March 2009 arXiv papers — page 5
Showing 401–500 of 5,470 papers
The transfer in mod-p group cohomology between Σ_p \int Σ_{p^{n-1}}, Σ_{p^{n-1}} \int Σ_p and Σ_{p^n}
math.ATNondas E. Kechagias
In this work we compute the induced transfer map: $$\barτ^\ast: \func{Im}(res^\ast:H^\ast(G) \to H^\ast(V)) \to \func{Im}(res^\ast: H^\ast (Σ_{p^n}) \to H^\ast(V))$$ in $\func{mod}p$-cohomology. Here $Σ_{p^{n}}$ is the symmetric group acting on an $n$-dimensional $\mathbb F_p$ vector space $V$, $G=Σ_{p^{n},p}$ a $p$-Sylow subgroup, $Σ_{p^{n-1}}\int Σ_{p}$, o
F. Richter, D. Yu. Vasylyev, K. Henneberger
We show that using the properties of the photon Green's function one can successfully describe the propagation of arbitrary nonclassical optical radiation through structured materials. In contrast to the similar input-output approach, our method is not restricted neither to the spatial homogeneous matter nor to the specific direction of light beam incide
Richard A. Low
We present a technique for derandomising large deviation bounds of functions on the unitary group. We replace the Haar distribution with a pseudo-random distribution, a k-design. k-designs have the first k moments equal to those of the Haar distribution. The advantage of this is that (approximate) k-designs can be implemented efficiently, whereas Haar random
S. M. Bilenky, F. von Feilitzsch, W. Potzel
We discuss different schemes of neutrino oscillations and the time-energy uncertainty relation. From the results of the K2K and MINOS accelerator experiments follows that neutrino oscillations are a non-stationary phenomenon and that the standard time-energy uncertainty relation is satisfied. Are these properties a general feature of neutrino oscillations? I
Comment on "Quantum critical paraelectrics and the Casimir effect in time"
cond-mat.stat-mechH. Chamati, N. S. Tonchev
At variance with the authors' statement [L. Pálová, P. Chandra and P. Coleman, Phys. Rev. B 79, 075101 (2009)], we show that the behavior of the universal scaling amplitude of the gap function in the phonon dispersion relation as a function of the dimensionality $d$, obtained within a self--consistent one--loop approach, is consistent with some previous
Paul H. Frampton
The use of the binary tetrahedral group ($T^{'}$) as flavor symmetry is discussed. I emphasize the CKM quark and PMNS neutrino mixings. I present a novel formula for the Cabibbo angle.
M. G. Silveirinha
Following our recent work [New J. Phys. 10, 053011, (2008)], here we demonstrate that due to strong nonlocal effects additional boundary conditions are essential to characterize the reflection of electromagnetic waves by nonconnected wire arrays using homogenization methods. Based on simple physical considerations, we derive the additional boundary condition
The Fully Covariant Energy Momentum Stress Tensor For Gravity and the Einstein Equation in General Relativity
gr-qcMaurice J. Dupré
We give a fully covariant energy momentum stress tensor for the gravitational field which is easily physically motivated, and which leads to a very general derivation of the Einstein equation for gravity. We do not need to assume any property of the surce matter fields' energy momentum stress tensor other than symmetry. We give a physical motivation for
A. Cavaliere, A. Lapi, R. Fusco-Femiano
[abridged] The equilibria of the intracluster plasma (ICP) and of the gravitationally dominant dark matter (DM) are governed by the hydrostatic and the Jeans equation. Jeans, with the DM `entropy' set to K ~ r^αand α~ 1.25 - 1.3 applying from groups to rich clusters, yields our radial α-profiles. In the ICP the entropy run k(r) is mainly shaped by shocks
A. F. Valeev, O. Sholukhova, S. Fabrika
We present a new luminous star in M33 located in the nuclear region. The star shows strong FeII and [FeII] forest, hydrogen emissions in the spectrum, as well as nebular lines. TiII and SiII lines were detected in absorption, their radial velocity shifted by ~ -30km/s relative to emission lines. The star is variable over seven years with 0.5 mag variations o
Changbo Chen, Marc Moreno Maza, Bican Xia, Lu Yang
Cylindrical algebraic decomposition is one of the most important tools for computing with semi-algebraic sets, while triangular decomposition is among the most important approaches for manipulating constructible sets. In this paper, for an arbitrary finite set $F \subset {\R}[y_1, ..., y_n]$ we apply comprehensive triangular decomposition in order to obtain
N. Mahdou, K. Ouarghi
The main aim of this paper is to investigate new class of rings called, for positive integers $n$ and $d$, $G-(n,d)-$rings, over which every $n$-presented module has a Gorenstein projective dimension at most $d$. Hence we characterize $n$-coherent $G-(n,0)-$rings. We conclude by various examples of $G-(n,d)-$rings.
A-M. Broomhall, W. J. Chaplin, G. R. Davies, Y. Elsworth
We present a list of "best possible" estimates of low-degree p-mode frequencies, from 8640 days of observations made by the Birmingham Solar-Oscillations Network (BiSON). This is the longest stretch of helioseismic data ever used for this purpose, giving exquisite precision in the estimated frequencies. Every effort has been made in the analysis to e
S. McGlynn, S. Foley, B. McBreen, L. Hanlon
(Abridged) GRB 061122 is one of the brightest GRBs detected within INTEGRAL's field of view to date. The two gamma-ray detectors on INTEGRAL were used to investigate the spectral characteristics of GRB 061122. A search for linear polarisation in the prompt emission was carried out using the SPI multiple event data in the energy range 100 keV-1 MeV. The p
Daniel C. Isaksen
Working over an algebraically closed field of characteristic zero, we compute the cohomology of the subalgebra A(2) of the motivic Steenrod algebra that is generated by Sq^1, Sq^2, and Sq^4. The method of calculation is a motivic version of the May spectral sequence. Speculatively assuming that there is a "motivic modular forms" spectrum with certain
T. A. Maier, S. Graser, D. J. Scalapino, P. J. Hirschfeld
We discuss the large gap anisotropy found for the A1g (s-wave) state in RPA spin-fluctuation and functional renormalization group calculations and show how the simple arguments leading to isotropic sign-switched s-wave states in these systems need to be supplemented by a consideration of pair scattering within Fermi surface sheets and between the individual
Shreekantha Sil, Santanu K. Maiti, Arunava Chakrabarti
We show that a diamond shaped periodic network, recently proposed as a model of a spin filter (A. Aharony {\em et al.} \cite{aharon08}) is capable of behaving as a p-type or an n-type semiconductor depending on a suitable choice of the on-site potentials of the atoms occupying the vertices of the lattice, and the strength of the magnetic flux threading each
A. Serrano, E. Fernandez Pinel, A. Quesada, I. Lorite
We report here the observation of ferromagnetism (FM) at 300 K in mixtures of TiO2 and Co3O4 powders despite the antiferromagnetic and diamagnetic character of both oxides respectively. The ferromagnetic behavior is found in the early stages of reaction and only for TiO2 in anatase structure; no FM is found for identical samples prepared with rutile-TiO2. Op
Long-term photometric monitoring with the Mercator telescope. Frequencies and multicolour amplitudes of $γ$ Doradus stars
astro-ph.GAJ. Cuypers, C. Aerts, P. De Cat, J. De Ridder
Gamma Doradus stars are excellent targets for asteroseismology since the gravity modes present in these stars probe the deep stellar interiors. Mode identification will improve the knowledge of these stars considerably. A selected group of Gamma Doradus stars and some candidates were observed with the Mercator telescope to find and/or confirm the periodiciti
Michael P. Kowalski, Martin Barstow, Frederick Bruhweiler, Raymond Cruddace
Million degree plasmas are ubiquitous in the Universe, and examples include the atmospheres of white dwarfs; accretion phenomena in young stars, cataclysmic variables and active galactic nuclei; the coronae of stars; and the interstellar medium of our own galaxy and of others. The bulk of radiation from million degree plasmas is emitted at extreme ultraviole
Plamen Djakov, Boris Mityagin
By using quasi--derivatives we develop a Fourier method for studying the spectral gaps of one dimensional Schrödinger operators with periodic singular potentials $v.$ Our results reveal a close relationship between smoothness of potentials and spectral gap asymptotics under a priori assumption $v \in H^{-1}_{loc} (\mathbb{R}).$ They extend and strengthen sim
S. Strauss, S. Mattiello, M. Beyer
In recent years light-front quantisation has been extended to allow for a consistent treatment of systems at finite temperature and density. This is in particular interesting for an investigation of the processes in nuclear matter under extreme condition as occurring, e.g., during a heavy ion collision. Utilising a Dyson expansion to the N-point Green functi
On the Necessary and Sufficient Condition of Greedy Routing Supporting Geographical Data Networks
cs.CGM. Ghaffari, B. Hariri, S. Shirmohammadi
Large scale decentralized communication systems have introduced the new trend towards online routing where routing decisions are performed based on a limited and localized knowledge of the network. Geometrical greedy routing has been among the simplest and most common online routing schemes. A perfect geometrical routing scheme is expected to deliver each pa
V. R. Chitnis, J. K. Pendharkar, D. Bose, V. K. Agrawal
We investigate the X-ray variability characteristics of hard X-ray selected AGNs (based on Swift/BAT data) in the soft X-ray band using the RXTE/ASM data. The uncertainties involved in the individual dwell measurements of ASM are critically examined and a method is developed to combine a large number of dwells with appropriate error propagation to derive lon
Ilia Gogoladze, Rizwan Khalid, Qaisar Shafi
We consider a left-right symmetric SU(4)_c \times SU(2)_L \times SU(2)_R (4-2-2) model with gravity mediated supersymmetry breaking. We find that with 4-2-2 compatible non-universal gaugino masses, t-b-τYukawa coupling unification is consistent with neutralino dark matter abundance and with constraints from collider experiments (except (g-2)_μ). The gluino m
Matthew England, John Gibbons
A reduction of Benney's equations is constructed corresponding to Schwartz-Christoffel maps associated with a family of genus six cyclic tetragonal curves. The mapping function, a second kind Abelian integral on the associated Riemann surface, is constructed explicitly as a rational expression in derivatives of the Kleinian sigma-function of the curve.
Mapping of transrectal ultrasonographic prostate biopsies: quality control and learning curve assessment by image processing
physics.med-phPierre Mozer, Michael Baumann, Gregoire Chevreau, Alexandre Moreau-Gaudry
Objective: Mapping of transrectal ultrasonographic (TRUS) prostate biopsies is of fundamental importance for either diagnostic purposes or the management and treatment of prostate cancer, but the localization of the cores seems inaccurate. Our objective was to evaluate the capacities of an operator to plan transrectal prostate biopsies under 2-dimensional TR
Guy Casale, Guillaume Duval, Andrzej J. Maciejewski, Maria Przybylska
We derive necessary conditions for integrability in the Liouville sense of natural Hamiltonian systems with homogeneous potential of degree zero. We derive these conditions through an analysis of the differential Galois group of variational equations along a particular solution generated by a non-zero solution $\vd\in\C^n$ of nonlinear equations $\grad V(\vd
Structure Transition in PSS/Lysozyme Complexes: A Chain-Conformation-Driven Process, as Directly Seen by Small Angle Neutron Scattering
cond-mat.softJérémie Gummel, Fabrice Cousin, François Boué
Measurements of chain conformation in proteins/polyelectrolytes complexes (lysozyme and PSSNa) show that the crossover observed between an open structure -a chain network crosslinked by the proteins, and a globular one - dense globules of ~ 10 nm aggregated in a fractal way, results from a conformation modification prior to the transition. Before showing thi
Piermarco Cannarsa, Pierre Cardaliaguet
It is well-known that solutions to the basic problem in the calculus of variations may fail to be Lipschitz continuous when the Lagrangian depends on t. Similarly, for viscosity solutions to time-dependent Hamilton-Jacobi equations one cannot expect Lipschitz bounds to hold uniformly with respect to the regularity of coefficients. This phenomenon raises the
Interface relaxation and electrostatic charge depletion in the oxide heterostructure LaAlO3/SrTiO3
cond-mat.mtrl-sciU. Schwingenschloegl, C. Schuster
Performing an analysis within density functional theory, we develop insight into the structural and electronic properties of the oxide heterostructure LaAlO3/SrTiO3. Electrostatic surface effects are decomposed from the internal lattice distortion in order to clarify their interplay. We first study the interface relaxation by a multi-layer system without sur
S. Stéphane Cuenot, H. Alem, G. Louarn, S. Demoustier-Champagne
The elastic properties of nanotubes fabricated by layer-by-layer (LbL) assembly of polyelectrolytes in the nanopores of polycarbonate track-etched membranes have been investigated by resonant contact Atomic Force Microscopy (AFM), for nanotube diameters in the range of 100 to 200 nm. The elastic modulus of the nanotubes was computed from the resonance freque
Global Regularity for the Navier-Stokes equations with large, slowly varying initial data in the vertical direction
math.APMarius Paicu, Zhifei Zhang
In a recent article, J.-Y. Chemin, I. Gallagher and M. Paicu obtained a class of large initial data generating a global smooth solution to the three dimensional, incompressible Navier-Stokes equations. This data varies slowly in the vertical direction (is a function on $εx_3$) and has a norm which blows up as the small parameter goes to zero. This type of in
Gael Pallares, Laurent Ponson, Antoine Grimaldi, Matthieu George
The opening profile of the cracks produced in the Double Cleavage Drilled Compression (DCDC) specimens for brittle materials is investigated. The study is achieved by combining Finite Element simulations of a DCDC linear elastic medium with experimental measurements by crack opening interferometry on pure silica glass samples. We show that the shape of the c
Yves C. Angel, Christophe Aristégui, Mihai Caleap
The propagation of SH waves in a solid containing a screen of line-like scatterers is investigated. When the scatterers are uniformly distributed, the amplitudes of the coherent waves inside and outside the screen are evaluated in closed form. In the analysis, multiple scattering effects are taken into account within the context of a first-order approximatio
Dynamical Study of a Second Order DPCM Transmission System Modeled by a Piece-Wise Linear Function
nlin.CDIna Taralova, D. Fournier-Prunaret
This paper analyses the behaviour of a second order DPCM (Differential Pulse Code Modulation) transmission system when the nonlinear characteristic of the quantizer is taken into consideration. In this way, qualitatively new properties of the DPCM system have been unravelled, which cannot be observed and explained if the nonlinearity of the quantizer is negl
V. I. Yukalov, D. Sornette
We present a general theory of quantum information processing devices, that can be applied to human decision makers, to atomic multimode registers, or to molecular high-spin registers. Our quantum decision theory is a generalization of the quantum theory of measurement, endowed with an action ring, a prospect lattice and a probability operator measure. The a
Voltage-tunable lateral shifts of ballistic electrons in semiconductor quantum slabs
cond-mat.mes-hallXi Chen, Yue Ban, Chun-Fang Li
It is investigated that the lateral shifts of the ballistic electrons transmitted through a semiconductor quantum slabs can be negative as well as positive, which are analogous to the anomalous lateral shifts of the transmitted light beam through a dielectric slab. The necessary condition for the shift to be negative is advanced. It is shown that the lateral
Evolution of unoccupied resonance during the synthesis of a silver dimer on Ag(111)
cond-mat.mtrl-sciAlexander Sperl, Joerg Kroeger, Richard Berndt, Andreas Franke
Silver dimers were fabricated on Ag(111) by single-atom manipulation using the tip of a cryogenic scanning tunnelling microscope. An unoccupied electronic resonance was observed to shift toward the Fermi level with decreasing atom-atom distance as monitored by spatially resolved scanning tunnelling spectroscopy. Density functional calculations were used to a
Yuriy A. Drozd
We show how matrix problems (bimodule categories) can be used in studying triangulated categories. Then we apply the general technique to the classification of stable homotopy types of polyhedra, find out the "representation types" of such problems and give a description of stable homotopy types in finite and tame cases.
A high resolution study of isotopic composition and chemical abundances of blue horizontal branch stars in the globular clusters NGC6397 and NGC6752
astro-ph.SRS. Hubrig, F. Castelli, G. De Silva, J. F. Gonzalez
Large abundance anomalies have been previously detected in Horizontal Branch B-type stars. We present the first high resolution study of isotopic anomalies and chemical abundances in six Horizontal Branch B-type stars in globular clusters NGC6397 and NGC6752 and compare them to those observed in HgMn stars. We obtained high-resolution (up to R~115000) UVES s
Numerical and Analytical Approach to the Quantum Dynamics of Two Coupled Spins in Bosonic Baths
quant-phAlessandro Sergi, Ilya Sinayskiy, Francesco Petruccione
The quantum dynamics of a spin chain interacting with multiple bosonic baths is described in a mixed Wigner-Heisenberg representation. The formalism is illustrated by simulating the time evolution of the reduced density matrix of two coupled spins, where each spin is also coupled to its own bath of harmonic oscillators. In order to prove the validity of the
Antonio Petrella
The current status of the determinations of CKM matrix element |Vub| via exclusive and inclusive charmless semileptonic B decays is reviewed.
Francois Nedelec, Dietrich Foethke
We develop a numerical method to simulate mechanical objects in a viscous medium at a scale where inertia is negligible. Fibers, spheres and other voluminous objects are represented with points. Different types of connections are used to link the points together and in this way create composite mechanical structures. The motion of such structures in a Browni
Shlomi Dolev, Marina Kopeetsky, Adi Shamir
We consider repeated communication sessions between a RFID Tag (e.g., Radio Frequency Identification, RFID Tag) and a RFID Verifier. A proactive information theoretic security scheme is proposed. The scheme is based on the assumption that the information exchanged during at least one of every n successive communication sessions is not exposed to an adversary
HYDJET++ simulations and reconstruction of the anisotropic flow in Pb+Pb collisions at the LHC
hep-phL. V. Bravina, G. Kh. Eyyubova, V. L. Korotkikh, I. P. Lokhtin
The azimuthal anisotropy of charged particles in heavy ion collisions is an important probe of quark-gluon plasma evolution at early stages. In the present paper the elliptic flow pattern in Pb+Pb collisions at sqrt{s}=5.5 TeV is analyzed for different hadron species in the frameworks of HYDJET++ Monte-Carlo model. The influence of resonance decays on partic
Olivier Giraud, Bertrand Georgeot, Dima L. Shepelyansky
We study the localization properties of eigenvectors of the Google matrix, generated both from the World Wide Web and from the Albert-Barabasi model of networks. We establish the emergence of a delocalization phase for the PageRank vector when network parameters are changed. In the phase of localized PageRank, a delocalization takes place in the complex plan
Takahiko Furuya, Nicole Snashall
In this paper we give necessary and sufficient conditions for the variety of a simple module over a (D,A)-stacked monomial algebra to be nontrivial. This class of algebras was introduced in [Green and Snashall, The Hochschild cohomology ring modulo nilpotence of a stacked monomial algebra, Colloq. Math. 105 (2006), 233-258] and generalizes Koszul and D-Koszu
Coherent configurations and triply regular association schemes obtained from spherical designs
math.COSho Suda
Delsarte-Goethals-Seidel showed that if $X$ is a spherical $t$-design with degree $s$ satisfying $t\geq 2s-2$, $X$ carries the structure of an association scheme. Also Bannai-Bannai showed that the same conclusion holds if $X$ is an antipodal spherical $t$-design with degree $s$ satisfying $t=2s-3$. As a generalization of these results, we prove that a union
Rakesh Pandey, H. S. Dhami
Formal work in linguistics has both produced and used important mathematical tools. Motivated by a survey of models for context and word meaning, syntactic categories, phrase structure rules and trees, an attempt is being made in the present paper to present a mathematical model for structuring of sentences from active voice to passive voice, which is is the
Jets from black hole X-ray binaries: testing, refining and extending empirical models for the coupling to X-rays
astro-ph.HER. P. Fender, J. Homan, T. M. Belloni
In this paper we study the relation of radio emission to X-ray spectral and variability properties for a large sample of black hole X-ray binary systems. This is done to test, refine and extend -- notably into the timing properties -- the previously published `unified model' for the coupling of accretion and ejection in such sources. In 14 outbursts from
Special value formula for the spectral zeta function of the non-commutative harmonic oscillator
math.NTKazufumi Kimoto
We calculate the special values of the spectral zeta function of the non-commutative harmonic oscillator, and give a general formula for them as integrals of certain algebraic functions. This is a generalization of the result by Ichinose-Wakayama (2005), in which the first two special values are studied.
More about the hypothesis of a new weak interaction of electromagnetic field in the hidden sector
hep-phWojciech Krolikowski
New hypothetical field equations (Eqs. (1) and (2)) are further discussed, unifying Maxwell's equations of the Standard Model (after the electroweak symmetry is spontaneously broken) with the dynamics of hidden sector (expected to be responsible for the cold dark matter). The hidden sector is represented by sterile spin-1/2 Dirac fermions ("sterinos&
J. Javier Brey, P. Maynar, M. I. Garcia de Soria
Starting from the kinetic equations for the fluctuations and correlations of a dilute gas of inelastic hard spheres or disks, a Boltzmann-Langevin equation for the one-particle distribution function of the homogeneous cooling state is constructed. This equation is the linear Boltzmann equation with a fluctuating white noise term. Balance equations for the fl
Helmut Finner, Thorsten Dickhaus, Markus Roters
In this paper we introduce and investigate a new rejection curve for asymptotic control of the false discovery rate (FDR) in multiple hypotheses testing problems. We first give a heuristic motivation for this new curve and propose some procedures related to it. Then we introduce a set of possible assumptions and give a unifying short proof of FDR control for
Helmut Friedrich
While there exist now formulations of initial boundary value problems for Einstein's field equations which are well posed and preserve constraints and gauge conditions, the question of geometric uniqueness remains unresolved. For two different approaches we discuss how this difficulty arises under general assumptions. So far it is not known whether it ca
M. E. Lucassen, H. J. van Driel, C. Morais Smith, R. A. Duine
We present a model for the dynamics of current- and field-driven domain-wall lines at nonzero temperature. We compute thermally-averaged drift velocities from the Fokker-Planck equation that describes the nonzero-temperature dynamics of the domain wall. As special limits of this general description, we describe rigid domain walls as well as vortex domain wal
Anthony Challinor, Hiranya Peiris
We review the theory of the temperature anisotropy and polarization of the cosmic microwave background (CMB) radiation, and describe what we have learned from current CMB observations. In particular, we discuss how the CMB is being used to provide precise measurements of the composition and geometry of the observable universe, and to constrain the physics of
Liliana Formiggini, Elia M. Leibowitz
We report on the discovery of a coherent periodicity in the B light curve of the symbiotic star BF Cyg. The signal was detected in some sections of the light curve of the star recorded in the year 2003 as double hump periodic variations with an amplitude of ~7 mmag. In the year 2004 the signal was also present in only a subsection of the light curve. In that
Abhay Shukla, Rakesh Kumar, Javed Mazher, Adrian Balan
We show that by using an original method, bulk graphite can be bonded onto borosilicate glass or potentially any insulating substrate with ionic conductivity and then cleaved off to leave single or few layer graphene on the substrate, identified optically and with Raman spectroscopy. This simple, inexpensive and fast method leads to the preparation of large
Ross Duncan
Just as conventional functional programs may be understood as proofs in an intuitionistic logic, so quantum processes can also be viewed as proofs in a suitable logic. We describe such a logic, the logic of compact closed categories and biproducts, presented both as a sequent calculus and as a system of proof-nets. This logic captures much of the necessary s
Jan Schepers
We describe a class of isolated nondegenerate hypersurface singularities that give a polynomial contribution to Batyrev's stringy E-function. These singularities are obtained by imposing a natural condition on the facets of the Newton polyhedron, and they are strictly canonical. We prove that Batyrev's conjecture concerning the nonnegativity of strin
Evaluation of potential energy of interaction between molecules using one-range addition theorems for Slater type orbitals and Coulomb-Yukawa like correlated interaction potentials
math-phI. I. Guseinov
Using one-range addition theorems for noninteger n Slater type orbitals and Coulomb-Yukawa like correlated interaction potentials with noninteger indices obtained by the author with the help of complete orthonormal sets of exponential type orbitals, the series of expansion formulas are established for the potential produced by molecule, and the potential ene
T. Tony Cai, Harrison H. Zhou
A data-driven block thresholding procedure for wavelet regression is proposed and its theoretical and numerical properties are investigated. The procedure empirically chooses the block size and threshold level at each resolution level by minimizing Stein's unbiased risk estimate. The estimator is sharp adaptive over a class of Besov bodies and achieves s
Mustapha Raïs
Explicit generators are given for the ring of invariant polynomials under the coadjoint representation of certain inhomogeneous groups.
Automated star-galaxy segregation using spectral and integrated band data for TAUVEX/ASTROSAT satellite data pipeline
astro-ph.GAArchana Bora, Ranjan Gupta, Harinder P. Singh, K. Duorah
We employ an Artificial Neural Network (ANN) based technique to develop a pipeline for automated segregation of stars from the galaxies to be observed by Tel-Aviv University Ultra-Violet Experiment (TAUVEX). We use synthetic spectra of stars from UVBLUE library and selected International Ultraviolet Explorer (IUE) low resolution spectra for galaxies in the u
Ian M. Wanless
A latin square of order $n$ is an $n\times n$ array of $n$ symbols in which each symbol occurs exactly once in each row and column. A transversal of such a square is a set of $n$ entries such that no two entries share the same row, column or symbol. Transversals are closely related to the notions of complete mappings and orthomorphisms in (quasi)groups, and
Grzegorz Bobinski
In the paper we describe the almost split sequences in the homotopy category of perfect complexes over a gentle algebra.
Robert A. Brown
A movement is underway to test the uniqueness of Earth. Sponsored primarily by NASA, it is enlisting talented researchers from many disciplines. It is conceiving new telescopes to discover and characterize other worlds like Earth around nearby stars and to obtain their spectra. The goal is to search for signs of biological activity and perhaps find other cra
Bao-Xi Sun, E. Oset
We study the radiative decay into $γ$ and a baryon of the SU(3) decuplet of ten resonances that are dynamically generated from the interaction of vector mesons with baryons of the decuplet. We obtain quite different partial decay widths for the various resonances, and for different charge states of the same resonance, suggesting that the experimental investi
S. Marchi, S. Mottola, G. Cremonese, M. Massironi
In this paper we present a new method for dating the surface of the Moon, obtained by modeling the incoming flux of impactors and converting it into a size distribution of resulting craters. We compare the results from this model with the standard chronology for the Moon showing their similarities and discrepancies. In particular, we find indications of a no
J. Zorec, L. Cidale, M. L. Arias, Y. Fremat
Effective temperatures of early-type supergiants are important to test stellar atmosphere- and internal structure-models of massive and intermediate mass objects at different evolutionary phases. However, these Teff values are more or less discrepant depending on the method used to determine them. We aim to obtain a new calibration of the Teff parameter for
Lower current-driven exchange switching threshold in noncollinear magnetic junctions under high spin injection
cond-mat.mtrl-sciS. G. Chigarev, E. M. Epshtein, P. E. Zilberman
Current-induced switching is considered in a magnetic junction. The junction includes pinned and free ferromagnetic layers which work in the regime of the high spin injection. It is shown that in such a regime the exchange magnetization reversal threshold can be lowered up to two times when the axes of the layers are noncollinear.
B. K. Nayak, U. Garg, M. Koss, T. Li
The excitation and subsequent proton decay of the isoscalar giant dipole resonance (ISGDR) in $^{208}$Pb have been investigated via the $^{208}$Pb($α, α^{\prime}p)^{207}$Tl reaction at 400 MeV. Excitation of the ISGDR has been identified by the difference-of-spectra method. The enhancement of the ISGDR strength at high excitation energies observed in the mul
Vesselin Petkov
A fifty-year old apparently paradoxical thought experiment involving two accelerating spaceships and a thread hat connects them states that the thread will break due to length contraction. This paradox still appears to be regarded by some physicists as a proof that (i) only physical bodies, but not space, undergo relativistic length contraction and (ii) a re
Andre C. R. Martins
Science is a fundamental human activity and we trust its results because it has several error-correcting mechanisms. Its is subject to experimental tests that are replicated by independent parts. Given the huge amount of information available, scientists have to rely on the reports of others. This makes it possible for social effects to influence the scienti
A. Borichev, Yu. Lyubarskii, E. Malinnikova, P. Thomas
We study radial behavior of analytic and harmonic functions, which admit a certain majorant in the unit disk. We prove that extremal growth or decay may occur only along small sets of radii and give precise estimates of these exceptional sets.
Feng Qi, Bai-Ni Guo
In this article, logarithmically complete monotonicity properties of some functions such as $\frac1{[Γ(x+1)]^{1/x}}$, $\frac{[{Γ(x+α+1)}]^{1/(x+α)}}{[{Γ(x+1)}]^{1/x}}$, $\frac{[Γ(x+1)]^{1/x}}{(x+1)^α}$ and $\frac{[Γ(x+1)]^{1/x}}{x^α}$ defined in $(-1,\infty)$ or $(0,\infty)$ for given real number $α\in\tr$ are obtained, some known results are recovered, exte
Xiaofei Huang
In a society of completely selfish individuals where everybody is only interested in maximizing his own payoff, does any equilibrium exist for the society? John Nash proved more than 50 years ago that an equilibrium always exists such that nobody would benefit from unilaterally changing his strategy. Nash Equilibrium is a central concept in game theory, whic
D. D. R. Bayliss, D. T. F. Weldrake, P. D. Sackett, B. W. Tingley
We present the results of a deep, wide-field transit survey targeting Hot Jupiter planets in the Lupus region of the Galactic plane conducted over 53 nights concentrated in two epochs separated by a year. Using the Australian National University 40-inch telescope at Siding Spring Observatory (SSO), the survey covered a 0.66 sq. deg. region close to the Galac
F. M. Montenegro-Montes, K. -H. Mack, C. R. Benn, R. Carballo
Broad Absorption Line Quasars (BAL QSOs) have been found to be associated with extremely compact radio sources. These reduced dimensions can be either due to projection effects or these objects might actually be intrinsically small. Exploring these two hypotheses is important to understand the nature and origin of the BAL phenomenon because orientation effec
Mo Li, W. H. P. Pernice, H. X. Tang
The optical binding forces between guided lightwaves in dielectric waveguides can be either repulsive or attractive. So far only attractive force has been observed. Here we experimentally demonstrate a bipolar optical force between coupled nanomechanical waveguides. Both attractive and repulsive optical forces are obtained. The sign of the force can be switc
Shen Jun, Wu Junde
In this paper, first, we answer affirmatively an open problem which was presented in 2005 by professor Gudder on the sub-sequential effect algebras. That is, we prove that if $(E,0,1, \oplus, \circ)$ is a sequential effect algebra and $A$ is a commutative subset of $E$, then the sub-sequential effect algebra $\bar{A}$ generated by $A$ is also commutative. Ne
Shen Jun, Wu Junde
A sequential effect algebra $(E,0,1, \oplus, \circ)$ is an effect algebra on which a sequential product $\circ$ with certain physics properties is defined, in particular, sequential effect algebra is an important model for studying quantum measurement theory. In 2005, Gudder asked the following problem: If $a, b\in (E,0,1,\oplus, \circ)$ and $a\bot b$ and $a
Thomas A. Trainor
Hard components of $p_t$ spectra can be identified with minimum-bias parton fragmentation in nuclear collisions. Minimum-bias fragment distributions (FDs) can be calculated by folding a power-law parton energy spectrum with parametrized fragmentation functions (FFs) derived from $e^+$-$e^-$ and p-p collisions. Alterations to FFs due to parton "energy los
Li Liu, Hairong Yuan
We show that for steady compressible potential flow in a class of straight divergent nozzles with arbitrary cross-section, if the flow is supersonic and spherically symmetric at the entry, and the given pressure (velocity) is appropriately large (small) and also spherically symmetric at the exit, then there exists uniquely one transonic shock in the nozzle.
Comment on "Mechanism of Terahertz Electromagnetic Wave Emission from Intrinsic Josephson Junctions"
cond-mat.supr-conShizeng Lin, Xiao Hu
In a recent Letter, Tachiki \emph{et al.} argued that the dynamic state of superconductivity phase in multi junctions characterized by $\pmπ$ kinks is hard to realize from an energetic point of view. Instead, they proposed a so-called "state without kink". In this Comment, we point out that their energetic consideration is inconsistent with the well
Alberto Castro, E. K. U. Gross
We propose the use of mixing strategies to accelerate the convergence of the common iterative algorithms utilized in Quantum Optimal Control Theory (QOCT). We show how the non-linear equations of QOCT can be viewed as a "fixed-point" non-linear problem. The iterative algorithms for this class of problems may benefit from mixing strategies, as it happ
Jae-Wook Chung
Based on the Kauffman bracket at $A=e^{i π/4}$, we defined an invariant for a special type of $n$-punctured ball tangles. The invariant $F^n$ takes values in the set $PM_{2\times2^n}(\mathbb Z)$ of $2\times 2^n$ matrices over $\mathbb Z$ modulo the scalar multiplication of $\pm1$. We provide the formula to compute the invariant of the $k_1 + ... + k_n$-punct
The vacuum thermal treatment effect on the optical absorption spectra of the TiO2 coated by Ni-B nano-clasters photocatalyst powders
cond-mat.mtrl-sciM. M. Nadareishvili, K. A. Kvavadze, G. I. Mamniashvili, T. N. Khoperia
The thermal vacuum treatment effect on the optical absorption spectra of the TiO2 nanopowders, both pure and coated by the Ni-B clasters with the original electroless method was investigated. It was observed that the thermal treatment of pure TiO2 nanopowders does not change their optical absorption spectrum while after the coating of these powder particles
Michela Redivo-Zaglia, Giuseppe Rodriguez
We introduce the smt toolbox for Matlab. It implements optimized storage and fast arithmetics for circulant and Toeplitz matrices, and is intended to be transparent to the user and easily extensible. It also provides a set of test matrices, computation of circulant preconditioners, and two fast algorithms for Toeplitz linear systems.
Hans-Juergen Sommers, Boris A Khoruzhenko
We derive an explicit simple formula for expectations of all Schur functions in the real Ginibre ensemble. It is a positive integer for all entries of the partition even and zero otherwise. The result can be used to determine the average of any analytic series of elementary symmetric functions by Schur function expansion.
P. Carrasco, A. M. Cegarra, A. R. Garzón
This paper explores the relationship amongst the various simplicial and pseudo-simplicial objects characteristically associated to any bicategory C. It proves the fact that the geometric realizations of all of these possible candidate `nerves of C' are homotopy equivalent. Any one of these realizations could therefore be taken as the classifying space BC
Luigi Cantini
We consider the qKZ equations based on the two boundaries Temperley Lieb algebra. We construct their solution in the case $s=q^{-3/2}$ using a recursion relation. At the combinatorial point $q^{1/2}= e^{-2πi/3}$ the solution reduces to the ground state of the dense O(1) loop model on a strip with open boundary conditions. We present an alternative constructi
Amelia Sparavigna
Image processing can be used for digital restoration of ancient papyri, that is, for a restoration performed on their digital images. The digital manipulation allows reducing the background signals and enhancing the readability of texts. In the case of very old and damaged documents, this is fundamental for identification of the patterns of letters. Some exa
Mehdi Neek-Amal, Reza Asgari
Nano-indentation of circular graphene flakes are studied by using Molecular Dynamics simulation. We show that the theory of continuum elasticity based on nonlinear Föpple-Hencky equations is applicable on a circular suspended graphene flake. Our simulation results are plenty compatible to those results calculated by the nonlinear elasticity theory. We find t
Comment on "Critical and slow dynamics in a bulk metallic glass exhibiting strong random magnetic anisotropy" [Appl. Phys. Lett. 92, 011923 (2008)]
cond-mat.mtrl-sciHa M. Nguyen, Pai-Yi Hsiao
In this comment, by using Monte Carlo simulation, we show that the perpendicular shift of hysteresis loops reported in the commented work is nothing special but simply due to the fact that the range of field does not surpass the reversible field beyond which the two branches of the loop merge. If the reversible field is exceeded, the shift is no longer obser
On Bogovski\uı and regularized Poincaré integral operators for de Rham complexes on Lipschitz domains
math.APMartin Costabel, Alan McIntosh
We study integral operators related to a regularized version of the classical Poincaré path integral and the adjoint class generalizing Bogovski\uı's integral operator, acting on differential forms in $R^n$. We prove that these operators are pseudodifferential operators of order -1. The Poincaré-type operators map polynomials to polynomials and can have
B. Ivlev
Quantum tunneling through a two-dimensional static barrier becomes unusual when a momentum of an electron has a tangent component with respect to a border of the prebarrier region. If the barrier is not homogeneous in the direction perpendicular to tunneling a fraction of the electron state is waves propagating away from the barrier. When the tangent momentu
Anisotropic spin fluctuations and multiple superconducting gaps in hole-doped Ba_0.7K_0.3Fe_2As_2: NMR in a single crystal
cond-mat.supr-conK. Matano, G. L. Sun, D. L. Sun, C. T. Lin
We report the first ^{75}As-NMR study on a single crystal of the hole-doped iron-pnictide superconductor Ba_{0.7}K_{0.3}Fe_2As_{2} (T_c = 31.5 K). We find that the Fe antiferromagnetic spin fluctuations are anisotropic and are weaker compared to underdoped copper-oxides or cobalt-oxide superconductors. The spin lattice relaxation rate 1/T_1 decreases below T