August 2008 arXiv papers — page 6

Y. Kohsaka, C. Taylor, P. Wahl, A. Schmidt

The antiferromagnetic ground state of copper oxide Mott insulators is achieved by localizing an electron at each copper atom in real space (r-space). Removing a small fraction of these electrons (hole doping) transforms this system into a superconducting fluid of delocalized Cooper pairs in momentum space (k-space). During this transformation, two distinctiv

S. E. Dahm

NGC 2362 is a richly populated Galactic cluster, devoid of natal molecular gas and dust. The cluster represents the final product of the star forming process and hosts an unobscured and near-complete initial mass function. NGC 2362 is dominated by the O9 Ib multiple star, tau CMa, as well as several dozen unevolved B-type stars. Distributed throughout the cl

Takashi Hamana, Satoshi Miyazaki, Nobunari Kashikawa, Richard S. Ellis

We present the first results of a MOS campaign to follow up cluster candidates located via weak lensing. Our main goals are to search for spatial concentrations of galaxies that are plausible optical counterparts of the weak lensing signals, and to determine the cluster redshifts from those of member galaxies. Around each of 36 targeted cluster candidates, w

Jane Gregorio-Hetem

The shape of the main arc formed by the Canis Major clouds has been suggested to result from a supernova explosion possibly triggering the recent star formation activity. The presence of dozens of OB stars and reflection nebulae forms the CMa OB1/R1 associations. More than a hundred emission line stars are found in this region, including the famous Z CMa, a

Feng Lu, Cui-Zhi Wang Wei-Hua Wang, Liang-Jian Zou

We present the zero-temperature superconducting (SC) ground states of the two-orbital asymmetric $t-J$ model on a square lattice by means of the auxiliary-boson approach. Besides the two-gap SC phase, we find an orbital selective SC (OSSC) phase, which is simultaneously SC in one orbit and normal in another orbit. The novel OSSC phase is stable only for suff

Oleg Miroshnichenko

We show that the local magnetization in the massive boundary Ising model on the half-plane with boundary magnetic field satisfies second order linear differential equation whose coefficients are expressed through Painleve function of the III kind.

E. Tutuc, R. Pillarisetty, M. Shayegan

We study the frictional drag in high mobility, strongly interacting GaAs bilayer hole systems in the vicinity of the filling factor $ν=1$ quantum Hall state (QHS), at the same fillings where the bilayer resistivity displays a reentrant insulating phase. Our measurements reveal a very large longitudinal drag resistivity ($ρ^{D}_{xx}$) in this regime, exceedin

Yoichi Takeda, Inwoo Han, Dong-Il Kang, Byeong-Cheol Lee

In an attempt of clarifying the connection between the photospheric abundance anomalies and the stellar rotation as well as of exploring the nature of "normal A" stars, the abundances of seven elements (C, O, Si, Ca, Ti, Fe, and Ba) and the projected rotational velocity for 46 A-type field stars were determined by applying the spectrum-fitting method

M. Rakhmanov, J. D. Romano, J. T. Whelan

Searches for gravitational waves with km-scale laser interferometers often involve the long-wavelength approximation to describe the detector response. The prevailing assumption is that the corrections to the detector response due to its finite size are small and the errors due to the long-wavelength approximation are negligible. Recently, however, Baskaran

M. T. Calef, D. P. Hardin

Let $A$ be a compact set in ${\mathbb R}^p$ of Hausdorff dimension $d$. For $s\in(0,d)$, the Riesz $s$-equilibrium measure $μ^s$ is the unique Borel probability measure with support in $A$ that minimizes $$ I_s(μ):=\iint\frac{1}{|x-y|^s}dμ(y)dμ(x)$$ over all such probability measures. If $A$ is strongly $({\mathcal H}^d, d)$-rectifiable, then $μ^s$ converges

Santosh Devasia

This article reconsiders the relative-velocity-dependent approach to modeling electromagnetism that was proposed initially by Weber before data from cathode-ray-tube (CRT) experiments was available. It is shown that identifying the nonlinear, relative-velocity terms using CRT data results in a model, which not only captures standard relativistic effects in o

Wouter J. Waalewijn

Anomalies are an infrared effect, but are often realized in effective theories in a non-trivial way. We study the chiral anomaly in Soft Collinear Effective Theory (SCET), where the anomaly equation has terms contributing at different orders in the power expansion. The chiral anomaly equations in SCET are computed up to NNLO in the power counting with extern

Nedzad Limić, Mladen Rogina

For a second order differential operator $A(\msx) =-\nabla a(\msx)\nabla + b'(\msx)\nabla+ \nabla \big(\msb''(\msx) \cdot\big)$ on a bounded domain $D$ with the Dirichlet boundary conditions on $\partial D$ there exists the inverse $T(λ, A)= (λI+A)^{-1}$ in $L_1(D)$. If $μ$ is a Radon (probability) measure on Borel algebra of subsets of $D$, then

Behrang Noohi

We define the notion of {\em classifying space} of a topological stack and show that every topological stack \X has a classifying space X which is a topological space well-defined up to weak homotopy equivalence. Under a certain paracompactness condition on \X, we show that X is actually well-defined up to homotopy equivalence. These results are formulated i

Raphael Ponge

The aim of this paper is to present the construction, out of the Kohn-Rossi complex, of a new hypoelliptic operator $Q_{L}$ on almost CR manifolds equipped with a real structure. The operator acts on all (p,q)-forms, but when restricted to (p,0)-forms and (p,n)-forms it is a sum of squares up to sign factor and lower order terms. Therefore, only a finite typ

Bin-Bin Zhang, Bing Zhang, En-Wei Liang, Xiang-Yu Wang

The apparent spectral evolution observed in the steep decay phase of many GRB early afterglows raises a great concern of the high-latitude "curvature effect" interpretation of this phase. However, previous curvature effect models only invoked a simple power law spectrum upon the cessation of the prompt internal emission. We investigate a model that i

Alison J. Hatt, Nicola A. Spaldin

We investigate the effect of epitaxial strain on [001]-oriented LaAlO3 using first-principles density functional calculations. We find a series of structural phase transitions between states characterized by distinct patterns of tilting of the AlO6 octahedra. By tuning the biaxial strain from compressive to tensile, we induce an evolution in the crystal stru

Jacob Trier Frederiksen, Mark Eric Dieckmann

In continuation of previous work, numerical results are presented, concerning relativistically counter-streaming plasmas. Here, the relativistic mixed mode instability evolves through, and beyond, the linear saturation -- well into the nonlinear regime. Besides confirming earlier findings, that wave power initially peaks on the mixed mode branch, it is obser

Brent C. Melot, Jennifer E. Drewes, Ram Seshadri, Arthur P. Ramirez

We present the magnetic properties of complete solid solutions of ZnCr$_2$O$_4$ and CoCr$_2$O$_4$: two well-studied oxide spinels with very different magnetic ground states. ZnCr$_2$O$_4$, with non-magnetic $d^{10}$ cations occupying the A site and magnetic $d^3$ cations on the B site, is a highly frustrated antiferromagnet. CoCr$_2$O$_4$, with magnetic $d^7

Eduardo G. Altmann, Tamas Tel

In order to simulate observational and experimental situations, we consider a leak in the phase space of a chaotic dynamical system. We obtain an expression for the escape rate of the survival probability applying the theory of transient chaos. This expression improves previous estimates based on the properties of the closed system and explains dependencies

A. Libal, C. J. Olson Reichhardt, C. Reichhardt

We demonstrate that it is possible to realize vortex ice states that are analogous to square and kagome ice. With numerical simulations, we show that the system can be brought into a state that obeys either global or local ice rules by applying an external current according to an annealing protocol. We explore the breakdown of the ice rules due to disorder i

A. Flesch, M. Cramer, I. P. McCulloch, U. Schollwoeck

In the study of relaxation processes in coherent non-equilibrium dynamics of quenched quantum systems, ultracold atoms in optical superlattices with periodicity two provide a very fruitful test ground. In this work, we consider the dynamics of a particular, experimentally accessible initial state prepared in a superlattice structure evolving under a Bose-Hub

Burak Tevfik Kaynak, Osman Teoman Turgut

We study the relativistic Lee model on static Riemannian manifolds. The model is constructed nonperturbatively through its resolvent, which is based on the so-called principal operator and the heat kernel techniques. It is shown that making the principal operator well-defined dictates how to renormalize the parameters of the model. The renormalization of the

Craig J. Copi, Dragan Huterer, Dominik J. Schwarz, Glenn D. Starkman

We investigate the angular two-point correlation function of temperature in the WMAP maps. Updating and extending earlier results, we confirm the lack of correlations outside the Galaxy on angular scales greater than about 60 degrees at a level that would occur in 0.025 per cent of realizations of the concordance model. This represents a dramatic increase in

Raphael Bousso, Ben Freivogel, I-Sheng Yang

We show that in expanding regions, the scale factor measure can be reformulated as a local measure: Observations are weighted by integrating their physical density along a geodesic that starts in the longest-lived metastable vacuum. This explains why some of its properties are similar to those of the causal diamond measure. In particular, both measures are f

Fang Peng, Daisuke Nagai

The uniformity of the helium-to-hydrogen abundance ratio in X-ray emitting intracluster medium (ICM) is one of the commonly adopted assumptions in X-ray analyses of galaxy clusters and cosmological constraints derived from these measurements. In this work, we investigate the effect of He sedimentation on X-ray measurements of galaxy clusters in order to asse

Ilijas Farah, N. Christopher Phillips, Juris Steprāns

Kirchberg asked in 2004 whether the commutant of L(H)$ in its (norm) ultrapower is trivial. Assuming the Continnuum Hypothesis, we prove that the answer depends on the choice of the ultrafilter.

Zheng Wang, Jie Luo

Guruswami and Indyk showed in [1] that Forney's error exponent can be achieved with linear coding complexity over binary symmetric channels. This paper extends this conclusion to general discrete-time memoryless channels and shows that Forney's and Blokh-Zyablov error exponents can be arbitrarily approached by one-level and multi-level concatenated c

Yong-Liang Ma

With the assumption that the recently observed X(1835) is a baryonium state we have studied the strong decays of $X(1835) \to η^{(\prime)} π^+ π^-, η^{(\prime)} π^0 π^0$ and the electromagnetic decay of $X(1835) \to 2γ$ in the framework of effective Lagrangian formalism. In the present investigation we have included the contributions from the iso-singlet lig

R. Ji, B. Ramsey

The property that the polynomial cohomology with coefficients of a finitely generated discrete group is canonically isomorphic to the group cohomology is called the (weak) isocohomological property for the group. In the case when a group is of type $HF^\infty$, i.e. that has a classifying space with the homotopy type of a cellular complex with finitely many

David Eppstein, Michael T. Goodrich

This paper studies real-world road networks from an algorithmic perspective, focusing on empirical studies that yield useful properties of road networks that can be exploited in the design of fast algorithms that deal with geographic data. Unlike previous approaches, our study is not based on the assumption that road networks are planar graphs. Indeed, based

T. A. Witten

We investigate the strong curvature that appears at the boundaries of a thin crumpled elastic membrane. We account for these high-curvature regions in terms of the stretching-ridge singularity believed to dominate the structure of strongly deformed elastic membranes. Using a membrane fastened to itself to form a bag shape with a single stretching ridge, we s

Michael Gronau, Jonathan L. Rosner

Studies of angular and time distributions and CP-violating observables in $B_s\to J/ψϕ$ decays yield a space of parameters which can be considerably reduced if relative strong phases among different amplitudes are specified. We show that the relations between $B_s \to J/ψϕ$ and $B^0 \to J/ψK^{*0}$ amplitudes given by flavor symmetry [actually U(3) rather tha

Antonio M. Garcia-Garcia, Emilio Cuevas

We provide evidence that as a general rule Anderson localization effects become weaker as the degree of differentiability of the disordered potential increases. In one dimension a band of metallic states exists provided that the disordered potential is sufficiently correlated and has some minimum degree of differentiability. Several examples are studied in d

Vladimir Cvetkovic, Zlatko Tesanovic

The key feature of the Fe-based superconductors is their quasi 2D multiband Fermi surface. By relating the problem to a negative U Hubbard model and its superconducting ground state, we show that the defining instability of such a Fermi surface is the valley density-wave (VDW), a combined spin/charge density-wave at the wavevector connecting the electron and

John Dixon

Cybersusy is a new mechanism for supersymmetry breaking in the standard supersymmetric model (SSM). Here we note that the superpotential for the SSM has a set of thirteen invariances, five of which are well known, and eight of which are new. The eight new invariances generate a sort of supersymmetric quark and lepton model, together with supersymmetry breaki

Eitan Altman, Francesco De Pellegrini

Delay tolerant Ad-hoc Networks make use of mobility of relay nodes to compensate for lack of permanent connectivity and thus enable communication between nodes that are out of range of each other. To decrease delivery delay, the information that needs to be delivered is replicated in the network. Our objective in this paper is to study replication mechanisms

Vladimir V. V'yugin

Using the game-theoretic framework for probability, Vovk and Shafer. have shown that it is always possible, using randomization, to make sequential probability forecasts that pass any countable set of well-behaved statistical tests. This result generalizes work by other authors, who consider only tests of calbration. We complement this result with a lower bo

Seckin Kurkcuoglu

Q-lumps associated with the noncommutative CP^N model in 2+1 dimensions are constructed. These are solitonic configurations which are time dependent and rotate with constant angular frequency. Energy of the Q-lumps is E=2 πk + α|Q|, and we find that in a regime in which the noncommutativity parameter θis related to the moduli determining the size of the lump

Hisaki Hatanaka, Kwei-Chou Yang

We study semileptonic B meson decays B to K_1(1270) l^+ l^- and K_1(1400) l^+ l^- (l=e, mu, tau), where the strange P-wave mesons, K_1(1270) and K_1(1400), are the mixtures of the K_{1A} and K_{1B}, which are the 1^3P_1 and 1^1P_1 states, respectively. We show that the ratio R_l = Br(B to K_1(1400) l^+ l^-)/Br(B to K_1(1270) l^+ l^-), insensitive to new-phys

D. Horns

The high-lights of ground-based very-high-energy (VHE, $E>100$ GeV) gamma-ray astronomy are reviewed. The summary covers both Galactic and extra-galactic sources. A total of at least 70 sources are currently known. Implications for our understanding of the non-thermal Universe are discussed. The next generation of ground based gamma-ray instruments aims to c

G. Pappas, M. Rapoport

We define the notion of a parahoric group scheme $\mathcal G$ over a smooth projective curve, and formulate four conjectures on the structure of the stack of $\mathcal G$-bundles, which generalize to this case well-known results on $G$-bundles with $G$ a constant reductive group. The conjectures concern the set of connected components, the uniformization by

Reynir Axelsson, Georg Schumacher

In a family of compact, canonically polarized, complex manifolds the first variation of the lengths of closed geodesics is computed. As an application, we show the coincidence of the Fenchel-Nielsen and Weil-Petersson symplectic forms on the Teichmueller spaces of compact Riemann surfaces in a purely geometric way. The method can also be applied to situation

Richard Atkins

We present an algebraic procedure that finds the Lie algebra of the local Killing fields of a smooth metric. In particular, we determine the number of independent local Killing fields about a given point on the manifold. Spaces of constant curvature and locally symmetric spaces are also discussed. Furthermore, we obtain a complete classification of the Lie a

E. Rozkotova, P. Nemec, N. Tesarova, P. Maly

We report single-color, time resolved magneto-optical measurements in ferromagnetic semiconductor (Ga,Mn)As. We demonstrate coherent optical control of the magnetization precession by applying two successive ultrashort laser pulses. The magnetic field and temperature dependent experiments reveal the collective Mn-moment nature of the oscillatory part of the

Peter Henseler, Johann Kroha, Boris Shapiro

We consider the change in electron localization due to the presence of electron-electron repulsion in the \HA model. Taking into account local Mott-Hubbard physics and static screening of the disorder potential, the system is mapped onto an effective single-particle Anderson model, which is studied within the self-consistent theory of electron localization.

Malcolm Brown, James Hinchcliffe, Marco Marletta, Serguei Naboko

In the setting of adjoint pairs of operators we consider the question: to what extent does the Weyl M-function see the same singularities as the resolvent of a certain restriction $A_B$ of the maximal operator? We obtain results showing that it is possible to describe explicitly certain spaces $\Sc$ and $\tilde{\Sc}$ such that the resolvent bordered by proje

Siva R. Athreya, Jan M. Swart

We consider contact processes on the hierarchical group, where sites infect other sites at a rate depending on their hierarchical distance, and sites become healthy with a constant recovery rate. If the infection rates decay too fast as a function of the hierarchical distance, then we show that the critical recovery rate is zero. On the other hand, we derive

Mladen Bestvina, Mark Feighn

For any finite collection $f_i$ of fully irreducible automorphisms of the free group $F_n$ we construct a connected $δ$-hyperbolic $Out(F_n)$-complex in which each $f_i$ has positive translation length.

A. Bhadra, K. K. Nandi

The gravitational time advancement is a natural but a consequence of curve space-time geometry. In the present work the expressions of gravitational time advancement have been obtained for geodesic motions. The situation when the distance of signal travel is small in comparison to the distance of closest approach has also been considered. The possibility of

Jian-Guo Liu, Tao Zhou, Bing-Hong Wang, Yi-Cheng Zhang

In this Letter, we introduce a modified collaborative filtering (MCF) algorithm, which has remarkably higher accuracy than the standard collaborative filtering. In the MCF, instead of the standard Pearson coefficient, the user-user similarities are obtained by a diffusion process. Furthermore, by considering the second order similarities, we design an effect

Lars Bergstrom, Torsten Bringmann, Joakim Edsjo

The space-borne antimatter experiment PAMELA has recently reported a surprising rise in the positron to electron ratio at high energies. It has also recently been found that electromagnetic radiative corrections in some cases may boost the gamma-ray yield from supersymmetric dark matter annihilations in the galactic halo by up to three or four orders of magn

Aji A. Anappara, Simone De Liberato, Alessandro Tredicucci, Cristiano Ciuti

In a microcavity, light-matter coupling is quantified by the vacuum Rabi frequency $Ω_R$. When $Ω_R$ is larger than radiative and non-radiative loss rates, the system eigenstates (polaritons) are linear superposition of photonic and electronic excitations, a condition actively investigated in diverse physical implementations. Recently, a quantum electrodynam

Michael Urban

The excitation spectra of the radial quadrupole and scissors modes of ultracold Fermi gases in elongated traps are studied across the BCS superfluid-normal phase transition in the framework of a transport theory for quasiparticles. In the limit of zero temperature, this theory reproduces the results of superfluid hydrodynamics, while in the opposite limit, a

Matthias R. Schindler, Daniel R. Phillips

We demonstrate and explicate Bayesian methods for fitting the parameters that encode the impact of short-distance physics on observables in effective field theories (EFTs). We use Bayes' theorem together with the principle of maximum entropy to account for the prior information that these parameters should be natural, i.e.O(1) in appropriate units. Margi

Shinya Saka, Hiroshi Takano

Two types of average structures of a single knotted ring polymer are studied by Brownian dynamics simulations. For a ring polymer with N segments, its structure is represented by a 3N -dimensional conformation vector consisting of the Cartesian coordinates of the segment positions relative to the center of mass of the ring polymer. The average structure is g

Antonaldo Diaferio, Luisa Ostorero

We run adiabatic N-body/hydrodynamical simulations of isolated self-gravitating gas clouds to test whether conformal gravity, an alternative theory to General Relativity, is able to explain the properties of X-ray galaxy clusters without resorting to dark matter. We show that the gas clouds rapidly reach equilibrium with a density profile which is well fit b

Michel Fliess

The signal to noise ratio, which plays such an important rôle in information theory, is shown to become pointless for digital communications where the demodulation is achieved via new fast estimation techniques. Operational calculus, differential algebra, noncommutative algebra and nonstandard analysis are the main mathematical tools.

Francisco M. Fernandez

We show that a recent non Born--Oppenheimer calculation of dipole moments exhibits obscure points and is not consistent with the well known Hellmann--Feynman theorem.

Yan-Mei Chen, Vivienne Wild, Guinevere Kauffmann, Jeremy Blaizot

We present a new method to estimate the average star formation rate per unit stellar mass (SSFR) of a stacked population of galaxies. We combine the spectra of 600-1000 galaxies with similar stellar masses and parameterise the star formation history of this stacked population using a set of exponentially declining functions. The strength of the Hydrogen Balm

L. S. Grigorio, M. S. Guimaraes, C. Wotzasek

We study $QED_3$ with magnetic-like defects using the Julia-Toulouse condensation mechanism (JTM). By a careful treatment of the symmetries we suggest a geometrical interpretation for distinct debatable issues in the MCS-monopole system: (i) the induction of the non-conserved electric current together with the Chern-Simons term (CS), (ii) the deconfinement t

Denis Denisov, Sergey Foss, Dmitry Korshunov

We study conditions under which $P(S_τ>x)\sim P(M_τ>x)\sim EτP(ξ_1>x)$ as $x\to\infty$, where $S_τ$ is a sum $ξ_1+...+ξ_τ$ of random size $τ$ and $M_τ$ is a maximum of partial sums $M_τ=\max_{n\leτ}S_n$. Here $ξ_n$, $n=1$, 2, ..., are independent identically distributed random variables whose common distribution is assumed to be subexponential. We consider m

Jeppe R. Andersen, Vittorio Del Duca, Chris D. White

We elucidate a new technique for estimating the production of multiple (at least two) hard jets in Higgs production via gluon-gluon fusion. The approach is based upon high energy factorisation, with the region of applicability extended by constraints on the analytic behaviour of the scattering amplitudes stemming from known all-order results. The method appr

J. Eisert, D. Gross

When locally exciting a quantum lattice model, the excitation will propagate through the lattice. The effect is responsible for a wealth of non-equilibrium phenomena, and has been exploited to transmit quantum information through spin chains. It is a commonly expressed belief that for local Hamiltonians, any such propagation happens at a finite "speed of

Xin Kang, Ying-Chang Liang, Arumugam Nallanathan, Hari Krishna Garg

A cognitive radio network (CRN) is formed by either allowing the secondary users (SUs) in a secondary communication network (SCN) to opportunistically operate in the frequency bands originally allocated to a primary communication network (PCN) or by allowing SCN to coexist with the primary users (PUs) in PCN as long as the interference caused by SCN to each

Rabin Banerjee, Bibhas Ranjan Majhi

We compute the corrections, using the tunneling formalisim based on a quantum WKB approach, to the Hawking temperature and Bekenstein-Hawking entropy for the Schwarzschild black hole. The results are related to the trace anomaly and are shown to be equivalent to findings inferred from Hawking's original calculation based on path integrals using zeta func

Beatriz Rodriguez Gonzalez

The present paper is devoted to study the homotopy category associated with a simplicial descent category (D,s,E) (arXiv:0808.3684v2). We prove that the class E of equivalences has a calculus of left fractions over a quotient category of D modulo homotopy. We study the fiber/cofiber sequences induced by a (co)simplicial descent structure. Examples of such fi

Beatriz Rodriguez Gonzalez

In this paper we study the question of how to transfer homotopic structure from the category sD of simplicial objects in a fixed category D to D. To this end we use a sort of homotopy colimit s : sD --> D, which we call simple functor. For instance, the Bousfield-Kan homotopy colimit in a Quillen simplicial model category is an example of simple functor. As

E. Solovieva, R. Chistov

We report results from a study of the charmed double strange baryons Ω_c^0 and Ω_c^{*0} at Belle. The Ω_c^0 is reconstructed using the Ω_c^0 --> Ω^- π^+ decay mode, and its mass is measured to be (2693.6 \pm 0.3 {+1.8 \atop -1.5}) MeV/c^2. The Ω_c^{*0} baryon is reconstructed in the Ω_c^0 γmode. The mass difference M_{Ω_c^{*0}} - M_{Ω_c^0} is measured to be

Stefan Horatschek, David Petroff

A Roche model for describing uniformly rotating rings is presented and the results are compared with numerical solutions to the full problem for polytropic rings. In the thin ring limit, the surfaces of constant pressure including the surface of the ring itself are given in analytic terms, even in the mass-shedding case.

Ulrich Menne

In this work it is shown that every integral varifold in an open subset of Euclidian space of locally bounded first variation can be covered by a countable collection of submanifolds of class C^2. Moreover, the mean curvature of each member of the collection agrees with the mean curvature of the varifold almost everywhere with respect to the varifold.

Tanju Gleisberg, Stefan Hoeche

We present a new tree-level matrix element generator, based on the colour dressed Berends-Giele recursive relations. We discuss two new algorithms for phase space integration, dedicated to be used with large multiplicities and colour sampling.

Akihiro Munemasa, Takuya Ikuta

Let X be a pseudocyclic association scheme in which all the nontrivial relations are strongly regular graphs with the same eigenvalues. We prove that the principal part of the first eigenmatrix of X is a linear combination of an incidence matrix of a symmetric design and the all-ones matrix. Amorphous pseudocyclic association schemes are examples of such ass

Andrew Das Arulsamy, Marco Fronzi

Electrons are indistinguishable, but the energy of each electron is different in different materials and if we can exploit this energy, then we can systematically study the changes of electronic properties in non free-electron metals.

Lei Wang, Zhaoshun Gao, Yanpeng Qi, Xianping Zhang

A series of polycrystalline SmO1-xFxFeAs bulks (x=0.15, 0.2, 0.3 and 0.4) were prepared by the conventional solid state reaction. Resistivity, susceptibility, magnetic hysteresis, critical current density and microstructure of these samples have been investigated. It is found that critical transition temperature Tc increases steadily with increasing fluorine

Milan Orlita, Clement Faugeras, Paulina Plochocka, Petr Neugebauer

Multi-layer epitaxial graphene (MEG) is investigated using far infrared (FIR) transmission experiments in the different limits of low magnetic fields and high temperatures. The cyclotron-resonance like absorption is observed at low temperature in magnetic fields below 50 mT, allowing thus to probe the nearest vicinity of the Dirac point and to estimate the c

Bin Chen, Xiao Liu

In this article we construct a tiny graviton matrix model for type IIB string theory on a plane-wave background with null dilaton. For the linear null dilaton case, we analyze its vacuum and the excitation spectrum around the vacuum, and discuss the time-dependent fuzzy three-sphere solutions and their evolution. It turns out that at very late time the non-A

Alice Fialowski, Friedrich Wagemann

We compute the second Hochschild cohomology space $HH^2(\mathcal{H}_1)$ of Connes-Moscovici's Hopf algebra $\mathcal{H}_1$, giving the infinitesimal deformations (up to equivalence) of the associative structure. $HH^2(\mathcal{H}_1)$ is shown to be one dimensional, and thus Connes-Moscovici's formal deformation of $\mathcal{H}_1$ using Rankin-Cohen b

Zhenting Hou, Xiangxing Kong, Dinghua Shi, Guanrong Chen

In this paper, we abstract a kind of stochastic processes from evolving processes of growing networks, this process is called growing network Markov chains. Thus the existence and the formulas of degree distribution are transformed to the corresponding problems of growing network Markov chains. First we investigate the growing network Markov chains, and obta

Ulrich Menne

In this work a local inequality is provided which bounds the distance of an integral varifold from a multivalued plane (height) by its tilt and mean curvature. The bounds obtained for the exponents of the Lebesgue spaces involved are shown to be sharp.

Lijun Zhang, Holger Hermanns, Friedrich Eisenbrand, David N. Jansen

Strong and weak simulation relations have been proposed for Markov chains, while strong simulation and strong probabilistic simulation relations have been proposed for probabilistic automata. However, decision algorithms for strong and weak simulation over Markov chains, and for strong simulation over probabilistic automata are not efficient, which makes it

U. Agvaanluvsan, A. C. Larsen, R. Chankova, M. Guttormsen

Radiative strength functions of 117Sn has been measured below the neutron separation energy using the (3He,3He'gamma) reactions. An increase in the slope of the strength functions around E_gamma= 4.5 MeV indicates the onset of a resonance-like structure, giving a significant enhancement of the radiative strength function compared to standard models in th

Daniel Greb, Stefan Kebekus, Sándor J. Kovács

Given a p-form defined on the smooth locus of a normal variety, and a resolution of singularities, we study the problem of extending the pull-back of the p-form over the exceptional set of the desingularization. For log canonical pairs and for certain values of p, we show that an extension always exists, possibly with logarithmic poles along the exceptional

Toshihiro Matsuo, Kin-ya Oda

We study the production cross section of a highly excited string with fixed angular momentum from an ultra-high energy collision of two light strings. We find that the cross section exhibits geometric behavior in a certain region of angular-momentum/impact-parameter space. This geometric behavior is common to the differential cross sections of a black hole p

Deepak Venkateshvaran, Matthias Althammer, Andrea Nielsen, Stephan Gepraegs

The ferrimagnetic spinel oxide Zn(x)Fe(3-x)O(4) combines high Curie temperature and spin polarization with tunable electrical and magnetic properties, making it a promising functional material for spintronic devices. We have grown epitaxial thin films with 0<=x<=0.9 on MgO(001) substrates with excellent structural properties both in pure Ar atmosphere and an

Sutapa Mukherji

In this paper, we show how a fixed point based boundary layer analysis can be used to understand phases and phase transitions in asymmetric simple exclusion processes (ASEPs) with open boundaries. In order to illustrate this method, we choose a two-species ASEP which has interesting phase transitions not seen in the one-species case. We also apply this metho

Colin Benjamin

The full counting statistics of a non adiabatic pure spin pump are calculated with particular emphasis on the second and third moments. We show that incoherence can change the sign of spin shot noise cross-correlations from negative to positive, implying entanglement for spin-singlet electronic sources, a truly counterintuitive result. The third moment on th

Naoki Kobayashi, Minami Izumi, Makoto Katori

The one-dimensional Brownian motion starting from the origin at time $t=0$, conditioned to return to the origin at time $t=1$ and to stay positive during time interval $0 < t < 1$, is called the Bessel bridge with duration 1. We consider the $N$-particle system of such Bessel bridges conditioned never to collide with each other in $0 < t < 1$, which is the c

Zosia A. C. Krusberg

This resource letter intends to provide physics instructors - particularly graduate student teaching assistants - at the introductory university level with a small but representative collection of resources to acquire a familiarity with research in physics education for guidance in everyday instruction. The resources are in the form of books, articles, websi

Peter Albers, Urs Frauenfelder

In this article we prove existence of Reeb orbits for Bohr-Sommerfeld Legendrians in certain pre-quantization spaces. We give a quantitative estimate from below. These estimates are obtained by studying Floer homology for fibre-wise quadratic Hamiltonian functions on negative line bundles.

Y. Tsutsumi, T. Kawakami, T. Mizushima, M. Ichioka

A concrete and experimentally feasible example for testing the putative Majorana zero energy state bound in a vortex is theoretically proposed for a parallel plate geometry of superfluid $^3$He-A phase. We examine the experimental setup in connection with ongoing rotating cryostat experiments. The theoretical analysis is based on the well-established Ginzbur

H. Moradi, S. M. Hanasoge, P. S. Cally

We investigate the direct contribution of strong, sunspot-like magnetic fields to helioseismic wave travel-time shifts via two numerical forward models, a 3D ideal MHD solver and MHD ray theory. The simulated data cubes are analyzed using the traditional time-distance center-to-annulus measurement technique. We also isolate and analyze the direct contributio

J. Wade Cherrington, J. Daniel Christensen

We derive an explicit formula for the vertex amplitude of dual SU(2) Yang-Mills theory in four dimensions on the lattice, and provide an efficient algorithm (of order j to the fourth power) for its computation. This opens the way for both numerical and analytic development of dual methods, previously limited to the case of three dimensions.

Ettore Aldrovandi, Behrang Noohi

Weak morphisms of non-abelian complexes of length 2, or crossed modules, are morphisms of the associated 2-group stacks, or gr-stacks. We present a full description of the weak morphisms in terms of diagrams we call butterflies. We give a complete description of the resulting bicategory of crossed modules, which we show is fibered and biequivalent to the 2-s

Tsung-Wei Chen, Guang-Yu Guo

We investigate torque and also conventionally defined spin-Hall currents in two-dimensional (2D) spin-orbit coupled systems of spin-1/2 particles within the linear response Kubo formalism. We obtain some interesting relations between the conventional and torque spin-Hall conductivities for the generic effective Hamiltonian $H_0=ε_k^0+A(k)σ_x-B(k)σ_y$, where

Kenneth W. Wachter, David R. Steinsaltz, Steven N. Evans

New models for evolutionary processes of mutation accumulation allow hypotheses about the age-specificity of mutational effects to be translated into predictions of heterogeneous population hazard functions. We apply these models to questions in the biodemography of longevity, including proposed explanations of Gompertz hazards and mortality plateaus, and us

Andrew T. Grier, Marko Cetina, Fedja Oručević, Vladan Vuletić

We demonstrate a double-trap system well suited to study cold collisions between trapped ions and trapped atoms. Using Yb$^+$ ions confined in a Paul trap and Yb atoms in a magneto-optical trap, we investigate charge-exchange collisions of several isotopes for collision energies down to 400 neV (5 mK). The measured rate coefficient of $6 \times 10^{-10}$ cm$

Jun-Feng Sun, Dong-Sheng Du, Yue-Ling Yang

The Bc --> J/psi pi, etac pi decays are studied with the perturbative QCD approach. It is found that form factors and branching ratios are sensitive to the parameters w, v, f_J/psi and f_etac, where w and v are the parameters of the charmonium wave functions for Coulomb potential and harmonic oscillator potential, respectively, f_J/psi and f_etac are the dec

Reginald D. Smith

Meroitic is the still undeciphered language of the ancient civilization of Kush. Over the years, various techniques for decipherment such as finding a bilingual text or cognates from modern or other ancient languages in the Sudan and surrounding areas has not been successful. Using techniques borrowed from information theory and natural language statistics,

S. Segan, B. Surlan, S. Vidojevic

We examine the possibility to extend leap second extrapolation for a near future based on some periodic terms in the Earth&#39;s rotation changes. The IERS data, covering the interval from 1962.15 to 2006.95, are analyzed. The difference $ΔT$ is extrapolated till to 2035 and compared with the IERS extrapolated values to the 2012. It can be seen that for the