January 2011 arXiv papers — page 16

Bernard d'Espagnat

Contrary to classical physics, which was strongly objective i.e. could be interpreted as a description of mind-independent reality, standard quantum mechanics (SQM) is only weakly objective, that is to say, its statements, though intersubjectively valid, still merely refer to operations of the mind. Essentially, in fact, they are predictive of observations.

Miklos Långvik, Tapio Salminen, Anca Tureanu

We investigate the validity of the Dirac Quantization Condition (DQC) for magnetic monopoles in noncommutative space-time. We use an approach which is based on an extension of the method introduced by Wu and Yang. To study the effects of noncommutativity of space-time, we consider the gauge transformations of $U_\star(1)$ gauge fields and use the correspondi

Claudia Pinzari

We give local upper and lower bounds for the eigenvalues of the modular operator associated to an ergodic action of a compact quantum group on a unital C*-algebra. They involve the modular theory of the quantum group and the growth rate of quantum dimensions of its representations and they become sharp if other integral invariants grow subexponentially. For

I. Rushkin, A. Ossipov, Y. V. Fyodorov

We calculate perturbatively the multifractality spectrum of wave-functions in critical random matrix ensembles in the regime of weak multifractality. We show that in the leading order the spectrum is universal, while the higher order corrections are model-specific. Explicit results for the anomalous dimensions are derived in the power-law and ultrametric ran

Michael Elkin, Ingemar Andre, David B. Lukatsky

Understanding design principles of biomolecular recognition is a key question of molecular biology. Yet the enormous complexity and diversity of biological molecules hamper the efforts to gain a predictive ability for the free energy of protein-protein, protein-DNA, and protein-RNA binding. Here, using a variant of the Derrida model, we predict that for a la

Zhi-Gang Wang

In this article, we study the vector meson transitions among the charmonium and bottomonium states with the heavy quark effective theory in an systematic way, and make predictions for the ratios among the vector meson decay widths of a special multiplet to another multiplet. The predictions can be confronted with the experimental data in the future.

Alexandru D. Ionescu, Benoit Pausader

In this paper we prove global well-posedness in $H^1$ for the energy-critical defocusing initial-value problem \begin{equation*} (i\partial_t+Δ_x)u=u|u|^2,\qquad u(0)=ϕ, \end{equation*} in the semiperiodic setting $x\in\R\times\T^3$.

J. Nahas

We use Reznick's Theorem for positive homogeneous polynomials to prove an elliptic regularity result for representations of enveloping algebras of Lie algebras. This allows us to relax a technical condition for a sum of squares decomposition for representations of these algebras.

Mathieu Feuillet, Matthieu Jonckheere, Balakrishna J. Prabhu

In multi-class communication networks, traffic surges due to one class of users can significantly degrade the performance for other classes. During these transient periods, it is thus of crucial importance to implement priority mechanisms that conserve the quality of service experienced by the affected classes, while ensuring that the temporarily unstable cl

Loredana Spezzi, Giacomo Beccari, Guido De Marchi, Erick T. Young

We use near-infrared data obtained with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope to identify objects having the colors of brown dwarfs (BDs) in the field of the massive galactic cluster NGC 3603. These are identified through use of a combination of narrow and medium band filters spanning the J and H bands, and which are particularly sensi

Alessandro B. Romeo, Joachim Wiegert

The Wang-Silk approximation, 1/Q ~ 1/Q_stars + 1/Q_gas, is frequently used for estimating the effective Q parameter in two-component discs of stars and gas. Here we analyse this approximation in detail, and show how its accuracy depends on the radial velocity dispersions and Toomre parameters of the two components. We then propose a much more accurate but st

N. L. Chuprikov

By probability theory the probability space to underlie the set of statistical data described by the squared modulus of a coherent superposition of microscopically distinct (sub)states (CSMDS) is non-Kolmogorovian and, thus, such data are mutually incompatible. For us this fact means that the squared modulus of a CSMDS cannot be unambiguously interpreted as

Hiroshi Iritani

In a previous paper, the author introduced a Z-structure in quantum cohomology defined by the K-theory and the Gamma class and showed that it is compatible with mirror symmetry for toric orbifolds. Applying the quantum Lefschetz principle to the previous results, we find an explicit relationship between solutions to the quantum differential equation for tori

Kerem Ege, Antoine Chaigne

The end conditions of piano strings can be approximated by the input admittance at the bridge. Proper measurements of this value are therefore required. A method of validation of admittance measurements on simple structures is proposed in this paper. High resolution signal analysis performed on string vibrations yields an estimate for the input admittance. T

Stephan Mandt, Akos Rapp, Achim Rosch

We consider a cloud of fermionic atoms in an optical lattice described by a Hubbard model with an additional linear potential. While homogeneous interacting systems mainly show damped Bloch oscillations and heating, a finite cloud behaves differently: It expands symmetrically such that gains of potential energy at the top are compensated by losses at the bot

Francesco Calabrese, Zbigniew Smoreda, Vincent D. Blondel, Carlo Ratti

In this study we analyze one year of anonymized telecommunications data for over one million customers from a large European cellphone operator, and we investigate the relationship between people's calls and their physical location. We discover that more than 90% of users who have called each other have also shared the same space (cell tower), even if th

Matthieu Deneufchâtel, Gérard Henry Edmond Duchamp, Vincel Hoang Ngoc Minh, Allan I. Solomon

We obtain a necessary and sufficient condition for the linear independence of solutions of differential equations for hyperlogarithms. The key fact is that the multiplier (i.e. the factor $M$ in the differential equation $dS=MS$) has only singularities of first order (Fuchsian-type equations) and this implies that they freely span a space which contains no p

M. Agnello, L. Benussi, M. Bertani, H. C. Bhang

A direct experimental evidence of the occurrence of the weak reaction $Λnp\rightarrow nnp$ in nuclei has been obtained by the FINUDA experiment. Three events have been found that can be attributed to $^{7}_Λ$Li and $^{9}_Λ$Be two nucleon-induced non mesonic weak decays. The kinematic analysis of such events is presented here.

Alexander Fel'shtyn

The main theme of this paper is to study for a symplectomorphism of a compact surface, the asymptotic invariant which is defined to be the growth rate of the sequence of the total dimensions of symplectic Floer homologies of the iterates of the symplectomorphism. We prove that the asymptotic invariant coincides with asymptotic Nielsen number and with asympto

Wolung Lee, Kin-Wang Ng, I-Chin Wang, Chun-Hsien Wu

We develop a Lagrangian approach based on the influence functional method so as to derive self-consistently the Langevin equation for the inflaton field in the presence of trapping points along the inflaton trajectory. The Langevin equation exhibits the backreaction and the fluctuation-dissipation relation of the trapping. The fluctuation is induced by a mul

Christophe Paul, Anthony Perez, Stéphan Thomassé

We develop a technique that we call Conflict Packing in the context of kernelization, obtaining (and improving) several polynomial kernels for editing problems on dense instances. We apply this technique on several well-studied problems: Feedback Arc Set in (Bipartite) Tournaments, Dense Rooted Triplet Inconsistency and Betweenness in Tournaments. For the fo

Leonhard Lücken, Serhiy Yanchuk

The subject of this paper is a system of phase-oscillators, which are globally pulse-coupled via excitatory interaction. The appearance and stability of one- and two-cluster-states is investigated for a family of unimodal phase-response-curves (PRC). The PRCs and their derivatives are assumed to be zero at the spiking point. We show that there exist stable h

Moon Ho Lee, Ying Guo

The partial interference cancellation (PIC) group decoding has recently been proposed to deal with the decoding complexity and code rate trade-off on the basis of space-time block code (STBC) design criterion when full diversity is achieved. It provides a framework to arrange the rate-complexity-performance tradeoff by choosing a suitable size of information

Drazen Adamovic, Ozren Perse

We give a general criterion for conformal embeddings of vertex operator algebras associated to affine Lie algebras at arbitrary levels. Using that criterion, we construct new conformal embeddings at admissible rational and negative integer levels. In particular, we construct all remaining conformal embeddings associated to automorphisms of Dynkin diagrams of

Lukas Katthän

Let Δbe a (d-1)-dimensional homology sphere on n vertices with m minimal non-faces. We consider the invariant α:= m - (n-d) and prove that for a given value of α, there are only finitely many homology spheres that cannot be obtained through one-point suspension and suspension from another. Moreover, we describe all homology spheres with αup to four and, as a

Jozsef Garai

The fundamental organizing principle resulting in the periodic table is the nuclear charge. Arranging the chemical elements in an increasing atomic number order, a symmetry pattern known as the Periodic Table is detectable. The correlation between nuclear charge and the Periodic System of the Chemical Elements (PSCE) indicates that the symmetry emerges from

Salam Akoum, Marios Kountouris, Robert W. Heath

Heterogeneous networks are a flexible deployment model that rely on low power nodes to improve the user broadband experience in a cost effective manner. Femtocells are an integral part of heterogeneous networks, whose main purpose is to improve the indoor capacity. When restricting access to home users, femtocells cause a substantial interference problem tha

Benedikt Bollig

We develop a general framework for the specification and implementation of systems whose executions are words, or partial orders, over an infinite alphabet. As a model of an implementation, we introduce class register automata, a one-way automata model over words with multiple data values. Our model combines register automata and class memory automata. It ha

The Pierre Auger Collaboration, P. Abreu, M. Aglietta, E. J. Ahn

The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful framework for the analysis of radio measurements of cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air shower radio emission in coincidence with the surface particle detectors and fluorescence telescopes of the Pierre Auger Obser

A. I. Ahmadov, Yu. M. Bystritskiy, E. A. Kuraev

Differential cross section of processes with high energy $p(\bar p)p$ collisions in frames of QED: creation of scalar, pseudoscalar and lepton pair - are considered in Weizsäcker - Williams approximation. In frames of QCD processes with conversion of initial proton (antiproton) to fermionic jets accompanied with one gluon jet as well as the state of two gluo

Nicolas Gauvrit, Jean-Paul Delahaye, Hector Zenil

The Online Encyclopedia of Integer Sequences (OEIS) is made up of thousands of numerical sequences considered particularly interesting by some mathematicians. The graphic representation of the frequency with which a number n as a function of n appears in that database shows that the underlying function decreases fast, and that the points are distributed in a

Neli I. Stoilova, Joris Van der Jeugt

We study a linear spin chain which was originally introduced by Shi et al. [Phys. Rev. A 71 (2005), 032309, 5 pages], for which the coupling strength contains a parameter $α$ and depends on the parity of the chain site. Extending the model by a second parameter $β$, it is shown that the single fermion eigenstates of the Hamiltonian can be computed in explici

Simon Kuttruf, Peter Müller

We prove that the homogeneous hierarchical Anderson model exhibits a Lifshits tail at the upper edge of its spectrum. The Lifshits exponent is given in terms of the spectral dimension of the homogeneous hierarchical structure. Our approach is based on Dirichlet-Neumann bracketing for the hierarchical Laplacian and a large-deviation argument.

Marie Piraud, Pierre Lugan, Philippe Bouyer, Alain Aspect

We theoretically study the Anderson localization of a matter wave packet in a one-dimensional disordered potential. We develop an analytical model which includes the initial phase-space density of the matter wave and the spectral broadening induced by the disorder. Our approach predicts a behavior of the localized density profile significantly more complex t

Shigenori Matsumoto

Given any Liouville number $α$, it is shown that the nullity of the Hausdorff dimension of the invariant measure is generic in the space of the orientation preserving $C^\infty$ diffeomorphisms of the circle with rotation number $α$.

Yi Zhou, Dong-Hui Xu, Fu-Chun Zhang, Wei-Qiang Chen

Possible superconductivity in recently discovered (Tl,K)Fe$_x$Se$_2$ compounds is studied from the viewpoint of doped Mott insulator. The Mott insulating phase is examined to be preferred in the parent compound at $x=1.5$ due to the presence of Fe vacancies. Partial filling of vacancies at the Fe-sites introduces electron carriers and leads to electron doped

Kwai-Kong Ng, Min-Fong Yang

By means of quantum Monte Carlo simulations implemented with a two-loop update scheme, the finite-temperature phase diagram of a three-body constrained attractive Bose lattice gas is investigated. The nature of the thermal phase transitions around the dimer superfluid and the atomic superfluid is unveiled. We find that the $Z_2$ symmetry-breaking transitions

Otis Chodosh

We characterize the action of isotropic pseudodifferential operators on functions in terms of their action on Hermite functions. We show that an operator $A : S(\mathbb{R}) \to S(\mathbb{R})$ is an isotropic pseudodifferential operator of order r if and only if its &#34;matrix&#34; $(K(A))_{m,n} := < Aϕ_n,ϕ_m>_{L^2(\mathbb{R})}$ is rapidly decreasing away fr

Qun Mo, Yi Shen

This paper demonstrates theoretically that if the restricted isometry constant $δ_K$ of the compressed sensing matrix satisfies $$ δ_{K+1} < \frac{1}{\sqrt{K}+1}, $$ then a greedy algorithm called Orthogonal Matching Pursuit (OMP) can recover a signal with $K$ nonzero entries in $K$ iterations. In contrast, matrices are also constructed with restricted isome

Junjie Cao, Lin Wang, Lei Wu, Jin Min Yang

The anomaly of the top quark forward-backward asymmetry $A^t_{FB}$ observed at the Tevatron can be explained by the t-channel exchange of a neutral gauge boson (Z&#39;) which has sizable flavor changing coupling for top and up quarks. This gauge boson can also induce the top quark flavor-changing neutral-current (FCNC) decays and the like-sign top pair produ

Li-Ming Cao, Oleg Evnin, Nobuyoshi Ohta

We describe a large class of solutions in pure gravity, dilaton gravity and supergravity corresponding to extended higher-dimensional black holes with strong (non-linear) gravitational waves propagating along their worldvolume. For pure gravity, the extended black holes are higher-dimensional analogs of the point-like Schwarzschild black hole in four dimensi

Adrian Röllin

Let $h$ be a three times partially differentiable function on $R^n$, let $X=(X_1,\dots,X_n)$ be a collection of real-valued random variables and let $Z=(Z_1,\dots,Z_n)$ be a multivariate Gaussian vector. In this article, we develop Stein&#39;s method to give error bounds on the difference $E h(X) - E h(Z)$ in cases where the coordinates of $X$ are not necess

Bon-Chul Koo, Christopher F. McKee, Kyung-Won Suh, Dae-Sik Moon

We report new mid-infrared observations of the remarkable object IRAS 15099-5856 using the space telescopes AKARI and Spitzer, which demonstrate the presence of prominent crystalline silicate emission in this bright source. IRAS 15099-5856 has a complex morphology with a bright central compact source (IRS1) surrounded by knots, spurs, and several extended (~

Li Yu

We define a notion of facets-pairing structure and its seal space on a nice manifold with corners. We will study facets-pairing structures on any cube in detail and investigate when the seal space of a facets-pairing structure on a cube is a closed manifold. In particular, for any binary square matrix $A$ with zero diagonal in dimension n, there is a canonic

Yu Ding

An orbifold $X$ is locally homeomorphic to $G_x\backslash B_r(0)$, where $G_x$ is a finite group acting on $B_r(0)\subset{\mathbb R}^n$, so that $G_x(0)=0$. For collapsing orbifolds with isolated singularities, we show there is a uniform bound in $|G_x|$.

Lenny Fukshansky, Kathleen Petersen

We investigate a connection between two important classes of Euclidean lattices: well-rounded and ideal lattices. A lattice of full rank in a Euclidean space is called well-rounded if its set of minimal vectors spans the whole space. We consider lattices coming from full rings of integers in number fields, proving that only cyclotomic fields give rise to wel

Guohui Song, Haizhang Zhang

A typical approach in estimating the learning rate of a regularized learning scheme is to bound the approximation error by the sum of the sampling error, the hypothesis error and the regularization error. Using a reproducing kernel space that satisfies the linear representer theorem brings the advantage of discarding the hypothesis error from the sum automat

Fang Qin, Ji-sheng Chen

The analytical expressions of the Joule-Thomson coefficient for homogeneous and harmonically trapped three-dimensional ideal anyons which obey Haldane fractional exclusion statistics are derived. For an ideal Fermi gas, the Joule-Thomson coefficient is negative, which means that there is no maximum Joule-Thomson inversion temperature. With careful study, it

Masaru Ikehata

The aim of this paper is to establish the framework of the enclosure method for some class of inverse problems whose governing equations are given by parabolic equations with discontinuous coefficients. The framework is given by considering a concrete inverse initial boundary value problem for a parabolic equation with discontinuous coefficients. The problem

Edwin Barnes, Sophia E. Economou

We introduce a method for solving the problem of an externally controlled electron spin in a quantum dot interacting with host nuclei via the hyperfine interaction. Our method accounts for generalized (non-unitary) evolution effected by external controls and the environment, such as coherent lasers combined with spontaneous emission. As a concrete example we

Wesley Pegden

We construct dense, triangle-free, chromatic-critical graphs of chromatic number $k$ for all $k\geq 4$. For $k\geq 6$ our constructions have $> (\frac{1}{4} -\varepsilon)n^2$ edges, which is asymptotically best possible by Turán&#39;s theorem. We also demonstrate (nonconstructively) the existence of dense $k$-critical graphs avoiding all odd cycles of length

Grenville J. Croll

Regarding some papers and notes submitted to, or presented at, the second congress of the International Torah Codes Society in Jerusalem, Israel, June 2000.

T. Kim, J. Choi, Y. H. Kim, C. S. Ryoo

In this paper, we investigate the properties of q-Hermite polynomials related to q-Bernstein polynomials. From these properties, we derive some interesting relations between q-Berstein polynomials and q-Hermite polynomials.

Alexander E. Holroyd

Peres and Winkler proved a &#34;censoring&#34; inequality for Glauber dynamics on monotone spins systems such as the Ising model. Specifically, if, starting from a constant-spin configuration, the spins are updated at some sequence of sites, then inserting another site into this sequence brings the resulting configuration closer in total variation to the sta

Heinz H. Bauschke, Sarah M. Moffat, Xianfu Wang

The notion of a firmly nonexpansive mapping is central in fixed point theory because of attractive convergence properties for iterates and the correspondence with maximal monotone operators due to Minty. In this paper, we systematically analyze the relationship between properties of firmly nonexpansive mappings and associated maximal monotone operators. Dual

Jim Geelen, Geoff Whittle

It is proved that for each prime field $GF(p)$, there is an integer $f(p)$ such that a 4-connected matroid has at most $f(p)$ inequivalent representations over $GF(p)$. We also prove a stronger theorem that obtains the same conclusion for matroids satisfying a connectivity condition, intermediate between 3-connectivity and 4-connectivity that we term &#34;$k

Francis N. Castro, Luis A. Medina

In this paper we give an improvement of the degree of the homogeneous linear recurrence with integer coefficients that exponential sums of symmetric Boolean functions satisfy. This improvement is tight. We also compute the asymptotic behavior of symmetric Boolean functions and provide a formula that allows us to determine if a symmetric boolean function is a

Ion Spanulescu, Ion Popescu, Victor Stoica, Anca Gheorghiu

In this paper we present an econophysic model for the description of shares transactions in a capital market. For introducing the fundamentals of this model we used an analogy between the electrical field produced by a system of charges and the overall of economic and financial information of the shares transactions from the stock-markets. An energetic appro

Alexander L. Dmitriev

Results of measurements of free falling acceleration of a closed container with a rotor of a mechanical gyroscope placed inside it on the frequency of the rotor rotation are briefly described. Time of separate accelerations measurements is 40 ms, the period of sampling is from 0.5 up to 1.0 minute. In rotation&#39;s frequencies range of 20-400 Hz, the negati

Deqi Wang, Jing Shi

In graphene devices with a varying degree of disorders as characterized by their carrier mobility and minimum conductivity, we have studied the thermoelectric power along with the electrical conductivity over a wide range of temperatures. We have found that the Mott relation fails in the vicinity of the Dirac point in high-mobility graphene. By properly taki

Anca Gheorghiu, Ion Spanulescu, Anda Gheorghiu

In this paper will be applied some principles and methods from econophysics in the case of the direct foreign investitions (D.F.I.), particularised for the Greenfield type, and mixed firms of trade and industrial production (Joint Ventures). To this aim will be used some similarities and parallelisms between the mentioned economic domains and some phenomena

Anca Gheorghiu, Ion Spânulescu

In this paper are made some considerations of the application of phenomenological thermodynamics in risk analysis for the transaction on financial markets, using the concept of economic entropy and the macrostate parameter introduced by us in a previous works [15,16]. The investment risk diagrams for a number of Romanian listed companies in 2008 and 2009 yea

Nicola Ferralis, Roya Maboudian, Carlo Carraro

The temperature-induced shift of the Raman G line in epitaxial graphene on SiC and Ni surfaces, as well as in graphene supported on SiO2, is investigated with Raman spectroscopy. The thermal shift rate of epitaxial graphene on 6H-SiC(0001) is found to be about three times that of freestanding graphene. This result is explained quantitatively as a consequence

E. M. Levenson-Falk, R. Vijay, I. Siddiqi

We present the driven response at T=30mK of 6 GHz superconducting resonators constructed from capacitively-shunted three dimensional (3D) aluminum nanobridge superconducting quantum interference devices (nanoSQUIDs). We observe flux modulation of the resonant frequency in quantitative agreement with numerical calculation and characteristic of near-ideal shor

Edmund R. Meyer, John L. Bohn

We present a theoretical investigation of the chemical reaction SrF + SrF $\rightarrow$ products, focusing on reactions at ultralow temperatures. We find that bond swapping, SrF + SrF $\rightarrow$ Sr$_2$ + F$_2$, is energetically forbidden at these temperatures. Rather, the only energetically allowed reaction is SrF + SrF $\rightarrow$ SrF$_2$ + Sr, and eve

Bruny Baret, Imre Bartos, Boutayeb Bouhou, Alessandra Corsi

We derive a conservative coincidence time window for joint searches of gravita-tional-wave (GW) transients and high-energy neutrinos (HENs, with energies above 100GeV), emitted by gamma-ray bursts (GRBs). The last are among the most interesting astrophysical sources for coincident detections with current and near-future detectors. We take into account a broa

Adrian Dumitrescu, Minghui Jiang

Given a convex region in the plane, and a sweep-line as a tool, what is best way to reduce the region to a single point by a sequence of sweeps? The problem of sweeping points by orthogonal sweeps was first studied in [2]. Here we consider the following \emph{slanted} variant of sweeping recently introduced in [1]: In a single sweep, the sweep-line is placed

David Lafrenière, Ray Jayawardhana, Markus Janson, Christiane Helling

We present the discovery of a substellar companion on a wide orbit around the ~2.5 Msun star HIP 78530, which is a member of the 5 Myr-old Upper Scorpius association. We have obtained follow-up imaging over two years and show that the companion and primary share common proper motion. We have also obtained JHK spectroscopy of the companion and confirm its low

Ehud Behar, Shlomo Dado, Arnon Dar, Ari laor

Observations with the Swift satellite of X-ray afterglows of more than a hundred gamma ray bursts (GRBs) with known redshift reveal ubiquitous soft X-ray absorption. The directly measured optical depth τat a given observed energy is found to be constant on average at redshift z > 2, i.e., <τ(0.5 keV) >_{z > 2} = 0.40+/- 0.02. Such an asymptotic optical depth

S. P. Flego, A. Plastino, A. R. Plastino

By recourse to i) the Hellmann-Feynman theorem and ii) the Virial one, the information-optimizing principle based on Fisher&#39;s information measure uncovers a Legendre-transform structure associated with Schrödinger&#39;s equation, in close analogy with the structure that lies behind the standard thermodynamical formalism. The present developments provide

H. Chen, W. Huo

We study the contributions to the branching ratios of $B_{s(d)}\to γγ$ decay in the sequential fourth generation model (SM4). We find that the theoretical values of the branching ratios, ${\rm BR}(B_{s(d)}\toγγ)$, including the contributions of $m_{t&#39;}$ and the new $4 \times 4$ CKM (CKM4) matrix factors, $|V^{*}_{t&#39;s}V_{t&#39;b}|$ and $|V^{*}_{t&#39;

Matthew J. Samuel

A monoid $M$ generated by a set $S$ of symbols can be described as the set of equivalence classes of finite words in $S$ under some relations that specify when some contiguous sequence of symbols can be replaced by another. If $a,b\in S$, a relation of the form $ab=ba$ is said to be a \emph{commutation relation}. Words that are equivalent using only a sequen

C. Battersby, J. Bally, A. Ginsburg, J. -P. Bernard

Context: Despite their profound effect on the universe, the formation of massive stars and stellar clusters remains elusive. In the past decade, compelling evidence has emerged that suggests Infrared Dark Clouds (IRDCs) may be precursors to stellar clusters. However, the usual method for identifying IRDCs is biased by the requirement that they are seen in ab

J. P. Stott, C. A. Collins, C. Burke, V. Hamilton-Morris

Recent reports suggest that elliptical galaxies have increased their size dramatically over the last ~8 Gyr. This result points to a major re-think of the processes dominating the latetime evolution of galaxies. In this paper we present the first estimates for the scale sizes of brightest cluster galaxies (BCGs) in the redshift range 0.8 < z < 1.3 from an an

John Kormendy, Ralf Bender

Supermassive black holes have been detected in all galaxies that contain bulge components when the galaxies observed were close enough so that the searches were feasible. Together with the observation that bigger black holes live in bigger bulges, this has led to the belief that black hole growth and bulge formation regulate each other. That is, black holes

William Fischer, Suzan Edwards, Lynne Hillenbrand, John Kwan

We present the first characterization of the excess continuum emission of accreting T Tauri stars between optical and near-infrared wavelengths. With nearly simultaneous spectra from 0.48 to 2.4 microns acquired with HIRES and NIRSPEC on Keck and SpeX on the IRTF, we find significant excess continuum emission throughout this region, including the I, Y, and J

I. Zhuravleva

We discuss various possibilities to constrain ICM turbulence in galaxy clusters using bright X-ray lines. Numerical simulations are used to find the most appropriate description of the 3D velocity field power spectrum (PDS) and to calibrate the relation of observables to this PDS. The impact of the velocity field on the surface brightness distribution and on

Dmitri Vassilevich

We give a nontechnical introduction to the problem of non-uniqueness of star products and describe a covariant resolution of this problem. Some implications (e.g., for noncommutative gravity) and further prospects are discussed.

Kyle N. Crabtree, Nick Indriolo, Holger Kreckel, Brian A. Tom

The excitation temperature T_01 derived from the relative intensities of the J = 0 (para) and J = 1 (ortho) rotational levels of H2 has been assumed to be an accurate measure of the kinetic temperature in interstellar environments. In diffuse molecular clouds, the average value of T_01 is ~70 K. However, the excitation temperature T(H3+) derived from the (J,

Serguei A. Mokhov, Marc-André Laverdière, Ali Benssam, Djamel Benredjem

We report on the software engineering design and implementation of an web- and LDAP-based secure file exchange system with bi-directional authentication of all parties involved in the process that is the user&#39;s browsers and the application server mutually authenticate, and the application and database servers authenticate using certificates, credentials,

D. H. Santamore, Eddy Timmermans

Ultra-cold alkali atoms trapped in two distinct hyperfine states in an external magnetic field can mimic magnetic systems of spin 1/2 particles. We describe the spin-dependent effective interaction as a spin-spin interaction. As a consequence of the zero-range, the interaction of spin 1/2 bosons can be described as an Ising or, alternatively, as an XY-coupli

David Koslicki

Topological entropy has been one of the most difficult to implement of all the entropy-theoretic notions. This is primarily due to finite sample effects and high-dimensionality problems. In particular, topological entropy has been implemented in previous literature to conclude that entropy of exons is higher than of introns, thus implying that exons are more

Thomas B. Bahder

Numerous quantum mechanical schemes have been proposed that are intended to improve the sensitivity to rotation provided by the classical Sagnac effect in gyroscopes. A general metric is needed that can compare the performance of the new quantum systems with the classical systems. The fidelity (Shannon mutual information between the measurement and the rotat

Serguei A. Mokhov, Marc-André Laverdière, Ali Benssam, Djamel Benredjem

This document presents brief software specification of a secure file exchange system prototype involving mutual authentication of the users via their browser and the application server with PKI-based certificates as credentials, the use of LDAP for credential management, and authentication between the application and database servers to maintain a high level

C. J. Burnham, G. F. Reiter, T. Hayashi, S. Mukamel

Water is often viewed as a collection of monomers interacting electrostatically with each other. We compare the water proton momentum distributions from recent neutron scattering data with those calculated from two electronic structure based models. We find that below 500 K the electrostatic models are not able to even qualitatively account for the sizable v

J. Bagchi, R. J. van Weeren, S. Raychaudhury, H. J. A. Rottgering

Deep X-ray data from CHANDRA and XMM-Newton, and GMRT radio data are presented for ZwCl 2341.1+0000, an extremely unusual and complex merging cluster of galaxies at the intersection of optical filaments. We propose that energetics of multiple mergers and accretion flows has resulted in wide-spread shocks, acceleration of cosmic ray particles and amplificatio

Banibrata Mukhopadhyay

The neutrino propagating in curved spacetimes, e.g. around black holes, in early curved universe, violates Lorentz and then CPT symmetry, at least in the local coordinate. This occurs due to coupling of spin of the neutrino to background spin connection which modifies the underlying dispersion relation. This results in the neutrino asymmetry and hence as a c

Banibrata Mukhopadhyay

We model two temperature viscous accretion flows in the sub-Keplerian, optically thin, regime around rotating black holes including important radiation effects self-consistently. The model successfully explains observed luminosities from ultra-luminous to under-luminous sources and predicts the spin parameter of black holes.

Igor I. Smolyaninov

Optical space in electromagnetic metamaterials may be engineered to emulate various exotic space-time geometries. However, these metamaterial models are limited in many respects. It is believed that real physical space-time strongly fluctuates on the Planck scale. These fluctuations are usually described as virtual black holes. Static metamaterial models int

Anthony G. O&#39;Farrell

This article is based on a talk given at a one-day meeting in NUI, Maynooth on the Fourth of April, 2008, held to honour David Walsh and Richard Watson. It surveys joint work with the author.

Daniel Pinto

Duality is the operation that interchanges hypervertices and hyperfaces on oriented hypermaps. The duality index measures how far a hypermap is from being self-dual. We say that an oriented regular hypermap has \emph{duality-type} $\{l,n\}$ if $l$ is the valency of its vertices and $n$ is the valency of its faces. Here, we study some properties of this duali

T. Driscoll, Y. V. Pershin, D. N. Basov, M. Di Ventra

We suggest and experimentally demonstrate a chaotic memory resistor (memristor). The core of our approach is to use a resistive system whose equations of motion for its internal state variables are similar to those describing a particle in a multi-well potential. Using a memristor emulator, the chaotic memristor is realized and its chaotic properties are mea

Cihan Tepedelenlioglu, Adithya Rajan, Yuan Zhang

Stochastic orders are binary relations defined on probability distributions which capture intuitive notions like being larger or being more variable. This paper introduces stochastic ordering of instantaneous SNRs of fading channels as a tool to compare the performance of communication systems over different channels. Stochastic orders unify existing perform

Angelo Bella, Mikhail Matveev, Santi Spadaro

A space $X$ is called selectively separable(R-separable) if for every sequence of dense subspaces $(D_n : n\inω)$ one can pick finite (respectively, one-point) subsets $F_n\subset D_n$ such that $\bigcup_{n\inω}F_n$ is dense in $X$. These properties are much stronger than separability, but are equivalent to it in the presence of certain convergence propertie

Banibrata Mukhopadhyay, Kanak Saha

The origin of hydrodynamic turbulence in rotating shear flow is a long standing puzzle. Resolving it is especially important in astrophysics when the flow angular momentum profile is Keplerian which forms an accretion disk having negligible molecular viscosity. Hence, any viscosity in such systems must be due to turbulence, arguably governed by magnetorotati

Banibrata Mukhopadhyay, Ranchu Mathew, Soumyendu Raha

Rotating shear flows, when angular momentum increases and angular velocity decreases as functions of radiation coordinate, are hydrodynamically stable under linear perturbation. The Keplerian flow is an example of such systems which appears in astrophysical context. Although decaying eigenmodes exhibit large transient energy growth of perturbation which coul

Wicher Bergsma

We propose a new method to test conditional independence of two real random variables $Y$ and $Z$ conditionally on an arbitrary third random variable $X$. %with $F_{.|.}$ representing conditional distribution functions, The partial copula is introduced, defined as the joint distribution of $U=F_{Y|X}(Y|X)$ and $V=F_{Z|X}(Z|X)$. We call this transformation of

Ritabrata Biswas, Subenoy Chakraborty, Tarun Deep Saini, Banibrata Mukhopadhyay

We study the accretion of modified Chaplygin gas upon different types of black hole. Modified Chaplygin gas is one of the best candidates for a combined model of dark matter and dark energy. In addition, from a field theoretical point of view the modified Chaplygin gas model is equivalent to that of a scalar field having a self-interacting potential. We form

Heinrich Hartmann

We study in detail mirror symmetry for the quartic K3 surface in P3 and the mirror family obtained by the orbifold construction. As explained by Aspinwall and Morrison, mirror symmetry for K3 surfaces can be entirely described in terms of Hodge structures. (1) We give an explicit computation of the Hodge structures and period maps for these families of K3 su

J. O. Sofo, A. M. Suarez, Gonzalo Usaj, P. S. Cornaglia

We study the electronic structure of diluted F atoms chemisorbed on graphene using density functional theory calculations. We show that the nature of the chemical bonding of a F atom adsorbed on top of a C atom in graphene strongly depends on carrier doping. In neutral samples the F impurities induce a sp^3-like bonding of the C atom below, generating a loca