August 2010 arXiv papers — page 15
Showing 1,401–1,500 of 5,306 papers
Optimal Gaussian squeezed states for atom-interferometry in the presence of phase diffusion
cond-mat.quant-gasIgor Tikhonenkov, Michael G. Moore, Amichay Vardi
We optimize the signal-to-noise ratio of a Mach-Zehnder atom interferometer with Gaussian squeezed input states, in the presence interactions. For weak interactions, our results coincide with Phys. Rev. Lett. {\bf 100}, 250406 (2008), with optimal initial number-variance $σ_o\propto N^{1/3}$ and optimal signal-to-noise ratio $s_o\propto N^{2/3}$ for total at
Meghan Rose Allen
Combinatorial games are played under two different play conventions: normal play, where the last player to move wins, and \mis play, where the last player to move loses. Combinatorial games are also classified into impartial positions and partizan positions, where a position is impartial if both players have the same available moves and partizan otherwise. \
Leonard Spiegel, Tobias Barvich, Burt Betchart, Saptaparna Bhattacharya
With an expected ten-fold increase in luminosity in S-LHC, the radiation environment in the tracker volumes will be considerably harsher for silicon-based detectors than the already harsh LHC environment. Since 2006, a group of CMS institutes, using a modified CMS DAQ system, has been exploring the use of Magnetic Czochralski silicon as a detector element fo
Kostantin S. Tikhonov, Mikhail V. Feigel'man, Alexei Yu. Kitaev
We consider spin-$\frac{1}{2}$ model on the honeycomb lattice~\cite{Kitaev06} in presence of a weak magnetic field $h_{α}\ll 1$. Such a perturbation destroys exact integrability of the model in terms of gapless fermions and \textit{static} $Z_{2}$ fluxes. We show that it results in appearance of a long-range tail in the irreducible dynamic spin correlation f
Gian Luca Giorgi
The occurrence of parity-time reversal ($\mathcal{PT}$) symmetry breaking is discussed in a non-Hermitian spin chain. The Hermiticity of the model is broken by the presence of an alternating, imaginary, transverse magnetic field. A full real spectrum, which occurs if and only if all the eigenvectors are $\mathcal{PT}$ symmetric, can appear only in presence o
Tracy L. Beck, Jeffery S. Bary, Peter J. McGregor
The majority of atomic hydrogen Brγ emission detected in the spectra of young stellar objects (YSOs) is believed to arise from the recombination regions associated with the magnetospheric accretion of circumstellar disk material onto the forming star. In this paper, we present the results of a K-band IFU spectroscopic study of Brγ emission in eight young pro
Piotr Bania
With the discovery of new exploit techniques, new protection mechanisms are needed as well. Mitigations like DEP (Data Execution Prevention) or ASLR (Address Space Layout Randomization) created a significantly more difficult environment for vulnerability exploitation. Attackers, however, have recently developed new exploitation methods which are capable of b
Is the Wannier threshold law for angular distribution in double photoionization of atoms true at practically attainable energies of ejected electrons?
physics.atom-phVladislav V. Serov, Tatyana A. Sergeeva
We calculated ab initio the three-fold differential cross section of a double single-photon Helium photoionization at equal energy sharing, and obtained from one the Gaussian width parameter, describing the angular interelectron correlations, for the total electrons energies range E from 0.1 eV to 100 eV. The results are in excellent agreement with experimen
Imran Sayed, Joanna Berzowska, Maksim Skorobogatiy
We present an overview of photonic textile displays woven on a Jacquard loom, using newly discovered polymer photonic bandgap fibers that have the ability to change color and appearance when illuminated with ambient or transmitted light. The photonic fiber can be thin (smaller than 300 microns in diameter) and highly flexible, which makes it possible to weav
Unconditional convergence of spectral decompositions of 1D Dirac operators with regular boundary conditions
math.SPPlamen Djakov, Boris Mityagin
One dimensional Dirac operators $$ L_{bc}(v) \, y = i \begin{pmatrix} 1 & 0 0 & -1 \end{pmatrix} \frac{dy}{dx} + v(x) y, \quad y = \begin{pmatrix} y_1 y_2 \end{pmatrix}, \quad x\in[0,π],$$ considered with $L^2$-potentials $ v(x) = \begin{pmatrix} 0 & P(x) Q(x) & 0 \end{pmatrix} $ and subject to regular boundary conditions ($bc$), have discrete spectrum. For
A. Doroshkevich, O. Verkhodanov
We show that the popular ILC approach is unstable in respect to the division of the sample of map pixels to the set of ``homogeneous'' subsamples. For suitable choice of such subsamples we can obtain the restored CMB signal with amplitudes ranged from zero to the amplitudes of the observed signal. We propose approach which allows us to obtain reasona
Maité Dupuis, Etera R. Livine
Projected spin network states are the canonical basis of quantum states of geometry for the most recent EPR-FK spinfoam models for quantum gravity. They are functionals of both the Lorentz connection and the time normal field. We analyze in details the map from these projected spin networks to the standard SU(2) spin networks of loop quantum gravity. We show
Yakov Shlapentokh-Rothman
The Faber-Krahn inequality states that among all open domains with a fixed volume in R^n, the ball minimizes the first Dirichlet eigenvalue of the Laplacian. We study an asymptotic discrete analogue of this for the combinatorial Dirichlet Laplacian acting on induced subgraphs of Z^2. Namely, an induced subgraph G with n vertices is called a minimizing subgra
Relativistic Treatment of the Spin-Zero Particles Subject to the q-Deformed Hyperbolic Modified Pöschl-Teller Potential
quant-phK. J. Oyewumi, T. T. Ibrahim, S. O. Ajibola, D. A. Ajadi
In this study, we solve the Klein-Gordon equation with equal scalar and vector q-deformed hyperbolic modified Pöschl-Teller potential. The explicit expressions of bound state spectra and the normalized eigenfunctions for s-wave bound states are obtained analytically. The energy equations and the corresponding wave functions for the special cases of the equal
Stephen L. Skinner, Manuel Guedel, Kevin R. Briggs, Sergei A. Lamzin
FU Orionis is the prototype of a class of eruptive young stars (``FUors'') characterized by strong optical outbursts. We recently completed an exploratory survey of FUors using XMM-Newton to determine their X-ray properties, about which little was previously known. The prototype FU Ori and V1735 Cyg were detected. The X-ray spectrum of FU Ori was fou
Spatial, Temporal and Spectral Properties of X-ray Emission from the Magnetar SGR~0501+4516
astro-ph.HEErsin Gogus, Peter M. Woods, Chryssa Kouveliotou, Yuki Kaneko
SGR~0501+4516 was discovered with the Swift satellite on 2008 August 22, after it emitted a series of very energetic bursts. Since then, the source was extensively monitored with Swift, the Rossi X-ray Timing Explorer (RXTE) and observed with Chandra and XMM-Newton, providing a wealth of information about its outburst behavior and burst induced changes of it
Ziyang Hu
In this paper we give a general geometrical framework for working with problems that can be described as a structure-preserving submersion defined on a suitable space with a geometrical structure. We give many examples of how to formulate familiar problems arsing from physics in our framework. Then, as an application of this framework we derive the new resul
Oliver G. King, Charles Copley, Rod Davies, Richard Davis
The C-Band All-Sky Survey (C-BASS) aims to produce sensitive, all-sky maps of diffuse Galactic emission at 5 GHz in total intensity and linear polarization. These maps will be used (with other surveys) to separate the several astrophysical components contributing to microwave emission, and in particular will allow an accurate map of synchrotron emission to b
Peter B. Shalen
We show that 0.29 is a Margulis number for all but finitely many hyperbolic 3-manifolds. The finitely many exceptions are all closed.
Howon Lee, Chunguang Xia, Nicholas X. Fang
Swelling-induced snap-buckling in a 3D micro hydrogel device, inspired by the insect-trapping action of Venus flytrap, makes it possible to generate astonishingly fast actuation. We demonstrate that elastic energy is effectively stored and quickly released from the device by incorporating elastic instability. Utilizing its rapid actuation speed, the device c
Ionization signals from electrons and alpha-particles in mixtures of liquid Argon and Nitrogen - perspectives on protons for Gamma Resonant Nuclear Absorption applications
physics.ins-detM. Zeller, I. Badhrees, S. Delaquis, A. Ereditato
In this paper we report on a detailed study of ionization signals produced by Compton electrons and alpha-particles in a Time Projection Chamber (TPC) flled with different mixtures of liquid Argon and Nitrogen. The measurements were carried out with Nitrogen concentrations up to 15% and a drift electric feld in the range 0-50 kV/cm. A prediction for proton i
M. I. Zhenirovskyy, D. V. Lande, A. A. Snarskii
A concept of implicit links for Complex Networks has been defined and a new value - cohesion factor, which allows to evaluate numerically the presence of such connection between any two nodes, has been introduced. We introduce a generalization of such characteristics as the betweenness, which allows to rank network nodes in more details. The effectiveness of
Martin C. Cooper, Stanislav Zivny
The constraint satisfaction problem (CSP) is a central generic problem in computer science and artificial intelligence: it provides a common framework for many theoretical problems as well as for many real-life applications. Soft constraint problems are a generalisation of the CSP which allow the user to model optimisation problems. Considerable effort has b
Complete symmetry analyses of the surface-induced piezomagnetic, piezoelectric and linear magnetoelectric effects
cond-mat.mtrl-sciEugene A. Eliseev
The impact of the surface on the magnetic symmetry is studied. It is shown how symmetry breaking transforms the "seeding" 90 bulk magnetic classes, which include 66 piezomagnetic classes and 58 magnetoelectric classes, into the 21 surface-induced magnetic classes, which all are piezomagnetic, piezoelectric and 19 of them are linear magnetoelectric. S
Paul S. Muhly, Baruch Solel
In this expository paper we describe the study of certain non-self-adjoint operator algebras, the Hardy algebras, and their representation theory. We view these algebras as algebras of (operator valued) functions on their spaces of representations. We will show that these spaces of representations can be parameterized as unit balls of certain $W^{*}$-corresp
Robin A. Moser, Dominik Scheder
Schoening in 1999 presented a simple randomized algorithm for k-SAT with running time O(a^n * poly(n)) for a = 2(k-1)/k. We give a deterministic version of this algorithm running in time O((a+epsilon)^n * poly(n)), where epsilon > 0 can be made arbitrarily small.
Manifestation of geometric resonance in current dependence of AC susceptibility for unshunted array of Nb-AlOx-Nb Josephson junctions
cond-mat.supr-conV. A. G. Rivera, S. Sergeenkov, E. Marega, F. M. Araujo-Moreira
A pronounced resonance-like structure has been observed in the current dependence of AC susceptibility for two-dimensional array of unshunted Nb-AlOx-Nb Josephson junctions. Using a single-plaquette approximation, we were able to successfully fit our data assuming that resonance structure is related to the geometric (inductive) properties of the array.
E. I. Lashin, S. Nasri, E. Malkawi, N. Chamoun
We present the general form of the unitary matrices keeping invariant the Majorana neutrino mass matrix of specific texture suitable for explaining oscillation data. In the case of the Tri-bimaximal pattern with two degenerate masses we give a specific realization of the underlying $U(1)$ symmetry which can be uplifted to a symmetry in a complete theory incl
Vitaly V. Bulatov, Yuriy V. Vladimirov
This work focuses on the mathematical modeling of wave dynamics in a stratified medium. Non-local absorbing boundary conditions are considered based on the two following assumptions: (i) a linear theory can be applied at large distances from perturbation sources; and (ii) there are no other sources of wave disturbance outside the mixing zone in the stratifie
Magnetism of mixed quaternary Heusler alloys: (Ni,T)$_{2}$MnSn (T=Cu,Pd) as a case study
cond-mat.mtrl-sciS. K. Bose, J. Kudrnovský, V. Drchal, I. Turek
The electronic properties, exchange interactions, finite-temperature magnetism, and transport properties of random quaternary Heusler Ni$_{2}$MnSn alloys doped with Cu- and Pd-atoms are studied theoretically by means of {\it ab initio} calculations over the entire range of dopant concentrations. While the magnetic moments are only weakly dependent on the all
The distribution of the square sum of Dirichlet random variables and a table with quantiles of Greenwood's statistic
math.STThomas Royen
The exact distribution of the square sum of Dirichlet random variables is given by two different univariate integral representations. Alternatively, three representations by orthogonal series with Jacobi or Legendre polynomials are derived. As a special case the distribution of the square sum of spacings - also called Greenwood's statistic - is obtained.
Scanning mid-IR-laser microscopy: an efficient tool for materials studies in silicon-based photonics and photovoltaics
cond-mat.mtrl-sciO. V. Astafiev, V. P. Kalinushkin, V. A. Yuryev
A method of scanning mid-IR-laser microscopy has recently been proposed for the investigation of large-scale electrically and recombination-active defects in semiconductors and non-destructive inspection of semiconductor materials and structures in the industries of microelectronics and photovoltaics. The basis for this development was laid with a wide cycle
Martin Lorenz, Loretta FitzGerald Tokoly
This note presents some results on projective modules and the Grothendieck groups K_0 and G_0 for Frobenius algebras and for certain Hopf Galois extensions. Our principal technical tools are the Higman trace for Frobenius algebras and a product formula for Hattori-Stallings ranks of projectives over Hopf Galois extensions.
P. R. Crompton
Following the recent approach of using order domains to construct Grobner bases from general projective varieties, we examine the parity and time-reversal arguments relating de Witt and Lyman's assertion that all path weights associated with homotopy in dimensions d <= 2 form a faithful representation of the fundamental group of a quantum system. We then
Martin Lorenz
This expository article presents a unified ring theoretic approach, based on the theory of Frobenius algebras, to a variety of results on Hopf algebras. These include a theorem of S. Zhu on the degrees of irreducible representations, the so-called class equation, the determination of the semisimplicity locus of the Grothendieck ring, the spectrum of the adjo
Time-dependent magnetotransport in an interacting double quantum wire with window coupling
cond-mat.mes-hallNzar Rauf Abdullah, Chi-Shung Tang, Vidar Gudmundsson
We present a double quantum wire system containing a coupling element in the middle barrier between the two parallel quantum wires. We explicitly account for the finite length of the double quantum wire with a time-dependent switching-on potential coupling the double-wire system and the leads. By tuning the magnetic field and the coupling window between the
C. Sivaram, Kenath Arun
Gamma ray bursts are the most luminous physical phenomena in the universe, consisting of flashes of gamma rays that last from seconds to hours. There have been attempts to observe gamma ray bursts, for example, from population III stars of about 500 solar mass at high redshifts. Here we argue that collapse of such high mass stars does not lead to gamma ray b
Vasily A. Khlebnikov, Kristian Zarb-Adami, Richard P. Armstrong, Michael E. Jones
In this paper, we consider the problem of optimum multi-domain real-time beamforming and high-precision beam pattern positioning in application to very large wideband array antennas, particularly to the Square Kilometre Array (SKA) aperture array antenna. We present a new structure for wideband space-frequency beamforming and beamsteering that maximizes dete
Application of scanning mid-IR-laser microscopy for characterization of semiconductor materials for photovoltaics
cond-mat.mtrl-sciV. P. Kalinushkin, O. V. Astafiev, V. A. Yuryev
The scanning mid-IR-laser microscopy was previously demonstrated as an effective tool for characterization of different semiconductor crystals. Now the technique has been successfully applied for the investigation of CZ SixGe1-x -- a promising material for photovoltaics - and multicrystalline silicon for solar cells. In addition, this technique was shown to
jorgen cherly
In this paper we state that the fraction of invertible m-times persymmetric matrices over F_2 is equal to \prod_{j=1}^{m}(1-2^{-j})
A J Faulkner, K Zarb Adami, J. G. Bij de Vaate, G. W. Kant
Beamforming is central to the processing function of all phased arrays and becomes particularly challenging with a large number of antenna element (e.g. >100,000). The ability to beamform efficiently with reasonable power requirements is discussed in this paper. Whilst the most appropriate beamforming technology will change over time due to semiconductor and
Elena Beretta, Elisa Francini
In this paper we investigate the boundary value problem ${div(γ\nabla u)=0 in Ω, u=f on \partialΩ$ where $γ$ is a complex valued $L^\infty$ coefficient, satisfying a strong ellipticity condition. In Electrical Impedance Tomography, $γ$ represents the admittance of a conducting body. An interesting issue is the one of determining $γ$ uniquely and in a stable
Pierre Degond, Jiale Hua, Laurent Navoret
In this paper, we study the numerical simulations for Euler system with maximal density constraint. This model is developed in [1, 3] with the constraint introduced into the system by a singular pressure law, which causes the transition of different asymptotic dynamics between different regions. To overcome these difficulties, we adapt and implement two asym
Guy Wolfovitz
We consider the K_4-free process. In this process, the edges of the complete n-vertex graph are traversed in a uniformly random order, and each traversed edge is added to an initially empty evolving graph, unless the addition of the edge creates a copy of K_4. Let M(n) denote the graph that is produced by that process. We prove that a.a.s., the number of edg
Federico Frascoli, Lennaert van Veen, Ingo Bojak, David T J Liley
Mean field models (MFMs) of cortical tissue incorporate salient features of neural masses to model activity at the population level. One of the common aspects of MFM descriptions is the presence of a high dimensional parameter space capturing neurobiological attributes relevant to brain dynamics. We study the physiological parameter space of a MFM of electro
T. Wolf, N. Bergeal, C. Ulysse, G. Faini
We have investigated the electrodynamic properties of High-Tc strip-lines made by ion irradiation, in order to evaluate the potentialities of such a technology for RSFQ superconductor digital electronic. SQUID loops of different length and width have been fabricated by ion bombardment of 70 nm thick films through e-beam lithographied shadow masks, and measur
On the generalized intelligent states and certain related nonclassical states of a quantum exactly solvable nonlinear oscillator
quant-phV Chithiika Ruby, M Senthilvelan
We construct nonlinear coherent states or f-deformed coherent states for a nonpolynomial nonlinear oscillator which can be considered as placed in the middle between the harmonic oscillator and the isotonic oscillator (Cariñena J F et al, J. Phys. A: Math. Theor. 41, 085301 (2008)). The deformed annihilation and creation operators which are required to const
Dominant role of impurity scattering over crystalline anisotropy for magnetotransport properties in the quasi-1D Hollandite Ba1.2Rh8O16
cond-mat.mtrl-sciAlain Pautrat, Wataru Kobayashi
Angular magnetotransport measurements have been performed to tackle the origin of the magnetoresistance in the quasi-1D Hollandite Ba1.2Rh8O16. Three samples of different impurities amount were measured. We observe that the low temperature resistivity upturn is not due to a charge density wave transition, and a dominant role of impurities scattering for low
R. Balakrishnan, N. Sridharan, K. V. Iyer
Given a simple connected undirected graph G, the Wiener index W(G) of G is defined as half the sum of the distances over all pairs of vertices of G. In practice, G corresponds to what is known as the molecular graph of an organic compound. We obtain a sharp lower bound for W(G) of an arbitrary graph in terms of the order, size and diameter of G.
S. Bardin, J-L. Briançon, F. Brochard, V. Martin
An algorithm has been developped, which makes it possible to automatically extract trajectories of a large number of particles from fast imaging data, allowing a statistical analysis of particles trajectories under various plasma conditions, a better understanding of their influence on plasma properties, and a better characterization of the plasma itself. In
Comment on "Einstein's Other Gravity and the Acceleration of the Universe''
astro-ph.COKazuharu Bamba, Chao-Qiang Geng, Chung-Chi Lee
We show that in the exponential $f(T)$ model studied by E. Linder [arXiv:1005.3039, Phys.Rev.D 81, 127301 (2010)], it is impossible to have the crossing of the phantom divide line $w_{\mathrm{DE}}=-1$.
Vladimir Kolmogorov
We study the complexity of valued constraint satisfaction problems (VCSP). A problem from VCSP is characterised by a \emph{constraint language}, a fixed set of cost functions over a finite domain. An instance of the problem is specified by a sum of cost functions from the language and the goal is to minimise the sum. We consider the case of so-called \emph{c
Christophe Ladroue
The solution of a (stochastic) differential equation (SDE) can be locally approximated by a stochastic expansion, a linear combination of iterated integrals. Quantities of interest, like moments, can then be approximated with the expansion. We present a formula for the case where the drivers of the equation are time and Wiener processes. We also present a Ma
Low temperature electron-spin relaxation in the crystalline and glassy states of solid ethanol
cond-mat.softMarina Kveder, Dalibor Merunka, Milan Jokić, Boris Rakvin
X-band electron paramagnetic resonance (EPR) spectroscopy was used to study the spectral properties of a nitroxide spin probe in ethanol glass and crystalline ethanol, at 5 - 11.5 K. The different anisotropy of molecular packing in the two host matrices was evidenced by different rigid limit values for maximal hyperfine splitting in the signal of the spin pr
Electron spin-lattice relaxation in solid ethanol: the effect of nitroxyl radical hydrogen bonding and matrix disorder
physics.chem-phMarina Kveder, Dalibor Merunka, Milan Jokić, Janja Makarević
The electron spin-lattice relaxation of TEMPO and TEMPONE was measured at temperatures between 5 and 80 K in crystalline and glassy ethanol using X-band electron paramagnetic resonance spectroscopy. The experimental data at the lowest temperatures studied were explained in terms of electron-nuclear dipolar interaction between the paramagnetic center and the
Lunar Palaeoregolith Deposits as Recorders of the Galactic Environment of the Solar System and Implications for Astrobiology
astro-ph.EPIan A. Crawford, Sarah A. Fagents, Katherine H. Joy, M. Elise Rumpf
One of the principal scientific reasons for wanting to resume in situ exploration of the lunar surface is to gain access to the record it contains of early Solar System history. Part of this record will pertain to the galactic environment of the Solar System, including variations in the cosmic ray flux, energetic galactic events (e.g, supernovae and/or gamma
Uniformly curated signaling pathways reveal tissue-specific cross-talks and support drug target discovery
q-bio.MNTamas Korcsmaros, Illes J. Farkas, Maté S. Szalay, Petra Rovo
Motivation: Signaling pathways control a large variety of cellular processes. However, currently, even within the same database signaling pathways are often curated at different levels of detail. This makes comparative and cross-talk analyses difficult. Results: We present SignaLink, a database containing 8 major signaling pathways from Caenorhabditis elegan
Bruce Blackadar, Leonel Robert, Aaron P. Tikuisis, Andrew S. Toms
The radius of comparison is an invariant for unital C*-algebras which extends the theory of covering dimension to noncommutative spaces. We extend its definition to general C*-algebras, and give an algebraic (as opposed to functional-theoretic) reformulation. This yields new permanence properties for the radius of comparison which strengthen its analogy with
Kuo-An Wu, Mathis Plapp, Peter W Voorhees
We investigate the possibility to control the symmetry of ordered states in phase-field crystal models by tuning nonlinear resonances. In two dimensions, we find that a state of square symmetry as well as coexistence between squares and hexagons can be easily obtained. In contrast, it is delicate to obtain coexistence of squares and liquid. We develop a gene
Xiaobo Zhu, Alexander Kemp, Shiro Saito, Kouichi Semba
We replace the Josephson junction defining a three-junction flux qubit's properties with a tunable direct current superconducting quantum interference devices (DC-SQUID) in order to tune the qubit gap during the experiment. We observe different gaps as a function of the external magnetic pre-biasing field and the local magnetic field through the DC-SQUID
Mazhar Ali
Quantum discord witnesses the nonclassicality of quantum states even when there is no entanglement in these quantum states. This type of quantum correlation also has some interesting and significant applications in quantum information processing. Quantum discord has been evaluated explicitly only for certain class of two-qubit states. We extend the previous
K. Srinivasan, I. Raja Mohamed, K. Murali, M. Lakshmanan
A novel time delayed chaotic oscillator exhibiting mono- and double scroll complex chaotic attractors is designed. This circuit consists of only a few operational amplifiers and diodes and employs a threshold controller for flexibility. It efficiently implements a piecewise linear function. The control of piecewise linear function facilitates controlling the
Peter Pflug, Wlodzimierz Zwonek
We show that the symmetrized bidisc may be exhausted by strongly linearly convex domains. It shows in particular the existence of a strongly linearly convex domain that cannot be exhausted by domains biholomorphic to convex ones.
Shinji Fukuhara
Let $G_{2n}$ be the Eisenstein series of weight $2n$ for the full modular group $Γ=SL_2(\ZZ)$. It is well-known that the space $M_{2k}$ of modular forms of weight $2k$ on $Γ$ has a basis $\{G_{4}^αG_{6}^β |\ α,β\in\ZZ,\ α,β\geq 0,\ 4α+6β=2k\}$. In this paper we will exhibit another (simpler) basis for $M_{2k}$. It is given by $\{G_{2k}\}\cup\{G_{4i}G_{2k-4i}
T. Felipe, E. Khomenko, M. Collados, C. Beck
We analyze the propagation of waves in sunspots from the photosphere to the chromosphere using time series of co-spatial Ca II H intensity spectra (including its line blends) and polarimetric spectra of Si I 10827 and the He I 10830 multiplet. From the Doppler shifts of these lines we retrieve the variation of the velocity along the line-of-sight at several
Phonon Calculations in Cubic and Tetragonal Phases of SrTiO3: a Comparative LCAO and Plane Wave Study
cond-mat.mtrl-sciRobert A. Evarestov, Evgeny Blokhin, Denis Gryaznov, Eugene A. Kotomin
The atomic, electronic structure and phonon frequencies have been calculated in a cubic and low-temperature tetragonal SrTiO3 phases at the ab initio level. We demonstrate that the use of hybrid exchange-correlation PBE0 functional gives the best agreement with experimental data. The results for the standard PBE and hybrid PBE0 are compared for the two types
Sinya Aoki
We report on new attempt to investigate baryon-baryon interactions in lattice QCD. From the Bethe-Salpeter (BS) wave function, we have successfully extracted the nucleon-nucleon ($NN$) potentials in quenched QCD simulations, which reproduce qualitative features of modern $NN$ potentials. The method has been extended to obtain the tensor potential as well as
Tianyi Zhou, Dacheng Tao, Xindong Wu
Support vector machines (SVMs) are invaluable tools for many practical applications in artificial intelligence, e.g., classification and event recognition. However, popular SVM solvers are not sufficiently efficient for applications with a great deal of samples as well as a large number of features. In this paper, thus, we present NESVM, a fast gradient SVM
Ahmed El-Samadony, Mohammed Nafie, Ahmed Sultan
A fundamental problem in cognitive radio systems is that the cognitive radio is ignorant of the primary channel state and the interference it inflicts on the primary license holder. In this paper we assume that the primary transmitter sends packets across an erasure channel and the primary receiver employs ACK/NAK feedback (ARQ) to retransmit erased packets.
Reversible shear thickening at low shear rates of electrorheological fluids under electric fields
cond-mat.softYu Tian, Minliang Zhang, Jile Jiang, Noshir Pesika
Shear thickening is a phenomenon of significant viscosity increase of colloidal suspensions. While electrorheological (ER) fluids can be turned into a solid-like material by applying an electric field, their shear strength is widely represented by the attractive electrostatic interaction between ER particles. By shearing ER fluids between two concentric cyli
A. K. Tomilin
Maxwell-Lorenz theory describes only vortex electromagnetic processes. Potential component of the magnetic field is usually excluded by the introduction of mathematical terms: Coulomb and Lorenz gauges. Proposed approach to the construction of the four-dimensional electrodynamics based on the total (four-dimensional) field theory takes into account both vort
Jonathan Andreasen, Hui Cao
We simulate the transition from amplified spontaneous emission (ASE) to lasing in random systems with varying degrees of mode overlap. This is accomplished by solving the stochastic Maxwell-Bloch equations with the finite-difference time-domain method. Below lasing threshold, the continuous emission spectra are narrowed by frequency-dependent amplification.
Giant Pulses with Nanosecond Time Resolution detected from the Crab Pulsar at 8.5 and 15.1 GHz
astro-ph.HEAxel Jessner, Mikhail V. Popov, Vladislav I. Kondratiev, Yuri Y. Kovalev
We present a study of shape, spectra and polarization properties of giant pulses (GPs) from the Crab pulsar at the very high frequencies of 8.5 and 15.1 GHz. Studies at 15.1 GHz were performed for the first time. Observations were conducted with the 100-m radio telescope in Effelsberg in Oct-Nov 2007 at the frequencies of 8.5 and 15.1 GHz as part of an exten
S. Alekhin
I review the current status of the nucleon PDFs determined from global fits with emphasis on the impact of recent experimental data and the remaining theoretical challenges.
Witnessing the key early phase of quasar evolution: an obscured AGN pair in the interacting galaxy IRAS 20210+1121
astro-ph.COE. Piconcelli, C. Vignali, S. Bianchi, S. Mathur
We report the discovery of an active galactic nucleus (AGN) pair in the interacting galaxy system IRAS 20210+1121 at z = 0.056. An XMM-Newton observation reveals the presence of an obscured (Nh ~ 5 x 10^{23} cm^-2), Seyfert-like (L_{2-10 keV} = 4.7 x 10^{42} erg/s) nucleus in the northern galaxy, which lacks unambiguous optical AGN signatures. Our spectral a
Dynamics and plasma properties of an X-ray jet from SUMER, EIS, XRT and EUVI A & B simultaneous observations
astro-ph.SRM. S. Madjarska
Small-scale transient phenomena in the quiet Sun are believed to play an important role in coronal heating and solar wind generation. One of them named as "X-ray jet" is the subject of our study. We indent to investigate the dynamics, evolution and physical properties of this phenomenon. We combine spatially and temporally multi-instrument observatio
Peng Wang, Ting Lei, Chi Ho Yeung, Bing-hong Wang
In this paper, we study two large data sets containing the information of two different human behaviors: blog-posting and wiki-revising. In both cases, the interevent time distributions decay as power-laws at both individual and population level. As different from previous studies, we put emphasis on time scales and obtain heterogeneous decay exponents in in
Maurizio Quadrio, Pierre Ricco
This paper considers plane channel flow modified by waves of spanwise velocity applied at the wall and travelling along the streamwise direction. Laminar and turbulent regimes for the streamwise flow are both studied. When the streamwise flow is laminar, it is unaffected by the spanwise flow induced by the waves. This flow is a thin, unsteady and streamwise-
Ali H. Chamseddine, Alain Connes
We study spectral action for Riemannian manifolds with boundary, and then generalize this to noncommutative spaces which are products of a Riemannian manifold times a finite space. We determine the boundary conditions consistent with the hermiticity of the Dirac operator. We then define spectral triples of noncommutative spaces with boundary. In particular w
A. Loinger, T. Marsico
If we take into account the Hilbertian gravitational repulsion, even a dust sphere with a zero fluido-dynamical pressure collapses to a body of a comparatively small, finite, volume.
Tom Morris, Daniel Mietchen
There is much debate on how public participation and expertise can be brought together in collaborative knowledge environments. One of the experiments addressing the issue directly is Citizendium. In seeking to harvest the strengths (and avoiding the major pitfalls) of both user-generated wiki projects and traditional expert-approved reference works, it is a
Amelia Carolina Sparavigna
We propose a survey of a rocky region in the north-east part of Sudan, using the satellite imagery from Google Maps. In particular we analyse the region which lies to the north of Nakasib Suture. Images reveal craters and ring complexes. To enhance their features, images are processed with a method based on fractional calculus. Two of these structures are pr
Yu. S. Dedkov, M. Fonin
The article presents the work on the investigation of the surface structure as well as electronic and magnetic properties of graphene layer on a lattice matched surface of a ferromagnetic material, Ni(111).
A. Bañón Navarro, P. Morel, M. Albrecht-Marc, F. Merz
In gyrokinetic theory, the quadratic nonlinearity is known to play an important role in the dynamics by redistributing (in a conservative fashion) the free energy between the various active scales. In the present study, the free energy transfer is analyzed for the case of ion temperature gradient driven turbulence. It is shown that it shares many properties
W. van Straten, M. Bailes
DSPSR is a high-performance, open-source, object-oriented, digital signal processing software library and application suite for use in radio pulsar astronomy. Written primarily in C++, the library implements an extensive range of modular algorithms that can optionally exploit both multiple-core processors and general-purpose graphics processing units. After
Fractional relaxation and wave equations for dielectrics characterized by the Havriliak-Negami response function
cond-mat.otherRenat T. Sibatov, Dmitry V. Uchaikin
A fractional relaxation equation in dielectrics with response function of the Havriliak-Negami type is derived. An explicit expression for the fractional operator in this equation is obtained and Monte Carlo algorithm for calculation of action of this operator is constructed. Relaxation functions calculated numerically according to this scheme coincide with
Bose-like condensation of Lagrangian particles and higher-order statistics in passive scalar turbulent advection
physics.flu-dynThierry Dombre
We establish an hitherto hidden connection between zero modes and instantons in the context of the Kraichanan model for passive scalar turbulent advection, that relies on the hypothesis that the production of strong gradients of the scalar is associated with Bose-like condensation of Lagrangian particles. It opens the way to the computation of scaling expone
Sylvain Chaty
The Large Area Telescope on the Fermi gamma-ray Space Telescope (FGST, ex-GLAST) provides unprecedented sensitivity for all-sky monitoring of gamma-ray activity. It is an adequate telescope to detect transient sources, since the observatory scans the entire sky every three hours and allows a general search for flaring activity on daily timescale. This search
Renat T. Sibatov, Vladimir V. Uchaikin
Probabilistic interpretation of transition from the dispersive transport regime to the quasi-Gaussian one in disordered semiconductors is given in terms of truncated Levy distributions. Corresponding transport equations with fractional order derivatives are derived. We discuss physical causes leading to truncated waiting time distributions in the process and
Centre-of-mass separation in quantum mechanics: Implications for the many-body treatment in quantum chemistry and solid state physics
physics.chem-phMichal Svrcek
We address the question to what extent the centre-of-mass (COM) separation can change our view of the many-body problem in quantum chemistry and solid state physics. It was shown that the many-body treatment based on the electron-vibrational Hamiltonian is fundamentally inconsistent with the Born-Handy ansatz so that such a treatment can never respect the CO
Smarajit Karmakar, Edan Lerner, Itamar Procaccia
The art of making structural, polymeric and metallic glasses is rapidly developing with many applications. A limitation to their use is their mechanical stability: under increasing external strain all amorphous solids respond elastically to small strains but have a finite yield stress which cannot be exceeded without effecting a plastic response which typica
Patrick Glaschke
The 88 constellations as defined by the IAU segment the sky into regions, separated by an intricate set of boundaries. A binary tree decomposition of this landscape is given which tessellates the celestial sphere into rectangles. This allows a fast determination of the constellation membership of any given sky coordinate.
Sharp Valence Change as Origin of Drastic Change of Fermi Surface and Transport Anomalies in CeRhIn5 under Pressure
cond-mat.str-elShinji Watanabe, Kazumasa Miyake
The drastic changes of Fermi surfaces as well as transport anomalies near P=Pc~2.35 GPa in CeRhIn5 are explained theoretically from the viewpoint of sharp valence change of Ce. It is pointed out that the key mechanism is the interplay of magnetic order and Ce-valence fluctuations. It is shown that the antiferromagnetic state with "small" Fermi surfac
Shou-hua Zhu
In this talk, we briefly review our recent investigations on the properties of dark matter (DM) particle.
Yulin V. Chang
In this work we present a mathematical framework that quantifies the gas-exchange processes in the lung. The theory is based on the solution of the one-dimensional diffusion equation on a simplified model of lung septum. Gases dissolved into different compartments of the lung are all treated separately with physiologically important parameters. The model can
Dynamic response of strongly correlated Fermi gases in the quantum virial expansion
cond-mat.quant-gasHui Hu, Xia-Ji Liu, Peter D. Drummond
By developing a quantum virial expansion theory, we quantitatively calculate the dynamic density response function of a trapped strongly interacting Fermi gas at high temperatures near unitarity. A clear transition from atomic to molecular responses is identified in the spectra when crossing from the BCS to BEC regimes, in qualitative agreement with recent B
Amin Saif, Adem Kilicman
Let $f:E\longrightarrow O$ be a Hurewicz fibration with a fiber space $F_{r_{o}}$ and a lifting function $L_{f}$. The \emph{$Lf-$function} $Θ_{L_{f}}$ of $f$ is defined by the restriction map of $L_{f}$ on the space $Ω(O,r_{o})\times F_{r_{o}}\times \{1\}$. The purpose of this paper is to give some results which show the role of $Lf-$functions in finding a f
Christiane Frigerio Martins
In the past years a wealth of observations has unraveled the structural properties of dark and luminous mass distribution in galaxies, a benchmark for understanding dark matter and the process of galaxy formation. The study of the kinematics of over thousand spirals has evidenced a dark-luminous matter coupling and the presence of a series of scaling laws, p
Manifestations of a spatial variation of fundamental constants on atomic clocks, Oklo, meteorites, and cosmological phenomena
physics.atom-phJ. C. Berengut, V. V. Flambaum
The remarkable detection of a spatial variation in the fine-structure constant, alpha, from quasar absorption systems must be independently confirmed by complementary searches. In this letter, we discuss how terrestrial measurements of time-variation of the fundamental constants in the laboratory, meteorite data, and analysis of the Oklo nuclear reactor can
Amin Saif, Adem Kilicman
The purpose of this paper is to give some solutions for the classification problem in fibration theory by using the homotopy sequences of fibrations (sequences of $n$-th homotopy groups $ π_{n}(S,s_{o}) $ of total spaces of fibrations). In particular, to show the role of homotopy sequence of $n$-th homotopy to get the required fiber map in Fadell-Dold theore