April 2008 arXiv papers — page 43

K. M. Howley, M. Geha, P. Guhathakurta, R. M. Montgomery

NGC 205, a close satellite of the M31 galaxy, is our nearest example of a dwarf elliptical galaxy. Photometric and kinematic observations suggest that NGC 205 is undergoing tidal distortion from its interaction with M31. Despite earlier attempts, the orbit and progenitor properties of NGC 205 are not well known. We perform an optimized search for these unkno

Clarina de la Cruz, Q. Huang, J. W. Lynn, Jiying Li

In high-transition temperature (high-Tc) copper oxides, it is generally believed that antiferromagnetism plays a fundamental role in the superconducting mechanism because superconductivity occurs when mobile electrons or holes are doped into the antiferromagnetic parent compounds. The recent discovery of superconductivity in the rare-earth (R) iron-based oxi

I. Krichever, T. Shiota

We introduce the notion of abelian solutions of the 2D Toda lattice equations and the bilinear discrete Hirota equation and show that all of them are algebro-geometric.

D. W. Boukhvalov, L. I. Vergara, V. V. Dobrovitski, M. I. Katsnelson

We present joint theoretical-experimental study of the correlation effects in the electronic structure of (pyH)$_3$[Mn$_4$O$_3$Cl$_7$(OAc)$_3$]$\cdot$2MeCN molecular magnet (Mn$_4$). Describing the many-body effects by cluster dynamical mean-field theory, we find that Mn$_4$ is predominantly Hubbard insulator with strong electron correlations. The calculated

Siavash Ekbatani, Farzad Etemadi, Hamid Jafarkhani

The topic of this study is the outage behavior of multiple-antenna slow fading channels with quantized feedback and partial power control. A fixed-rate communication system is considered. It is known from the literature that with error-free feedback, the outage-optimal quantizer for power control has a circular structure. Moreover, the diversity gain of the

Jorge S. Diaz

The AdS/CFT correspondence has been tested through the reproduction of standard results. Following this approach, we use the correspondence to obtain the Hawking temperature of a black hole in 1+1 dimensions. Using an auxiliary Liouville field, the holographic energy-momentum tensor is found and compared with a radiation energy-momentum tensor, verifying tha

Sebastian Zamfir, Jack W. Sulentic, Paola Marziani

We search fora dichotomy/bimodality between Radio Loud (RL) and Radio Quiet (RQ) Type 1 Active Galactic Nuclei (AGN). We examine several samples of SDSS QSOs with high S/N optical spectra and matching FIRST/NVSS radio observations. We use the radio data to identify the weakest RL sources with FRII structure to define a RL/RQ boundary which corresponds to log

Harm Derksen, Theodore Owen

To a directed graph without loops and 2-cycles, we can associate a skew-symmetric matrix with integer entries. Mutations of such skew-symmetric matrices, and more generally skew-symmetrizable matrices, have been defined in the context of cluster algebras by Fomin and Zelevinsky. The mutation class of a graph G is the set of all isomorphism classes of graphs

Mikhail Lyubich, Marco Martens

We study highly dissipative Hénon maps $$ F_{c,b}: (x,y) \mapsto (c-x^2-by, x) $$ with zero entropy. They form a region $Π$ in the parameter plane bounded on the left by the curve $W$ of infinitely renormalizable maps. We prove that Morse-Smale maps are dense in $Π$, but there exist infinitely many different topological types of such maps (even away from $W$

Wen-Yu Wen

We refine the definition of universal ratio c/\tilde{c} obtained via AdS/CFT correspondence as shown in arXiv:0801.2785 [hep-th], denoted as γ_c, and apply it to non-CFTs whose dual gravitational theory have metric of asymptotic AdS. We conjecture that γ_c=1 is the lower bound being saturated at high temperature regime and serves as an ordering parameter as

Michael C. Ogilvie, Peter N. Meisinger

Recently developed methods for PT-symmetric models can be applied to quantum-mechanical matrix and vector models. In matrix models, the calculation of all singlet wave functions can be reduced to the solution a one-dimensional PT-symmetric model. The large-N limit of a wide class of matrix models exists, and properties of the lowest-lying singlet state can b

Brayton Gray

Recently Stephen Theriault and I found an elementary construction of Anick's spaces and proved their main properties(arXiv:0710.1024).In this work the fundamental fibration is decomposed. This is useful in studying maps out of Anick's spaces and will be needed in order to determine it's universal properties.

Massimo Cencini, Fabio Cecconi, Massimo Falcioni, Angelo Vulpiani

Several years after the pioneering work by Fermi Pasta and Ulam, fundamental questions about the link between dynamical and statistical properties remain still open in modern statistical mechanics. Particularly controversial is the role of deterministic chaos for the validity and consistency of statistical approaches. This contribution reexamines such a deba

Assaf Sharon, Matteo Viale

We study the approachability ideal I[κ^+] in the context of large cardinals properties of the regular cardinals below a singular κ. As a guiding example consider the approachability ideal I[\aleph_{ω+1}] assuming that \aleph_ωis strong limit. In this case we obtain that club many points in \aleph_{ω+1} of cofinality \aleph_n for some n>1 are approachable ass

Lilia Anguelova, Vincenzo Calo

We summarize our work on the O'Raifeartaigh uplifted KKLT model at finite temperature. We study the system for parameter values for which the zero temperature potential for the volume modulus has a dS minimum. The temperature-dependent part of the effective potential has a runaway behaviour for one exponent in the superpotential, whereas it can have loca

Antoine Chambaz, Judith Rousseau

The efficiency of two Bayesian order estimators is studied. By using nonparametric techniques, we prove new underestimation and overestimation bounds. The results apply to various models, including mixture models. In this case, the errors are shown to be $O(e^{-an})$ and $O((\log n)^b/\sqrt{n})$ ($a,b>0$), respectively.

D. Ebert, K. G. Klimenko, A. V. Tyukov, V. Ch. Zhukovsky

In the framework of an extended Nambu--Jona-Lasinio model we are studying pion condensation in quark matter with an asymmetric isospin composition in a gravitational field of the static Einstein universe at finite temperature and chemical potential. This particular choice of the gravitational field configuration enables us to investigate phase transitions of

Luc Museur, Demetrios Anglos, Jean-Pierre Petitet, Jean Pierre Michel

We report on the UV laser induced fluorescence of hexagonal boron nitride (h-BN) following nanosecond laser irradiation of the surface under vacuum and in different environments of nitrogen gas and ambient air. The observed fluorescence bands are tentatively ascribed to impurity and mono (VN), or multiple (m-VN with m = 2 or 3) nitrogen vacancies. A structur

James Aird, Kirpal Nandra, Antonis Georgakakis, Elise S. Laird

We combine Lyman-break colour selection with ultradeep (> 200 ks) Chandra X-ray imaging over a survey area of ~0.35 deg^2 to select high redshift AGN. Applying careful corrections for both the optical and X-ray selection functions, the data allow us to make the most accurate determination to date of the faint end of the X-ray luminosity function (XLF) at z~3

Matthias S. Keil

Psychophysical experiments suggested a relative importance of a narrow band of spatial frequencies for recognition of face identity in humans. There exists, however, no conclusive evidence of why it is that such frequencies are preferred. To address this question, I examined the amplitude spectra of a large number of face images, and observed that face spect

Yacine Aït-Sahalia

This paper provides closed-form expansions for the log-likelihood function of multivariate diffusions sampled at discrete time intervals. The coefficients of the expansion are calculated explicitly by exploiting the special structure afforded by the diffusion model. Examples of interest in financial statistics and Monte Carlo evidence are included, along wit

A. A. Golubtsova, V. D. Ivashchuk

We present a description of computational program (written in Maple) for calculation of fluxbrane polynomials corresponding to classical simple Lie algebras. These polynomials define certain special solutions to open Toda chain equations.

Giancarlo Rinaldo

We compute the Betti numbers of the resolution of a special class of square-free monomial ideals, the ideals of mixed products. Moreover when these ideals are Cohen-Macaulay we calculate their type.

M. Billó

We consider systems of magnetized D9 branes on orbifolds supporting N=1 gauge theories. In such realizations, the matter multiplets arise from "twisted" strings connecting different stacks of branes. The introduction of Euclidean 5-branes wrapped on the six-dimensional compact space leads to instanton effects. We examine the interplay between the ann

Alexander Bolonkin

Many small countries are in need of additional territory. They build landfills and expensive artificial islands. The ocean covers 71 per cent of the Earth surface. Those countries (or persons of wealth) starting the early colonization of the ocean may obtain advantages through additional territory or creating their own independent state. An old idea is build

Raphael Yuster

For every fixed graph $H$ and every fixed $0 < α< 1$, we show that if a graph $G$ has the property that all subsets of size $αn$ contain the ``correct&#39;&#39; number of copies of $H$ one would expect to find in the random graph $G(n,p)$ then $G$ behaves like the random graph $G(n,p)$; that is, it is $p$-quasi-random in the sense of Chung, Graham, and Wilso

Yi Liao

We construct the propagator for a free fermionic unparticle field from basic considerations of scale and Lorentz invariance. The propagator is fixed up to a normalization factor which is required to recover the result of a free massless fermion field in the canonical limit of the scaling dimension. Two new features appear compared to the bosonic case. The pr

Raymond Bergmann, Devaraj van der Meer, Stephan Gekle, Arjan van der Bos

In this paper we study the transient surface cavity which is created by the controlled impact of a disk of radius h0 on a water surface at Froude numbers below 200. The dynamics of the transient free surface is recorded by high speed imaging and compared to boundary integral simulations. An excellent agreement is found between both. The flow surrounding the

Jan W. Kantelhardt

Data series generated by complex systems exhibit fluctuations on many time scales and/or broad distributions of the values. In both equilibrium and non-equilibrium situations, the natural fluctuations are often found to follow a scaling relation over several orders of magnitude, allowing for a characterisation of the data and the generating complex system by

David Bebbington, Laura Carrea, Ernst Krokager

A new approach to polarization algebra is introduced. It exploits the geometric properties of spinors in order to represent wave states consistently in arbitrary directions in three dimensional space. In this first expository paper of an intended series the basic derivation of the spinorial wave state is seen to be geometrically related to the electromagneti

George V. Moustakides

In sequential change detection, existing performance measures differ significantly in the way they treat the time of change. By modeling this quantity as a random time, we introduce a general framework capable of capturing and better understanding most well-known criteria and also propose new ones. For a specific new criterion that constitutes an extension t

Piotr Fryzlewicz, Theofanis Sapatinas, Suhasini Subba Rao

We investigate the time-varying ARCH (tvARCH) process. It is shown that it can be used to describe the slow decay of the sample autocorrelations of the squared returns often observed in financial time series, which warrants the further study of parameter estimation methods for the model. Since the parameters are changing over time, a successful estimator nee

Clemens Heuberger, Helmut Prodinger

Wu, Lou, Lai and Chang proposed a multi-exponentiation algorithm using binary complements and the non-adjacent form. The purpose of this paper is to show that neither the analysis of the algorithm given by its original proposers nor that by other authors are correct. In fact it turns out that the complement operation does not have significant influence on th

Gunnar Pruessner, Ole Peters

In [Braz. J. Phys. 30, 27 (2000)] Dickman et al. suggested that self-organized criticality can be produced by coupling the activity of an absorbing state model to a dissipation mechanism and adding an external drive. We analyzed the proposed mechanism in [Phys. Rev. E 73, 025106R (2006)] and found that if this mechanism is at work, the finite-size scaling fo

Paul Jameson, Arsen Khvedelidze

The classical dynamics of a charged particle traveling in a laser field modeled by an elliptically polarized monochromatic electromagnetic plane wave is discussed within the time reparametrization invariant form of the non-relativistic Hamilton-Jacobi theory. The exact parametric representation for a particle&#39;s orbit in an arbitrary plane wave background

Yohai Roichman, Bo Sun, Allan Stolarski, David G. Grier

We demonstrate both experimentally and theoretically that a colloidal sphere trapped in a static optical tweezer does not come to equilibrium, but rather reaches a steady state in which its probability flux traces out a toroidal vortex. This non-equilibrium behavior can be ascribed to a subtle bias of thermal fluctuations by non-conservative optical forces.

Alain Berthomieu

This is the final part of the work started in math.DG/0611281 and math.DG/0703916. Here the question of double fibration ois adressed both for relative k-theory and free multiplicative K-theory. In the case of relative and ``nonfree&#39;&#39; multiplicative K-theory, the direct image is proved to be functorial for double submersions.

Nicolas Destainville, Lionel Foret

We propose a unifying, analytical theory accounting for the self-organization of colloidal systems in nano- or micro-cluster phases. We predict the distribution of cluter sizes with respect to interaction parameters and colloid concentration. In particular, we anticipate a proportionality regime where the mean cluster size grows proportionally to the concent

Federica Galluzzi, Giuseppe Lombardo, Chris Peters

Every indefinite binary form occurs as the Picard lattice of some K3-surface. The group of its isometries, or automorphs, coincides with the automorphism group of the K3-surface, but only up to finite groups. The classical theory of automorphs for binary forms can then be applied to study these automorphism groups. The result is a precise description of all

Pascal Schweitzer

We reveal a connection between the incompressibility method and the Lovasz local lemma in the context of Ramsey theory. We obtain bounds by repeatedly encoding objects of interest and thereby compressing strings. The method is demonstrated on the example of van der Waerden numbers. It applies to lower bounds of Ramsey numbers, large transitive subtournaments

Ethan B. Anderes, Michael L. Stein

This paper presents a new approach to the estimation of the deformation of an isotropic Gaussian random field on $\mathbb{R}^2$ based on dense observations of a single realization of the deformed random field. Under this framework we investigate the identification and estimation of deformations. We then present a complete methodological package--from model a

Oliver Linton, Stefan Sperlich, Ingrid Van Keilegom

This paper proposes consistent estimators for transformation parameters in semiparametric models. The problem is to find the optimal transformation into the space of models with a predetermined regression structure like additive or multiplicative separability. We give results for the estimation of the transformation when the rest of the model is estimated no

Wojciech Broniowski, Enrique Ruiz Arriola, Krzysztof Golec-Biernat

Generalized Parton Distributions of the pion are evaluated in chiral quark models with the help of double distributions. As a result the polynomiality conditions are automatically satisfied. In addition, positivity constraints, proper normalization and support, sum rules, and soft pion theorems are fulfilled. We obtain explicit expressions holding at the low

R. J. Young, R. M. Stevenson, A. J. Hudson, C. A. Nicoll

Here we demonstrate, for the first time, violation of Bell&#39;s inequality using a triggered quantum dot photon-pair source without post-selection. Furthermore, the fidelity to the expected Bell state can be increased above 90% using temporal gating to reject photons emitted at times when collection of uncorrelated light is more probable. A direct measureme

Ning Bo Zhao, An Min Wang

We propose a protocol for local implementation of two consecutive nonlocal operations by three parters. It consumes one shared GHZ state in this protocol. We also demonstrate that these resources are sufficient and necessary to locally implement two consecutive CNOT operations.

Aurore Delaigle, Peter Hall, Alexander Meister

In a large class of statistical inverse problems it is necessary to suppose that the transformation that is inverted is known. Although, in many applications, it is unrealistic to make this assumption, the problem is often insoluble without it. However, if additional data are available, then it is possible to estimate consistently the unknown error density.

P. North, J. Babel, D. Erspamer

The many peculiarities of Ap stars (not only chemical ones, but also magnetic field and slow rotation) may vary during the main-sequence evolution of these stars. We review here briefly the evidences found in the last thirty years for such evolution, with an emphasis on the more recent research. The position in the HR diagram of low mass Ap stars with a sign

Lie Wang, Lawrence D. Brown, T. Tony Cai, Michael Levine

Variance function estimation in nonparametric regression is considered and the minimax rate of convergence is derived. We are particularly interested in the effect of the unknown mean on the estimation of the variance function. Our results indicate that, contrary to the common practice, it is not desirable to base the estimator of the variance function on th

O. Esquivel, D. Page

Ultra-high-energy cosmic rays (UHECRs) have been tried to be related to the most varied and powerful sources known in the universe. Gamma-ray bursts (GRBs) are natural candidates. Here, we argue that cosmic rays can be accelerated by large amplitude electromagnetic waves (LAEMWs) when the MHD approximation of the field in the wind generated by the GRB&#39;s

A. C. Callan-Jones, J. -F. Joanny, J. Prost

We present a novel flow instability that can arise in thin films of cytoskeletal fluids if the friction with the substrate on which the film lies is sufficiently strong. We consider a two dimensional, membrane-bound fragment containing actin filaments that is perturbed from its initially circular state, where actin polymerizes at the edge and flows radially

Athanase Papadopoulos, Marc Troyanov

We discuss general notions of metrics and of Finsler structures which we call weak metrics and weak Finsler structures. Any convex domain carries a canonical weak Finsler structure, which we call its tautological weak Finsler structure. We compute distances in the tautological weak Finsler structure of a domain and we show that these are given by the so-call

Anatole Castella

We show the analogue of Muhlherr&#39;s [Coxeter groups in Coxeter groups, Finite Geom. and Combinatorics, Cambridge Univ. Press (1993), 277-287] for Artin-Tits monoids, and for Artin-Tits groups of spherical type. That is, the submonoid (resp. subgroup) of an Artin-Tits monoid (resp. group of spherical type) induced by an admissible partition of the Coxeter

Sara A. van de Geer

We consider high-dimensional generalized linear models with Lipschitz loss functions, and prove a nonasymptotic oracle inequality for the empirical risk minimizer with Lasso penalty. The penalty is based on the coefficients in the linear predictor, after normalization with the empirical norm. The examples include logistic regression, density estimation and c

H. Bary-Soroker, O. Entin-Wohlman, Y. Imry

We consider the mesoscopic normal persistent current (PC) in a very low-temperature superconductor with a bare transition temperature $T_c^0$ much smaller than the Thouless energy $E_c$. We show that in a rather broad range of pair-breaking strength, $T_c^0 \lesssim \hbar/τ_s \lesssim E_c$, the transition temperature is renormalized to zero, but the PC is ha

M. De la Sen

This paper is mainly concerned with the robustly stable adaptive control of single-input single-output impulse-free linear time-invariant singular dynamic systems of known order and unknown parameterizations subject to single external point delays. The control law is of pole-placement type and based on input/output measurements and parametrical estimation on

Zorica Cvetkovc, Istvan Vince, Slobodan Ninkovic

In the paper new orbital elements obtained from speckle interferometric measurements only for 15 Mon are reported. For this binary they were determined earlier by combining spectroscopic and speckle measurements and spectroscopic and astrometric measurements. A new speckle measurement dating after the periastron passage of the secondary has a significant dis

Gennaro Amendola

We define an invariant, which we call surface-complexity, of closed 3-manifolds by means of Dehn surfaces. The surface-complexity of a manifold is a natural number measuring how much the manifold is complicated. We prove that it fulfils interesting properties: it is subadditive under connected sum and finite-to-one on P2-irreducible manifolds. Moreover, for

P. Salomé, Y. Revaz, F. Combes, J. Pety

We recently found extended CO(2-1) emission from cold molecular gas embedded in the network of Halpha filaments surrounding the galaxy NGC 1275 (Salome et al. 2006). We now present CO(2-1) interferometer maps of the eastern filaments, at high spatial and spectral resolutions. The cold molecular gas is detected by the Plateau de Bure Interferometer along the

Jian Huang, Joel L. Horowitz, Shuangge Ma

We study the asymptotic properties of bridge estimators in sparse, high-dimensional, linear regression models when the number of covariates may increase to infinity with the sample size. We are particularly interested in the use of bridge estimators to distinguish between covariates whose coefficients are zero and covariates whose coefficients are nonzero. W

Valeriy A. Yumaguzhin

The natural bundle $π:E\to M$ of almost-complex structures is considered. The action of the pseudogroup of all diffeomorphisms of $M$ on the total space $E$ is investigated. A nontrivial 1-st order differential invariant of this action is constructed. It is proved that the Nijenhuise tensor of an almost-complex structures is equal to zero iff the constructed

Kay Yakushiji, Shinji Yuasa, Taro Nagahama, Akio Fukushima

We fabricated a current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) nanopillar with a 1-nm-thick FePt free layer having perpendicular anisotropy using the alternate monatomic layer deposition method. Nanopillars consisting of [Fe (1 monolayer (ML))/Pt (1 ML)]n (n: the number of the alternation period) ferromagnetic layers and an Au spacer layer

Kiran S. Kedlaya, Xuancheng Shao

For any group G of order n, a subset A of G is said to be product-free if there is no solution of the equation ab=c with a,b,c in A. Previous results of Gowers showed that the size of any product-free subset of G is at most n/d^(1/3), where d is the smallest dimension of a nontrivial representation of G. However, this upper bound does not match the best lowe

Masahito Hayashi

The optimal exponential error rate for adaptive discrimination of two channels is discussed. In this problem, adaptive choice of input signal is allowed. This problem is discussed in various settings. It is proved that adaptive choice does not improve the exponential error rate in these settings. These results are applied to quantum state discrimination.

J. F. Donati, M. M. Jardine, S. G. Gregory, J. Bouvier

Whereas the understanding of most phases of stellar evolution made considerable progress throughout the whole of the twentieth century, stellar formation remained rather enigmatic and poorly constrained by observations until about three decades ago, when major discoveries (e.g., that protostars are often associated with highly collimated jets) revolutionized

Sudhakar Pandey, Avinash Singh

The effects of correlation-induced coupling between spin and charge fluctuations on spin-wave excitations in a band ferromagnet are investigated by including self-energy and vertex corrections within a systematic inverse-degeneracy expansion scheme which explicitly preserves the Goldstone mode. Arising from the scattering of a magnon into intermediate spin-e

Ulrike von Luxburg, Mikhail Belkin, Olivier Bousquet

Consistency is a key property of all statistical procedures analyzing randomly sampled data. Surprisingly, despite decades of work, little is known about consistency of most clustering algorithms. In this paper we investigate consistency of the popular family of spectral clustering algorithms, which clusters the data with the help of eigenvectors of graph La

A. Cintio, G. Morchio

Frequency sum rules are derived in extended quantum systems of non relativistic fermions from a minimal set of assumptions on dynamics in infinite volume, for ground and thermal states invariant under space translations or a lattice subgroup. For the jellium Coulomb model, they imply the one point result for the plasmon energy spectrum in the zero momentum l

Valeriy A. Yumaguzhin

In this paper, we investigate the action of pseudogroup of all point transformations on the natural bundle of equations $y&#39;&#39;=a^3(x,y)(y&#39;)^3+a^2(x,y)(y&#39;)^2+a^1(x,y)y&#39;+a^0(x,y)$. We construct differential invariants of this action and solve the equivalence problem for some classes of these equations in particular for generic equations.

David Feldman, Mehmet Orhon, Andreas Blass

A celebrated argument of F. Hartogs (1915) deduces the Axiom of Choice from the hypothesis of comparability for any pair of cardinals. We show how each of a sequence of seemingly much weaker hypotheses suffices. Fixing a finite number $k>1$, the Axiom of Choice follows if merely any family of $k$ cardinals contains at least one comparable pair.

James P. Hobert, Dobrin Marchev

The data augmentation (DA) algorithm is a widely used Markov chain Monte Carlo (MCMC) algorithm that is based on a Markov transition density of the form $p(x|x&#39;)=\int_{\mathsf{Y}}f_{X|Y}(x|y)f_{Y|X}(y|x&#39;) dy$, where $f_{X|Y}$ and $f_{Y|X}$ are conditional densities. The PX-DA and marginal augmentation algorithms of Liu and Wu [J. Amer. Statist. Assoc

Surendra Singh, Saibal Basu, S. K. Ghosh

We present a detailed study of the interface morphology of an electro-deposited (ED) Ni/Cu bilayer film by using off-specular (diffuse) neutron reflectivity technique and Atomic Force Microscopy (AFM). The Ni/Cu bilayer has been electro-deposited on seed layers of Ti/Cu. These two seed layers were deposited by magnetron sputtering. The depth profile of densi

Hosho Katsura, Shigeki Onoda, Jung Hoon Han, Naoto Nagaosa

We study the quantum dynamics/fluctuation of the cycloidal helical magnet in terms of the Schwinger boson approach. In sharp contrast to the classical fluctuation, the quantum fluctuation is collinear in nature which gives rise to the collinear spin density wave state slightly above the helical cycloidal state as the temperature is lowered. Physical properti

Sahin Buyukdagli, Alexander V. Savin, Bambi Hu

We propose a new method for computing the temperature dependence of the heat capacity in complex molecular systems. The proposed scheme is based on the use of the Langevin equation with low frequency color noise. We obtain the temperature dependence of the correlation time of random noises, which enables to model the partial thermalization of high-frequency

Takayuki Morifuji

In this paper, we discuss relations among several invariants of 3-manifolds including Meyer&#39;s function, the eta-invariant, the von Neumann rho-invariant and the Casson invariant from the viewpoint of the mapping class group of a surface.

Mikko J. Alava, Lasse Laurson, Alessandro Vespignani, Stefano Zapperi

According to Pruessner and Peters [Phys. Rev. E {\bf 73}, 025106(R) (2006)], the finite size scaling exponents of the order parameter in sandpile models depend on the tuning of driving and dissipation rates with system size. We point out that the same is not true for {\em avalanches} in the slow driving limit.

J. Hashimoto, M. Tamura, R. Kandori, N. Kusakabe

We report the detection of eighteen infrared reflection nebulae (IRNe) in the $J$, $H$, & $Ks$ linear polarimetric observations of the NGC 6334 massive star-formation complex, of which 16 IRNe are new discoveries. Our images cover $\sim$180 square arcminutes, one of the widest near-infrared polarization data in star-formation regions so far. These IRNe are m

David J. P. Ellis, Anthony J. Bennett, Samuel J. Dewhurst, Christine A. Nicoll

We report the observation of a Purcell enhancement in the electroluminescence decay rate of a single quantum dot, embedded in a microcavity light-emitting-diode structure. Lateral confinement of the optical mode was achieved using an annulus of low-refractive-index aluminium oxide, formed by wet oxidation. The same layer acts as a current aperture, reducing

Ken&#39;ichiro Nakazato, Kohsuke Sumiyoshi, Shoichi Yamada

We construct an equation of state including the hadron-quark phase transition. The mixed phase is obtained by the Gibbs conditions for finite temperature. We adopt the equation of state based on the relativistic mean field theory for the hadronic phase taking into account pions. As for the quark phase, the MIT bag model of the deconfined 3-flavor strange qua

Luca Roversi

Weak affine light typing (WALT) assigns light affine linear formulae as types to a subset of lambda-terms of System F. WALT is poly-time sound: if a lambda-term M has type in WALT, M can be evaluated with a polynomial cost in the dimension of the derivation that gives it a type. The evaluation proceeds under any strategy of a rewriting relation which is a mi

Boris Skoric

We introduce a problem setting which we call ``the freedom fighters&#39; problem&#39;&#39;. It subtly differs from the prisoners&#39; problem. We propose a steganographic method that allows Alice and Bob to fool Wendy the warden in this setting. Their messages are hidden in encryption keys. The recipient has no prior knowledge of these keys, and has to crypt

Madalina Olteanu, Joseph Rynkiewicz

BIC criterion is widely used by the neural-network community for model selection tasks, although its convergence properties are not always theoretically established. In this paper we will focus on estimating the number of components in a mixture of multilayer perceptrons and proving the convergence of the BIC criterion in this frame. The penalized marginal-l

Igor Pak

The square peg problem asks whether every Jordan curve in the plane has four points which form a square. The problem has been resolved (positively) for various classes of curves, but remains open in full generality. We present two new direct proofs for the case of piecewise linear curves.

Xu Cao, Xi-Guo Lee

We study the near-threshold $η&#39;$ production mechanism in nucleon-nucleon and $πN$ collisions under the assumption that sub-threshold resonance $N^{*}(1535)$ is predominant. In an effective Lagrangian approach which gives a reasonable description to the $pN \to pN η$ and $πp \to p η$ reactions, it is found that t-channel $π$ exchange make the dominate con

T. Sako, T. Sekiguchi, M. Sasaki, K. Okajima

We have developed a wide-field mosaic CCD camera, MOA-cam3, mounted at the prime focus of the Microlensing Observations in Astrophysics (MOA) 1.8-m telescope. The camera consists of ten E2V CCD4482 chips, each having 2kx4k pixels, and covers a 2.2 deg^2 field of view with a single exposure. The optical system is well optimized to realize uniform image qualit

Satoshi Iso

The universal behavior of Hawking radiation is originated in the conformal symmetries of matter fields near the black hole horizon. We explain the origin of this universality based on (1) the gravitational anomaly and its higher-spin generalizations and (2) conformal transformation properties of fluxes.

Anne Ruiz, Nathalie Villa

The aim of this study is to compare two supervised classification methods on a crucial meteorological problem. The data consist of satellite measurements of cloud systems which are to be classified either in convective or non convective systems. Convective cloud systems correspond to lightning and detecting such systems is of main importance for thunderstorm

Jonathan L. Rosner

A panel discussion on scalar mesons was held with the participation of David Bugg, Yulia Kalashnikova, Keh-Fei Liu, Michael Scadron, the author, and members of the audience. Some introductory remarks are noted here.

Jonathan L. Rosner

Results on light scalar mesons in charmed particle decays studied by the CLEO Collaboration at the Cornell Electron Storage Ring are reviewed.

Yoshi Taniguchi

We present recent progress in searching for galaxies at redshift from z = 5 to z = 10. Wide-field and senstive surveys with 8m class telescopes have been providing more than several hundreds of star forming galaxies at z =5 - 7 that are probed in the optical window. These galaxies are used to study the early cosmic star formation activity as well as the earl

Yuqun Chen, Chanyan Zhong

In this paper, we generalize the Shirshov&#39;s Composition Lemma by replacing the monomial order for others. By using Groebner-Shirshov bases, the normal forms of HNN extension of a group and the alternating group are obtained.

Yuqun Chen

In this paper, by using the Groebner-Shirshov bases, we give characterizations of the Schreier extensions of groups when the group is presented by generators and relations. An algorithm to find the conditions of a group to be a Schreier extension is obtained. By introducing a special total order, we obtain the structure of the Schreier extension by an HNN gr

Thotsaporn ``Aek&#39;&#39; Thanatipanonda

We show the value of positions of the combinatorial game ``Toads and Frogs&#39;&#39;. We present new values of starting positions. Moreover, we discuss the values of all positions with exactly one $\Box, \regT^{a}\Box\Box \regF^{a}, \regT^{a} \Box \Box \Box \regF \regF \regF,\regT^{a}\Box\Box \regF^{b}$, $\regT^{a}\Box\Box\Box \regF^{b}$. At the end, we post

Yuqun Chen

An algebra $\cal{R}$ is called an extension of the algebra $M$ by $B$ if $M^2=0$, $M$ is an ideal of $\cal{R}$ and $\cal{R}$$/M\cong B$ as algebras. In this paper, by using the Gröbner-Shirshov bases, we characterize completely the extensions of $M$ by $B$. An algorithm to find the conditions of an algebra $A$ to be an extension of $M$ by $B$ is obtained.

Masaaki Harada, Akihiro Munemasa

Ternary self-dual codes have been classified for lengths up to 20. At length 24, a classification of only extremal self-dual codes is known. In this paper, we give a complete classification of ternary self-dual codes of length 24 using the classification of 24-dimensional odd unimodular lattices.

Urs Niesen, Devavrat Shah, Gregory Wornell

We consider the problem of lossy source coding with a mismatched distortion measure. That is, we investigate what distortion guarantees can be made with respect to distortion measure $\tildeρ$, for a source code designed such that it achieves distortion less than $D$ with respect to distortion measure $ρ$. We find a single-letter characterization of this mis

Michael Courtney

A method is presented for determining the initial conditions of classical orbits from the quantum spectra of the diamagnetic hydrogen atom. Each classical trajectory which is closed at the nucleus produces a sinusoidal fluctuation in the photoabsorption spectrum. The amplitude of each orbit&#39;s contribution appears in the Fourier transform of a spectrum co

Laurent Freidel

In this note we clarify the dictionary between pure quantum gravity on the bulk in the presence of a cosmological constant and a CFT on the boundary. We show for instance that there is a general correspondence between quantum gravity ``radial states&#39;&#39; and a pair of CFT&#39;s. Restricting to one CFT is argued to correspond to states possessing an asym

P. Palmeri, P. Quinet, C. Mendoza, M. A. Bautista

The HFR and AUTOSTRUCTURE atomic structure codes are used to compute complete data sets of level energies, wavelengths, A-values, and radiative and Auger widths for K-vacancy states of the Ne, Mg, Si, S, Ar, and Ca isonuclear sequences. Ions with electron number N>9 are treated for the first time. Detailed comparisons with previous measurements and theoretic

Shlomo Dado, Arnon Dar, A. De Rujula

We show that the properties of gamma ray burst 080319B and its afterglow are well reproduced by the cannonball model of long gamma ray bursts (GRBs). It was an ordinary GRB, produced by a jet of highly relativistic plasmoids (CBs), ejected in a core-collapse supernova (SN) and viewed, as some others before, particularly close to the CB-emission axis. It stil

J. E. Cieza Montalvo, Nelson V. Cortez, M. D. Tonasse

The SU(3)$_L\otimesU(1)_N$ electroweak model predicts new Higgs bosons beyond the one of the standard model. In this work we investigate the signature and production of doubly charged Higgs bosons in the $e^-e^+$ International Linear Collider and in the CERN Linear Collider. We compute the branching ratios for the doubly charged gauge bosons of the model.