December 2010 arXiv papers
Showing 1–100 of 6,281 papers
The Degrees of Freedom Regions of Two-User and Certain Three-User MIMO Broadcast Channels with Delayed CSIT
cs.ITChinmay S. Vaze, Mahesh K. Varanasi
The degrees of freedom (DoF) region of the fast-fading MIMO (multiple-input multiple-output) Gaussian broadcast channel (BC) is studied when there is delayed channel state information at the transmitter (CSIT). In this setting, the channel matrices are assumed to vary independently across time and the transmitter is assumed to know the channel matrices with
Measuring support for a hypothesis about a random parameter without estimating its unknown prior
math.STDavid R. Bickel
For frequentist settings in which parameter randomness represents variability rather than uncertainty, the ideal measure of the support for one hypothesis over another is the difference in the posterior and prior log odds. For situations in which the prior distribution cannot be accurately estimated, that ideal support may be replaced by another measure of s
Equilibrium and Stability of Polarization in Ultrathin Ferroelectric Films with Ionic Surface Compensation
cond-mat.mtrl-sciG. Brian Stephenson, Matthew J. Highland
Thermodynamic theory is developed for the ferroelectric phase transition of an ultrathin film in equilibrium with a chemical environment that supplies ionic species to compensate its surface. Equations of state and free energy expressions are developed based on Landau-Ginzburg-Devonshire theory, using electrochemical equilibria to provide ionic compensation
Tristram Bogart, Eric Katz
Tropicalization is a procedure that takes subvarieties of an algebraic torus to balanced weighted rational complexes in space. In this paper, we study the tropicalizations of curves in surfaces in 3-space. These are balanced rational weighted graphs in tropical surfaces. Specifically, we study the `lifting' problem: given a graph in a tropical surface, c
Lei Zhang, Dongning Guo
A novel solution is proposed to undertake a frequent task in wireless networks, which is to let all nodes broadcast information to and receive information from their respective one-hop neighboring nodes. The contribution is two-fold. First, as each neighbor selects one message-bearing codeword from its unique codebook for transmission, it is shown that decod
Zhi-Hui Wang, V. V. Dobrovitski
Dynamical decoupling (DD) is a promising tool for preserving the quantum states of qubits. However, small imperfections in the control pulses can seriously affect the fidelity of decoupling, and qualitatively change the evolution of the controlled system at long times. Using both analytical and numerical tools, we theoretically investigate the effect of the
Jiangyong Jia, W. A. Horowitz, Jinfeng Liao
Focusing on four types of correlation plots, $R_{\rm AA}$ vs. $v_2$, $R_{\rm AA}$ vs. $I_{\rm AA}$, $I_{\rm AA}$ vs. $v_2^{I_{\rm AA}}$ and $v_2$ vs.\ $v_2^{I_{\rm AA}}$, we demonstrate how the centrality dependence of \emph{correlations} between multiple jet quenching observables provide valuable insight into the energy loss mechanism in a quark-gluon plasm
On the Capacity of the Heat Channel, Waterfilling in the Time-Frequency Plane, and a C-NODE Relationship
cs.ITEdwin Hammerich
The heat channel is defined by a linear time-varying (LTV) filter with additive white Gaussian noise (AWGN) at the filter output. The continuous-time LTV filter is related to the heat kernel of the quantum mechanical harmonic oscillator, so the name of the channel. The channel's capacity is given in closed form by means of the Lambert W function. Also a
Will Grilliette
This paper characterizes the unital C*-algebra generated by a single invertible element as the unital free product of C[0,1] and C(T). To do this, I develop techniques to split and merge presentations of C*-algebras using free products in tandem with the Tietze transformations devised in my previous paper.
Seth T. Rittenhouse, J. von Stecher, J. P. D'Incao, N. P. Mehta
The problem of a few interacting fermions in quantum physics has sparked intense interest, particularly in recent years owing to connections with the behavior of superconductors, fermionic superfluids, and finite nuclei. This review addresses recent developments in the theoretical description of four fermions having finite-range interactions, stressing insig
Agostino Prástaro
In the framework of the PDE's algebraic topology, previously introduced by A. Prástaro, are considered {\em exotic differential equations}, i.e., differential equations admitting Cauchy manifolds $N$ identifiable with exotic spheres, or such that their boundaries $\partial N$ are exotic spheres. For such equations are obtained local and global existence
Mauricio Cataldo, Luis Chimento
In this paper we consider a spatially flat Friedmann-Robertson-Walker (FRW) cosmological model with cosmological constant, containing a stiff fluid and a classical Dirac field. The proposed cosmological scenario describes the evolution of effective dark matter and dark energy components reproducing, with the help of that effective multifluid configuration, t
A. E. Jaskot, D. K. Strickland, M. S. Oey, Y. -H. Chu
The hot, X-ray-emitting gas in superbubbles imparts energy and enriched material to the interstellar medium (ISM) and generates the hot ionized medium, the ISM's high-temperature component. The evolution of superbubble energy budgets is not well understood, however, and the processes responsible for enhanced X-ray emission in superbubbles remain a matter
Nestor Guillen, Russell Schwab
In this work we provide an Aleksandrov-Bakelman-Pucci type estimate for a certain class of fully nonlinear elliptic integro-differential equations, the proof of which relies on an appropriate generalization of the convex envelope to a nonlocal, fractional-order setting and on the use of Riesz potentials to interpret second derivatives as fractional order ope
Valentina Kiritchenko, Evgeny Smirnov, Vladlen Timorin
We describe a new approach to the Schubert calculus on complete flag varieties using the volume polynomial associated with Gelfand-Zetlin polytopes. This approach allows us to compute the intersection products of Schubert cycles by intersecting faces of a polytope.
Mehdi Torbatian, Hossein Najafi, Mohamed Oussama Damen
A constant K-user interference channel in which the users are not symbol-synchronous is considered. It is shown that the asynchronism among the users facilitates aligning interfering signals at each receiver node while it does not affect the total number of degrees of freedom (DoF) of the channel. To achieve the total K/2 DoF of the channel when single anten
Yu Zhang, Jaeok Park, Mihaela van der Schaar
Sustaining cooperation among self-interested agents is critical for the proliferation of emerging online social communities, such as online communities formed through social networking services. Providing incentives for cooperation in social communities is particularly challenging because of their unique features: a large population of anonymous agents inter
Subadditivity of the minimum output entropy and superactivation of the classical capacity of quantum multiple access channels
quant-phLukasz Czekaj
We study subadditivity of the minimum output entropy ($H_{min}$) of quantum multiple access channels (MACs). We provide an example of violation of the additivity theorem for $H_{min}$ known in classical information theory. Our result is based on a fundamental property of $MACs$ i.e. independence of each sender. The channels used in the example can be constru
Cheng-Ju Lin
The last unknown neutrino mixing angle $\theta_{13}$ is one of the fundamental parameters of nature; it is also a crucial parameter for determining the sensitivity of future long-baseline experiments aimed to study CP violation in the neutrino sector. Daya Bay is a reactor neutrino oscillation experiment designed to achieve a sensitivity on the value of $sin
Andrzej M. Sołtan
Most of the X-ray background (XRB) is generated by discrete X-ray sources. It is likely that still unresolved fraction of the XRB is composed from a population of the weak sources below the present detection thresholds and a truly diffuse component. It is a matter of discussion a nature of these weak sources. The goal of the present paper is to explore the e
Veeresh Singh, Prajval Shastri, Guido Risaliti
Aims: The unification scheme of Seyfert galaxies predicts that the observed differences between type 1 and type 2 Seyfert galaxies are solely due to the differing orientations of the toroidal-shaped obscuring material around AGN. The observed X-ray spectra of Seyfert type 2s compared to type 1s are expected to be affected by higher absorbing column density d
Magnetic field-induced exchange effects between Mn ions and free carriers in ZnSe quantum well through the intermediate nonmagnetic barrier studied by photoluminescence
cond-mat.mes-hallD. M. Zayachuk, T. Slobodskyy, G. V. Astakhov, A. Slobodskyy
Photoluminescence (PL) of the 50 nm $Zn_{0.9}Be_{0.05}Mn_{0.05}Se$/ $d$ nm $Zn_{0.943}Be_{0.057}Se$/ 2.5 nm $ZnSe$/ 30 nm $Zn_{0.943}Be_{0.057}Se$ structures is investigated as a function of magnetic field ($B$) and thickness ($d$) of intermediate $Zn_{0.943}Be_{0.057}Se$ nonmagnetic barrier between the $Zn_{0.9}Be_{0.05}Mn_{0.05}Se$ semimagnetic barrier and
W. Y. Wang
Semileptonic B decays into excited charmed mesons $D'_0$ and $D'_1$ are studied in the framework of heavy quark effective field theory (HQEFT) up to order $1/m_Q$. They are characterized by a single leading Isgur-Wise function $τ$ and several wave functions arising at $1/m_Q$ order. $τ$ and the $1/m_Q$ order functions $χ^b_0$, $χ^c_0$ related to the
Jaydip Sen
Since it is impossible to predict and identify all the vulnerabilities of a network, and penetration into a system by malicious intruders cannot always be prevented, intrusion detection systems (IDSs) are essential entities for ensuring the security of a networked system. To be effective in carrying out their functions, the IDSs need to be accurate, adaptive
Lei Gu
We pose the question of what effect the statistical fluctuation causes if it induces a non-unitary evolution. We apply this idea to the BCS model and study fluctuation around the mean-field average. We find that, dynamics of the thermalization influences the equilibrium besides the non-unitary evolution, and the resulting equilibrium state is no longer the c
Jaydip Sen
A mobile ad hoc network (MANET) is a collection of mobile nodes that communicate with each other by forming a multi-hop radio network. Security remains a major challenge for these networks due to their features of open medium, dynamically changing topologies, reliance on cooperative algorithms, absence of centralized monitoring points, and lack of clear line
Jaydip Sen
Intrusion detection in wireless ad hoc networks is a challenging task because these networks change their topologies dynamically, lack concentration points where aggregated traffic can be analyzed, utilize infrastructure protocols that are susceptible to manipulation, and rely on noisy, intermittent wireless communications. Security remains a major challenge
J. M. Aldaz
We extend Dragomir's refinement of Jensen's inequality from the dicrete to the general case, identifying the equality conditions.
M. Weides, R. C. Bialczak, M. Lenander, E. Lucero
We have developed a novel Josephson junction geometry with minimal volume of lossy isolation dielectric, being suitable for higher quality trilayer junctions implemented in qubits. The junctions are based on in-situ deposited trilayers with thermal tunnel oxide, have micron-sized areas and a low subgap current. In qubit spectroscopy only a few avoided level
A. M. Hriscu, Yu. V. Nazarov
In order to illustrate the emergence of Coulomb blockade from coherent quantum phase-slip processes in thin superconducting wires, we propose and theoretically investigate two elementary setups, or "devices". The setups are derived from Cooper-pair box and Cooper-pair transistor, so we refer to them as QPS-box and QPS-transistor, respectively. We dem
Geoffrey Powell
An explicit chain complex is constructed to calculate the derived functors of destabilization at an odd prime, generalizing constructions of Zarati and of Hung and Sum. The methods are based on the ideas of Singer and Miller and also apply at the prime two. A structural result on the derived functors of destabilization is deduced.
Marcella Massardi, Anna Bonaldi, Laura Bonavera, Marcos López-Caniego
The Planck-ATCA Co-eval Observations (PACO) have provided flux density measurements of well defined samples of AT20G radio sources at frequencies below and overlapping with Planck frequency bands, almost simultaneously with Planck observations. We have observed with the Australia Telescope Compact Array (ATCA) a total of 482 sources in the frequency range be
Qing Jin, Zhen Wang, Zhen Wang, Yi-Ling Wang
Previous studies suggest that punishment is a useful way to promote cooperation in the well-mixed public goods game, whereas it still lacks specific evidence that punishment maintains cooperation in spatial prisoner's dilemma game as well. To address this issue, we introduce a mechanism of recorded punishment, involved with memory and punishment, into sp
Vitalii Ozvenchuk, Elena Bratkovskaya, Olena Linnyk, Mark Gorenstein
We study the kinetic and chemical equilibration in 'infinite' parton-hadron matter within the Parton-Hadron-String Dynamics transport approach, which is based on a dynamical quasiparticle model for partons matched to reproduce lattice-QCD results - including the partonic equation of state - in thermodynamic equilibrium. The 'infinite' matter is simulated wit
Meihua Chen, Chong Der Hu
We considered a spin chain with nearest neighbor and next nearest neighbor exchange interactions, anisotropic exchange interaction and Dzyaloshinskii-Moriya interaction. The conditions of the spiral spin state as the ground state were analyzed. Our method was to build the connection between the spiral state and the fully polarized state with a unitary transf
Tobias Meng, Mehul Dixit, Markus Garst, Julia S. Meyer
We consider electrons in a quantum wire interacting via a long-range Coulomb potential screened by a nearby gate. We focus on the quantum phase transition from a strictly one-dimensional to a quasi-one-dimensional electron liquid, that is controlled by the dimensionless parameter $n x_0$, where $n$ is the electron density and $x_0$ is the characteristic leng
Pallab Basu
In the current work we study various models of holographic superconductors at low temperature. Generically the zero temperature limit of those models are solitonic solution with a zero sized horizon. Here we generalized simple version of those zero temperature solutions to small but non-zero temperature T. We confine ourselves to cases where near horizon geo
Yujiro Kawamata
The paper has been withdrawn by the author due to a crucial error.
Sarika Jalan, Guimei Zhu, Baowen Li
We study spectra of directed networks with inhibitory and excitatory couplings. We investigate in particular eigenvector localization properties of various model networks for different value of correlation among their entries. Spectra of random networks, with completely uncorrelated entries show a circular distribution with delocalized eigenvectors, where as
Low-velocity anisotropic Dirac fermions on the side surface of topological insulators
cond-mat.mes-hallChang-Youn Moon, Jinhee Han, Hyungjun Lee, Hyoung Joon Choi
We report anisotropic Dirac-cone surface bands on a side-surface geometry of the topological insulator Bi$_2$Se$_3$ revealed by first-principles density-functional calculations. We find that the electron velocity in the side-surface Dirac cone is anisotropically reduced from that in the (111)-surface Dirac cone, and the velocity is not in parallel with the w
Asymmetric simple exclusion process in one-dimensional chains with long-range links
cond-mat.stat-mechMina Kim, Ludger Santen, Jae Dong Noh
We study the boundary-driven asymmetric simple exclusion process (ASEP) in a one-dimensional chain with long-range links. Shortcuts are added to a chain by connecting $pL$ different pairs of sites selected randomly where $L$ and $p$ denote the chain length and the shortcut density, respectively. Particles flow into a chain at one boundary at rate $α$ and out
Li Ping Qian, Ying Jun, Zhang, Mung Chiang
Transmit power control in wireless networks has long been recognized as an effective mechanism to mitigate co-channel interference. Due to the highly non-convex nature, optimal power control is known to be difficult to achieve if a system utility is to be maximized. To date, there does not yet exist a distributed power control algorithm that maximizes any fo
Changhong Li, Lingfei Wang, Yeuk-Kwan E. Cheung
We introduce a string-inspired model for a bouncing/cyclic universe, utilizing the scalar-tachyon coupling as well as contribution from curvature in a closed universe. The universe undergoes the locked inflation, tachyon matter dominated rolling expansion, turnaround and contraction, as well as the subsequent deflation and "bounce" in each cycle of t
Piotr M. Hajac, Jan Rudnik, Bartosz Zielinski
Let $G'$ be a closed subgroup of a topological group $G$. A principal $G$-bundle $X$ is reducible to a locally trivial principal $G'$-bundle $X'$ if and only if there exists a local trivialisation of $X$ such that all transition functions take values in $G'$. We prove a noncommutative-geometric counterpart of this theorem. To this end, we employ the concept
Amir Feizpour, Xingxing Xing, Aephraim M. Steinberg
We show that weak measurement can be used to "amplify" optical nonlinearities at the single- photon level, such that the effect of one properly post-selected photon on a classical beam may be as large as that of many un-post-selected photons. We find that "weak-value amplification" offers a marked improvement in signal-to-noise ratio in the p
S. N. Storchak
We derive Wong's equations for the finite-dimensional dynamical system representing the motion of a scalar particle on a compact Riemannian manifold with a given free isometric smooth action of a compact semisimple Lie group. The obtained equations are written in terms of dependent coordinates which are typically used in an implicit description of the lo
Juan C. Marrero, David Martínez Torres, Edith Padron
We obtain universal models for several types of locally conformal symplectic manifolds via pullback or reduction. The relation with recent embedding results for locally conformal Kähler manifolds is discussed.
Antiferromagnetic long range order in the uniform resonating valence bond state on square lattice
cond-mat.str-elTao Li
With extensive variational Monte Carlo simulation, we show that the uniform resonating valence bond state(U-RVB) on square lattice is actually antiferromagnetic long range ordered. The ordered moment is estimated to be $m\approx 0.17$. Finite size scaling analysis on lattice up to lattice size of $50\times 50$ shows that the spin structure factor at the anti
Boundary correlation functions of the six and nineteen vertex models with domain wall boundary conditions
math-phKohei Motegi
Correlation functions of the six and nineteen vertex models on an N \times N lattice with domain wall boundary conditions are studied. The general expression of the boundary correlation functions is obtained for the six vertex model by use of the quantum inverse scattering method. The correlation functions which are not "boundary" can be expressed as
Craig van Coevering
The metrics of S. Y. Cheng and S.-T. Yau are considered on a strictly pseudoconvex domains in a complex manifold. Such a manifold carries a complete Kähler-Einstein metric if and only if its canonical bundle is positive. We consider the restricted case in which the CR structure on $\partial M$ is normal. In this case M must be a domain in a resolution of the
G. T. von Nessi, M. J. Hole, J. Svensson, L. Appel
In this paper, current profiles for plasma discharges on the Mega-Ampere Spherical Tokamak (MAST) are directly calculated from pickup coil, flux loop and Motional-Stark Effect (MSE) observations via methods based in the statistical theory of Bayesian analysis. By representing toroidal plasma current as a series of axisymmetric current beams with rectangular
Modelling to study its non-linear effects on Communication System's performance with BER as performance measure
cs.ITAripirala Manoj Kumar, G. Bharath Reddy, G. Krishna Chaitanya Reddy
This paper is a study of non-linear effects of RF Amplifiers on Communication Systems Performance. High speed data communication is made possible by Multilevel Modulation schemes. This paper presents a study of these non linear effects on multilevel Modulation schemes like MPSK and MQAM. We make use of Bit Error Ratio (BER) as performance measure. BER vs SNR
Edward Grefenstette, Mehrnoosh Sadrzadeh, Stephen Clark, Bob Coecke
Coecke, Sadrzadeh, and Clark (arXiv:1003.4394v1 [cs.CL]) developed a compositional model of meaning for distributional semantics, in which each word in a sentence has a meaning vector and the distributional meaning of the sentence is a function of the tensor products of the word vectors. Abstractly speaking, this function is the morphism corresponding to the
A. R. Usha Devi, Sudha
Recent years have witnessed revolutionary improvement in the production, manipulation, characterization and quantification of multiatom (multiqubit) states - because of their promising applications in high precision atomic clocks, atomic interferrometry, quantum metrology and quantum information protocols. In the characterization and quantification of non-cl
T. Barnes
Recent years have seen rapid developments in our knowledge and understanding of meson spectroscopy, especially in the charm quark sectors. In my invited overview I discussed some of these recent new developments, including theoretical developments, new production mechanisms such as B decays and double charmonium production, and the discovery of several of th
T. Barnes
In this invited talk I discuss two recent applications of charmonium (Psi) decays to N Nbar m final states, where N is a nucleon and m is a light meson. There are several motivations for studying these decays: 1) They are useful for the study of N* spectroscopy; 2) they can be used to estimate cross sections for the associated charmonium production processes
Mingsheng Ying, Yangjia Li, Nengkun Yu, Yuan Feng
We define a formal framework for reasoning about linear-time properties of quantum systems in which quantum automata are employed in the modeling of systems and certain closed subspaces of state (Hilbert) spaces are used as the atomic propositions about the behavior of systems. We provide an algorithm for verifying invariants of quantum automata. Then automa
Rami Atar, Tsachy Weissman
Let $X$ be a non-negative random variable and let the conditional distribution of a random variable $Y$, given $X$, be ${Poisson}(γ\cdot X)$, for a parameter $γ\geq 0$. We identify a natural loss function such that: 1) The derivative of the mutual information between $X$ and $Y$ with respect to $γ$ is equal to the \emph{minimum} mean loss in estimating $X$ b
Matthew Brand
By tooling an spot-illuminated surface to control the flow of specular glints under motion, one can produce holographic view-dependent imagery. This paper presents the differential equation that governs the shape of the specular surfaces, and illustrates how solutions can be constructed for different kinds of motion, lighting, host surface geometries, and fa
Emmanuel N. Saridakis
We review some general aspects of Horava-Lifshitz cosmology. Formulating it in its basic version, we extract the cosmological equations and we use observational data in order to constrain the parameters of the theory. Through a phase-space analysis we extract the late-time stable solutions, and we show that eternal expansion, and bouncing and cyclic behavior
S. Das Sarma, E. H. Hwang
We calculate theoretically the disorder-limited conductivity of monolayer and bilayer graphene on hexagonal boron nitride (h-BN) substrates, comparing our theoretical results with the recent experimental results. The comparison leads to a direct quantitative estimate of the underlying disorder strength for both short-range and long-range disorder in the grap
Marco Herrera-Valdez, Sergei K. Suslov
We propose a simple graphical approach to steady state solutions of the cable equation for a general model of dendritic tree with tapering. A simple case of transient solutions is also briefly discussed.
Shaun A. Thomas, Stephen A. Appleby, Jochen Weller
We examine general physical parameterisations for viable gravitational models in the $f(R)$ framework. This is related to the mass of an additional scalar field, called the scalaron, that is introduced by the theories. Using a simple parameterisation for the scalaron mass $M(a)$ we show there is an exact correspondence between the model and popular parameter
Mikhail Khovanov, Radmila Sazdanovic
We develop a diagrammatic categorification of the polynomial ring $Z[x]$. Our categorification satisfies a version of Bernstein-Gelfand-Gelfand reciprocity property with the indecomposable projective modules corresponding to $x^n$ and standard modules to $(x-1)^n$ in the Grothendieck ring.
Assessment of Dressed Time-Dependent Density-Functional Theory for the Low-Lying Valence States of 28 Organic Chromophores
cond-mat.mes-hallMiquel Huix-Rotllant, Andrei Ipatov, Angel Rubio, Mark E. Casida
Almost all time-dependent density-functional theory (TDDFT) calculations of excited states make use of the adiabatic approximation, which implies a frequency-independent exchange-correlation kernel that limits applications to one-hole/one-particle states. To remedy this problem, Maitra et al.[J.Chem.Phys. 120, 5932 (2004)] proposed dressed TDDFT (D-TDDFT), w
Guizhen Zhu, Daqing Wan
Let F_q be the finite field of q elements. Let H be a multiplicative subgroup of F_q^*. For a positive integer k and element b\in F_q, we give a sharp estimate for the number of k-element subsets of H which sum to b.
Carlo Ewerz, Andreas von Manteuffel, Otto Nachtmann
We study the dipole picture of high-energy virtual-photon-proton scattering. It is shown that different choices for the energy variable in the dipole cross section used in the literature are not related to each other by simple arguments equating the typical dipole size and the inverse photon virtuality, contrary to what is often stated. We argue that the goo
Xibo Zhang, Chen-Lung Hung, Shih-Kuang Tung, Nathan Gemelke
Critical behavior developed near a quantum phase transition, interesting in its own right, offers exciting opportunities to explore the universality of strongly-correlated systems near the ground state. Cold atoms in optical lattices, in particular, represent a paradigmatic system, for which the quantum phase transition between the superfluid and Mott insula
T. Barnes
This invited summary gives some concluding remarks regarding theoretical aspects of the research presented at Charm2010. I will specialize to the role of theory and the relative reach of theory and experiment in three of the major areas of charm physics address at this conference, specifically 1) charm production, 2) charm weak decays, and 3) charm hadron sp
E. Díaz-Valdés, G. S. Contreras-Puente, N. Campos-Rivera, C. Falcony-Guajardo
We have fabricated and characterized samples of the superconducting- semiconducting Bi-Pb-Sb-Sr-Ca-Cu-O/CdS composite. Nano-size particles of CdS were deposited and introduced into the porosities of the Bi-Pb-Sb-Sr-Ca-Cu-O material by the spray pyrolysis technique. The morphology and hollow size in the porous superconducting material as well as the grain siz
A. B. Balantekin
These summer school lectures cover the use of algebraic techniques in various subfields of nuclear physics. After a brief description of groups and algebras, concepts of dynamical symmetry, dynamical supersymmetry, and supersymmetric quantum mechanics are introduced. Appropriate tools such as quasiparticles, quasispin, and Bogoliubov transformations are disc
E. C. Blomberg, M. A. Tanatar, A. Kreyssig, N. Ni
Intrinsic, in-plane anisotropy of electrical resistivity was studied on mechanically detwinned single crystals of SrFe$_2$As$_2$ above and below the temperature of the coupled structural/magnetic transition, $T_{\textrm{TO}}$. Resistivity is smaller for electrical current flow along the orthorhombic $a_o$ direction (direction of antiferromagnetically alterna
D. Fargion, D. D'Armiento
Ultra High Cosmic Rays (UHECR) should be tracing their sources, making a new astronomy. Their events counting are finally growing, by Auger experiment, into cosmic sky. Their map should follow the mass distribution in a narrow cosmic volume (the GZK cut off region, correlated with Super Galactic Plane (SPG) or Local Group) if they were protons, as most expec
Martin Paul Nawrot, Sabine Krofczik, Farzad Farkhooi, Randolf Menzel
Insects identify and evaluate behaviorally relevant odorants in complex natural scenes where odor concentrations and mixture composition can change rapidly. In the honeybee, a combinatorial code of activated and inactivated projection neurons (PNs) develops rapidly within tens of milliseconds at the first level of neural integration, the antennal lobe (AL).
"On the engineers' new toolbox" or Analog Circuit Design, using Symbolic Analysis, Computer Algebra, and Elementary Network Transformations
cs.SCEberhard H. -A. Gerbracht
In this paper, by way of three examples - a fourth order low pass active RC filter, a rudimentary BJT amplifier, and an LC ladder - we show, how the algebraic capabilities of modern computer algebra systems can, or in the last example, might be brought to use in the task of designing analog circuits.
Exact Tkachenko modes and their damping in the vortex lattice regime of rapidly rotating bosons
cond-mat.quant-gasS. I. Matveenko, G. V. Shlyapnikov
We have found an exact analytical solution of the Bogoliubov-de Gennes equations for the Tkachenko modes of the vortex lattice in the lowest Landau level (LLL) in the thermodynamic limit at any momenta and calculated their damping rates. At finite temperatures both Beliaev and Landau damping leads to momentum independent damping rates in the low-energy limit
B. Dubrovin, T. Grava, C. Klein
This article is concerned with a conjecture by one of the authors on the formation of dispersive shocks in a class of Hamiltonian dispersive regularizations of the quasilinear transport equation. The regularizations are characterized by two arbitrary functions of one variable, where the condition of integrability implies that one of these functions must not
Guillaume W. Zinbiel
This is a cornucopia of types of algebras with some of their properties from the operadic point of view.
Nikolai Dokuchaev
The following optimization problem is considered. For a linear vector Ito equation. it is required to find an optimal deterministic control vector which minimizes a quadratic the functional. A necessary and sufficient condition for the existence of a optimal control are formulated in the form of frequency inequalities. It is shown that an optimal control can
Non-monotonic recursive polynomial expansions for linear scaling calculation of the density matrix
physics.comp-phEmanuel H. Rubensson
As it stands, density matrix purification is a powerful tool for linear scaling electronic structure calculations. The convergence is rapid and depends only weakly on the band gap. However, as will be shown in this paper, there is room for improvements. The key is to allow for non-monotonicity in the recursive polynomial expansion. Based on this idea, new pu
Richard Laugesen, Bartlomiej Siudeja
The sum of the first $n \geq 1$ eigenvalues of the Laplacian is shown to be maximal among simplexes for the regular simplex (the regular tetrahedron, in three dimensions), maximal among parallelepipeds for the hypercube, and maximal among ellipsoids for the ball, provided the volume and moment of inertia of an "inverse" body are suitably normalized.
High Speed and Area Efficient 2D DWT Processor based Image Compression" Signal & Image Processing
cs.GRSugreev Kaur, Rajesh Mehra
This paper presents a high speed and area efficient DWT processor based design for Image Compression applications. In this proposed design, pipelined partially serial architecture has been used to enhance the speed along with optimal utilization and resources available on target FPGA. The proposed model has been designed and simulated using Simulink and Syst
Jean-Paul Blaizot
This is a personal summary of the meeting "Saturation, the Color Glass Condensate and Glasma: What Have we Learned from RHIC?" that took place at BNL in May 2010. The purpose of the meeting was to discuss the status of high density QCD and parton saturation, and to review the progress that RHIC has allowed in the field.
Jonathan Bayless, Dominic Klyve
Two numbers $m$ and $n$ are considered amicable if the sum of their proper divisors, $s(n)$ and $s(m)$, satisfy $s(n) = m$ and $s(m) = n$. In 1981, Pomerance showed that the sum of the reciprocals of all such numbers, $P$, is a constant. We obtain both a lower and an upper bound on the value of $P$.
S. B. Wilkins, X. Liu, Y. Wakabayashi, J. -W. Kim
We report temperature-dependent surface x-ray scattering studies of the orbital ordered surface in La$_{0.5}$Sr$_{1.5}$MnO$_4$. We find that the interfacial width of the electronic order grows as the bulk ordering temperature is approached from below, though the bulk correlation length remains unchanged. Close to the transition, the surface is so rough that
E. B. Magnusson, I. A. Shelykh
In the present article we give a brief overview of the theories of the 0.7 anomaly of the ballistic conductance. The special attantion is given to the concept of a fractional quantization of the ballistic conductance arising from exchange interaction of the Heisenberg type between the carrier localized in the region of the quantum point contact and freely pr
Reza Hosseini
We show that the definition of neighbor in Markov random fields as defined by Besag (1974) when the joint distribution of the sites is not positive is not well-defined. In a random field with finite number of sites we study the conditions under which giving the value at extra sites will change the belief of an agent about one site. Also the conditions under
Karin Erdmann, Kai Meng Tan
The Lie module of the group algebra $FS_n$ of the symmetric group is known to be not projective if and only if the characteristic $p$ of $F$ divides $n$. We show that in this case its non-projective summands belong to the principal block of $FS_n$. Let $V$ be a vector space of dimension $m$ over $F$, and let $L^n(V)$ be the $n$-th homogeneous part of the fre
Edwin S. Kite, Scot C. R. Rafkin, Timothy Michaels, William E. Dietrich
Channel networks on the plateau adjacent to Juventae Chasma have the highest drainage densities reported on Mars.We model frozen precipitation on the Juventae plateau,finding that the trigger for forming these channel networks could have been ephemeral lakeshore precipitation,and that they do not require past temperatures higher than today.If short-lived and
Jaydip Sen
Wireless Sensor Networks (WSNs) are highly distributed networks consisting of a large number of tiny, low-cost, light-weight wireless nodes deployed to monitor an environment or a system. Each node in a WSN consists of three subsystems: the sensor subsystem which senses the environment, the processing subsystem which performs local computations on the sensed
Structural optimization of the Ziegler's pendulum: singularities and exact optimal solutions
math.OCOleg N. Kirillov
Structural optimization of non-conservative systems with respect to stability criteria is a research area with important applications in fluid-structure interactions, friction-induced instabilities, and civil engineering. In contrast to optimization of conservative systems where rigorously proven optimal solutions in buckling problems have been found, for no
Shubham Chakraborty
In this paper I will show how to use Python programming with a computer interface such as Phoenix-M 1 to drive simple robots. In my quest towards Artificial Intelligence(AI) I am experimenting with a lot of different possibilities in Robotics. This one will try to mimic the working of a simple insect's nervous system using hard wiring and some minimal so
Liang Wang, Nies Huijsmans, Michael S. Lew, Dan Tsymbala
In this work SVG will be translated into VML or HTML by using Javascript based on Backbase Client Framework. The target of this project is to implement SVG to be viewed in Internet Explorer without any plug-in and work together with other Backbase Client Framework languages. The result of this project will be added as an extension to the current Backbase Cli
Xiaojing Chen, Michael S. Lew
Accumulating evidence has shown that iron is involved in the mechanism underlying many neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Abnormal (higher) iron accumulation has been detected in the brains of most neurodegenerative patients, especially in the basal ganglia region. Presence of ir
Andrew Gordon Wilson, Zoubin Ghahramani
We introduce a stochastic process with Wishart marginals: the generalised Wishart process (GWP). It is a collection of positive semi-definite random matrices indexed by any arbitrary dependent variable. We use it to model dynamic (e.g. time varying) covariance matrices. Unlike existing models, it can capture a diverse class of covariance structures, it can e
E. Benckiser, M. W. Haverkort, S. Brueck, E. Goering
The occupation of d-orbitals controls the magnitude and anisotropy of the inter-atomic electron transfer in transition metal oxides and hence exerts a key influence on their chemical bonding and physical properties. Atomic-scale modulations of the orbital occupation at surfaces and interfaces are believed to be responsible for massive variations of the magne
A Framework for Real-Time Face and Facial Feature Tracking using Optical Flow Pre-estimation and Template Tracking
cs.CVE. R. Gast, Michael S. Lew
This work presents a framework for tracking head movements and capturing the movements of the mouth and both the eyebrows in real-time. We present a head tracker which is a combination of a optical flow and a template based tracker. The estimation of the optical flow head tracker is used as starting point for the template tracker which fine-tunes the head es
R. A. Garcia
Today, asteroseismology is entering in its golden age thanks to the observations provided by the CoRoT and Kepler space missions. In particular, we will make significant progresses in the understanding of the structure and evolution of solar-like oscillating stars. These stars have acoustic modes stochastically excited by the near-surface convection. Thanks
Analysis of Using Browser-native Technology to Build Rich Internet Applications for Image Manipulation
cs.HCThomas Steenbergen, Michael S. Lew
In this work we investigate whether browser-native technologies can be used to perform photo manipulation tasks e.g cropping, resizing or rotating an image within the current mainstream browser. By the use of a case study we will analyze problems that have occurred during the implementation of a prototype web application that utilizes browser-native web tech
Ruoyun Gao, Michael S. Lew, Ling Shao
This work aims to present novel description methods for human action recognition. Generally, a video sequence can be represented as a collection of spatial temporal words by detecting space-time interest points and describing the unique features around the detected points (Bag of Words representation). Interest points as well as the cuboids around them are c