Research archive
arXiv papers from October 2009
The most recent 100 records published that month. Open any paper for its original abstract, citation metadata, related research, and reading tools.
Mei Yin
The renormalization group (RG) approach is largely responsible for the considerable success that has been achieved in developing a quantitative theory of phase transitions. Physical properties emerge from spectral properties of the linearization of the RG map at a fixed point. This article considers RG for classical Ising-type lattice systems. The linearizat
Andrzej Okninski
Discrete time dynamics on the SU(1,1) group is studied. It is shown that a map acting in the dual space is the stroboscopic map for a SU(1,1) Bloch equation. Exact solution of the map is used to elucidate the corresponding dynamics. It is shown that dynamics of the SU(1,1) Bloch equation in the elliptic case bears close analogy to the SU(2) Bloch dynamics.
Ian Pratt-Hartmann, Ivo Düntsch
A "numerical set-expression" is a term specifying a cascade of arithmetic and logical operations to be performed on sets of non-negative integers. If these operations are confined to the usual Boolean operations together with the result of lifting addition to the level of sets, we speak of "additive circuits". If they are confined to the usual Boolean operat
- Streamwise oscillation of spanwise velocity at the wall of a channel for turbulent drag reductionphysics.flu-dyn
Claudio Viotti, Maurizio Quadrio, Paolo Luchini
Steady forcing at the wall of a channel flow is studied via DNS to assess its ability of yielding reductions of turbulent friction drag. The wall forcing consists of a stationary distribution of spanwise velocity that alternates in the streamwise direction. The idea behind the forcing builds upon the existing technique of the spanwise wall oscillation, and e
Ljudmila A. Bordag
Families of exact solutions are found to a nonlinear modification of the Black-Scholes equation. This risk-adjusted pricing methodology model (RAPM) incorporates both transaction costs and the risk from a volatile portfolio. Using the Lie group analysis we obtain the Lie algebra admitted by the RAPM equation. It gives us the possibility to describe an optima
Nikos Bagis
In this note we solve theoretically the Schrodingers differential equation using results based on our previous work which concern semigroup operators. Our method does not use eigenvectors or eigenvalues and the solution depends only from the selected base of the Hilbert space.
Sergei K. Suslov
We show that the diagonal matrix elements $< Or^{p} >,$ where $O$ $={1,\beta,i\mathbf{\alpha n}\beta}$ are the standard Dirac matrix operators and the angular brackets denote the quantum-mechanical average for the relativistic Coulomb problem, may be considered as difference analogs of the radial wave functions. Such structure provides an independent way of
V. Majernik, S. Shpyrko
In this article we exploit the Bhattacharyya statistical divergence to determine the similarity of probability distributions of quantum observables. After brief review of useful characteristics of the Bhattacharyya divergence we apply it to determine the similarity of probability distributions of two non-commuting observables. An explicit expression for the
Paweł J. Szabłowski
We define and study distributions in R^{d} that we call q-Normal. For q=1 they are really multidimensional Normal, for q\in(-1,1) they have densities, compact support and many properties that resemble properties of ordinary multidimensional Normal distribution. We also consider some generalizations of these distributions and indicate close relationship of th
M. V. Bondarenco
For volume reflection process in a bent crystal, exact analytic expressions for positively- and negatively-charged particle trajectories are obtained within a model of parabolic continuous potential in each interplanar interval, with the neglect of incoherent multiple scattering. In the limit of the crystal bending radius greatly exceeding the critical value
Yaming Yu
A fast new algorithm is proposed for numerical computation of (approximate) D-optimal designs. This "cocktail algorithm" extends the well-known vertex direction method (VDM; Fedorov 1972) and the multiplicative algorithm (Silvey, Titterington and Torsney, 1978), and shares their simplicity and monotonic convergence properties. Numerical examples show that th
- Two-band electronic metal and neighboring spin liquid (spin Bose-metal) on a zigzag strip with longer-ranged repulsioncond-mat.str-el
Hsin-Hua Lai, Olexei I. Motrunich
We consider an electronic model for realizing the Spin Bose-metal (SBM) phase on a 2-leg triangular strip --a spin liquid phase found by D. N. Sheng et al [Phys. Rev. B {\bf 79}, 205112 (2009)] in a spin-1/2 model with ring exchanges. The SBM can be viewed as a "C1S2" Mott insulator of electrons where the overall charge transporting mode is gapped out. We st
William Cherowitzo
This is the first in a series of articles devoted to providing a foundation for a theory of flocks of arbitrary cones in PG(3,q). The desire to have such a theory stems from a need to better understand the very significant and applicable special case of flocks of quadratic cones in PG(3,q). Flocks of quadratic cones have connections with several other geomet
Debraj Chakrabarti, Mei-Chi Shaw
We establish the $L^2$ theory for the Cauchy-Riemann equations on product domains provided that the Cauchy-Riemann operator has closed range on each factor. We deduce regularity of the canonical solution on $(p,1)$-forms in special Sobolev spaces represented as tensor products of Sobolev spaces on the factors of the product. This leads to regularity results
I. Georgantopoulos, A. Akylas
We investigate claims according to which the X-ray selection of AGN is not as efficient compared to that based on [OIII] selection because of the effects of X-ray absorption.We construct the predicted X-ray luminosity function both for all Seyferts as well as separately for Seyfert-1 and Seyfert-2 type galaxies, by combining the optical AGN [OIII] luminosity
Ivan D. Remizov, Alexei V. Savvateev
In this note, we propose a formula for the subdifferential of the maximum functional $m(f) = \max_K f$ on the space of real-valued continuous functions $f$ defined on an arbitrary metric compact $K$. We show that, given $f$, the subdifferential of $m(f)$ always coincides with the set of all probability measures on the arg-maximum (the set of all points in $K
Luiz C. L. Botelho
We propose a quantum surface wave functional describing the interaction between a colored membrane and a quantized Yang Mills. Additionally, we deduce its associated wave equation in the t'Hooft Nc-infinite limit. We show that it reproduces the Yang Mills Field Theory at a large rigid random surface scale.
G. V. Gelashvili, M. O. Mdivnishvili, I. S. Nanobashvili, S. I. Nanobashvili
The purpose of the given work is detailed research of toroidal shock wave movement process to the center of symmetry in air by normal atmosphere pressure. The wave is generated by plazma which is generated by a ring discharger.
Edward Hanson
Let $V$ denote a vector space with finite positive dimension. We consider an ordered pair of linear transformations $A: V\to V$ and $A^*: V\to V$ that satisfy (i) and (ii) below: (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is irreducible tridiagonal and the matrix representing $A^*$ is diagonal. (ii) There exists a basi
- Self-referenced characterization of optical frequency combs and arbitrary waveforms using a simple, linear, zero-delay implementation of spectral shearing interferometryphysics.optics
V. R. Supradeepa, Christopher M. Long, Daniel E. Leaird, Andrew M. Weiner
We discuss a simple, linear, zero-delay implementation of spectral shearing interferometry for amplitude and phase characterization of optical frequency comb sources and arbitrary waveforms. We demonstrate this technique by characterizing two different high repetition rate (~10 GHz) frequency comb sources, generated respectively by strong external and intrac
Simon Blackburn, Michel Côté, Steven G. Louie, Marvin L. Cohen
Using density functional theory within the local density approximation we report a study of the electron-phonon coupling in NbC$_{1-x}$N$_x$ and NbN crystals in the rocksalt structure. The Fermi surface of these systems exhibits important nesting. The associated Kohn anomaly greatly increases the electron-phonon coupling and induces a structural instability
- Measurement of azimuthal asymmetries associated with deeply virtual Compton scattering on an unpolarized deuterium targethep-ex
The HERMES Collaboration, A. Airapetian
Azimuthal asymmetries in exclusive electroproduction of a real photon from an unpolarized deuterium target are measured with respect to beam helicity and charge. They appear in the distribution of these photons in the azimuthal angle phi around the virtual-photon direction, relative to the lepton scattering plane. The extracted asymmetries are attributed to
George Moschelli, Sean Gavin
Correlation measurements indicate that excess two particle correlations extend over causally disconnected rapidity ranges. Although, this enhancement is broad in relative rapidity $\eta=\eta_1 - \eta_2$, it is focused in a narrow region in relative azimuthal angle $\phi=\phi_1 - \phi_2$. The resulting structure looks like a ridge centered at $\eta = \phi=0$.
- Spin-down Measurement of PSR J1852+0040 in Kesteven 79: Central Compact Objects as Anti-Magnetarsastro-ph.HE
J. P. Halpern, E. V. Gotthelf
Using XMM-Newton and Chandra, we achieved phase-connected timing of the 105 ms X-ray pulsar PSR J1852+0040 that provides the first measurement of the spin-down rate of a member of the class of Central Compact Objects (CCOs) in supernova remnants. We measure P-dot = 8.68(9)E-18, and find no evidence for timing noise or variations in X-ray flux over 4.8 yr. In
Russell Lyons, Fedor Nazarov
We prove that in every bipartite Cayley graph of every non-amenable group, there is a perfect matching that is obtained as a factor of independent uniform random variables. We also discuss expansion properties of factors and improve the Hoffman spectral bound on independence number of finite graphs.
A. Lesov
Understanding of the weak force is traced from Fermi's theory of beta decay to the V-A theory of the mid 1950's. The theoretical suggestion and experimental confirmation of parity violation in the weak force is discussed. Topics are presented chronologically, leaving room for biographical sketches and introducing basic mathematical and physical concepts as n
- Nuclear-mass dependence of azimuthal beam-helicity and beam-charge asymmetries in deeply virtual Compton scatteringhep-ex
The HERMES collaboration, A. Airapetian
The nuclear-mass dependence of azimuthal cross section asymmetries with respect to charge and longitudinal polarization of the lepton beam is studiedfor hard exclusive electroproduction of real photons. The observed beam-charge and beam-helicity asymmetries are attributed to the interference between the Bethe-Heitler and deeply virtual Compton scattering pro
Tullio Ceccherini-Silberstein, Wolfgang Woess
Let $G$ be a finitely generated group, $A$ a finite set of generators and $K$ a subgroup of $G$. We call the pair $(G,K)$ context-free if the set of all words over $A$ that reduce in $G$ to an element of $K$ is a context-free language. When $K$ is trivial, $G$ itself is called context-free; context-free groups have been classified more than 20 years ago in c
Melda Yuksel, Xi Liu, Elza Erkip
In this work a four terminal Gaussian network composed of a source, a destination, an eavesdropper and a jammer relay is studied. The jammer relay does not hear the source transmission. It assists the eavesdropper and aims to decrease the achievable secrecy rates. The source, on the other hand, aims to increase the achievable secrecy rates. Assuming Gaussian
Sergey V. Faleev, Oleg N. Mryasov, Thomas R. Mattsson
Modifications to the quasiparticle self-consistent GW (QSGW) method needed to correctly describe metal/vacuum interfaces and other systems having extended regions with small electron density are identified and implemented. The method's accuracy is investigated by calculating work functions for the Al(111), Al(100), and Al(110) surfaces. We find that the resu
Rong-Jun Wu, Zhao-Long Wang
We calculate the long-range interactions between two simple branes placed parallel at a separation in diverse dimensions via an effective field theory approach. We also compute for the first time the explicit long-range interaction between two D-branes with each carrying a world-volume non-abelian magnetic flux in three special cases, respectively. In partic
Roland Speicher
Free probability theory was created by Dan Voiculescu around 1985, motivated by his efforts to understand special classes of von Neumann algebras. His discovery in 1991 that also random matrices satisfy asymptotically the freeness relation transformed the theory dramatically. Not only did this yield spectacular results about the structure of operator algebra
Jean Cardinal, Samuel Fiorini, Gwenaël Joret, Raphaël Jungers
We revisit the well-known problem of sorting under partial information: sort a finite set given the outcomes of comparisons between some pairs of elements. The input is a partially ordered set P, and solving the problem amounts to discovering an unknown linear extension of P, using pairwise comparisons. The information-theoretic lower bound on the number of
Kari Ragnarsson, Radu Stancu
We give a new, unexpected characterization of saturated fusion systems on a p-group S in terms of idempotents in the p-local double Burnside ring of S that satisfy a Frobenius reciprocity relation, and reformulate fusion-theoretic phenomena in the language of idempotents. Interpreting our results in stable homotopy, we answer a long-standing question on stab
Tae Keun Choi, Kyung Sik Kim, Byung Geel Yu
The properties of the $\Lambda(1405)$ resonance have been investigated from radiative decay of $K^- p\to Y\gamma$ and photoproduction $\gamma p\to K^+\Lambda(1405)$ within the framework of the isobar model. For a consistent result with recently measured branching ratios, the axial vector meson $K_1(1270)$ is taken into account. Strong and electromagnetic cou
D. Dudal, N. Vandersickel, H. Verschelde, S. P. Sorella
The existence of gauge (Gribov) copies disturbs the usual Faddeev-Popov quantization procedure in the Landau gauge. It is a very hard job to treat these in the continuum, even in a partial manner. A decent way to do so was worked out by Gribov, and later on by Zwanziger. The final point was a renormalizable action (the Gribov-Zwanziger action), implementing
- A detailed investigation of the properties of a Vlasov-Maxwell equilibrium for the force-free Harris sheetphysics.plasm-ph
Thomas Neukirch, Fiona Wilson, Michael G. Harrison
A detailed discussion is presented of the Vlasov-Maxwell equilibrium for the force-free Harris sheet recently found by Harrison and Neukirch (Phys. Rev. Lett. 102, 135003, 2009). The derivation of the distribution function and a discussion of its general properties and their dependence on the distribution function parameters will be given. In particular, the
J. Bellissard, A. Julien, J. Savinien
Let T be an aperiodic and repetitive tiling of R^d with finite local complexity. Let O be its tiling space with canonical transversal X. The tiling equivalence relation R_X is the set of pairs of tilings in X which are translates of each others, with a certain (etale) topology. In this paper R_X is reconstructed as a generalized "tail equivalence" on a Bratt
X. Caillet, A. Orieux, A. Lemaitre, P. Filloux
We experimentally demonstrate an integrated semiconductor ridge microcavity source of counterpropagating twin photons at room temperature in the telecom range. Based on parametric down conversion with a counterpropagating phase-matching, pump photons generate photon pairs with an efficiency of about 10^(-11) and a spectral linewidth of 0.3 nm for a 1mm long
Xu Xiu-Lian, Fu Chun-Hua, Liu Ai-Fen, He Da-Ren
We show that the heterogeneity index, which was proposed by Hu and Wang (Physica A 2008 387 3769), can be used to describe the disparity of the cooperation sharing or competition gain distributions that is very important for the cooperation/competition system dynamic understanding. An analytical relation between the distribution parameters and the heterogene
Ebru Kis-Cam, Ekrem Aydiner
In this study, we have considered the three dimensional mixed ferro-ferrimagnetic ternary alloy model of the type AB$_{p}$C$_{1-p}$ where the A and X (X=B or C) ions are alternately connected and have different Ising spins S$^{A}$=3/2, S$^{B}$=1 and S$^{C}$=5/2, respectively. We have investigated the dependence of the critical and compensation temperatures o
Felix Finster
A method is developed for realizing entanglement and general second quantized fermionic and bosonic fields in the framework of the fermionic projector.
Tapan Mukhopadhyay, D. N. Basu
Photonuclear reactions at energies covering the giant dipole resonance (GDR) region are analyzed with an approach based on nuclear photoabsorption followed by the process of competition between light particle evaporation and fission for the excited nucleus. The photoabsorption cross section at energies covering the GDR region is contributed by both the Loren
Paolo Benincasa
We explore the phase structure for defect theories in full generality using the gauge/gravity correspondence. On the gravity side, the systems are constructed by introducing M (probe) D(p+4-2k)-branes in a background generated by N Dp-branes to obtain a codimension-k intersection. The dual gauge theory is a U(N) Supersymmetric Yang-Mills theory on a (1+p-k)-
Paul F. X. Mueller
We prove that for any operator $T$ on $ \ell^\infty(H^1 (\bT))$, the identity factores through $T$ or $\Id - T$. We re-prove analogous results of H.M. Wark for the spaces $\ell^infty(H^p(\bT))$, $1<p <\infty$. In the present paper direct combinatorics of colored dyadic intervals replaces the dependence on Szemeredi's theorem in the work of H. M. Wark.
Bikashkali Midya, Barnana Roy, Atreyee Biswas
The coherent state of a nonlinear oscillator having a nonlinear spectrum is constructed using Gazeau Klauder formalism. The weighting distribution and the Mandel parameter are studied. Details of the revival structure arising from different time scales underlying the quadratic energy spectrum are investigated by the phase analysis of the autocorrelation func
Iogann Tolbatov
Superconducting nanodrop model is constructed on the basis of the assumption of equality of the free energy functional gradient term to zero due to the order parameter value constancy in the superconducting nanodrop volume. In the investigation, we have defined the superconducting nanodrop thermodynamical characteristics: partition function, the magnitudes o
Holger F. Hofmann
In this presentation, I argue that weak measurements empirically support the notion of quantum superpositions as statistical alternatives. In short, weak measurements show that Schroedinger's cat is already dead or alive before the measurement. The collapse of the wavefunction in a strong measurement should therefore be separated into the statistical selecti
Gwyn Bellamy
We study those finite dimensional quotients of the rational Cherednik algebra at t=0 that are supported at a point of the centre. It is shown that each such quotient is Morita equivalent to a certain cuspidal quotient of a rational Cherednik algebra associated to a parabolic subgroup of W.
Oleg N. Kirillov, Frank Stefani
The magnetorotational instability (MRI) plays a crucial role for cosmic structure formation by enabling turbulence in Keplerian disks which would be otherwise hydrodynamically stable. With particular focus on MRI experiments with liquid metals, which have small magnetic Prandtl numbers, it has been shown that the helical version of this instability (HMRI) ha
Andrej Bauer
In the effective topos there exists a chain-complete distributive lattice with a monotone and progressive endomap which does not have a fixed point. Consequently, the Bourbaki-Witt theorem and Tarski's fixed-point theorem for chain-complete lattices do not have constructive (topos-valid) proofs.
Gwyn Bellamy
We show that it is possible to deduce the Calogero-Moser partition of the irreducible representations of the complex reflection groups G(m,d,n) from the corresponding partition for G(m,1,n). This confirms, in the case W = G(m,d,n), a conjecture of Gordon and Martino relating the Calogero-Moser partition to Rouquier families for the corresponding cyclotomic H
Daoyi Dong, Ian R. Petersen
This paper proposes a new robust control method for quantum systems with uncertainties involving sliding mode control (SMC). Sliding mode control is a widely used approach in classical control theory and industrial applications. We show that SMC is also a useful method for robust control of quantum systems. In this paper, we define two specific classes of sl
Mattias Dahl, Emmanuel Humbert
Let $g$ be a metric on $S^3$ with positive Yamabe constant. When blowing up $g$ at two points, a scalar flat manifold with two asymptotically flat ends is produced and this manifold will have compact minimal surfaces. We introduce the $\Th$-invariant for $g$ which is an isoperimetric constant for the cylindrical domain inside the outermost minimal surface of
- Electronic structure and Peierls instability in graphene nanoribbons sculpted in graphanecond-mat.mes-hall
Valentina Tozzini, Vittorio Pellegrini
Graphene nanoribbons are semiconductor nanostructures with great potentials in nanoelectronics. Their realization particularly with small lateral dimensions below a few nanometers, however, remains challenging. Here we theoretically analyze zig-zag graphene nanoribbons created in a graphane substrate (a fully saturated two-dimensional hydrocarbon with formul
Diego Rodriguez-Gomez
In this note we study some aspects of the so-called dual ABJM theory introduced by Hanany, Vegh & Zaffaroni. We analyze the spectrum of chiral operators, and compare it with the spectrum of functions on the mesonic moduli space M=C^2\times C^2/Z_k, finding expected agreement for the coherent branch. A somewhat mysterious extra branch of dimension N^2 opens u
Xiao-Hui Ni, Zhi-Qiang Jiang, Gao-Feng Gu, Fei Ren
The order submission and cancelation processes are two crucial aspects in the price formation of stocks traded in order-driven markets. We investigate the dynamics of order cancelation by studying the statistical properties of inter-cancelation durations defined as the waiting times between consecutive order cancelations of 22 liquid stocks traded on the She
J. M. Deutsch
It is argued that a typical many body energy eigenstate has a well defined thermodynamic entropy and that individual eigenstates possess thermodynamic characteristics analogous to those of generic isolated systems. We examine large systems with eigenstate energies equivalent to finite temperatures. When quasi-static evolution of a system is adiabatic (in the
Roman Golovko
We calculate the relative versions of embedded contact homology, contact homology and cylindrical contact homology of the sutured solid torus $(S^1\times D^2,\Gamma)$, where $\Gamma$ consists of $2n$ parallel longitudinal sutures.
Sham M. Kakade, Ohad Shamir, Karthik Sridharan, Ambuj Tewari
The versatility of exponential families, along with their attendant convexity properties, make them a popular and effective statistical model. A central issue is learning these models in high-dimensions, such as when there is some sparsity pattern of the optimal parameter. This work characterizes a certain strong convexity property of general exponential fam
Hui Chen, Sanjit Karmakar, Zhenda Xie, Yanhua Shih
We wish to report an experimental observation of anti-correlation from first-order incoherent classical chaotic light. We explain why the classical statistical theory does not apply and provide a quantum interpretation. In quantum theory, either correlation or anti-correlation is a two-photon interference phenomenon, which involves the superposition of two-p
Jeffrey Picka
Models for wildfires must be stochastic if their ability to represent wildfires is to be objectively assessed. The need for models to be stochastic emerges naturally from the physics of the fire, and methods for assessing fit are constructed to exploit information found in the time evolution of the burn region.
Hyoungshick Kim, Ji Won Yoon
We present a method to analyse the scientific contributions between research groups. Given multiple research groups, we construct their journal/proceeding graphs and then compute the similarity/gap between them using network analysis. This analysis can be used for measuring similarity/gap of the topics/qualities between research groups' scientific contributi
Jeffrey Picka
Validation of models for powder flow requires that the models be stochastic and that they be fit by statistical inference. Methods from spatial and multivariate statistics can be used for model fitting and assessment. If the quality of the fitted model is not assessed, there is a significant risk the model will fail to represent the physics of powder flow.
Ethan Anderes, Michael Stein
We develop a weighted local likelihood estimate for the parameters that govern the local spatial dependency of a locally stationary random field. The advantage of this local likelihood estimate is that it smoothly downweights the influence of far away observations, works for irregular sampling locations, and when designed appropriately, can trade bias and va
L. A. Antonelli, P. D Avanzo, R. Perna, L. Amati
Aims. With an observed and rest-frame duration of < 2s and < 0.5s, respectively, GRB090426 could be classified as a short GRB. The prompt detection, both from space and ground-based telescopes, of a bright optical counterpart to this GRB offered a unique opportunity to complete a detailed study. Methods. Based on an extensive ground-based observational campa
Zicong Zhou, Bela Joos
We study the effects of intrinsic sequence-dependent curvature for a two dimensional semiflexible biopolymer with short-range correlation in intrinsic curvatures. We show exactly that when not subjected to any external force, such a system is equivalent to a system with a well-defined intrinsic curvature and a proper renormalized persistence length. We find
- Colour Gradients and the Colour-Magnitude Relation: Different Properties of Brightest Cluster Galaxies and E/S0 Galaxies in the Sloan Digital Sky Surveyastro-ph.CO
Nathan Roche, Mariangela Bernardi, Joseph Hyde
We examine the colour-magnitude relation of approximately 5000 Brightest Cluster Galaxies (BCGs) in the Sloan Digital Sky Survey, and compare with non-BCG E/S0 galaxies. The colour-magnitude and colour-sigma (velocity dispersion) relations are flatter in slope (by a factor of about 2) for BCGs than for non-BCG E/S0s, and the BCGs also tend to be redder by 0.
- A posteriori error analysis for finite element solution of elliptic differential equations using equidistributing meshesmath.NA
Yinnian He, Weizhang Huang
The paper is concerned with the adaptive finite element solution of linear elliptic differential equations using equidistributing meshes. A strategy is developed for defining this type of mesh based on residual-based a posteriori error estimates and rigorously analyzing the convergence of a linear finite element approximation using them. The existence and co
F. M. Andrade, M. G. E. da Luz
Coin and scattering are the two major formulations for discrete quantum walks models, each believed to have its own advantages in different applications. Although they are related in some cases, it was an open question their equivalence in arbitrary topologies. Here we present a general construction for the two models for any graph and also for position depe
- Competing Phases, Strong Electron-Phonon Interaction and Superconductivity in Elemental Calcium under High Pressurecond-mat.supr-con
Z. P. Yin, F. Gygi, W. E. Pickett
The observed "simple cubic" (sc) phase of elemental Ca at room temperature in the 32-109 GPa range is, from linear response calculations, dynamically unstable. By comparing first principle calculations of the enthalpy for five sc-related (non-close-packed) structures, we find that all five structures compete energetically at room temperature in the 40-90 GPa
Gene Golovchinsky, Scott Carter, Jacob Biehl
We developed a system that augments traditional office whiteboards with computation for the purposes of retrieving, reusing, and sharing whiteboard content. Our system automatically captures changes to whiteboard images, detects significant changes, and identifies potential collaborative activities. Users then browse and search the collection of images captu
SungBin Lee, Ribhu K. Kaul, Leon Balents
Motivated by CoNb2O6 (belonging to the columbite family of minerals), we theoretically study the physics of quantum ferromagnetic Ising chains coupled anti-ferromagnetically on a triangular lattice in the plane perpendicular to the chain direction. We combine exact solutions of the chain physics with perturbative approximations for the transverse couplings.
- Antiphase magnetic boundaries in iron-based superconductors: A first-principle density-functional theory studycond-mat.supr-con
Z. P. Yin, W. E. Pickett
Superconductivity arises in the layered iron-pnictide compounds when magnetic long range order disappears. We use first principles density functional methods to study magnetic arrangements that may compete with long range order near the phase boundary. Specifically, we study the energetics and charge density distribution (through calculation of the electric
- Large electronic bandwidth in solution-processable pyrene crystals: The role of close-packed crystal structurecond-mat.mtrl-sci
Francoise Provencher, Jean-Frederic Laprade, Gabrielle Simard, Nicolas Berube
We examine the interdependence of structural and electronic properties of two substituted pyrene crystals by means of combined spectroscopic probes and density-functional theory calculations. One derivative features n-hexyl side groups, while the other one contains branched silanyl groups. Both derivatives form triclinic crystal structures when grown from so
E. Furlan, W. J. Forrest, B. A. Sargent, P. Manoj
We use Spitzer data to infer that the small infrared excess of V819 Tau, a weak-lined T Tauri star in Taurus, is real and not attributable to a "companion" 10 arcsec to the south. We do not confirm the mid-infrared excess in HBC 427 and V410 X-ray 3, which are also non-accreting T Tauri stars in the same region; instead, for the former object, the excess ari
Patrick Draper, Tao Liu, Carlos E. M. Wagner
We analyze the Tevatron and Large Hadron Collider (LHC) reach for the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM) in the presence of explicit CP-violation. Using the most recent studies from the Tevatron and LHC collaborations, we examine the CPX benchmark scenario for a range of CP-violating phases in the soft trilinear and gluino mass
D. T. Lussier, Y. Ventikos
Video of argon nanodroplet impacting onto wetting and non-wetting surface. This video was submitted as part of the Gallery of Fluid Motion 2009 which is showcase of fluid dynamics videos.
- A Comparison of the Red and Green Coronal Line Intensities at the 29 March 2006 and the 1 August 2008 Total Solar Eclipses: Considerations of the Temperature of the Solar Coronaastro-ph.SR
A. Voulgaris, T. Athanasiadis, J. H. Seiradakis, J. M. Pasachoff
During the total solar eclipse at Akademgorodok, Siberia, Russia, in 1 August 2008, we imaged the flash spectrum with a slitless spectrograph. We have spectroscopically determined the duration of totality, the epoch of the 2nd and 3rd contacts and the duration of the flash spectrum (63 s during ingress and 48 s during egress). Here we compare the 2008 flash
- Generation of polarization entangled photons using type-II doubly periodically poled lithium niobate waveguidesquant-ph
K. Thyagarajan, K. Sinha, J. Lugani, S. Ghosh
In this paper, we address the issue of the generation of non-degenerate cross-polarization-entangled photon pairs using type-II periodically poled lithium niobate. We show that, by an appropriate engineering of the quasi-phase-matching grating, it is possible to simultaneously satisfy the conditions for two spontaneous parametric down-conversion processes, n
Miguel Couceiro, Lucien Haddad
Let A be a finite non-singleton set. For |A|=2 we show that the partial clone consisting of all selfdual monotone partial functions on A is not finitely generated, while it is the intersection of two finitely generated maximal partial clones on A. Moreover for |A| >= 3 we show that there are pairs of finitely generated maximal partial clones whose intersecti
Goran Senjanovic
It is often said that neutrino mass is a window to a new physics beyond the standard model (SM). This is certainly true if neutrinos are Majorana particles since the SM with Majorana neutrino mass is not a complete theory. The classical text-book test of neutrino Majorana mass, the neutrino-less double beta decay depends on the completion, and thus cannot pr
Frédéric Bourgeois, Tobias Ekholm, Yakov Eliashberg
The paper is a summary of the results of the authors concerning computations of symplectic invariants of Weinstein manifolds and contains some examples and applications. Proofs are sketched. The detailed proofs will appear in our forthcoming paper. In the Appendix written by S. Ganatra and M. Maydanskiy it is shown that the results of this paper imply P. Sei
Tim Gillespie
Given unitary automorphic cuspidal representations $\pi$ and $\pi'$ defined on $GL_n(\mathbb{A}_E)$ and $GL_m(\mathbb{A}_F)$, respectively, with $E$ and $F$ solvable algebraic number fields we deduce a prime number theorem for the Rankin-Selberg L-function $L(s,AI_{E/\mathbb{Q}}(\pi)\times AI_{F/\mathbb{Q}}(\pi'))$ under a self-contragredient assumption and
John M. Cornwall
Topological confinement by center vortices does not immediately explain either a minimum-area law for non-planar Wilson loops or the L\"uscher term. I conjecture that both a minimal-area law and a L\"uscher term arise in a confinement model of random ensembles of vortices with no propagating gluons (a polymer model), and propose their test by polymer-like la
C. A. Ballon Bayona, Henrique Boschi-Filho, Nelson R. F. Braga, Marcus A. C. Torres
We calculate elastic and non-elastic electromagnetic form factors for vector and axial-vector mesons in the holographic D4-D8 brane model. We obtain the mass spectrum and Regge trajectories for these particles. From the elastic form factors we extract the electric radius, the magnetic and quadrupole moments. Form factors for transverse and longitudinal polar
- Searching for Evidence of Energetic Feedback in Distant Galaxies: A Galaxy Wide Outflow in a z~2 Ultraluminous Infrared Galaxyastro-ph.CO
D. M. Alexander, A. M. Swinbank, I. Smail, R. McDermid
Leading models of galaxy formation require large-scale energetic outflows to regulate the growth of distant galaxies and their central black holes. However, current observational support for this hypothesis at high redshift is mostly limited to rare z>2 radio galaxies. Here we present Gemini-North NIFS Intregral Field Unit (IFU) observations of the [OIII] em
Stanislaw Mrowczynski
Since the quark-gluon plasma, which is unstable due to anisotropic momentum distribution, evolves fast in time, plasma's characteristics have to be studied as initial value problems. The chromodynamic fluctuations and the momentum broadening of a fast parton traversing the plasma are discussed here. The two quantities are shown to exponentially grow in time.
- Demonstration of fine pitch FCOB (Flip Chip on Board) assembly based on solder bumps at Fermilabphysics.ins-det
M. Trimpl, E. Skup, R. Yarema, J. C. Yun
Bump bonding is a superior assembly alternative compared to conventional wire bond techniques. It offers a highly reliable connection with greatly reduced parasitic properties. The Flip Chip on Board (FCOB) procedure is an especially attractive packaging method for applications requiring a large number of connections at moderate pitch. This paper reports on
Jacob Lurie
In this paper, we study algebras over the little cubes operads introduced by Boardman and Vogt, using the formalism of higher category theory.
- Fully reversible transition from Wenzel to Cassie-Baxter states on corrugated superhydrophobic surfacescond-mat.soft
R. J. Vrancken, H. Kusumaatmaja, K. Hermans, A. M. Prenen
Liquid drops on textured surfaces show different dynamical behaviors depending on their wetting states. They are extremely mobile when they are supported by composite solid-liquid-air interfaces (Cassie-Baxter state) and immobile when they fully wet the textured surfaces (Wenzel state). By reversibly switching between these two states, it will be possible to
- Stochastic conversions of TeV photons into axion-like particles in extragalactic magnetic fieldsastro-ph.HE
Alessandro Mirizzi, Daniele Montanino
Very-high energy photons emitted by distant cosmic sources are absorbed on the extragalactic background light (EBL) during their propagation. This effect can be characterized in terms of a photon transfer function at Earth. The presence of extragalactic magnetic fields could also induce conversions between very high-energy photons and hypothetical axion-like
Alhaji Cherif, Kamal Barley
Current theories from biosocial (e.g.: the role of neurotransmitters in behavioral features), ecological (e.g.: cultural, political, and institutional conditions), and interpersonal (e.g.: attachment) perspectives have grounded interpersonal and romantic relationships in normative social experiences. However, these theories have not been developed to the poi
M. L. Blow, H. Kusumaatmaja, J. M. Yeomans
We present and interpret simulation results showing how a fluid moves on a hydrophilic substrate patterned by a square array of triangular posts. We demonstrate that the shape of the posts leads to anisotropic spreading, and discuss how this is influenced by the different ways in which the posts can pin the advancing front.
Andreas Glatz, I. S. Beloborodov
We study heating effects of a single metallic quantum dot weakly coupled to two leads. The dominant mechanism for heating at low temperatures is due to inelastic electron cotunneling processes. We calculate the grain temperature profile as a function of grain parameters, bias voltage, and time and show that for nanoscale size grains the heating effects are p
Pedro Lacerda
Kuiper belt object 136108 Haumea is one of the most fascinating bodies in our solar system. Approximately 2000x1600x1000 km in size, it is one of the largest Kuiper belt objects (KBOs) and an unusually elongated one for its size. The shape of Haumea is the result of rotational deformation due to its extremely short 3.9-hour rotation period. Unlike other 1000
Pedro Lacerda
One of the most fundamental problems in the study of Kuiper belt objects (KBOs) is to know their true physical size. Without knowledge of their albedos we are not able to distinguish large and dark from small and bright KBOs. Spitzer produced rough estimates of the sizes and albedos of about 20 KBOs, and the Herschel space telescope will improve on those ini
E. Treister, C. Cardamone, K. Schawinski, C. M. Urry
We study the properties of a sample of 211 heavily-obscured Active Galactic Nucleus (AGN) candidates in the Extended Chandra Deep Field-South selecting objects with f_24/f_R>1000 and R-K>4.5. Of these, 18 were detected in X-rays and found to be obscured AGN with neutral hydrogen column densities of ~10^23 cm^-2. In the X-ray undetected sample, the following
Tara Murphy, Elaine M. Sadler, Ronald D. Ekers, Marcella Massardi
We present the full source catalogue from the Australia Telescope 20 GHz (AT20G) Survey. The AT20G is a blind radio survey carried out at 20 GHz with the Australia Telescope Compact Array (ATCA) from 2004 to 2008, and covers the whole sky south of declination 0 deg. The AT20G source catalogue presented here is an order of magnitude larger than any previous c
M. Kachelriess, P. D. Serpico, M. Aa. Solberg
Interpretations of indirect searches for dark matter (DM) require theoretical predictions for the annihilation or decay rates of DM into stable particles of the standard model. These predictions include usually only final states accessible as lowest order tree-level processes, with electromagnetic bremsstrahlung and the loop-suppressed two gamma-ray line as