuities in the entropy are apparently pr

Gul Rahman

Using first-principles calculations within generalized gradient approximation, the electronic and magnetic properties of zinc blende (zb) CrP/MnP superlattice are investigated. The equilibrium lattice constant is calculated to be $5.33\,$Å. The stability of ferromagnetic zb CrP/MnP superlattice against antiferromagnetism is considered and it is found that th

Vito Iacovino

We consider Open Gromov-Witten invariants for noncompact Calabi-Yau in the case the Lagrangian has the topology of $\R^2 \times S^1$. The definition of the invariant involves the choice of a frame for the Lagrangian, in accord with string theory. Our result applies to the examples arising from Large $N$-duality. In particular it leads to knot and link invari

Christian Saemann

We perform a high-temperature expansion of scalar quantum field theory on fuzzy CP^n to third order in the inverse temperature. Using group theoretical methods, we rewrite the result as a multitrace matrix model. The partition function of this matrix model is evaluated via the saddle point method and the phase diagram is analyzed for various n. Our results c

Scott Sheffield, Nike Sun

We show that, under mild assumptions on the limiting curve, a sequence of simple chordal planar curves converges uniformly whenever certain Loewner driving functions converge. We extend this result to random curves. The random version applies in particular to random lattice paths that have chordal $\mathrm {SLE}_κ$ as a scaling limit, with $κ<8$ (nonspace-fi

Jose A. Capitan, Gustav W. Delius

A striking feature of the marine ecosystem is the regularity in its size spectrum: the abundance of organisms as a function of their weight approximately follows a power law over almost ten orders of magnitude. We interpret this as evidence that the population dynamics in the ocean is approximately scale-invariant. We use this invariance in the construction

Frank Wilczek

Invited talk at the EPS-HEPP meeting in Krakow, July 2009. My first thought, and presumably the default expectation, was that I&#39;d talk in a general way about the grandeur of high energy physics and the exciting future we anticipate, especially with LHC coming on line. But an unfortunate byproduct of the delays at LHC and the slow pace of other experiment

Akimasa Miyake

We elaborate the idea of quantum computation through measuring the correlation of a gapped ground state, while the bulk Hamiltonian is utilized to stabilize the resource. A simple computational primitive, by pulling out a single spin adiabatically from the bulk followed by its measurement, is shown to make any ground state of the one-dimensional isotropic Ha

Laura M. Stanford, Gary S. Da Costa, John E. Norris

Abundances relative to iron for carbon, nitrogen, strontium and barium are presented for 33 stars on the red giant branch of the globular cluster omega Centauri. They are based on intermediate-resolution spectroscopic data covering the blue spectral region analyzed using spectrum synthesis techniques. The data reveal the existence of a broad range in the abu

Jakub Mielczarek, Thomas Cailleteau, Julien Grain, Aurelien Barrau

Loop quantum cosmology provides an efficient framework to study the evolution of the Universe beyond the classical Big Bang paradigm. Because of holonomy corrections, the singularity is replaced by a &#34;bounce&#34;. The dynamics of the background is investigated into the details, as a function of the parameters of the model. In particular, the conditions r

E. Torrontegui, J. G. Muga, J. Martorell, D. W. L. Sprung

Post-exponential decay of the probability density of a quantum particle leaving a trap can be reproduced accurately, except for interference oscillations at the transition to the post-exponential regime, by means of an ensemble of classical particles emitted with constant probability per unit time and the same half-life as the quantum system. The energy dist

C. M. Chandrashekar, Subhashish Banerjee, R. Srikanth

Quantum walk models have been used as an algorithmic tool for quantum computation and to describe various physical processes. This paper revisits the relationship between relativistic quantum mechanics and the quantum walks. We show the similarities of the mathematical structure of the decoupled and coupled form of the discrete-time quantum walk to that of t

Serban A. Basarab

Using suitable deformations of simplicial trees and the duality theory for median sets, we show that every free action on a median set can be extended to a free and transitive one. We also prove that the category of median groups is a reflective full subcategory of the category of free actions on pointed median sets.

Tatiana Nizkaya, Jean-Regis Angilella, Michel Bues

We investigate theoretically the motion of tiny heavy passive particles transported in a plane inviscid flow consisting of two point vortices, in order to understand particle dispersion and trapping during vortex interaction. In spite of their large density, particles are not necessarily centrifugated away from vortices. It is observed that they can have var

Sanjay Gupta, Tribikram Gupta

We consider a heterostructure of a metal and a barrier with onsite correlation at half filling using unrestricted Hartree Fock. We find that above a certain value of correlation strength in the barrier planes, the system is a Mott insulator, while below this value the system still behaves like a gapless insulator. The energy spectrum is found to be very nove

Jared Wunsch, Maciej Zworski

We give pole free strips and estimates for resolvents of semiclassical operators which, on the level of the classical flow, have normally hyperbolic smooth trapped sets of codimension two in phase space. Such trapped sets are structurally stable and our motivation comes partly from considering the wave equation for Kerr black holes and their perturbations, w

D. Hennig, A. D. Burbanks, C. Mulhern, A. H. Osbaldestin

We propose a minimal model for the emergence of a directed flow in autonomous Hamiltonian systems. It is shown that internal breaking of the spatio-temporal symmetries, via localised initial conditions, that are unbiased with respect to the transporting degree of freedom, and transient chaos conspire to form the physical mechanism for the occurrence of a cur

R. A. Garcia, S. Mathur, J. Ballot, C. Regulo

The analysis of the first solar-like targets done by CoRoT has shown that the oscillation amplitudes are about 25% below the theoretical amplitudes while the convective backgrounds are up to three times higher than in the solar case (Michel et al. 2008). In such conditions, the comb-like structure of the acoustic modes has smaller signal-to-noise ratios than

Artur Avila, Giovanni Forni, Corinna Ulcigrai

We consider reparametrizations of Heisenberg nilflows. We show that if a Heisenberg nilflow is uniquely ergodic, all non-trivial time-changes within a dense subspace of smooth time-changes are mixing. Equivalently, in the language of special flows, we consider special flows over linear skew-shift extensions of irrational rotations of the circle. Without assu

Robert Haslhofer

In this article, we introduce a new method (based on Perelman&#39;s lambda-functional) to study the stability of compact Ricci-flat metrics. Under the assumption that all infinitesimal Ricci-flat deformations are integrable we prove: (A) a Ricci-flat metric is a local maximizer of lambda in a C^2,alpha-sense iff its Lichnerowicz Laplacian is nonpositive, (B)

Luca Motto Ros

In reference [8] we have considered a wide class of "well-behaved" reducibilities for sets of reals. In this paper we continue with the study of Borel reducibilities by proving a dichotomy theorem for the degree-structures induced by good Borel reducibilities. This extends and improves the results of [8] allowing to deal with a larger class of notions of red

Andrew Das Arulsamy, Kristina Elersic, Uros Cvelbar, Miran Mozetic

Metal-oxide sensors are widely used due to their sensitivities to different types of gaseous, and these sensors are suitable for long-term applications, even in the presence of corrosive environments. However, the microscopic mechanisms with quantum effects, which are required to understand the gas-oxide interactions are not well developed despite the oxide

Kentaro Aoki

I present the discovery of Balmer-line absorption from H alpha to H9 in iron low-ionizaton broad absorption line (FeLoBAL) quasar, SDSS~J172341.10+555340.5 by near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) attached to the Subaru telescope. The redshift of the Balmer-line absorption troughs is 2.0530 +/- 0.0003, an

J. P. Carmelo

In this paper we consider the simplified form that a recently introduced general operator description of the Hubbard model on the square lattice with $N_a^2\gg 1$ sites, effective transfer integral $t$, and onsite repulsion $U$ has in a suitable one- and two-electron subspace. Such an operator description is that consistent with the model exact global symmet

L. J. Chang, Y. Su, Y. -J. Kao, Y. Z. Chou

We present single-crystal neutron-diffuse-scattering measurements with polarization analysis on the spin ice Ho2-xYxTi2O7 (x = 0, 0.3, and 1). At 2 K, the spin flip scattering patterns are typical of a nearest-neighbor spin ice and the effects of Y doping are seen in the width of the pinch points. At low-T, the spin flip patterns are characteristic of a dipo

A. Neronov, D. V. Semikoz, Ie. Vovk

We construct a systematic survey of extragalactic γ-ray sky at the energies above 100 GeV using the data of Fermi telescope. Such survey has not been previously done by the ground-based Cherenkov gamma-ray telescopes which have, contrary to Fermi, narrow field of view. We study a map of arrival directions of the highest energy photons detected by Fermi at Ga

Sylvain Barre, Mikael Pichot

We introduce and study a family of countable groups constructed from Euclidean buildings by &#34;removing&#34; suitably chosen subsets of chambers.

Jens Marklof

We embed multidimensional Farey fractions in large horospheres and explain under which conditions they become uniformly distributed in the ambient homogeneous space. This question has recently been investigated in the case of SL(d,Z) to prove the asymptotic distribution of Frobenius numbers. The present paper extends these studies to general lattices in SL(d

R. S. Costas-Santos, J. J. Moreno-Balcázar

We say that the polynomial sequence $(Q^{(λ)}_n)$ is a semiclassical Sobolev polynomial sequence when it is orthogonal with respect to the inner product $$ <p, r>_S=<{\bf u} ,{p\, r}> +λ<{\bf u}, {{\mathscr D}p \,{\mathscr D}r}>, $$ where ${\bf u}$ is a semiclassical linear functional, ${\mathscr D}$ is the differential, the difference or the $q$--difference

Kingman Cheung, Kuo-Hsing Tsao, Tzu-Chiang Yuan

For the milli-charged Dirac dark matter in the Stueckelberg Z&#39; model, we discuss the contributions from the vector couplings of the dark matter with the neutral gauge bosons to the spin-independent scattering cross section in the direct detections. We also compute the effective coupling between the fermionic dark matter particle and the standard model Hi

Martin Mevissen, Jean-Bernard Lasserre, Didier Henrion

Combining recent moment and sparse semidefinite programming (SDP) relaxation techniques, we propose an approach to find smooth approximations for solutions of problems involving nonlinear differential equations. Given a system of nonlinear differential equations, we apply a technique based on finite differences and sparse SDP relaxations for polynomial optim

E. Harikumar, A. K. Kapoor

We study the modification of Newton&#39;s second law, upto first order in the deformation parameter $a$, in the $κ$-space-time. We derive the deformed Hamiltonian, expressed in terms of the commutative phase space variables, describing the particle moving in a central potential in the $κ$-space-time. Using this, we find the modified equations of motion and s

M. Wimmer, A. R. Akhmerov, F. Guinea

We analyze the single particle states at the edges of disordered graphene quantum dots. We show that generic graphene quantum dots support a number of edge states proportional to circumference of the dot over the lattice constant. Our analytical theory agrees well with numerical simulations. Perturbations breaking electron-hole symmetry like next-nearest nei

S. R. Fleurke, M. Formentin, C. Kuelske

We present classes of models in which particles are dropped on an arbitrary fixed finite connected graph, obeying adhesion rules with screening. We prove that there is an invariant distribution for the resulting height profile, and Gaussian concentration for functions depending on the paths of the profiles. As a corollary we obtain a law of large numbers for

Daniel Rings, Romy Schachoff, Markus Selmke, Frank Cichos

We derive the generalized Markovian description for the non-equilibrium Brownian motion of a heated particle in a simple solvent with a temperature-dependent viscosity. Our analytical results for the generalized fluctuation-dissipation and Stokes-Einstein relations compare favorably with measurements of laser-heated gold nano-particles and provide a practica

E. Torrontegui, J. Echanobe, A. Ruschhaupt, D. Guéry-Odelin

We study the dynamics of neutral cold atoms in an $L$-shaped crossed-beam optical waveguide formed by two perpendicular red-detuned lasers of different intensities and a blue-detuned laser at the corner. Complemented with a vibrational cooling process this setting works as a one-way device or &#34;atom diode&#34;.

David Viennot

We show that the holonomy of a connection defined on a principal composite bundle is related by a non-abelian Stokes theorem to the composition of the holonomies associated with the connections of the component bundles of the composite. We apply this formalism to describe the non-abelian geometric phase (when the geometric phase generator does not commute wi

Agung Trisetyarso

We propose a mathematical model of \textit{quantum} transistor in which bandgap engineering corresponds to the tuning of Dirac potential in the complex four-vector form. The transistor consists of $n$-relativistic spin qubits moving in \textit{classical} external electromagnetic fields. It is shown that the tuning of the direction of the external electromagn

Paolo Lodone

In the context of Large Extra Dimensions the fundamental Planck scale can be as low as the TeV scale. If this is the way of nature, quantum gravity effects could be visible at the LHC or other High energy colliders. A model independent signal is given by elastic scattering at small angles and transplanckian energy, which can be computed in the eikonal approx

V. Kuznetsov, M. V. Polyakov, V. Bellini, T. Boiko

The first study of quasi-free Compton scattering on the neutron in the energy range of $E_γ=0.75 - 1.5$ GeV is presented. The data reveals a narrow peak at $W\sim 1.685$ GeV. This result, being considered in conjunction with the recent evidence for a narrow structure at $W\sim 1.68$GeV in the $η$ photoproduction on the neutron, suggests the existence of a ne

Alexander B. Balakin, José P. S. Lemos, Alexei E. Zayats

We discuss new exact solutions of a three-parameter nonminimal Einstein-Maxwell model. The solutions describe static spherically symmetric objects with and without center, supported by an electric field nonminimally coupled to gravity. We focus on a unique one-parameter model, which admits an exact solution for a traversable electrically charged wormhole con

Jian Fu, Qi Guo, Guinevere Kauffmann

We introduced a semi-analytic model to study the detail of radial related processes on galaxy disks. Based on this recipe, we can calculate neutral and molecular gas in interstellar medium, and include the molecular phase into star formation recipes. From our model, we reproduced the radial surface density profiles and mass functions shown in the observation

Elizabeth K. Mahony, Elaine M. Sadler, Tara Murphy, Ronald D. Ekers

The high-frequency radio sky, like the gamma-ray sky surveyed by the Fermi satellite, is dominated by flat spectrum radio quasars and BL Lac objects at bright flux levels. To investigate the relationship between radio and gamma-ray emission in extragalactic sources, we have cross-matched the Australia Telescope 20 GHz survey catalog (AT20G) with the Fermi-LA

Edward Frenkel, Robert Langlands, Ngo Bao Chau

We outline an approach to proving functoriality of automorphic representations using trace formula. More specifically, we construct a family of integral operators on the space of automorphic forms whose eigenvalues are expressed in terms of the L-functions of automorphic representations and begin the analysis of their traces using the orbital side of the sta

Masahito Hayashi

In a unified viewpoint in quantum channel estimation, we compare the Cramer-Rao and the mini-max approaches, which gives the Bayesian bound in the group covariant model. For this purpose, we introduce the local asymptotic mini-max bound, whose maximum is shown to be equal to the asymptotic limit of the mini-max bound. It is shown that the local asymptotic mi

Sunhee Lee, Hoon Ryu, Zhengping Jiang, Gerhard Klimeck

Semiconductor devices are scaled down to the level which constituent materials are no longer considered continuous. To account for atomistic randomness, surface effects and quantum mechanical effects, an atomistic modeling approach needs to be pursued. The Nanoelectronic Modeling Tool (NEMO 3-D) has satisfied the requirement by including emprical $sp^{3}s^{*

Allison Lewko, Mark Lewko

We investigate the structure of finite sets $A \subseteq \Z$ where $|A+A|$ is large. We present a combinatorial construction that serves as a counterexample to natural conjectures in the pursuit of an &#34;anti-Freiman&#34; theory in additive combinatorics. In particular, we answer a question along these lines posed by O&#39;Bryant. Our construction also ans

D. Nikolić, T. W. Gorczyca, K. T. Korista, N. R. Badnell

We present a theoretical investigation of dielectronic recombination (DR) of Ar-like ions that sheds new light on the behavior of the rate coefficient at low-temperatures where these ions form in photoionized plasmas. We provide results for the total and partial Maxwellian-averaged DR rate coefficients from the initial ground level of K II -- Zn XIII ions. I

Meng Wang, Weiyu Xu, Ao Tang

This paper investigates the uniqueness of a nonnegative vector solution and the uniqueness of a positive semidefinite matrix solution to underdetermined linear systems. A vector solution is the unique solution to an underdetermined linear system only if the measurement matrix has a row-span intersecting the positive orthant. Focusing on two types of binary m

Walt A. de Heer, Claire Berger, Xiaosong Wu, Mike Sprinkle

Since its inception in 2001, the science and technology of epitaxial graphene on hexagonal silicon carbide has matured into a major international effort and is poised to become the first carbon electronics platform. A historical perspective is presented and the unique electronic properties of single and multilayered epitaxial graphenes on electronics grade s

K. M. F. Shahil, M. Z. Hossain, D. Teweldebrhan, A. A. Balandin

We report results of micro-Raman spectroscopy investigation of the &#34;graphene-like&#34; mechanically exfoliated single-crystal bismuth telluride films with the thickness ranging from a few-nm-range to bulk limit. It is found that the optical phonon mode A1u, which is not-Raman active in bulk bismuth telluride crystals, appears in the atomically-thin films

X. Li, D. Li

We show that $n$-tangle, the generalization of the 3-tangle to even $n$ qubits, is the square of the SLOCC polynomial invariant of degree 2. We find that the $n$-tangle is not the residual entanglement for any even $n\geq 4$\ qubits. We give a necessary and sufficient condition for the vanishing of the concurrence $C_{1(2...n)}$. The condition implies that t

Victor M. Velasco Herrera, Jorge Perez-Peraza, Graciela Velasco H., Laura Luna Gonzalez

We study the specific influence of African dust on each one of the categories of Atlantic hurricanes. By applying wavelet analysis, we find a strong decadal modulation of African dust on Category 5 hurricanes and an annual modulation on all other categories of hurricanes. We identify the formation of Category 5 hurricanes occurring mainly around the decadal

X. Marti, T. Cechal, L. Horak, V. Novak

We prepared Ga0.95Mn0.05As films on top of periodic arrays of InAs quantum dots. X-ray diffraction reveals periodically strained films, commensurate to substrate&#39;s patterning. The dots produce a tensile strain in GaMnAs while between the dots strain is compressive. Our experiments confirm that the average tensile strain in the film increases with decreas

Changxin Shi, Randall A. Berry, Michael L. Honig

We study distributed algorithms for adjusting beamforming vectors and receiver filters in multiple-input multiple-output (MIMO) interference networks, with the assumption that each user uses a single beam and a linear filter at the receiver. In such a setting there have been several distributed algorithms studied for maximizing the sum-rate or sum-utility as

Vladimir Tolstykh

Let F be an infinitely generated free group and R a fully invariant subgroup of F such that (a) R is contained in the commutator subgroup F&#39; of F and (b) the quotient group F/R is residually torsion-free nilpotent. Then the automorphism group Aut(F/R&#39;) of the group F/R&#39; is complete. In particular, the automorphism group of any infinitely generate

Guillaume Stern, Baptiste Allard, Martin Robert-de-Saint-Vincent, Jean-Philippe Brantut

We demonstrate a compact laser source suitable for the trapping and cooling of potassium. By frequency doubling a fiber laser diode at 1534 nm in a waveguide, we produce 767 nm laser light. A current modulation of the diode allows to generate the two required frequencies for cooling in a simple and robust apparatus. We successfully used this laser source to

Eyal Z. Goren, Kristin E. Lauter

Genus 2 curves are useful in cryptography for both discrete-log based and pairing-based systems, but a method is required to compute genus 2 curves such that the Jacobian has a given number of points. Currently, all known methods involve constructing genus 2 curves with complex multiplication via computing their three Igusa class polynomials. These polynomia

Jorg-Uwe Pott, Matt A. Malkan, Moshe Elitzur, Andrea M. Ghez

After recent sensitivity upgrades at the Keck Interferometer (KI), systematic interferometric 2um studies of the innermost dust in nearby Seyfert nuclei are within observational reach. Here, we present the analysis of new interferometric data of NGC 4151, discussed in context of the results from recent dust reverberation, spectro-photometric and interferomet

M. E. Carrington, R. Kobes, G. Kunstatter, D. Ostapchuk

In the standard geometric approach, the entanglement of a pure state is $\sin^2θ$, where $θ$ is the angle between the entangled state and the closest separable state of products of normalised qubit states. We consider here a generalisation of this notion by considering separable states that consist of products of unnormalised states of different dimension. T

Jacob Linder, Yukio Tanaka, Takehito Yokoyama, Asle Sudbø

We study theoretically proximity-induced superconductivity and ferromagnetism on the surface of a topological insulator. In particular, we investigate how the Andreev-bound states are influenced by the interplay between these phenomena, taking also into account the possibility of unconventional pairing. We find a qualitative difference in the excitation spec

HongSheng Zhao, Benoit Famaey

There exists several modified gravity theories designed to reproduce the empirical Milgrom&#39;s formula (MOND). Here we derive analytical results in the context of the static weak-field limit of two of them (BIMOND, leading for a given set of parameters to QUMOND, and TeVeS). In this limit, these theories are constructed to give the same force field for sph

Jun Chang, A. J. Fedro, Michel van Veenendaal

An explanation is provided for the ultrafast photo-excited electron dynamics in low-spin Ruthenium (II) organic complexes. The experimentally-observed singlet to triplet decay in the metal-to-ligand charge-transfer (MLCT) states contradicts the expectation that the system should oscillate between the singlet and triplet states in the presence of a large spin

João N. Laia

In supersymmetric quantum mechanics, the non-Abelian Berry phase is known to obey certain differential equations. Here we study N=(0,4) systems and show that the non-Abelian Berry connection over R^{4n} satisfies a generalization of the self-dual Yang-Mills equations. Upon dimensional reduction, these become the tt* equations. We further study the Berry conn

J. A. Nieto

We establish a connection between oriented matroid theory and loop quantum gravity in (2+2) (two time and two space dimensions) and 8-dimensions. We start by observing that supersymmetry implies that the structure constants of the real numbers, complex numbers, quaternions and octonions can be identified with the chirotope concept. This means, among other th

Fawzi Boudjema, Joakim Edsjo, Paolo Gondolo

With present and upcoming SUSY searches both directly, indirectly and at accelerators, the need for accurate calculations is large. We will here go through some of the tools available both from a dark matter point of view and at accelerators. For natural reasons, we will focus on public tools, even though there are some rather sophisticated private tools as

Andrei M. Nemilentsau, Gregory Ya. Slepyan, Sergey A. Maksimenko, Akhlesh Lakhtakia

The use of carbon nanotubes as optical probes for scanning near-field optical microscopy requires an understanding of their near-field response. As a first step in this direction, we investigated the lateral resolution of a carbon nanotube tip with respect to an ideal electric dipole representing an elementary detected object. A Fredholm integral equation of

Y. S. Yoon, H. S. Ahn, M. G. Bagliesi, G. Bigongiari

The CREAM calorimeter, designed to measure the spectra of cosmic-ray nuclei from under 1 TeV to 1000 TeV, is a 20 radiation length (X0) deep sampling calorimeter. The calorimeter is comprised of 20 layers of tungsten interleaved with 20 layers of scintillating fiber ribbons, and is preceded by a pair of graphite interaction targets providing about 0.42 proto

S. A. Trigger

The problem of anomalous diffusion in momentum (velocity) space is considered based on the master equation and the appropriate probability transition function (PTF). The approach recently developed by the author for coordinate space, is applied with necessary modifications to velocity space. A new general equation for the time evolution of the momentum distr

David M. Rogers, Thomas L. Beck

The extension of the classical Bayesian penalized spline method to inference on vector-valued functions is considered, with an emphasis on characterizing the suitability of the method for general application.We show that the standard quadratic penalty is exactly analogous to the energy of a stretched string, with the penalty parameter corresponding to its te

Carlo Petronio

This survey article describes the algorithmic approaches successfully used over the time to construct hyperbolic structures on 3-dimensional topological &#34;objects&#34; of various types, and to classify several classes of such objects using such structures.

Y. S. Yoon, H. S. Ahn, M. G. Bagliesi, G. Bigongiari

The Cosmic Ray Energetics And Mass (CREAM) calorimeter is designed to measure the spectra of cosmic-ray particles over the energy range from ~10^11 eV to ~10^15 eV. Its first flight as part of the CREAM-I balloon-borne payload in Antarctica during the 2004/05 season resulted in a recordbreaking 42 days of exposure. Calorimeter calibration using various beam