December 2007 arXiv papers — page 34

Tomasz Dietl

The presence of localized spins exerts a strong influence on quantum localization in doped semiconductors. At the same time carrier-mediated interactions between the localized spins are modified or even halted by carriers' localization. The interplay of these effects is discussed for II-VI and III-V diluted magnetic semiconductors. This insight is exploi

Shotaro Morohoshi, Yoshiyuki Fukumoto

The quarter-filling extended Hubbard model on the triangular lattice is studied to explore pairing instability in the three-fold charge-ordered (CO) metal. We derive a second-order strong-coupling effective Hamiltonian of doped carriers into the three-fold CO insulator at electron density of $n=2/3$, and then study the $f$- and $d_{xy}$-wave superconductivit

C. R. Das, L. V. Laperashvili

In the present paper we have developed a concept of parallel ordinary (O) and mirror (M) worlds. We have shown that in the case of a broken mirror parity (MP), the evolutions of fine structure constants in the O- and M-worlds are not identical. It is assumed that E_6-unification inspired by superstring theory restores the broken MP at the scale \sim 10^{18}

J. -W. He, Q. -S. Wu

The concept of Koszul differential graded algebra (Koszul DG algebra) is introduced. Koszul DG algebras exist extensively, and have nice properties similar to the classic Koszul algebras. A DG version of the Koszul duality is proved. When the Koszul DG algebra $A$ is AS-regular, the Ext-algebra $E$ of $A$ is Frobenius. In this case, similar to the classical

David P. Blecher, Upasana Kashyap

We give a new Banach module characterization of $W^*$-modules, also known as selfdual Hilbert $C^*$-modules over a von Neumann algebra. This leads to a generalization of the notion, and the theory, of W*-modules, to the setting where the operator algebras are $σ$-weakly closed algebras of operators on a Hilbert space. That is, we find the appropriate weak* t

Dimitri Skliros, Mark Hindmarsh

We calculate the equation of state of a gas of strings at high density in a large toroidal universe, and use it to determine the cosmological evolution of background metric and dilaton fields in the entire large radius Hagedorn regime, (ln S)^{1/d} << R << S^{1/d} (with S the total entropy). The pressure in this regime is not vanishing but of O(1), while the

Christina Manolatou, Farhan Rana

We propose and analyze a family of nanoscale cavities for electrically-pumped surface-emitting semiconductor lasers that use surface plasmons to provide optical mode confinement in cavities which have dimensions in the 100-300 nm range. The proposed laser cavities are in many ways nanoscale optical versions of micropatch antennas that are commonly used at mi

K. Yano, T. Sakakibara, T. Tayama, M. Yokoyama

To identify the superconducting gap structure in URu2Si2 we perform field-angle-dependent specific heat measurements for the two principal orientations in addition to field rotations, and theoretical analysis based on microscopic calculations. The Sommerfeld coefficient γ(H)&#39;s in the mixed state exhibit distinctively different field-dependence. This come

Kshitij Khare

The Dynkin isomorphism associates a Gaussian field to a Markov chain. These Gaussian fields can be used as priors for prediction and time series analysis. Dynkin&#39;s construction gives Gaussian fields with all non-negative covariances. We extend Dynkin&#39;s construction (by introducing a sign structure on the Markov chain) to allow general covariance sign

C. Soubiran, O. Bienayme, T. V. Mishenina, V. V. Kovtyukh

We present the parameters of 891 stars, mostly clump giants, including atmospheric parameters, distances, absolute magnitudes, spatial velocities, galactic orbits and ages. One part of this sample consists of local giants, within 100 pc, with atmospheric parameters either estimated from our spectroscopic observations at high resolution and high signal-to-noi

Ivan Rungger, Stefano Sanvito

We present a complete prescription for the numerical calculation of surface Green&#39;s functions and self-energies of semi-infinite quasi-onedimensional systems. Our work extends the results of Sanvito et al. [1] generating a robust algorithm to be used in conjunction with ab initio electronic structure methods. We perform a detailed error analysis of the s

B. Mosser, F. Bouchy, M. Martic

This paper reports a 9-night asteroseismic observation program conducted in January 2007 with the new spectrometer Sophie at the OHP 193-cm telescope, on the F5 IV-V target Procyon A. This first asteroseismic program with Sophie was intended to test the performance of the instrument with a bright but demanding asteroseismic target and was part of a multisite

Daniel M. Greenberger, Noam Erez, Marlan O. Scully, Anatoly A. Svidzinsky

The interplay between optical and statistical physics is a rich and exciting field of study. Black body radiation was the first application of photon statistics, although it was initially treated as a problem of the cavity oscillators in equilibrium with the photon field. However Planck surprisingly resisted the idea that anything physical would be quantized

Erwin Miña-Díaz

We consider polynomials that are orthogonal over an analytic Jordan curve L with respect to a positive analytic weight, and show that each such polynomial of sufficiently large degree can be expanded in a series of certain integral transforms that converges uniformly in the whole complex plane. This expansion yields, in particular and simultaneously, Szego&#

Alexei Vazquez

Population stratification is a problem encountered in several areas of biology and public health. We tackle this problem by mapping a population and its elements attributes into a hypergraph, a natural extension of the concept of graph or network to encode associations among any number of elements. On this hypergraph, we construct a statistical model reflect

Stefano Gandolfi

In this thesis, I discuss the use of the Auxiliary Field Diffusion Monte Carlo method to compute the ground state of nuclear Hamiltonians, and I show several applications to interesting problems both in nuclear physics and in nuclear astrophysics. In particular, the AFDMC algorithm is applied to the study of several nuclear systems, finite, and infinite matt

Olivier Finkel

We solve some decision problems for timed automata which were recently raised by S. Tripakis in [ Folk Theorems on the Determinization and Minimization of Timed Automata, in the Proceedings of the International Workshop FORMATS&#39;2003, LNCS, Volume 2791, p. 182-188, 2004 ] and by E. Asarin in [ Challenges in Timed Languages, From Applied Theory to Basic Th

Hyunsoo Yang, See-Hun Yang, Stuart Parkin

Recently, it has been shown that magnetic tunnel junctions with thin MgO tunnel barriers exhibit extraordinarily high tunneling magnetoresistance (TMR) values at room temperature1, 2. However, the physics of spin dependent tunneling through MgO barriers is only beginning to be unravelled. Using planar magnetic tunnel junctions in which ultra-thin layers of m

Deanna Needell, Roman Vershynin

We demonstrate a simple greedy algorithm that can reliably recover a d-dimensional vector v from incomplete and inaccurate measurements x. Here our measurement matrix is an N by d matrix with N much smaller than d. Our algorithm, Regularized Orthogonal Matching Pursuit (ROMP), seeks to close the gap between two major approaches to sparse recovery. It combine

Olivier Finkel

We show that, from a topological point of view, considering the Borel and the Wadge hierarchies, 1-counter Büchi automata have the same accepting power than Turing machines equipped with a Büchi acceptance condition. In particular, for every non null recursive ordinal alpha, there exist some Sigma^0_alpha-complete and some Pi^0_alpha-complete omega context f

Deborah N. Aguilera, José A. Pons, Juan A. Miralles

The impact of strong magnetic fields B>10e13 G on the thermal evolution of neutron stars is investigated, including crustal heating by magnetic field decay. For this purpose, we perform 2D cooling simulations with anisotropic thermal conductivity considering all relevant neutrino emission processes for realistic neutron stars. The standard cooling models of

Yaroslav Zolotaryuk

Fluxon transmission through several impurities of different strength and type (i.e., microshorts and microresistors), placed in a long Josephson junction is investigated. Threshold pinning current on the impurities is computed as a function of the distance between them, their amplitudes and the dissipation parameter. It is shown that in the case of consequen

Víctor M. Eguíluz, Martín G. Zimmermann, Camilo J. Cela-Conde, Maxi San Miguel

By means of extensive computer simulations, the authors consider the entangled coevolution of actions and social structure in a new version of a spatial Prisoner&#39;s Dilemma model that naturally gives way to a process of social differentiation. Diverse social roles emerge from the dynamics of the system: leaders are individuals getting a large payoff who a

M. Slater, C. Adolphsen, R. Arnold, S. Boogert

The main physics programme of the International Linear Collider (ILC) requires a measurement of the beam energy at the interaction point with an accuracy of $10^{-4}$ or better. To achieve this goal a magnetic spectrometer using high resolution beam position monitors (BPMs) has been proposed. This paper reports on the cavity BPM system that was deployed to t

P. N. Bibikov

Analytic expressions for uniform and staggered magnetizations of a spin ladder with a staggered Dzyaloshinskii-Moriya interaction along rungs are obtained in the lowest perturbative orders. The obtained formulas describe magnetic behavior in two marginal regions related to low ($h\ll h_c$) and high ($h\gg h_s$) magnetic fields.

Patrick Wils, Ioannis Rozakis, Stelios Kleidis, Franz-Josef Hambsch

Stars pulsating in three radial modes are very rare; only three examples are known in the Galaxy. These stars are very useful since their periods may be measured very precisely, and this will constrain the global stellar parameters and the models of the star&#39;s interior. The purpose of this paper is to present a new example of the class of triple-mode rad

Emilio Elizalde

After reviewing some essential features of the Casimir effect and, specifically, of its regularization by zeta function and Hadamard methods, we consider the dynamical Casimir effect (or Fulling-Davis theory), where related regularization problems appear, with a view to an experimental verification of this theory. We finish with a discussion of the possible

Emilio Elizalde

A review of some recent advances in zeta function techniques is given, in problems of pure mathematical nature but also as applied to the computation of quantum vacuum fluctuations in different field theories, and specially with a view to cosmological applications.

Adriano Barra

Aim of this work is not trying to explore a macroscopic behavior of some recent model in statistical mechanics but showing how some recent techniques developed within the framework of spin glasses do work on simpler model, focusing on the method and not on the analyzed system. To fulfil our will the candidate model turns out to be the paradigmatic mean field

M. Sachkov, O. Kochukhov, T. Ryabchikova, F. Leone

We present the analysis of spectroscopic time-series observations of the roAp star 10 Aql. Observations were carried out in July 2006 with the UVES and SARG spectrographs simultaneously with the MOST mini-satellite photometry. All these data were analysed for radial velocity (RV) variations. About 150 lines out of the 1000 measured reveal clear pulsation sig

Stefano Buzzi, H. Vincent Poor

This paper focuses on the cross-layer issue of joint multiuser detection and resource allocation for energy efficiency in wireless CDMA networks. In particular, assuming that a linear multiuser detector is adopted in the uplink receiver, the case considered is that in which each terminal is allowed to vary its transmit power, spreading code, and uplink recei

A. B. J. Kuijlaars, A. Martinez-Finkelshtein, F. Wielonsky

We study a model of $n$ non-intersecting squared Bessel processes in the confluent case: all paths start at time $t = 0$ at the same positive value $x = a$, remain positive, and are conditioned to end at time $t = T$ at $x = 0$. In the limit $n \to \infty$, after appropriate rescaling, the paths fill out a region in the $tx$-plane that we describe explicitly

Maria J. Esteban, Patricio Felmer, Alexander Quaas

In this paper we deal with existence and uniqueness of solution to super-linear problems for the Pucci operator: $$ -\M^+(D^2u)+|u|^{s-1}u=f(x) \quad {in} \RR^n, $$ where $s>1$ and $f$ satisfies only local integrability conditions. This result is well known when, instead of the Pucci operator, the Laplacian or a divergence form operator is considered. Our ex

M. Guedel, S. L. Skinner, M. Audard, K. R. Briggs

We have obtained and analyzed Chandra ACIS-S observations of the strongly accreting classical T Tauri star DG Tau. Our principal goals are to map the immediate environment of the star to characterize possible extended X-rays formed in the jet, and to re-visit the anomalous, doubly absorbed X-ray spectrum of DG Tau itself. We combine our new ACIS-S data with

Qi S. Zhang

We prove a uniform Sobolev inequality for Ricci flow, which is independent of the number of surgeries. As an application, under less assumptions, a non-collapsing result stronger than Perelman&#39;s $κ$ non-collapsing with surgery is derived. The proof is shorter and seems more accessible. The result also improves some earlier ones where the Sobolev inequali

Rong Luo, Zhaoyong Huang

In this paper, we study the problem when a finitely generated torsionless module is projective. Let $Λ$ be an Artinian local algebra with radical square zero. Then a finitely generated torsionless $Λ$-module $M$ is projective if ${\rm Ext^1_Λ}(M,M)=0$. For a commutative Artinian ring $Λ$, a finitely generated torsionless $Λ$-module $M$ is projective if the f

Corey A. Hoelscher

A cohomogeneity one manifold is a manifold with the action of a compact Lie group, whose quotient is one dimensional. Such manifolds are of interest in Riemannian geometry, in the context of nonnegative sectional curvature, as well as in other areas of geometry and in physics. In this paper we classify compact simply connected cohomogeneity one manifolds in

Giulio Chiribella, Giacomo Mauro D&#39;Ariano, Paolo Perinotti

We present a method for optimizing quantum circuits architecture. The method is based on the notion of &#34;quantum comb&#34;, which describes a circuit board in which one can insert variable subcircuits. The method allows one to efficiently address novel kinds of quantum information processing tasks, such as storing-retrieving, and cloning of channels.

Daniel Lenz

We give an introduction into diffraction theory for aperiodic order. We focus on an approach via dynamical systems and the phenomenon of pure point diffraction. We review recent results and sketch proofs. We then present a new uniform Wiener/Wintner type result generalizing various earlier results of this type.

P. SanGiorgio, S. Reymond, M. R. Beasley, J. H. Kwon

We have experimentally investigated the density of states (DOS) in Nb/Ni (S/F) bilayers as a function of Ni thickness, $d_F$. Our thinnest samples show the usual DOS peak at $\pmΔ_0$, whereas intermediate-thickness samples have an anomalous ``double-peak&#39;&#39; structure. For thicker samples ($d_F \geq 3.5$ nm), we see an ``inverted&#39;&#39; DOS which ha

Alexandru E. Stanculescu

We put a Quillen model structure on the category of small categories enriched in simplicial $k$-modules and non-negatively graded chain complexes of $k$-modules, where $k$ is a commutative ring. The model structure is obtained by transfer from the model structure on simplicial categories due to J. Bergner.

Laszlo E. Szabo

In 1935 Einstein, Podolsky, and Rosen (EPR) published an important paper in which they claimed that the whole formalism of quantum mechanics together with what they called &#34;Reality Criterion&#34; imply that quantum mechanics cannot be complete. That is, there must exist some elements of reality that are not described by quantum mechanics. There must be,

Luis Dieulefait

In this survey paper we present recent results obtained by Khare, Wintenberger and the author that have led to a proof of Serre&#39;s conjecture, such as existence of compatible families, modular upper bounds for universal deformation rings and existence of minimal lifts, prime switching and modularity propagation, weight reduction (via existence of conjugat

Nicola Atkinson, Christopher J. Conselice, Nicole Fox

Recent observations of distant disk galaxies show that there is little to no evolution in the relation between maximum rotation speed and stellar mass at z < 1.2. There is however a significant scatter between these two quantities whose origin is uncertain. We show in this paper that this scatter is at least partially the result of galaxy merging, revealing

Paul S. Wesson

We review the current status of dimensions, as the result of a long and controversial history that includes input from philosophy and physics. Our conclusion is that they are subjective but essential concepts which provide a kind of book-keeping device, their number increasing as required by advances in physics. The world almost certainly has more than the f

N. S. Borisov, N. A. Bazhanov, A. A. Belyaev, J. Broz

A frozen spin polarized deuteron target cooled by the 3He/4He dilution refrigerator is described. Fully deuterated 1,2-propanediol was used as a target material. Deuteron vector polarization about 40% was obtained for the target in the shape of a cylinder of 2 cm diameter and 6 cm length. The target is intended for a study of 3N interactions at the polarized

Nora Brambilla

We briefly review how nonrelativistic effective field theories give us a definition of the QCD potentials and a coherent field theory derived quantum mechanical scheme to calculate the properties of bound states made by two or more heavy quarks. In this framework heavy quarkonium properties depend only on the QCD parameters (quark masses and $\als$) and nonp

Song He, Hongbao Zhang

The generalized second law of thermodynamics for a system containing a black hole dynamical horizon is proposed in a covariant way. Its validity is also tested in case of adiabatically collapsing thick light shells.

Michael Ghil, Ilya Zaliapin, Sylvester Thompson

We consider a delay differential equation (DDE) model for El-Nino Southern Oscillation (ENSO) variability. The model combines two key mechanisms that participate in ENSO dynamics: delayed negative feedback and seasonal forcing. We perform stability analyses of the model in the three-dimensional space of its physically relevant parameters. Our results illustr

John H. Hubbard, Robyn L. Miller

We provide a self-contained, accessible introduction to Ratner&#39;s Equidistribution Theorem in the special case of horocyclic flow on a complete hyperbolic surface of finite area. This equidistribution result was first obtained in the early 1980s by Dani and Smillie and later reappeared as an illustrative special case of Ratner&#39;s work on the equidistri

P. -M. Dejardin, H. Kachkachi, Yu. P. Kalmykov

The relaxation rate and temperature-dependent switching field curve of a spherical magnetic nanocluster are calculated by taking into account the effect of surface anisotropy via an effective anisotropy model. In particular, it is shown that surface anisotropy may change the thermally activated magnetization reversal by more than an order of magnitude, and t

R. A. Jishi, H. M. Alyahyaei

We report first principles calculations, within density functional theory, of copper intercalated titanium diselenides, CuxTiSe2, for values of x ranging from 0 to 0.11. The effect of intercalation on the energy bands and densities of states of the host material is studied in order to better understand the cause of the superconductivity that was recently obs

Jeffrey Humpherys, Gregory Lyng, Kevin Zumbrun

Extending recent results in the isentropic case, we use a combination of asymptotic ODE estimates and numerical Evans-function computations to examine the spectral stability of shock-wave solutions of the compressible Navier--Stokes equations with ideal gas equation of state. Our main results are that, in appropriately rescaled coordinates, the Evans functio

Peter Petersen, William Wylie

We show that the only complete shrinking gradient Ricci solitons with vanishing Weyl tensor are quotients of the standard ones. This gives a new proof of the Hamilton-Ivey-Perel&#39;man classification of 3-dimensional shrinking gradient solitons. We also prove a classification for expanding gradient Ricci solitons with constant scalar curvature and suitably

David Nevado, Antonio Pineda

We compute the spin-independent structure functions of the forward virtual-photon Compton tensor of the proton at one loop using heavy baryon chiral perturbation theory and dispersion relations. We study the relation between both approaches. We use these results to generalize some sum rules to virtual photon transfer momentum and relate them with sum rules i

Kenji Tomita, Kaiki Taro Inoue

We study second order gravitational effects of local inhomogeneities on the cosmic microwave background radiation in flat universes with matter and a cosmological constant $Λ$. We find that the general relativistic correction to the Newtonian approximation is negligible at second order provided that the size of the inhomogeneous region is sufficiently smalle

Fatemeh Ebrahimi

The shape of two-dimensional invasion percolation clusters are studied numerically for both non-trapping (NTIP) and trapping (TIP) invasion percolation processes. Two different anisotropy quantifiers, the anisotropy parameter and the asphericity are used for probing the degree of anisotropy of clusters. We observe that in spite of the difference in scaling p

J. Hisano, M. Nagai, P. Paradisi

The Standard Model (SM) predictions for the hadronic electric dipole moments (EDMs) are well far from the present experimental resolutions, thus, the EDMs represent very clean probes of New Physics (NP) effects. Especially, within an MSSM framework with flavor-changing (but not necessarily CP violating) soft terms, large and potentially visible effects to th

Sacha E. Kopp

The MINOS experiment at Fermilab has released an updated result on muon disappearance based upon 2.5 x 10^20 protons on target. The experiment utilizes the intense source of muon neutrinos provided by the NuMI beam line. This note summarizes the systematic uncertainties in the experiment's knowledge of the flux and energy spectrum of the neutrinos from NuMI.

Vladimir Vovk

A new definition of events of game-theoretic probability zero in continuous time is proposed and used to prove results suggesting that trading in financial markets results in the emergence of properties usually associated with randomness. This paper concentrates on &#34;qualitative&#34; results, stated in terms of order (or order topology) rather than in ter

Dirk Oliver Theis

The Symmetric Traveling Salesman Polytope $S_n$ for a fixed number $n$ of cities is a face of the corresponding Graphical Traveling Salesman Polyhedron $P_n$. This has been used to study facets of $S_n$ using $P_n$ as a tool. In this paper, we study the operation of &#34;rotating&#34; (or &#34;lifting&#34;) valid inequalities for $S_n$ to obtain a valid ineq

R. Lazkoz, S. Nesseris, L. Perivolaropoulos

We compare the dark energy model constraints obtained by using recent standard ruler data (Baryon Acoustic Oscillations (BAO) at z=0.2 and z=0.35 and Cosmic Microwave Background (CMB) shift parameters R and l_a) with the corresponding constraints obtained by using recent Type Ia Supernovae (SnIa) standard candle data (ESSENCE+SNLS+HST from Davis et. al.). We

Zoran Hadzibabic, Peter Krüger, Marc Cheneau, Steffen Patrick Rath

We analyze the results of a recent experiment with bosonic rubidium atoms harmonically confined in a quasi-two-dimensional geometry. In this experiment a well defined critical point was identified, which separates the high-temperature normal state characterized by a single component density distribution, and the low-temperature state characterized by a bimod

Aalok Misra, Pramod Shukla

Continuing with the ideas of (section 4 of) [1], after inclusion of perturbative and non-perturbative alpha&#39; corrections to the Kaehler potential and (D1- and D3-) instanton generated superpotential, we show the possibility of slow-roll axionic inflation in the large volume limit of Swiss-Cheese Calabi-Yau orientifold compactifications of type IIB string

S. Boettcher, B. Goncalves, H. Guclu

Two new classes of networks are introduced that resemble small-world properties. These networks are recursively constructed but retain a fixed, regular degree. They consist of a one-dimensional lattice backbone overlayed by a hierarchical sequence of long-distance links. Both types of networks, one 3-regular and the other 4-regular, lead to distinct behavior

Vasileios Paschalidis, Jakob Hansen, Alexei Khokhlov

In a recent paper the first coauthor presented a new parabolic extension (PADM) of the standard 3+1 Arnowitt, Deser, Misner formulation of the equations of general relativity. By parabolizing first-order ADM in a certain way, the PADM formulation turns it into a mixed hyperbolic - second-order parabolic, well-posed system. The surface of constraints of PADM

Savas Dimopoulos, Peter W. Graham, Jason M. Hogan, Mark A. Kasevich

We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of the Stanford $10 \text{m}$ atom interferometer presently under construction. The terrestrial experiment can operate with strain sensitivity $ \sim \frac{10^{-19}}{\sqrt{\text{Hz}}}$ in the 1 Hz - 10 Hz band,

K. T. Law, D. E. Feldman

We consider cold polar molecules confined in a helical optical lattice similar to those used in holographic microfabrication. An external electric field polarizes molecules along the axis of the helix. The large-distance inter-molecular dipolar interaction is attractive but the short-scale interaction is repulsive due to geometric constraints and thus preven

Luis A. Dupont, Rafael H. Villarreal

Let G be a simple graph and let J be its ideal of vertex covers. We give a graph theoretical description of the irreducible b-vertex covers of G, i.e., we describe the minimal generators of the symbolic Rees algebra of J. Then we study the irreducible b-vertex covers of the blocker of G, i.e., we study the minimal generators of the symbolic Rees algebra of t

Lev Cherbanski

In this article the algorithm for transformation of logic functions which are given by truth tables is considered. The suggested algorithm allows the transformation of many-valued logic functions with the required number of variables and can be looked in this sense as universal.

J. M. Wrobel, Y. Terashima, L. C. Ho

The nearby elliptical galaxies NGC 4621 and NGC 4697 each host a supermassive black hole with a mass more than 1e8 Solar masses. Analysis of archival Chandra data and new NRAO Very Large Array data shows that each galaxy contains a low-luminosity active galactic nucleus (LLAGN), identified as a faint, hard X-ray source that is astrometrically coincident with

Alejandro Fernandez-Martinez, Gabriel J. Cuello, Gabriela Roman-Ross, Mark R. Johnson

Here we report on two structural studies performed on As-doped gypsum (CaSO4 2H2O) and calcite (CaCO3), using neutron (D20-ILL) and x-ray (ID11-ESRF) diffraction data and EXAFS (BM8-ESRF). The aim of this study is to determine whether As gets into the bulk of gypsum and calcite structures or is simply adsorbed on the surface. Different mechanisms of substitu

P. Dey, T. K. Nath, P. K. Manna, S. M. Yusuf

We have investigated the effect of nanometric grain size on magnetic properties of single phase, nanocrystalline, granular La0.7Ca0.3MnO3 (LCMO) sample. We have considered core-shell structure of our LCMO nanoparticles, which can explain its magnetic properties. From the temperature dependence of field cooled (FC) and zero-field cooled (ZFC) dc magnetization

Ilya Zaliapin, Andrei Gabrielov, Vladimir Keilis-Borok, Henry Wong

Earthquake aftershock identification is closely related to the question "Are aftershocks different from the rest of earthquakes?" We give a positive answer to this question and introduce a general statistical procedure for clustering analysis of seismicity that can be used, in particular, for aftershock detection. The proposed approach expands the analysis o

Vladimir Nikiforov

Let G be a graph of n vertices and m edges, and let G has no cycles of length 4. We give upper bounds on the adjacency spectral radius of G in terms of n and m.

O. V. Melnyk, A. A. Elyiv, I. B. Vavilova

3D Voronoi&#39;s tessellation method was first applied to identify groups of galaxies in the structure of a supercluster. The sample under consideration consists of more than 7000 galaxies of the Local Supercluster (LS) with radial velocities up to 3100 km/s. Because of an essential non-homogeneity of the LS catalogue, it was proposed to overscale distances

Venkateswaran P. Krishnan

In this note, we give a generalization of the inversion formulas of Pestov-Uhlmann for the geodesic ray transform of functions and vector fields on simple 2-dimensional manifolds of constant curvature. The inversion formulas given here hold for 2-dimensional simple manifolds whose curvatures close to a constant.

Ciprian Demeter, Michael Lacey, Terence Tao, Christoph Thiele

We study the Walsh model of a certain maximal truncation of Carleson&#39;s operator, related to the Return Times Theorem from Ergodic Theory.

N. Blümer

We present a new method for extracting numerically exact imaginary-time Green functions from standard Hirsch-Fye quantum Monte Carlo (HF-QMC) simulations within dynamical mean-field theory. By analytic continuation, angular resolved spectra are obtained without the discretization bias previously associated with HF-QMC results. The method is shown to be accur

A. Zangwill, D. D. Vvedensky

A discussion of epitaxial growth is presented for those situations (OMVPE, CBE, ALE, MOMBE, GSMBE, etc.) when the kinetics of surface processes associated with molecular precursors may be rate limiting. Emphasis is placed on the identification of various {\it characteristic length scales} associated with the surface processes. Study of the relative magnitude

Takayuki Matsuki, Toshiyuki Morii, Kazutaka Sudoh

Studying our semirelativistic potential model and the numerical results, which succeeds in predicting and reproducing recently discovered higher resonances of $D$, $D_s$, $B$, and $B_s$, we find a simple expression for the mass gap between two spin multiplets of heavy-light mesons, $(0^-,1^-)$ and $(0^+,1^+)$. The mass gap between chiral partners defined by

Bernhard Heim

In this paper we prove the Miyawaki conjecture related to the spinor $L$--function of a Siegel cusp form of weight 12 and degree 3 as a special example of results related to Miyawaki lifts of odd degree.

Gennady N. Chuev, Pascal Quemerais

Applying semi-analytical models of nonideal plasma, we evaluate the behavior of the metallic phase in metal-ammonia solutions (MAS). This behavior is mainly controlled by the degenerate electron gas, which remains stable down to 5 MPM due to high solvent polarizability and strong dielectric screening of solvated ions. Comparing the behavior of the metallic s

Tsuyoshi Sawada, Norio Ikeda, Kazuyoshi Sunada, Nario Kuno

We have developed spectral line On-The-Fly (OTF) observing mode for the Nobeyama Radio Observatory 45-m and the Atacama Submillimeter Telescope Experiment 10-m telescopes. Sets of digital autocorrelation spectrometers are available for OTF with heterodyne receivers mounted on the telescopes, including the focal-plane 5 x 5 array receiver, BEARS, on the 45-m.

Bao-quan Ai, Hui-zhang Xie, Liang-gang Liu

Efficiency of a Brownian particle moving along the axis of a three-dimensional asymmetric periodic channel is investigated in the presence of a symmetric unbiased force and a load. Reduction of the spatial dimensionality from two or three physical dimensions to an effective one-dimensional system entails the appearance of entropic barriers and an effective d

D. J. Singh, Chul-Hong Park

We elucidate a mechanism for obtaining polar behavior in magnetic perovskites based on A-site disorder and demonstrate this mechanism by density functional calculations for the double perovskite (La,Lu)MnNiO$_6$ with Lu concentrations at and below 50%. We show that this material combines polar behavior and ferromagnetism. The mechanism is quite general and m

Salvatore Caporaso, Nicola Corriero

The recursion theorem in the weak form {e}(z)=x(e,z) (universal function not needed) and in Rogers form {n}(z)={{x}(n)}(z) and Rice theorem are proved a first time using programs in C, and a second time with scripts in Bash.

K. Komathiraj, S. D. Maharaj

We find two new classes of exact solutions to the Einstein-Maxwell system of equations. The matter content satisfies a linear equation of state consistent with quark matter; a particular form of one of the gravitational potentials is specified to generate solutions. The exact solutions can be written in terms of elementary functions, and these can be related

Mikhail S. Kalenkov, Andrei D. Zaikin

We theoretically analyze non-local effects in electron transport across three-terminal ballistic normal-superconducting-normal (NSN) structures with spin-active interfaces. Subgap electrons entering S-electrode from one N-metal may form Cooper pairs with their counterparts penetrating from another N-metal. This phenomenon of crossed Andreev reflection is hig

Carlo Ferrigno, Alberto Segreto, Teresa Mineo, Andrea Santangelo

We analyze 1050 ks of INTEGRAL data of the high mass X-ray binary pulsar 1E 1145.1-6141 to study its properties over a long time baseline, from June 2003 to June 2004, with wide spectral coverage. We study three high luminosity episodes, two of them at the system apoastron, three brightening with lower intensity, two at the periastron, and one extended perio

Lorenzo Iorio

In this paper we use the ratio of the corrections to the standard Newtonian/Einsteinian secular precessions of the longitudes of perihelia of Jupiter and Saturn, recently estimated by the Russian astronomer E.V. Pitjeva by fitting almost one century of data with the EPM ephemerides, to make an independent, planetary-based test of the hypothesis that the Pion

P. A. Ivanov, B. T. Torosov, N. V. Vitanov

We introduce a technique that allows one to connect any two arbitrary (pure or mixed) superposition states of an N-state quantum system. The proposed solution to this inverse quantum mechanical problem is analytical, exact, and very compact. The technique uses standard and generalized quantum Householder reflections (QHRs), which require external pulses of p

Anastasios Mallios, Patrice P. Ntumba

Sheaf theoretically based Abstract Differential Geometry incorporates and generalizes all the classical differential geometry. Here, we undertake to partially explore the implications of Abstract Differential Geometry to classical symplectic geometry. The full investigation will be presented elsewhere.

Motohiko Ezawa

Graphene nanodisk is a graphene derivative with a closed edge. The trigonal zigzag nanodisk with size $N$ has $N$-fold degenerated zero-energy states. We investigate electron-electron interaction effects in the zero-energy sector. We explicitely derive the direct and exchange interactions, which are found to have no SU($N$) symmetry. Then, regarding a nanodi

Ricardo Faccio, Helena Pardo, Pablo A. Denis, Rodrigo Yoshikawa Oeiras

We present an ab initio DFT study of the magnetic moments that arise in graphite by creating single carbon vacancies in a 3-D graphite network, using a full potential, all electron, spin polarized electronic structure calculations. In previous reports the appearance of magnetic moments was explained in a 2-D graphene sheet just through the existence of the v

A. V. Kuznetsov, N. V. Mikheev

The neutrino spin flip radiative conversion processes nu_L -> nu_R + gamma^* and nu_L + gamma^* -> nu_R in medium are considered. It is shown in part that an analysis of the so-called spin light of neutrino without a complete taking account of both the neutrino and the photon dispersion in medium is physically inconsistent.

Oswaldo Velásquez Castañón

We study the distribution of the zeros of functions of the form $f(s)=h(s) \pm h(2a-s)$, where $h(s)$ is a meromorphic function, real on the real line, $a$ a real number. One of our results establishes sufficient conditions under which all but finitely many of the zeros of $f(s)$ lie on the line $\Re s = a$, called the {\it critical line} for the function $f

Ren-Gui Zhu, An-Min Wang

One-dimensional anyon models are renewedly constructed by using path integral formalism. A statistical interaction term is introduced to realize the anyonic exchange statistics. The quantum mechanics formulation of statistical transmutation is presented.

M. Vavoulidis, K. D. Kokkotas, A. Stavridis

We study low-amplitude crustal oscillations of slowly rotating relativistic stars consisting of a central fluid core and an outer thin solid crust. We estimate the effect of rotation on the torsional toroidal modes and on the interfacial and shear spheroidal modes. The results compared against the Newtonian ones for wide range of neutron star models and equa

Jan Kunes, Alexey V. Lukoyanov, Vladimir I. Anisimov, Richard T. Scalettar

The metal-insulator transition in correlated electron systems, where electron states transform from itinerant to localized, has been one of the central themes of condensed matter physics for more than half a century. The persistence of this question has been a consequence both of the intricacy of the fundamental issues and the growing recognition of the comp