December 2010 arXiv papers — page 23

Anh T. Ngo, Edson Vernek, Sergio E. Ulloa

We present studies of the Coulomb blockade and Kondo regimes of transport through a quantum dot connected to current leads through spin-polarizing quantum point contacts (QPCs). This structure, arising from the effect of lateral spin-orbit fields defining the QPCs, results in spin-polarized currents even in the absence of external magnetic fields and greatly

A. G. Parkhomov

Analysis results of data of long-term radioactivity measurements of 3H, 56Mn, 32Si, 36Cl, 60Co, 137Cs, 90Sr-90Y, 226Ra, 238Pu and 239Pu sources are presented. For beta-radioactive sources, their activity in addition to the exponential drop is characterized by rhythmic variations with a period of 1 year and magnitude of 0.1-0.35% from the average value. These

S P Luttrell

This paper shows how a folded Markov chain network can be applied to the problem of processing data from multiple sensors, with an emphasis on the special case of 2 sensors. It is necessary to design the network so that it can transform a high dimensional input vector into a posterior probability, for which purpose the partitioned mixture distribution networ

Alessandro Ruzzi

The symmetric projective varieties of rank one are all smooth and Fano by a classic result of Akhiezer. We classify the locally factorial (respectively smooth) projective symmetric $G$-varieties of rank 2 which are Fano. When $G$ is semisimple we classify also the locally factorial (respectively smooth) projective symmetric $G$-varieties of rank 2 which are

Patrizio Frosini

The present lack of a stable method to compare persistent homology groups with torsion is a relevant problem in current research about Persistent Homology and its applications in Pattern Recognition. In this paper we introduce a pseudo-distance d_T that represents a possible solution to this problem. Indeed, d_T is a pseudo-distance between multidimensional

Khaled Abdel-Waged, Nuha Felemban, V. V. Uzhinskii

Geant4 has an abundant set of physics models that handle the diverse interaction of particles with matter across a wide energy range. However, there are also many well established reaction codes currently used in the same fields where Geant4 is applied. One such code is the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model. In order to take advanta

M. Arisawa

The periodic homogenization problem of integro-differential equations of the alpha stable L{é}vy operators is studied in this paper. Thanking to the symmetry of the L{é}vy density, we can use the method of the formal asymptotic expansion, to connect the problem to the ergodic cell problem. A rigorous proof is given by the perturbed test function's method

Mihai Popa

The paper presents a Fock space model suitable for constructions of c-free algebras. Immediate applications are direct proofs for the properties of the c-free R- and S-transforms.

Jean-Claude Belfiore, Frederique Oggier

It has been shown recently that coding for the Gaussian Wiretap Channel can be done with nested lattices. A fine lattice intended to the legitimate user must be designed as a usual lattice code for the Gaussian Channel, while a coarse lattice is added to introduce confusion at the eavesdropper, whose theta series must be minimized. We present a design criter

Marcelo Samuel Berman, Newton C. A. da Costa

We argue that the Robertson-Walker's Universe is a zero-energy stable one, even though it may possess a rotational state besides expansion.

Ippei Danshita, Rafael Hipolito, Vadim Oganesyan, Anatoli Polkovnikov

We propose an experimental scheme for studying the Fermi-Pasta-Ulam (FPU) phenomenon in a quantum mechanical regime using ultracold atoms. Specifically, we suggest and analyze a setup of one-dimensional Bose gases confined into an optical lattice. The strength of quantum fluctuations is controlled by tuning the number of atoms per lattice sites (filling fact

Rufus Willett, Guoliang Yu

In this paper, the second of a series of two, we continue the study of higher index theory for expanders. We prove that if a sequence of graphs has girth tending to infinity, then the maximal coarse Baum-Connes assembly map is an isomorphism for the associated metric space $X$. As discussed in the first paper in this series, this has applications to the Baum

Rufus Willett, Guoliang Yu

In this paper, the first of a series of two, we continue the study of higher index theory for expanders. We prove that if a sequence of graphs is an expander and the girth of the graphs tends to infinity, then the coarse Baum-Connes assembly map is injective, but not surjective, for the associated metric space $X$. Expanders with this girth property are a ne

Sergiu I. Vacaru

We analyze the foundations of Finsler gravity theories with metric compatible connections constructed on nonholonomic tangent bundles, or (pseudo) Riemannian manifolds. There are considered "minimal" modifications of Einstein gravity (including theories with violation of local Lorentz invariance) and shown how the general relativity theory and genera

Koji Fujiwara, Tetsu Toyoda

We prove that a random group has fixed points when it isometrically acts on a CAT(0) cube complex. We do not assume that the action is simplicial.

Oleg L. Berman, Vladimir S. Boyko, Roman Ya. Kezerashvili, Anton A. Kolesnikov

A novel type of photonic crystal formed by embedding a periodic array of constituent stacks of alternating graphene and dielectric discs into a background dielectric medium is proposed. The photonic band structure and transmittance of such photonic crystal are calculated. The graphene-based photonic crystals can be used effectively as the frequency filters a

M. Arisawa

A uniform gradient for functions u which satisfy a system of N second-order partial differential inequalities is given in this paper. Some structure conditions are given for the coefficients of the matrices of second-order terms and of first-order terms. This result can be applied to study the gradient estimate of a class of second-order degenerate elliptic

Zhi He, Jian Zou, Bin Shao, Shu-Yan Kong

We consider four two-level atoms interacting with independent non-Markovian reservoirs with detuning. We mainly investigate the effects of the detuning and the length of the reservoir correlation time on the decoherence dynamics of the multipartite entanglement. We find that the time evolution of the entanglement of atomic and reservoir subsystems is determi

Rui Albuquerque

Natural metric structures on the tangent bundle and tangent sphere bundles $S_rM$ of a Riemannian manifold $M$ with radius function $r$ enclose many important unsolved problems. Admitting metric connections on $M$ with torsion, we deduce the equations of induced metric connections on those bundles. Then the equations of reducibility of $TM$ to the almost Her

David R. de Souza, Tânia Tomé, Robert M. Ziff

The critical behavior of the stochastic susceptible-infected-recovered model on a square lattice is obtained by numerical simulations and finite-size scaling. The order parameter as well as the distribution in the number of recovered individuals is determined as a function of the infection rate for several values of the system size. The analysis around criti

Vít Jelínek, Eva Jelínková, Jan Kratochvíl, Bernard Lidický

It is known that every planar graph has a planar embedding where edges are represented by non-crossing straight-line segments. We study the planar slope number, i.e., the minimum number of distinct edge-slopes in such a drawing of a planar graph with maximum degree $Δ$. We show that the planar slope number of every planar partial 3-tree and also every plane

Zhenghao Zhang, Wei Hu, Jin Xie

In this paper, we study Coded relay (Crelay) in multi-hop wireless networks. Crelay exploits both partial packets and overhearing capabilities of the wireless nodes, and uses Forward Error Correction code in packet forwarding. When a node overhears a partial packet from an upstream node, it informs the upstream node about the number of parity bytes needed to

Xiaoshan Xu, Shuangye Yin, Ramiro Moro, Anthony Liang

The cobalt and iron clusters CoN, FeN (20 < N < 150) measured in a cryogenic molecular beam are found to be bistable with magnetic moments per atom both μN/N 2μB in the ground states and μN */N μB in the metastable excited states (for iron clusters, μN ~3NμB and μN* NμB). This energy gap between the two states vanish for large clusters, which explains the ra

Chuichiro Hayashi, Miwa Hayashi

Using unknotting number, we introduce a link diagram invariant of Hass and Nowik type, which changes at most by 2 under a Reidemeister move. As an application, we show that a certain infinite sequence of diagrams of the trivial two-component link need quadratic number of Reidemeister moves for being unknotted with respect to the number of crossings. Assuming

Oleg Bogopolski

We prove that for any natural n>1, the abstract commensurator group of the Baumslag - Solitar group BS(1,n) is isomorphic to the group of 2 by 2 upper triangular matrices A over rational numbers with A_{11}=1. We also prove that for any finitely generated group G with the unique root property the natural homomorphisms Aut(G)--> Comm(G)--> QI(G) are embedding

Andrei Gagarin, Vadim Zverovich

The bondage number b(G) of a graph G is the smallest number of edges of G whose removal from G results in a graph having the domination number larger than that of G. We show that, for a graph G having the maximum vertex degree $Δ(G)$ and embeddable on an orientable surface of genus h and a non-orientable surface of genus k, $b(G)\le \min\{Δ(G)+h+2, Δ(G)+k+1\

Gilad Lerman, Teng Zhang

We assume data sampled from a mixture of d-dimensional linear subspaces with spherically symmetric distributions within each subspace and an additional outlier component with spherically symmetric distribution within the ambient space (for simplicity we may assume that all distributions are uniform on their corresponding unit spheres). We also assume mixture

Marijn A. M. Versteegh, Dennis Dieks

Identical classical particles are distinguishable. This distinguishability affects the number of ways W a macrostate can be realized on the micro-level, and from the relation S = k ln W leads to a non-extensive expression for the entropy. This result is usually considered incorrect because of its inconsistency with thermodynamics. It is sometimes concluded f

George Ciprian Modoi, Jan Stovicek

We show that for the homotopy category K(Ab) of complexes of abelian groups, both Brown representability and Brown representability for the dual fail. We also provide an example of a localizing subcategory of K(Ab) for which the inclusion into K(Ab) does not have a right adjoint.

Tatiana Bandman, Nikolai Gordeev, Boris Kunyavskii, Eugene Plotkin

Given an element $P(X_1,...,X_d)$ of the finitely generated free Lie algebra, for any Lie algebra $g$ we can consider the induced polynomial map $P: g^d\to g$. Assuming that $K$ is an arbitrary field of characteristic $\ne 2$, we prove that if $P$ is not an identity in $sl(2,K)$, then this map is dominant for any Chevalley algebra $g$. This result can be vie

Goran Senjanovic

I argue that LHC may shed light on the nature of neutrino mass through the probe of the seesaw mechanism. The smoking gun signature is lepton number violation through the production of same sign lepton pairs, a collider analogy of the neutrinoless double beta decay. I discuss this in the context of L-R symmetric theories, which led originally to neutrino mas

Rajan Amit Mehta, Xiang Tang

We apply the bar construction to the nerve of a double Lie groupoid to obtain a local Lie 2-groupoid. As an application, we recover Haefliger&#39;s fundamental groupoid from the fundamental double groupoid of a Lie groupoid. In the case of a symplectic double groupoid, we study the induced closed 2-form on the associated local Lie 2-groupoid, which leads us

Hsiang-nan Li, Yue-Long Shen, Yu-Ming Wang, Hao Zou

We calculate next-to-leading-order (NLO) correction to the pion electromagnetic form factor at leading twist in the $k_T$ factorization theorem. Partons off-shell by $k_T^2$ are considered in both quark diagrams and effective diagrams for the transverse-momentum-dependent (TMD) pion wave function. The light-cone singularities in the TMD pion wave function ar

Louigi Addario-Berry, Simon Griffiths

For a fixed d-regular graph H, a random n-lift is obtained by replacing each vertex v of H by a &#34;fibre&#34; containing n vertices, then placing a uniformly random matching between fibres corresponding to adjacent vertices of H. We show that with extremely high probability, all eigenvalues of the lift that are not eigenvalues of H, have order O(sqrt(d)).

Nick E. Mavromatos, Vasiliki A. Mitsou, Sarben Sarkar, Ariadne Vergou

Within the context of supersymmetric space-time (D-particle) foam in string/brane-theory, we discuss a Finsler-induced Cosmology and its implications for (thermal) Dark Matter abundances. This constitutes a truly microscopic model of dynamical space-time, where Finsler geometries arise naturally. The D-particle foam model involves point-like brane defects (D

Vladimir Paar, Matko Glunčić, Ivan Basar, Marija Rosandić

Comparison of human and chimpanzee genomes has received much attention, because of paramount role for understanding evolutionary step distinguishing us from our closest living relative. In order to contribute to insight into Y chromosome evolutionary history, we study and compare tandems, higher order repeats (HORs), and regularly dispersed repeats in human

Francesco Caravelli

In this short note we use results from the theory of crystallizations to prove that color in group field theories garantees orientability of the piecewise linear pseudo-manifolds associated to each graph generated perturbatively. The origin of orientability is the presence of two interaction vertices.

Hokuto Uehara

Bernardi and Tirabassi show the existence of full strong exceptional collections consisting of line bundles on smooth toric Fano $3$-folds under assuming Bondal&#39;s conjecture, which states that the Frobenius push-forward of the structure sheaf $\mc O_X$ generates the derived category $D^b(X)$ for smooth projective toric varieties $X$. In this article, we

Greyson Gilson

A nonlocal theory of optical real image formation is developed from the basic quantum physics linked to an optical real image formation apparatus. Optical real images are formed by photons. Photons are nonlocal quantum objects that exhibit wave-like properties and particle-like properties. Optical real image formation is nonlocal because at least two separat

Michel Habib, Thu-Hien To

A graph is a $k$-leaf power of a tree $T$ if its vertices are leaves of $T$ and two vertices are adjacent in $T$ if and only if their distance in $T$ is at most $k$. Then $T$ is a $k$-leaf root of $G$. This notion was introduced by Nishimura, Ragde, and Thilikos [2002] motivated by the search for underlying phylogenetic trees. We study here an extension of t

Christophe Cauet, Heinrich Päs, Sören Wiesenfeldt

In minimal trinification models light neutrino masses can be generated via a radiative see-saw mechanism, where the masses of the right-handed neutrinos originate from loops involving Higgs and fermion fields at the unification scale. This mechanism is absent in models aiming at solving or ameliorating the hierarchy problem, such as low-energy supersymmetry,

Thomas Bitoun

For a smooth variety $Y$ over a perfect field of positive characteristic, the sheaf $D_Y$ of crystalline differential operators on $Y$ (also called the sheaf of $PD$-differential operators) is known to be an Azumaya algebra over $T^*_{Y'},$ the cotangent space of the Frobenius twist $Y'$ of $Y.$ Thus to a sheaf of modules $M$ over $D_Y$ one can assign a clos

Etienne Roquain

This paper presents a survey on some recent advances for the type I error rate control in multiple testing methodology. We consider the problem of controlling the $k$-family-wise error rate (kFWER, probability to make $k$ false discoveries or more) and the false discovery proportion (FDP, proportion of false discoveries among the discoveries). The FDP is con

Kaibin Huang, Vincent K. N. Lau, Dongku Kim

Spatial interference avoidance is a simple and effective way of mitigating interference in multi-antenna wireless networks. The deployment of this technique requires channel-state information (CSI) feedback from each receiver to all interferers, resulting in substantial network overhead. To address this issue, this paper proposes the method of distributive c

Rainer Grauer, Holger Homann, Jean-Francois Pinton

Using exact relations between velocity structure functions (Hill, Hill and Boratav, and Yakhot) and neglecting pressure contributions in a first approximation, we obtain a closed system and derive simple order-dependent rescaling relationships between longitudinal and transverse structure functions. By means of numerical data with turbulent Reynolds numbers

Gregor Schaffrath, Stefan Schmid, Anja Feldmann

This paper attends to the problem of embedding flexibly specified CloudNets, virtual networks connecting cloud resources (such as storage or computation). We attend to a scenario where customers can request CloudNets at short notice, and an infrastructure provider (or a potential itermediate broker or reseller) first embeds the CloudNet fast (e.g., using a s

Chenglin Zhang, Meng Wang, Huiqian Luo, Miaoyin Wang

We report inelastic neutron scattering experiments on single crystals of superconducting Ba0.67K0.33Fe2As2 (Tc = 38 K). In addition to confirming the resonance previously found in powder samples, we find that spin excitations in the normal state form longitudinally elongated ellipses along the QAFM direction in momentum space, consistent with density functio

Mohsen Vafaee, Firoozeh Sami, Babak Shokri, Behnaz Buzari

A new simulation box setup is introduced for the precise description of the wavepacket evolution of two electronic systems in intense laser pulses. In this box, the regions of the hydrogen molecule H$_{2} $, and singly and doubly ionized species, H$_{2}^+ $ and H$_{2}^{+2} $, are well recognized and their time-dependent populations are calculated at differen

Muneto Nitta, Walter Vinci

We use the moduli matrix approach to study the moduli space of 1/4 BPS kinks supported by vortices in the Higgs phase of N = 2 supersymmetric U(N) gauge theories when non-zero masses for the matter hypermultiplets are introduced. We focus on the case of degenerate masses. In these special cases vortices acquire new orientational degrees of freedom, and becom

Brett McInnes

We show that, in a gravitational theory [in any number of dimensions greater than 3] which admits BPS branes and AdS-Reissner-Nordstrom black holes with flat event horizons, the specific [dimensionless] temperature of such a black hole is bounded below by approximately 0.156875. This confirms the recent suggestion by Hartnoll and Tavanfar, to the effect that

Darius Bayegan, Megumi Harada

In this manuscript we develop the theory of poset pinball, a combinatorial game recently introduced by Harada and Tymoczko for the study of the equivariant cohomology rings of GKM-compatible subspaces of GKM spaces. Harada and Tymoczko also prove that in certain circumstances, a successful outcome of Betti poset pinball yields a module basis for the equivari

Darius Bayegan, Megumi Harada

The main result of this note is a Giambelli formula for the Peterson Schubert classes in the $S^1$-equivariant cohomology ring of a type $A$ Peterson variety. Our results depend on the Monk formula for the equivariant structure constants for the Peterson Schubert classes derived by Harada and Tymoczko. In addition, we give proofs of two facts observed by H.

H. Fukaya, S. Aoki, T. W. Chiu, S. Hashimoto

We calculate the chiral condensate of QCD with 2, 2+1 and 3 flavors of sea quarks. Lattice QCD simulations are performed employing dynamical overlap fermions with up and down quark masses covering a range between 3 and 100 MeV. On L ~ 1.8-1.9 fm lattices at a lattice spacing ~ 0.11 fm, we calculate the eigenvalue spectrum of the overlap-Dirac operator. By ma

Kenta Hayano

Auroux, Donaldson and Katzarkov introduced broken Lefschetz fibrations as a generalization of Lefshcetz fibrations in order to describe near-symplectic 4-manifolds. We first study monodromy representations of higher sides of genus-1 simplified broken Lefschetz fibrations. We then completely classify diffeomorphism types of such fibrations with connected fibe

Paul Smith

We consider the Schrödinger map initial value problem into the sphere in 2+1 dimensions with smooth, decaying, subthreshold initial data. Assuming an a priori $L^4$ boundedness condition on the solution, we prove that the Schrödinger map system admits a unique global smooth solution provided that the initial data is sufficiently energy-dispersed. Also shown

Zhi-Hong Sun, Lin-Lin Wang

Let $\{E_n\}$ be the Euler numbers. In the paper we determine $E_{2^mk+b}-E_b$ modulo $2^{m+7}$, where $k$ and $m$ are positive integers and $b\in{0,2,4,...}$.

D. S. Inosov, J. T. Park, A. Charnukha, Yuan Li

Superconductors are classified by their pairing mechanism and the coupling strength, measured as the ratio of the energy gap to the critical temperature, Tc. We present an extensive comparison of the gap ratios among many single- and multiband superconductors from simple metals to high-Tc cuprates and iron pnictides. Contrary to the recently suggested univer

Thomas P. Sotiriou, Baojiu Li, John D. Barrow

We analyze the relation between teleparallelism and local Lorentz invariance. We show that generic modifications of the teleparallel equivalent to general relativity will not respect local Lorentz symmetry. We clarify the reasons for this and explain why the situation is different in general relativity. We give a prescription for constructing teleparallel eq

E. G. Delgado-Acosta, Mauro Napsuciale, Simon Rodriguez

We develop a second order formalism for spin 1/2 fermions based on the projection over Poincaré invariant subspaces in the $(1/2,0)\oplus(0,1/2)$ representation of the homogeneous Lorentz group. Using $U(1)_{em}$ gauge principle we obtain second order description for the electromagnetic interactions of a spin 1/2 fermion with two free parameters, the gyromag

K. -M. Lee, K. Yabana, G. F. Bertsch

We apply the adiabatic time-dependent density functional theory to magnetic ci the real-space, real-time computational method. The standard formulas for the MCD response and its A and B terms are derived from the observables in the time-dependent wave function. We find the real time method is well suited for calculating the overall spectrum, particularly at

C. W. Wong

The Lorenz electromagnetic theory of light, published two years after the Maxwell theory, starts by postulating that both scalar and vector potentials are retarded. We show that in spite of this postulate, Lorenz&#39;s theory gives a longitudinal electric field in vacuum that remains the instantaneous action at a distance it is in the Maxwell theory. There i

Stephen Luttrell

The processing of mega-dimensional data, such as images, scales linearly with image size only if fixed size processing windows are used. It would be very useful to be able to automate the process of sizing and interconnecting the processing windows. A stochastic encoder that is an extension of the standard Linde-Buzo-Gray vector quantiser, called a stochasti

Ivan Yu. Katkov, Igor V. Chilingarian

We present a new approach to the sky subtraction for long-slit spectra suitable for low-surface brightness objects based on the controlled reconstruction of the night sky spectrum in the Fourier space using twilight or arc-line frames as references. It can be easily adopted for FLAMINGOS-type multi-slit data. Compared to existing sky subtraction algorithms,

M. Arisawa

The quasi-periodic homogenization for some classes of first-order Hamilton-Jaconi-Bellman equation is studied in this paper. The cell problem of the quasi-periodic homogenization satisfies the non-resonance condition, under which the corresponding deterministic system is ergodic. The almost periodic homogenization for the same classes of equations is also so

M. Ochman, R. Szafron, M. Zralek

Description of neutrino oscillation in the case of Non-Standard neutrino Interaction (NSI) is briefly presented. The NSI causes the entanglement between internal degrees of freedom of neutrinos (mass, spin, flavour) and other accompanying particles in the production and detection processes. In such case neutrinos are mostly in the mixed states. Role of the d

Amber Tomas, Krista J. Gile

Respondent-driven sampling is a widely-used network sampling technique, designed to sample from hard-to-reach populations. Estimation from the resulting samples is an area of active research, with software available to compute at least four estimators of a population proportion. Each estimator is claimed to address deficiencies in previous estimators, howeve

Steven R. Spangler, Allison H. Savage, Seth Redfield

Most phases of the interstellar medium contain neutral atoms in addition to ions and electrons. This introduces differences in plasma physics processes in those media relative to the solar corona and the solar wind at a heliocentric distance of 1 astronomical unit. In this paper, we consider two well-diagnosed, partially-ionized interstellar plasmas. The fir

R. V. Gurjar, M. Koras, M. Miyanishi, P. Russell

We show that a homology plane of general type has at worst a single cyclic quotient singular point. An example of such a surface with a singular point does exist. We also show that the automorphism group of a smooth contractible surface of general type is cyclic.

Igor Chilingarian, Ivan Zolotukhin

We discuss what hampers the rate of scientific progress in our exponentially growing world. The rapid increase in technologies leaves the growth of research result metrics far behind. The reason for this lies in the education of astronomers lacking basic computer science aspects crucially important in the data intensive science era.

Sergey V. Tsirel, Askar Akaev, Alexey Fomin, Andrey V. Korotayev

This working paper analyzes the gold price dynamics on the basis of methodology developed by Didier Sornette. Our calculations indicate that this dynamics is close to the one of the &#34;bubbles&#34; studied by Sornette and that the most probable timing of the &#34;burst of the gold bubble&#34; is April - June 2011. The obtained result has been additionally

Michael Krauss, David J. Hilton, Hans Christian Schneider

We present experimental and theoretical results on hole-spin dynamics in bulk GaAs after ultrafast optical excitation. The experimental differential transmission are compared with a dynamical calculation of the momentum-resolved hole distributions, which includes the carrier-carrier, carrier-phonon and carrier-impurity interaction at the level of Boltzmann s

Tzu-Chieh Wei, Smitha Vishveshwara, Paul M. Goldbart

The entanglement in quantum XY spin chains of arbitrary length is investigated via the geometric (measure of) entanglement. The emergence of entanglement is explained intuitively from the perspective of perturbations. The model is solved exactly and the energy spectrum is determined and analyzed in particular for the lowest two levels. The entanglement is ob

Khaled Dridi, Nadeem Javaid, Karim Djouani, Boubaker Daachi

In this paper, we carry-out a study of the Quality of Service (QoS) mechanism in IEEE802.11e Enhanced Distribution Coordination Function (EDCF) and how it is achieved by providing traffics with different priorities. It can perform the access to the radio channel or just simply it can considerably be declined subsequently to a variation of network dynamicity.

L. Padilla, H. O. Mártin, J. L. Iguain

On certain self-similar substrates the time behavior of a random walk is modulated by logarithmic periodic oscillations on all time scales. We show that if disorder is introduced in a way that self-similarity holds only in average, the modulating oscillations are washed out but subdiffusion remains as in the perfect self-similar case. Also, if disorder distr

Gorm B. Andresen, Mohammad D. Ashkezari, Marcelo Baquero-Ruiz, William Bertsche

We present the results of an experiment to search for trapped antihydrogen atoms with the ALPHA antihydrogen trap at the CERN Antiproton Decelerator. Sensitive diagnostics of the temperatures, sizes, and densities of the trapped antiproton and positron plasmas have been developed, which in turn permitted development of techniques to precisely and reproducibl

C. G. Bollini, M. C. Rocca

We study the half advanced and half retarded Wheeler Green function and its relation to Feynman propagators. First for massless equation. Then, for Klein-Gordon equations with arbitrary mass parameters; real, imaginary or complex. In all cases the Wheeler propagator lacks an on-shell free propagation. The Wheeler function has support inside the light-cone (w

Nicholas Cross, Ross Collins, Echhard Sutorius, Nigel Hambly

The two fastest near infrared survey telescopes are UKIRT-WFCAM and VISTA. The data from both these instruments are being archived by Wide Field Astronomy Unit (WFAU) at the IfA, Edinburgh, using the same curation pipeline, with some instrument specific processing. The final catalogues from these surveys will contain many tens of billions of detections. Data

Khodusov Valery, Naumovets Artem

The possibility of propagation of second sound waves in diamond single crystals depending on their dimensions, concentrations of isotopes and temperature is studied. At this correct account of phonon scattering on boundaries is important. The calculation of phonon collision frequencies is carried out in the reduced isotropic crystal model using second and th

Rebecca G. Martin, Stephen H. Lubow

We analyse some properties of circumplanetary discs. Flow through such discs may provide most of the mass to gas giant planets, and such discs are likely sites for the formation of regular satellites. We model these discs as accretion discs subject to the tidal forces of the central star. The tidal torques from the star remove the disc angular momentum near

R. Acharyya, H. Y. T. Nguyen, W. P. Pratt, J. Bass

To study spin flipping within the antiferromagnet IrMn, we extended prior Current-Perpendicular-to-Plane (CPP) Giant Magnetoresistance (GMR) studies of Py-based exchange-biased-spin-valves containing IrMn inserts to thicker IrMn layers-5 nm less than or equal to t(IrMn) less than or equal to 30 nm. Unexpectedly, AΔR = A[R(AP) - R(P)]--the difference in speci

Christoph Uiberacker, Christian Stecher, Josef Oswald

In the present article we investigate the influence of the contact region on the distribution of the chemical potential in integer quantum Hall samples, as well as the longitudinal and Hall resistance as a function of the magnetic field. First we use a standard quantum Hall sample geometry and analyse the influence of the length of the leads where current en

H. Y. T. Nguyen, R. Acharyya, W. P. Pratt, J. Bass

From measurements of the current-perpendicular-to-plane (CPP) magnetoresistance of ferromagnetically coupled [Co(90)Fe(10)/Cu]xn multilayers, within sputtered Permalloy-based double exchange biased spin-valves, we determine the parameter delta[(Co(90)Fe(10))/Cu] = 0.19 +/- 0.04 that sets the probability P of spin-flipping at a Co(90)Fe(10)/Cu interface via t

E. J. Fuller, M. K. Vemuri

An analogue of Brylinski&#39;s knot beta function is defined for a submanifold of d-dimensional Euclidean space. This is a meromorphic function on the complex plane. The first few residues are computed for a surface in three dimensional space.

S. Strauch, S. Malace, M. Paolone

Nucleon properties are modified in the nuclear medium. To understand these modifications and their origin is a central issue in nuclear physics. For example, a wide variety of QCD-based models, including quark-meson coupling and chiral-quark soliton models, predict that the nuclear constituents change properties with increasing density. These changes are pre

Sanjaya Paudel, Thorsten Lisker, Harald Kuntschner

(Abridged) We present a comprehensive analysis of the spatially resolved stellar population properties of 26 early-type dwarf (dE) galaxies in the Virgo cluster. Using Lick/IDS absorption line indices we derive simple stellar population(SSP)-equivalent age, metallicity and [$α$/Fe] abundance ratio. In particular, we focus on the comparison of the stellar pop

Christoph Uiberacker, Werner Jakubetz

We investigate population dynamics in N-level systems driven beyond the linear regime by a strong external field, which couples to the system through an operator with nonzero diagonal elements. As concrete example we consider the case of dipolar molecular systems. We identify limiting cases of the Hamiltonian leading to wavefunctions that can be written in t

J. Silva Lobo, R. S. Ward

This letter deals with triply-periodic (crystalline) solutions in a family of Skyrme systems, namely where the field takes values in the squashed 3-sphere. The family includes the standard Skyrme model (round 3-sphere), and the Skyrme-Faddeev case (maximal squashing). In the round case, the lowest-energy crystal is the well-known cubic lattice of half-skyrmi

S. G. Chigarev, E. M. Epshtein, I. V. Malikov, G. M. Mikhailov

A magnetic tunnel junction Fe3O4/MgO/Fe with (001) layer orientation is considered. The junction magnetic energy is analyzed as a function of the angle between the layer magnetization vectors under various magnetic fields. The tunnel magnetoresistance is calculated as a function of the external magnetic field. In contrast with junctions with unidirectional a

Chao Fan, Jin-Li Guo, Yi-Long Zha

The study of human dynamics has attracted much interest from many fields recently. In this paper, the fractal characteristic of human behaviors is investigated from the perspective of time series constructed with the amount of library loans. The Hurst exponents and length of non-periodic cycles calculated through Rescaled Range Analysis indicate that the tim

Yusuke Nambu, Liang L. Zhao, Emilia Morosan, Kyoo Kim

Magnetism in the orthorhombic metal CaFe$_4$As$_3$ was examined through neutron diffraction for powder and single crystalline samples. Incommensurate (${\bm q}_{\rm m}\approx (0.37-0.39)\times{\bm b}^{\ast}$) and predominantly longitudinally ($\parallel b$) modulated order develops through a 2nd order phase transition at $T_{\rm N}=89.63(6)$ K with a 3D Heis

Hiroyuki R. Takahashi, Kei Kotake, Nobutoshi Yasutake

Bearing in mind the application to the outer crust of the neutron stars (NSs), we investigate the magnetic field decay by means of the fully relativistic Particle-In-Cell simulations. Numerical computations are carried out in 2-dimensions, in which the initial magnetic fields are set to be composed both of the uniform magnetic fields that model the global fi

Laurent Poinsot

Perfect nonlinear functions from a finite group $G$ to another one $H$ are those functions $f: G \rightarrow H$ such that for all nonzero $α\in G$, the derivative $d_αf: x \mapsto f(αx) f(x)^{-1}$ is balanced. In the case where both $G$ and $H$ are Abelian groups, $f: G \rightarrow H$ is perfect nonlinear if and only if $f$ is bent i.e for all nonprincipal c

Andreas Hartmann, William T. Ross

Functions in backward shift invariant subspaces have nice analytic continuation properties outside the spectrum of the inner function defining the space. Inside the spectrum of the inner function, Ahern and Clark showed that under some distribution condition on the zeros and the singular measure of the inner function, it is possible to obtain non-tangential

Laurent Poinsot

Even in spaces of formal power series is required a topology in order to legitimate some operations, in particular to compute infinite summations. Many topologies can be exploited for different purposes. Combinatorists and algebraists may think to usual order topologies, or the product topology induced by a discrete coefficient field, or some inverse limit t

P. E. Ryabov, M. P. Kharlamov

In the problem of motion of the Kowalevski top on two constant fields (the A.G.Reyman - M.A.Semenov-Tian-Shansky case) the type of all critical points of the momentum map is calculated.

Woong-Kee Loh, Yang-Sae Moon, Wookey Lee

Since the release of human genome sequences, one of the most important research issues is about indexing the genome sequences, and the suffix tree is most widely adopted for that purpose. The traditional suffix tree construction algorithms have severe performance degradation due to the memory bottleneck problem. The recent disk-based algorithms also have lim

S. Miyahara, K. Takubo, T. Suzuki, T. Katsufuji

Unconventional peak structure in the Raman spectra due to magnon excitation at low temperature is observed in spinel magnet ${\rm MnV_2O_4}$, where a noncollinear spin state is realized by geometrical frustration. We propose a new mechanism to induce such a Raman scattering process due to a one-magnon excitation of the noncollinear spin state. Novel features

M. P. Kharlamov, I. I. Kharlamova, E. G. Shvedov

We consider the problem of motion of the heavy gyrostat in the case of Kowalevski-Yehia. To classify the bifurcation diagrams on iso-energetic levels we establish the existence of motion conditions in terms of parameters on the bifurcation surfaces. Obtaining these conditions in the form of explicit inequalities we build the separating set in the &#34;energy

Toshikazu Miyashita

The compact exceptional Lie groups F4, E6, E7 and E8 have spinor groups as a subgroup as follows: E8 \supset Ss(16) \supset Spin(15) \supset Spin(14) \supset Spin(13), E7 \supset Spin(12) \supset Spin(11), E6 \supset Spin(10), F4 \supset Spin(9) \supset Spin(8) \supset Spin(7) \supset \cdot \cdot \cdot \supset Spin(1) \ni 1. We know the involution σ&#39; ind

M. Dance

The paper \cite{Dance0601} tentatively suggested a physical picture that might underlie string theories. The string parameters $τ$ and $σ_i $ were interpreted as spacetime dimensions which a simple quantum mechanical observer can observe, while symmetries of the relevant observer states could limit the observability of other dimensions. The present paper ext