December 2007 arXiv papers — page 27

S. Zenitani, M. Hoshino

We study the role of the guide field in relativistic magnetic reconnection in a Harris current sheet of pair ($e^{\pm}$) plasmas, using linear theories and particle-in-cell (PIC) simulations. Two-dimensional PIC simulations exhibit the guide field dependence to the linear instabilities; the tearing or reconnection modes are relatively insensitive, while the

Paolo Benincasa, Alex Buchel, Michal P. Heller, Romuald A. Janik

We study string theory duals of the expanding boost invariant conformal gauge theory plasmas at strong coupling. The dual supergravity background is constructed as an asymptotic late-time expansion, corresponding to equilibration of the gauge theory plasma. The absence of curvature singularities in the first few orders of the late-time expansion of the dual

Mathias Schulze, Uli Walther

The Euler-Koszul complex is the fundamental tool in the homological study of A-hypergeometric differential systems and functions. We compare Euler-Koszul homology with D-module direct images from the torus to the base space through orbits in the corresponding toric variety. Our approach generalizes a result by Gel'fand et al. and yields a simpler, more a

Reinier Broker, Peter Stevenhagen

We present a very efficient algorithm to construct an elliptic curve E and a finite field F such that the order of the point group E(F) is a given prime number N. Heuristically, this algorithm only takes polynomial time Otilde((\log N)^3), and it is so fast that it may profitably be used to tackle the related problem of finding elliptic curves with point gro

Patrick Dorey, Clare Dunning, Ferdinando Gliozzi, Roberto Tateo

Within the framework of the ODE/IM correspondence, we show that the minimal conformal field theories with c<1 emerge naturally from the monodromy properties of certain families of ordinary differential equations.

Vahid Karimipour, Laleh Memarzadeh

We introduce a simple representation for irreducible spherical tensor operators of the rotation group of arbitrary integer or half integer rank and use these tensor operators to construct matrix product states corresponding to all the variety of valence-bond states proposed in the Affleck-Kennedy-Lieb-Tasaki (AKLT) construction. These include the fully dimer

Thomas Jorg, Helmut G. Katzgraber, Florent Krzakala

We study the existence of a spin-glass phase in a field using Monte Carlo simulations performed along a nontrivial path in the field--temperature plane that must cross any putative de Almeida-Thouless instability line. The method is first tested on the Ising spin glass on a Bethe lattice where the instability line separating the spin glass from the paramagne

Igor V. Moskalenko, Troy A. Porter, Seth W. Digel, Peter F. Michelson

We calculate the gamma-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids (MBAs), Jovian and Neptunian Trojan asteroids, and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the gamma-ray albedo for the Main Belt, Trojans, and Kuiper Belt strongly depends on the small-body size distributi

S. Hesselbach, D. J. Miller, G. Moortgat-Pick, R. Nevzorov

We study the neutralino sector of the Minimal Non-minimal Supersymmetric Standard Model (MNSSM) where the $μ$ problem of the Minimal Supersymmetric Standard Model (MSSM) is solved without accompanying problems related with the appearance of domain walls. In the MNSSM as in the MSSM the lightest neutralino can be the absolutely stable lightest supersymmetric

Benedek Valko, Balint Virag

We show that at any location away from the spectral edge, the eigenvalues of the Gaussian unitary ensemble and its general beta siblings converge to Sine_beta, a translation invariant point process. This process has a geometric description in term of the Brownian carousel, a deterministic function of Brownian motion in the hyperbolic plane. The Brownian caro

Niharika Mohapatra, Kartik K Iyer, E. V. Sampathkumaran

We report a large entropy change (DeltaS) below 300 K, peaking near TC= 220 K, due to isothermal change of magnetic field, for Gd4Co3, with a refrigeration capacity higher than that of Gd. Notably, the isothermal magnetization is nonhysteretic - an important criterion for magnetic refrigeration without loss. DeltaS behavior is also compared with that of magn

Cenalo Vaz, Sashideep Gutti, Claus Kiefer, T. P. Singh

In a recent publication we developed a canonical quantization program describing the gravitational collapse of a spherical dust cloud in 2+1 dimensions with a negative cosmological constant $-Λ\equiv -l^{-2}<0$. In this paper we address the quantization of the Banados--Teitelboim--Zanelli (BTZ) black hole. We show that the mass function describing the black

M. N. Chernodub, Antti J. Niemi

We introduce a new supercurrent in the electroweak sector of the standard model. Its interaction with the hypergauge field influences the mass of the Z boson but has no effect on the W^\pm-boson masses. In the leptonic sector it affects the numerical value of the vector and axial coupling constants between neutral currents and the Z boson, and a comparison w

Holger Mueller, Sheng-wey Chiow, Quan Long, Sven Herrmann

We present up to 24-photon Bragg diffraction as a beam splitter in light-pulse atom interferometers to achieve the largest splitting in momentum space so far. Relative to the 2-photon processes used in the most sensitive present interferometers, these large momentum transfer beam splitters increase the phase shift 12-fold for Mach-Zehnder (MZ-) and 144-fold

Xiaohu Shang, Gerhard Kramer, Biao Chen

A new outer bound on the capacity region of Gaussian interference channels is developed. The bound combines and improves existing genie-aided methods and is shown to give the sum-rate capacity for noisy interference as defined in this paper. Specifically, it is shown that if the channel coefficients and power constraints satisfy a simple condition then singl

S. Kraml, D. T. Nhung

We compute the three-body decays of charged sleptons and sneutrinos into other sleptons. These decays are of particular interest in SUSY-breaking models with non-universal Higgs mass parameters, where the left-chiral sleptons can be lighter than the right-chiral ones, and lighter than the lightest neutralino. We present the formulas for the three-body decay

R. Caimmi

The empirical differential metallicity distribution (EDMD) is deduced for (i) local thick disk stars; (ii) likely metal-weak thick disk stars; (iii) chemically selected local G dwarfs, with the corrections performed in order to take into account the stellar scale height; in addition to previous results related to (iv) solar neighbourhood halo subdwarfs; and

R. Keith Ellis, Giulia Zanderighi

We construct a basis set of infra-red and/or collinearly divergent scalar one-loop integrals and give analytic formulas, for tadpole, bubble, triangle and box integrals, regulating the divergences (ultra-violet, infra-red or collinear) by regularization in $D=4-2ε$ dimensions. For scalar triangle integrals we give results for our basis set containing 6 diver

K. Dusling, I. Zahed

In this work we discuss the emission of low mass dilepton radiation from a hydrodynamic evolution model of Au-Au collisions and make comparisons with recent PHENIX measurements. The dilepton emission rates from the hadronic phase are treated at finite temperature and baryon density and are completely constrained by broken chiral symmetry in a density expansi

Shiang Yong Looi, Li Yu, Vlad Gheorghiu, Robert B. Griffiths

Graph states are generalized from qubits to collections of $n$ qudits of arbitrary dimension $D$, and simple graphical methods are used to construct both additive and nonadditive quantum error correcting codes. Codes of distance 2 saturating the quantum Singleton bound for arbitrarily large $n$ and $D$ are constructed using simple graphs, except when $n$ is

C. Schill

A fast readout system for the upgrade of the COMPASS RICH detector has been developed and successfully used for data taking in 2006 and 2007. The new readout system for the multi-anode PMTs in the central part of the photon detector of the RICH is based on the high-sensitivity MAD4 preamplifier-discriminator and the dead-time free F1-TDC chip characterized b

Fiammetta Battaglia, Elisa Prato

The purpose of this article is to view the Penrose kite from the perspective of symplectic geometry.

M. N. Rebelo

We review some recent results on the connection between CP violation at low energies and Leptogenesis in the framework of specific flavour structures for the fundamental leptonic mass matrices with zero textures.

A. Martínez Torres, K. P. Khemchandani, E. Oset

We evaluate the &#34;$σ$&#34; exchange contribution to the $\bar{K}N\to\bar{K}N$ scattering within a chiral unitary approach. We show that the chiral transition potentials for $ππ\to K \bar{K}$ in the $t$-channel lead to a &#34;$σ$&#34; contribution that vanishes in the $\bar{K}$ forward direction and, hence, would produce a null &#34;$σ$&#34; exchange contr

L. Tagliacozzo, Thiago. R. de Oliveira, S. Iblisdir, J. I. Latorre

The power of matrix product states to describe infinite-size translational-invariant critical spin chains is investigated. At criticality, the accuracy with which they describe ground state properties of a system is limited by the size $χ$ of the matrices that form the approximation. This limitation is quantified in terms of the scaling of the half-chain ent

Fan Wang, Jungho Kim, G. D. Gu, Young-June Kim

We have carried out a comprehensive investigation of magnetic properties of LuFe$_2$O$_4$, using AC susceptibility, DC magnetization and specific heat. A magnetic phase transition around $\sim$236 K was observed with DC magnetization and specific heat measurements, which is identified as a paramagnetic to ferrimagnetic transition based on the nonlinear susce

E. Epelbaum, H. Krebs, Ulf-G. Meißner

We study the three-nucleon force in chiral effective field theory with explicit Delta-resonance degrees of freedom. We show that up to next-to-next-to-leading order, the only contribution to the isospin symmetric three-nucleon force involving the spin-3/2 degrees of freedom is given by the two-pion-exchange diagram with an intermediate delta, frequently call

V. R. Shaginyan, A. Z. Msezane, K. G. Popov, V. A. Stephanovich

On the example of two-dimensional (2D) 3He we demonstrate that the main universal features of its experimental temperature T - density x phase diagram [see M. Neumann, J. Nyéki, J. Saunders, Science 317, 1356 (2007)] look like those in the heavy-fermion metals. Our comprehensive theoretical analysis of experimental situation in 2D 3He allows us to propose a

C. Quesne

The bound-state solutions and the su(1,1) description of the $d$-dimensional radial harmonic oscillator, the Morse and the $D$-dimensional radial Coulomb Schrödinger equations are reviewed in a unified way using the point canonical transformation method. It is established that the spectrum generating su(1,1) algebra for the first problem is converted into a

Michel Bauer, Denis Bernard, Kalle Kytola

Two dimensional loop erased random walk (LERW) is a random curve, whose continuum limit is known to be a Schramm-Loewner evolution (SLE) with parameter kappa=2. In this article we study ``off-critical loop erased random walks'', loop erasures of random walks penalized by their number of steps. On one hand we are able to identify counterparts for some LERW ob

M. O. Nestoklon, E. L. Ivchenko, J. -M. Jancu, P. Voisin

Effect of electric field on spin splitting in SiGe quantum wells (QWs) has been studied theoretically. Microscopical calculations of valley and spin splittings are performed in the effective $sp^3d^5s^*$ tight-binding model. The splittings oscillate as a function of the QW width due to inter-valley reflection of the electron wave off the interfaces. In accor

Mohammad R. Garousi

By explicit calculation, we show that the expansion of the disk level S-matrix element of one RR field, two open string tachyons and one gauge field that has been recently found corresponds to the derivative expansion of the Wess-Zumino action of D-brane-anti-D-brane systems.

Olivier Zindy

We consider one-dimensional directed trap models and suppose that the trapping times are heavy-tailed. We obtain the inverse of a stable subordinator as scaling limit and prove an aging phenomenon expressed in terms of the generalized arcsine law. These results confirm the status of universality described by Ben Arous and Černý for a large class of graphs.

O. V. Selyugin, O. V. Teryaev

The Dirac and Pauli form factors of the proton and neutron are obtained in the framework of the generalized parton distributions (GPDs) with some simple momentum transfer dependence. It is shown that both sets of the existing experimental data of the form factors, obtained by the Rosenbluth and polarization transfer, can be described by changing only the slo

Igor A. Bandos

The covariant quantization of massless D=11 superparticle (M0-brane) in its twistor-like Lorentz harmonic formulation is used to clarify the origin and some properties of the Berkovits pure spinor approach to quantum superstring and to search for hidden symmetries of D=11 supergravity. In the twistor like Lorentz harmonic formulation, the SO(16) symmetry is

Sergio Palomares-Ruiz

If dark matter (DM) is unstable, in order to be present today, its lifetime needs to be longer than the age of the Universe, t_U ~ 4 10^{17} s. It is usually assumed that if DM decays it would do it with some strength through a radiative mode. In this case, very constraining limits can be obtained from observations of the diffuse gamma ray background. Howeve

Miguel Sánchez

Global hyperbolicity is a central concept in Mathematical Relativity. Here, we review the different approaches to this concept explaining both, classical approaches and recent results. The former includes Cauchy hypersurfaces, naked singularities, and the space of the causal curves connecting two events. The latter includes structural results on globally hyp

Ward Whitt

This is an expository review paper elaborating on the proof of the martingale functional central limit theorem (FCLT). This paper also reviews tightness and stochastic boundedness, highlighting one-dimensional criteria for tightness used in the proof of the martingale FCLT. This paper supplements the expository review paper Pang, Talreja and Whitt (2007) ill

E. J. Bergholtz, A. Karlhede

We consider spin-polarized electrons in a single Landau level on a torus. The quantum Hall problem is mapped onto a one-dimensional lattice model with lattice constant $2π/L_1$, where $L_1$ is a circumference of the torus (in units of the magnetic length). In the Tao-Thouless limit, $L_1\to 0$, the interacting many-electron problem is exactly diagonalized at

Pierre A. M. Guichon, Anthony W. Thomas, Kazuo Tsushima

The most recent development of the quark-meson coupling (QMC) model, in which the effect of the mean scalar field in-medium on the hyperfine interaction is also included self-consistently, is used to compute the properties of finite hypernuclei. The calculations for $Λ$ and $Ξ$ hypernuclei are of comparable quality to earlier QMC results without the addition

Georges Girardi, Richard Grimm, Benjamin Labonne, Jean Orloff

In analogy to the chiral-linear multiplet correspondence we establish a relationship between the 3-form (or gaugino condensate) multiplet and a coupled non-minimal (0,1/2) multiplet, illustrated by a simple explicit example.

Fanny Godet

For the class of stationary Gaussian long memory processes, we study some properties of the least-squares predictor of X_{n+1} based on (X_n, ..., X_1). The predictor is obtained by projecting X_{n+1} onto the finite past and the coefficients of the predictor are estimated on the same realisation. First we prove moment bounds for the inverse of the empirical

J. Macutkevic, J. Banys, R. Grigalaitis, Yu. Vysochanski

In this article mixed CuInP$_2$(S$_x$Se$_{1-x}$)$_6$ crystals were investigated by broadband dielectric spectroscopy (20 Hz - 3 GHz). From these results the complete phase diagram has been obtained. In the middle part of the phase diagram the dipolar glass phase has been observed. The phase diagram of investigated crystals is strongly asymmetric - the decrea

Jerome K. Vanclay

An expert ranking of forestry journals was compared with journal impact factors and h-indices computed from the ISI Web of Science and internet-based data. Citations reported by Google Scholar appear to offer the most efficient way to rank all journals objectively, in a manner consistent with other indicators. This h-index exhibited a high correlation with t

Angelos Fotopoulos, P. Marios Petropoulos, Nikolaos Prezas, Konstadinos Sfetsos

We consider general planar deformations of a circular distribution of NS5-branes. The near-horizon region of the latter admits, after a T-duality transformation, an exact conformal-field-theory description in terms of the coset model SU(2)/U(1) X SL(2,R)/U(1). We derive the exactly marginal operators corresponding to an infinitesimal planar deformation using

A. A. Krutov, A. P. Martynenko

On the basis of the perturbation theory in the fine structure constant $α$ and the ratio of the electron to muon masses we calculate one-loop vacuum polarization and electron vertex corrections and the nuclear structure corrections to the hyperfine splitting of the ground state of muonic helium atom $(μe ^4_2He)$. We obtain total result for the ground state

V. B. Belyaev, S. A. Rakityansky, W. Sandhas

Possible bound and resonant states of the hypernuclear systems $Λnn$ and $ΛΛn$ are sought as zeros of the corresponding three-body Jost functions calculated within the framework of the hyperspherical approach with local two-body S-wave potentials describing the $nn$, $Λn$, and $ΛΛ$ interactions. Very wide near-threshold resonances are found for both three-bo

S. N. Shevchenko, A. N. Omelyanchouk, A. M. Zagoskin, S. Savel&#39;ev

Rabi oscillations are coherent transitions in a quantum two-level system under the influence of a resonant perturbation, with a much lower frequency dependent on the perturbation amplitude. These serve as one of the signatures of quantum coherent evolution in mesoscopic systems. It was shown recently [N. Gronbech-Jensen and M. Cirillo, Phys. Rev. Lett. 95, 0

A. M. Kamchatnov, L. P. Pitaevskii

Stability of dark solitons generated by a supersonic flow of Bose-Einstein condensate past an obstacle is investigated. It is shown that in the reference frame attached to the obstacle a transition occurs at some critical value of the flow velocity from absolute instability of dark solitons to their convective instability. This leads to decay of disturbances

The Pierre Auger Collaboration

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau-neutrinos $ν_τ$ that interact in the Earth&#39;s crust. Tau leptons from $ν_τ$ charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 Januar

Ferdinand Helmer, Matteo Mariantoni, Enrique Solano, Florian Marquardt

We analyze the detection of itinerant photons using a quantum non-demolition (QND) measurement. We show that the backaction due to the continuous measurement imposes a limit on the detector efficiency in such a scheme. We illustrate this using a setup where signal photons have to enter a cavity in order to be detected dispersively. In this approach, the meas

Florent Benaych-Georges

We prove some general results about the asymptotics of the distribution of the number of cycles of given length of a random permutation whose distribution is invariant under conjugation. These results were first established to be applied in a forthcoming paper (Cycles of free words in several random permutations with restricted cycles lengths), where we prov

Matthieu Romagny

To each associative unitary finite-dimensional algebra over a normal base, we associative a canonical multiplicative function called its determinant. We give various properties of this construction, as well as applications to the topology of the moduli stack of n-dimensional algebras.

Lingaraj Sahu, Michael Schürmann, Kalyan B. Sinha

The aim of this article is to characterize unitary increment process by a quantum stochastic integral representation on symmetric Fock space. Under certain assumptions we have proved its unitary equivalence to a Hudson-Parthasarathy flow.

Massimo Bianchi, Jose F. Morales

We discuss Fermi interactions of four hyperini generated by ``stringy&#39;&#39; instantons in a Type I / Heterotic dual pair on T^4/Z_2.

Hagai B. Perets

In recent years several hypervelocity stars (HVSs) have been observed in the halo of our Galaxy. Such stars are thought to be ejected through dynamical interactions near the massive black hole (MBH) in the Galactic center. Three scenarios have been suggested for their ejection; binary disruption by a MBH, scattering by inspiraling IMBH and scattering by stel

C. Bobeth, B. Grinstein, M. Savrov

We consider an effective field theory for the nonleptonic decay in which a heavy quark decays into a pair of a heavy quark and antiquark having a small relative velocity and one relativistic (massless) quark. This effective theory is a combination of HQET, SCET, and a covariant modification of NRQCD. In the leading logarithm approximation the effective theor

M. Kormos, G. Takacs

We describe the volume dependence of matrix elements of local boundary fields to all orders in inverse powers of the volume. Using the scaling boundary Lee-Yang model as testing ground, we compare the matrix elements extracted from boundary truncated conformal space approach to exact form factors obtained using the bootstrap method. We obtain solid confirmat

L. Benfatto, S. G. Sharapov, J. P. Carbotte

We calculate the optical sum associated with the in-plane conductivity of a graphene bilayer. A bilayer asymmetry gap generated in a field-effect device can split apart valence and conduction bands, which otherwise would meet at two K points in the Brillouin zone. In this way one can go from a compensated semimetal to a semiconductor with a tunable gap. Howe

Zhongmu Li, Zhanwen Han

More than about 50% stars of galaxies are in binaries, but most stellar population studies take single star-stellar population (ss-SSP) models, which do not take binary interactions into account. In fact, the integrated peculiarities of ss-SSPs are various from those of stellar populations with binary interactions (bs-SSPs). Therefore, it is necessary to inv

D. Li, X. Li, H. Huang, X. Li

In Phys. Rev. A 62, 062314 (2000), Dür, Vidal and Cirac indicated that there are infinitely many SLOCC classes for four qubits. Verstraete, Dehaene, and Verschelde in Phys. Rev. A 65, 052112 (2002) proposed nine families of states corresponding to nine different ways of entangling four qubits. In Phys. Rev. A 75, 022318 (2007), Lamata et al. reported that th

Ryo Takahashi

Let A be a commutative noetherian ring. In this paper, we interpret localizing subcategories of the derived category of A by using subsets of Spec A and subcategories of the category of A-modules. We unify theorems of Gabriel, Neeman and Krause.

Alexander E. Holroyd, Robin Pemantle, Yuval Peres, Oded Schramm

Suppose that red and blue points occur as independent homogeneous Poisson processes in R^d. We investigate translation-invariant schemes for perfectly matching the red points to the blue points. For any such scheme in dimensions d=1,2, the matching distance X from a typical point to its partner must have infinite d/2-th moment, while in dimensions d>=3 there

Andrei Gagarin, Gilbert Labelle, Pierre Leroux, Timothy Walsh

We adapt the classical 3-decomposition of any 2-connected graph to the case of simple graphs (no loops or multiple edges). By analogy with the block-cutpoint tree of a connected graph, we deduce from this decomposition a bicolored tree tc(g) associated with any 2-connected graph g, whose white vertices are the 3-components of g (3-connected components or pol

Jeong-Eun Lee

A new type of object called &#34;Very Low Luminosity Objects (VeLLOs)&#34; has been discovered by the Spitzer Space Telescope. VeLLOs might be substellar objects forming by accretion. However, some VeLLOs are associated with strong outflows, indicating the previous existence of massive accretion. The thermal history, which significantly affects the chemistry

Nemanja Kaloper, Scott Watson

We consider the effects of graviton multiplet fields on transitions between string gas phases. Focusing on the dilaton field, we show that it may obstruct transitions between different thermodynamic phases of the string gas, because the sign of its dimensionally reduced, $T$-duality invariant, part is conserved when the energy density of the universe is posi

De-en Jiang, Sheng Dai

Mobius graphene nanoribbons have only one edge topologically. How the magnetic structures, previously associated with the two edges of zigzag-edged flat nanoribbons or cyclic nanorings, would change for their Mobius counterparts is an intriguing question. Using spin-polarized density functional theory, we shed light on this question. We examine spin states o

Xiao-Gang He

The Standard Model for CP violation, the CKM model, works very well in explaining all laboratory experimental data. However, this model does not address the question that where it comes from. The origin of CP violation is still a mystery. In this talk I discuss a model\cite{model} addressing this problem in which the CP violating phase in the CKM matrix is i

Satoru Yamamoto, Hiroshi Kimura, Evgenij Zubko, Hiroshi Kobayashi

According to our common understandings, the original surface of a short-period comet nucleus has been lost by sublimation processes during its close approaches to the Sun. Sublimation results in the formation of a dust mantle on the retreated surface and in chemical differentiation of ices over tens or hundreds of meters below the mantle. In the course of NA

Kiki Vierdayanti, Ken-ya Watarai, Shin Mineshige

We propose a methodology to derive a black-hole mass for super-critical accretion flow. Here, we use the extended disk blackbody (extended DBB) model, a fitting model in which the effective temperature profile obeys the relation $T_{\rm eff} \propto r^{-p}$, with $r$ being the disk radius and $p$ being treated as a fitting parameter. We first numerically cal

Kazufumi Kimoto, Yoshinori Yamasaki

A variation of multiple $L$-values, which arises from the description of the special values of the spectral zeta function of the non-commutative harmonic oscillator, is introduced. In some special cases, we show that its generating function can be written in terms of the gamma functions. This result enables us to obtain explicit evaluations of them.

Andrew Inglis, Luis Cruz, Dan L. Roe, H. E. Stanley

Individual locations of many neuronal cell bodies (>10^4) are needed to enable statistically significant measurements of spatial organization within the brain such as nearest-neighbor and microcolumnarity measurements. In this paper, we introduce an Automated Neuron Recognition Algorithm (ANRA) which obtains the (x,y) location of individual neurons within di

R. Khasanov, A. Shengelaya, A. Maisuradze, D. Di Castro

The results of the muon-spin rotation experiments on BCS superconductors NbB_2+x (x = 0.2, 0.34) are reported. Both samples, studied in the present work, exhibit rather broad transitions to the superconducting state, suggesting a distribution of the volume fractions with different transition temperatures (T_c)&#39;s. By taking these distributions into accoun

Allan Sandage

The Teerikorpi incompleteness bias in the distance modulus of a galaxy cluster that is determined from incomplete data using the Tully-Fisher (TF) method is discussed differently than has been done in earlier papers of this series. A toy cluster is made with zero intrinsic TF dispersion but with slopes that differ between the calibrators and the cluster data

Vladimir Pestov

We perform a deeper analysis of an axiomatic approach to the concept of intrinsic dimension of a dataset proposed by us in the IJCNN&#39;07 paper (arXiv:cs/0703125). The main features of our approach are that a high intrinsic dimension of a dataset reflects the presence of the curse of dimensionality (in a certain mathematically precise sense), and that dime

Hugues Chaté, Francesco Ginelli, Guillaume Grégoire, Franck Raynaud

We present a comprehensive study of Vicsek-style self-propelled particle models in two and three space dimensions. The onset of collective motion in such stochastic models with only local alignment interactions is studied in detail and shown to be discontinuous (first-order like). The properties of the ordered, collectively moving phase are investigated. In

Raymundo Baptista, Alexandre Bortoletto

We report the analysis of a uniform sample of 31 light curves of the nova-like variable UU Aqr with eclipse mapping techniques. The data were combined to derive eclipse maps of the average steady-light component, the long-term brightness changes, and low- and high-frequency flickering components. The long-term variability responsible for the &#39;low&#39; an

S. Schumacher, N. H. Kwong, R. Binder, Arthur L. Smirl

Using a microscopic many-particle theory, we propose all-optical switching in planar semiconductor microcavities where a weak beam switches a stronger signal. Based on four-wave-mixing instabilities, the general scheme is a semiconductor adaptation of a recently demonstrated switch in an atomic vapor [Dawes et al., Science 308, 672 (2005)].

Rakesh P. Tiwari, D. Stroud

We consider a superconducting persistent-current qubit consisting of a three-junction superconducting loop in an applied magnetic field. We show that by choosing the field, Josephson couplings, and offset charges suitably, we can perfectly suppress the tunneling between two oppositely directed states of circulating current, leading to a vanishing of the spli

Elisha Peterson

Can the cross product be generalized? Why are the trace and determinant so important in matrix theory? What do all the coefficients of the characteristic polynomial represent? This paper describes a technique for `doodling&#39; equations from linear algebra that offers elegant solutions to all these questions. The doodles, known as trace diagrams, are graphs

James A. Stickney, Rudra P. Kafle, Dana Z. Anderson, Alex A. Zozulya

The operation of a BEC based atom interferometer, where the atoms are held in a weakly-confining magnetic trap and manipulated with counter-propagating laser beams, is analyzed. A simple analytic model is developed to describe the dynamics of the interferometer. It is used to find the regions of parameter space with high and low contrast of the interference

B. J. Senkowicz, R. J. Mungall, Y. Zhu, J. Jiang

Magnesium diboride (MgB2) powder was mechanically alloyed by high energy ball milling with C to a composition of Mg(B0.95C0.05)2 and then sintered at 1000 C in a hot isostatic press. Milling times varied from 1 minute to 3000 minutes. Full C incorporation required only 30-60 min of milling. Grain size of sintered samples decreased with increased milling time

Don Colladay, Patrick McDonald

The explicit one-loop renormalizability of the gluon sector of QCD with Lorentz violation is demonstrated. The result is consistent with multiplicative renormalization as the required counter terms are consistent with a single re-scaling of the Lorentz-violation parameters. In addition, the resulting beta functions indicate that the CPT-even Lorentz-violatin

Libin Jiang, Jean Walrand

The fairness of IEEE 802.11 wireless networks (including Wireless LAN and Ad-hoc networks) is hard to predict and control because of the randomness and complexity of the MAC contentions and dynamics. Moreover, asymmetric channel conditions such as those caused by capture and channel errors often lead to severe unfairness among stations. In this paper we prop

D. Hernandez-Serrano, J. M. Muñoz Porras, F. J. Plaza Martin

In this paper the moduli space of Higgs pairs over a fixed smooth projective curve with extra formal data is defined and it is endowed with a scheme structure. We introduce a relative version of the Krichever map using a fibration of Sato Grassmannians and show that this map is injective. This fact and the characterization of the points of the image of the K

Andrew Baker

We investigate stable operations in supersingular elliptic cohomology using isogenies of supersingular elliptic curves over finite fields. Our main results provide a framework in which we give a conceptually simple proof of an elliptic cohomology version of the Morava change of rings theorem and also gives models for explicit stable operations in terms of is

A. Balinsky, W. D. Evans, Y. Saito

The paper analyses the decay of any zero modes that might exist for a massless Dirac operator $H:= \ba \cdot (1/i) \bgrad + Q, $ where $Q$ is $4 \times 4$-matrix-valued and of order $O(|\x|^{-1})$ at infinity. The approach is based on inversion with respect to the unit sphere in $\R^3$ and establishing embedding theorems for Dirac-Sobolev spaces of spinors $

Burt Totaro

We give the first examples of nef line bundles on smooth projective varieties over finite fields which are not semi-ample. More concretely, we find smooth curves on smooth projective surfaces over finite fields such that the normal bundle has degree zero, but no positive multiple of the curve moves in a family of disjoint curves. This answers questions by Ke

Zhenyu Yan, Sergey V. Buldyrev, Pradeep Kumar, Nicolas Giovambattista

We perform molecular dynamics simulations of a well-known water model (the TIP5P pair potential) and a simple liquid model (a two-scale repulsive ramp potential) to compare the regions of anomalous behavior in their phase diagrams. We select the parameters of the ramp potential by mapping it to an effective pair potential derived from the TIP5P model. We fin

Yue Shen, Michael A. Strauss, Patrick B. Hall, Donald P. Schneider

We select a sample of $\sim 4200$ traditionally defined broad absorption line quasars (BALQs) from the Fifth Data Release quasar catalog of the Sloan Digital Sky Survey. For a statistically homogeneous quasar sample with $1.7\le z\le 4.2$, the BAL quasar fraction is $\sim 14%$ and is almost constant with redshift. We measure the auto-correlation of non-BAL q

I. V. Dobrovolska, R. S. Tutik

The explicit semiclassical treatment of the logarithmic perturbation theory for the bound-state problem for the spherical anharmonic oscillator and the screened Coulomb potential is developed. Based upon the $\hbar$-expansions and suitable quantization conditions a new procedure for deriving perturbation expansions is offered. Avoiding disadvantages of the s

F. Lechenault, O. Dauchot, G. Biroli, J. P. Bouchaud

We track the motion of a horizontally vibrated amorphous assembly of bidisperse hard disks, for densities ranging across the jamming transition. We derive on very general grounds a bound on the dynamical susceptibility in terms of the response of the dynamics to a change in density. This generalizes a similar bound recently derived for equilibrium liquids. W

F. Slanina, K. Sznajd-Weron, P. Przybyla

In this paper we introduce modified version of one-dimensional outflow dynamics (known as a Sznajd model) which simplifies the analytical treatment. We show that simulations results of the original and modified rules are exactly the same for various initial conditions. We obtain the analytical formula for exit probability using Kirkwood approximation and we

Ahmad El Soufi, Rola Kiwan

We prove that among all doubly connected domains of $\mathbb{R}^n$ bounded by two spheres of given radii, the second eigenvalue of the Dirichlet Laplacian achieves its maximum when the spheres are concentric (spherical shell). The corresponding result for the first eigenvalue has been established by Hersch in dimension 2, and by Harrell, Kröger and Kurata an

Rafael A. Porto, Ira Z. Rothstein

In this comment we explain the discrepancy found between the results in arXiv:0712.1716v1 for the 3PN spin-spin potential and those previously derived in gr-qc/0604099. We point out that to compare one must include sub-leading lower order spin-orbit effects which contribute to the spin-spin potential once one transforms to the PN frame. When these effects ar

Volodymyr Sushch

We study a discrete model of the Laplacian in $\mathbb{R}^2$ that preserves the geometric structure of the original continual object. This means that, speaking of a discrete model, we do not mean just the direct replacement of differential operators by difference ones but also a discrete analog of the Riemannian structure. We consider this structure on the a

Philip C. Argyres, John R. Wittig

We show that a proposed duality [arXiv:0711.0054] between infinitely coupled gauge theories and superconformal field theories (SCFTs) with weakly gauged flavor groups predicts the existence of new rank 1 SCFTs. These superconformal fixed point theories have the same Coulomb branch singularities as the rank 1 E_6, E_7, and E_8 SCFTs, but have smaller flavor s

Yu Luo, Hongsheng Chen, Jingjing Zhang, Lixin Ran

We investigate a general class of electromagnetic devices created with any continuous transformation functions by rigorously calculating the analytical expressions of the electromagnetic field in the whole space. Some interesting phenomena associated with these transformation devices, including the invisibility cloaks, concentrators, and field rotators, are

T. J. Echtermeyer, M. C. Lemme, M. Baus, B. N. Szafranek

Conventional field effect transistor operation in graphene is limited by its zero gap and minimum quantum conductivity. In this work, we report on controlled electrochemical modification of graphene such that its conductance changes by more than six orders of magnitude, which enables reversible bipolar switching devices. The effect is explained by a chemical

Barbara Bigot, Sebastien Galtier, Helene Politano

We investigate the influence of a uniform magnetic field ${\bf B_0}=B_0 e//$ on energy decay laws in incompressible magnetohydrodynamic (MHD) turbulence. The nonlinear transfer reduction along $B_0$ is included in a model that distinguishes parallel and perpendicular directions, following a phenomenology {\it à la} Kraichnan. We predict a slowing down of the