October 2010 arXiv papers — page 42

Volker Braun

F-theory models are constructed where the 7-brane has a non-trivial fundamental group. The base manifolds used are a toric Fano variety and a smooth toric threefold coming from a reflexive polyhedron. The discriminant locus of the elliptically fibered Calabi-Yau fourfold can be chosen such that one irreducible component it is not simply connected (namely, an

L. G. López, D. H. Linares, A. J. Ramirez-Pastor, S. A. Cannas

Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior in a two-dimensional system of particles with two bonding sites that, by decreasing temperature or increasing density, polymerize reversibly into chains with discrete orientational degrees of freedom and, at the same time, undergo a continuous isotro

P. Chayer, J. Dupuis

Elements heavier than hydrogen or helium that are present in the atmospheres of white dwarfs with effective temperatures lower than 25,000 K, are believed to be the result of accretion. By measuring the abundances of these elements and by assuming a steady-state accretion, we can derive the composition of the accreted matter and infer its source. The presenc

L. G. López, D. H. Linares, A. J. Ramirez-Pastor

Using Monte Carlo simulations and finite-size scaling analysis, the critical behavior of self-assembled rigid rods on triangular and honeycomb lattices at intermediate density has been studied. The system is composed of monomers with two attractive (sticky) poles that, by decreasing temperature or increasing density, polymerize reversibly into chains with th

A. J. Korn

I review some of the current limitations in modelling stellar atmospheres of solar-type stars and approaches to overcome them.

D. Witthaut

We propose a scheme for the realization of a quantum walker and a quantum simulator for the Dirac equation with ultracold spinor atoms in driven optical lattices. A precise control of the dynamics of the atomic matter wave can be realized using time-dependent external forces. If the force depends on the spin state of the atoms, the dynamics will entangle the

M. Ahsan Zeb

Arising from the Article: Nature Phys. 2, 620-625 (2006), By M. I. Katsnelson, K. S. Novoselov, and A. K. Geim.

Michael Mayer, Mario Liu

The anisotropic, stress-dependent velocity of elastic waves in glass beads -- as observed by Y. Khidas and X. Jia, see [Phys. Rev. E, 81:021303, Feb. 2010] -- is shown to be well accounted for by ``granular solid hydrodynamics,'' a broad-range macroscopic theory of granular behavior. As the theory makes no reference to fabric anisotropy, the influenc

D. Brutin, B. Sobac, B. Loquet, J. Sampol

The drying of a drop of human blood exhibits coupled physical mechanisms, such as Marangoni flow, evaporation and wettability. The final stage of a whole blood drop evaporation reveals regular patterns with a good reproducibility for a healthy person. Other experiments on anaemic and hyperlipidemic people were performed, and different patterns were revealed.

Matthew Browning

Stars of sufficiently low mass are convective throughout their interiors, and so do not possess an internal boundary layer akin to the solar tachocline. Because that interface figures so prominently in many theories of the solar magnetic dynamo, a widespread expectation had been that fully convective stars would exhibit surface magnetic behavior very differe

Wilfred D. Kepseu, Paul Woafo, H. Sakaguchi

It is shown, by means of numerical simulations, that intercellular spiral waves of calcium can be initiated in a network of coupled cells as a result of a de-synchronization between Ca2+ oscillations in two domains. No artificial heterogeneities need to be imposed to the system for spontaneous formation of spiral waves. The de-synchronization occurs near the

Kyle Cranmer, Itay Yavin

Searches for new physics by experimental collaborations represent a significant investment in time and resources. Often these searches are sensitive to a broader class of models than they were originally designed to test. We aim to extend the impact of existing searches through a technique we call 'recasting'. After considering several examples, whic

Theodore Th. Voronov

We show how the relation between $Q$-manifolds and Lie algebroids extends to ``higher'' or ``non-linear'' analogs of Lie algebroids. We study the identities satisfied by a new algebraic structure that arises as a replacement of operations on sections of a Lie algebroid. When the base is a point, we obtain a generalization of Lie superalgebras

Lukasz Kosinski

We show that the equality $m_1(f(x))=m_2(g(x))$ for $x$ in a neighborhood of a point $a$ remains valid for all $x$ provided that $f$ and $g$ are open holomorphic maps, $f(a)=g(a)=0$ and $m_1,$ $m_2$ are Minkowski functionals of bounded balanced domains. Moreover, a polynomial relation between $f$ and $g$ is obtained. Next we generalize these results to bound

Matteo Cantiello, Jonathan Braithwaite, Axel Brandenburg, Fabio Del Sordo

Hot luminous stars show a variety of phenomena in their photospheres and in their winds which still lack clear physical explanations at this time. Among these phenomena are non-thermal line broadening, line profile variability (LPVs), discrete absorption components (DACs), wind clumping and stochastically excited pulsations. Cantiello et al. (2009) argued th

Judy Y. Cheng, S. M. Faber, Luc Simard, Genevieve J. Graves

(abridged) In the last decade, the advent of enormous galaxy surveys has motivated the development of automated morphological classification schemes to deal with large data volumes. Existing automated schemes can successfully distinguish between early and late type galaxies and identify merger candidates, but are inadequate for studying detailed morphologies

David M. Kipping

We show that for a transiting exoplanet accompanied by a moon which also transits, the absolute masses and radii of the star, planet and moon are determinable. For a planet-star system, it is well known that the density of the star is calculable from the lightcurve by manipulation of Kepler's Third Law. In an analogous way, the planetary density is calcu

Michal Maciejewski, Mark Vogelsberger, Simon D. M. White, Volker Springel

We analyse the coarse-grained phase-space structure of the six Galaxy-scale dark matter haloes of the Aquarius Project using a state-of-the-art 6D substructure finder. Within r_50, we find that about 35% of the mass is in identifiable substructures, predominantly tidal streams, but including about 14% in self-bound subhaloes. The slope of the differential su

H. M. Khudaverdian, Th. Th. Voronov

We give a short proof of the Buchstaber-Rees theorem concerning symmetric powers. The proof is based on the notion of a formal characteristic function of a linear map of algebras.

Arnold Stein

Assuming the holographic principle, the gravitational force can be formulated thermodynamically as an entropic force, but the mechanism by which the attraction between two masses occurs is not clear. The physical basis for the holographic principle is also unknown. My primary assumption is that empty space consists of discrete countable units that have on th

Dominik A. Riechers, Axel Weiss, Fabian Walter, Jeff Wagg

We report the detection of surprisingly strong HCN, HNC, and HCO+(J=6-5) emission in the host galaxy of the z=3.91 quasar APM08279+5255 through observations with CARMA. HCN, HNC, and HCO+ are typically used as star formation indicators, tracing dense molecular hydrogen gas [n(H2) > 10^5,cm^-3] within star-forming molecular clouds. However, the strength of th

A. Badertscher, A. Curioni, S. Horikawa, L. Knecht

In this paper we present results from a test of a small Liquid Argon Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC). This detector concept provides a 3D-tracking and calorimetric device capable of charge amplification, suited for next-generation neutrino detectors and possibly direct Dark Matter searches. During a test of a 3~lt chamber equi

Zhengfeng Ji, Zhaohui Wei, Bei Zeng

The problem of finding the ground state of a frustration-free Hamiltonian carrying only two-body interactions between qubits is known to be solvable in polynomial time. It is also shown recently that, for any such Hamiltonian, there is always a ground state that is a product of single- or two-qubit states. However, it remains unclear whether the whole ground

Sergio del Campo, Victor H. Cardenas, Ramon Herrera

We study the evolution of spatial curvature for thawing class of dark energy models. We examine the evolution of the equation of state parameter, $w_ϕ$, as a function of the scale factor $a$, for the case in which the scalar field $ϕ$ evolve in nearly flat scalar potential. We show that all such models provide the corresponding approximate analytical express

David Uminsky, C. Eugene Wayne, Alethea Barbaro

In this paper we introduce simplified, combinatorially exact formulas that arise in the vortex interaction model found in (Nagem, et al., SIAM J. Appl. Dyn. Syst. 2009). These combinatorial formulas allow for the efficient implementation and development of a new multi-moment vortex method (MMVM) using a Hermite expansion to simulate 2D vorticity. The method

Dušan Repovš, Lyubomyr Zdomskyy

We study M-separability as well as some other combinatorial versions of separability. In particular, we show that the set-theoretic hypothesis b=d implies that the class of selectively separable spaces is not closed under finite products, even for the spaces of continuous functions with the topology of pointwise convergence. We also show that there exists no

Jayanta Ghosh, T. K. Samanta

In this paper we have studied the relation between the fuzzy left (respectively right) ideals of $Γ-$semiring and that of operator semiring. Thereafter, we have established that the Lattices of all fuzzy left (respectively right) ideal of $Γ-$semiring is equivalent to that of Left operator semiring. Also we have established few properties relating the $k-$id

Bivas Dinda, Tuhin Bera, T. K. Samanta

In this paper, generalised intuitionistic fuzzy soft sets and relations on generalised intuitionistic fuzzy soft sets are defined and a few of their properties are studied. An application of generalised intuitionistic fuzzy soft sets in decision making with respect to degree of preference is investigated.

Yair Caro, Michael A. Henning

A directed dominating set in a directed graph $D$ is a set $S$ of vertices of $V$ such that every vertex $u \in V(D) \setminus S$ has an adjacent vertex $v$ in $S$ with $v$ directed to $u$. The directed domination number of $D$, denoted by $γ(D)$, is the minimum cardinality of a directed dominating set in $D$. The directed domination number of a graph $G$, d

Ruo-Wei Hung

The $n$-dimensional hypercube network $Q_n$ is one of the most popular interconnection networks since it has simple structure and is easy to implement. The $n$-dimensional locally twisted cube, denoted by $LTQ_n$, an important variation of the hypercube, has the same number of nodes and the same number of connections per node as $Q_n$. One advantage of $LTQ_

Loet Leydesdorff, Jung C. Shin

Fractional counting of citations can improve on ranking of multi-disciplinary research units (such as universities) by normalizing the differences among fields of science in terms of differences in citation behavior. Furthermore, normalization in terms of citing papers abolishes the unsolved questions in scientometrics about the delineation of fields of scie

Yair Caro, Michael A. Henning

A directed dominating set in a directed graph $D$ is a set $S$ of vertices of $V$ such that every vertex $u \in V(D) \setminus S$ has an adjacent vertex $v$ in $S$ with $v$ directed to $u$. The directed domination number of $D$, denoted by $γ(D)$, is the minimum cardinality of a directed dominating set in $D$. The directed domination number of a graph $G$, d

R. V. E. Lovelace, K. R. Covey, J. P. Lloyd

Magnetospheric accretion is an important process for a wide range of astrophysical systems, and may play a role in the formation of gas giant planets. Extending the formalism describing stellar magnetospheric accretion into the planetary regime, we demonstrate that magnetospheric processes may govern accretion onto young gas giants in the isolation phase of

D. Barrado, B. Stelzer, M. Morales-Calderón, A. Bayo

This is the first paper of a series devoted to the Lambda Orionis star-forming region, from the X-ray perspective, which will provide a comprehensive view of this complex region. In this paper we focus in uncovering the population of the central, young cluster Collinder 69 (C69), and in particular those diskless members not identified by previous near- and m

Malgorzata Krawczyk, Lev Muchnik, Anna Mańka-Krasoń, Krzysztof Kułakowski

The line graphs are clustered and assortative. They share these topological features with some social networks. We argue that this similarity reveals the cliquey character of the social networks. In the model proposed here, a social network is the line graph of an initial network of families, communities, interest groups, school classes and small companies.

I. Exius, K. P. Schmidt, B. Lake, D. A. Tennant

We combine the results of perturbative continuous unitary transformations with a mean-field calculation to determine the evolution of the single-mode, i.e., one-triplon, contribution to the dynamic structure factor of a two-leg $S=1/2$ ladder on increasing temperature from zero to a finite value. The temperature dependence is induced by two effects: (i) no t

Andela Šarić, Behnaz Bozorgui, Angelo Cacciuto

We use numerical simulations to study the phase behavior of a system of purely repulsive soft dumbbells as a function of size ratio of the two components and their relative degree of deformability. We find a plethora of different phases which includes most of the mesophases observed in self-assembly of block copolymers, but also crystalline structures formed

Andrés Ernesto Guzman, Guido Garay, Kate Jane Brooks

We report the discovery made using the Australia Telescope Compact Array of a remarkable string of radio emission towards IRAS 16562-3959, a luminous infrared source with a bolometric luminosity of $7.0\times10^4$ \Lsun. The radio emission arises from a compact, bright central component, two inner lobes, which are separated by about 7\arcsec\ and symmetrical

Leonid Barenboim, Michael Elkin

We study the {edge-coloring} problem in the message-passing model of distributed computing. This is one of the most fundamental and well-studied problems in this area. Currently, the best-known deterministic algorithms for (2Delta -1)-edge-coloring requires O(Delta) + log-star n time \cite{PR01}, where Delta is the maximum degree of the input graph. Also, re

Andela Šarić, Angelo Cacciuto

We use numerical simulations to show how noninteracting hard particles binding to a deformable elastic shell may self-assemble into a variety of linear patterns. This is a result of the nontrivial elastic response to deformations of shells. The morphology of the patterns can be controlled by the mechanical properties of the surface, and can be fine-tuned by

Antonio Parravano, Christopher F. McKee, David J. Hollenbach

We derive a semi-empirical galactic initial mass function (IMF) from observational constraints. We assume that the star formation rate in a galaxy can be expressed as the product of the IMF, $ψ(m)$, which is a smooth function of mass $m$ (in units of \msun), and a time- and space-dependent total rate of star formation per unit area of galactic disk. The mass

P. A. Jones, M. G. Burton, N. F. H. Tothill, M. R. Cunningham

We have undertaken a spectral-line imaging survey of a 6 x 6 arcmin^2 area around Sgr B2 near the centre of the Galaxy, in the range from 30 to 50 GHz, using the Mopra telescope. The spatial resolution varies from 1.0 to 1.4 arcmin and the spectral resolution from 1.6 to 2.7 km s^-1 over the frequency range. We present velocity-integrated emission images for

Tatini Mal-Sarkar, Swarup Bhunia

With increasing complexity of modern-day mobile devices, security of these devices in presence of myriad attacks by an intelligent adversary is becoming a major issue. The vast majority of cell phones still remain unsecured from many existing and emerging security threats. To address the security threats in mobile devices we are exploring a technology, which

Daria Schymura

Let A be a bounded subset of IR^d. We give an upper bound on the volume of the symmetric difference of A and f(A) where f is a translation, a rotation, or the composition of both, a rigid motion. The volume is measured by the d-dimensional Hausdorff measure, which coincides with the Lebesgue measure for Lebesgue measurable sets. We bound the volume of the sy

Pawel Blasiak

Non-commutativity is ubiquitous in mathematical modeling of reality and in many cases same algebraic structures are implemented in different situations. Here we consider the canonical commutation relation of quantum theory and discuss a simple urn model of the latter. It is shown that enumeration of urn histories provides a faithful realization of the Heisen

Mark Strikman

We review theory of the leading twist nuclear shadowing, and describe phenomenon of post-selection suppression of leading parton spectrum (effective fractional energy losses) in the proximity of the black disk regime. We argue that $2 \to 2$ mechanism dominates in the inclusive leading pion production in d-Au collisions and explain that the post-selection na

Dino Sejdinovic, Oliver Johnson

An information theoretic perspective on group testing problems has recently been proposed by Atia and Saligrama, in order to characterise the optimal number of tests. Their results hold in the noiseless case, where only false positives occur, and where only false negatives occur. We extend their results to a model containing both false positives and false ne

Omar Mehanna, John Marcos, Nihar Jindal

We study the Han-Kobayashi (HK) achievable sum rate for the two-user symmetric Gaussian interference channel. We find the optimal power split ratio between the common and private messages (assuming no time-sharing), and derive a closed form expression for the corresponding sum rate. This provides a finer understanding of the achievable HK sum rate, and allow

Chih-Chun Wang

This paper focuses on the 1-to-K broadcast packet erasure channel (PEC), which is a generalization of the broadcast binary erasure channel from the binary symbol to that of arbitrary finite fields GF(q) with sufficiently large q. We consider the setting in which the source node has instant feedback of the channel outputs of the K receivers after each transmi

A. D. Parks, J. E. Gray

Exact pointer states are obtained for projection operator measurements performed upon pre-selected (PS) and upon pre- and post-selected (PPS) quantum systems. These states are used to provide simple exact expressions for both the pointer spatial probability distribution profiles and the mean values of arbitrary pointer observables associated with PS and PPS

Chih-Chun Wang

This paper focuses on the 1-to-K broadcast packet erasure channel (PEC), which is a generalization of the broadcast binary erasure channel from the binary symbol to that of arbitrary finite fields GF(q) with sufficiently large q. We consider the setting in which the source node has instant feedback of the channel outputs of the K receivers after each transmi

Rachit Mohan Garg, Shipra Kapoor, Kapil Kumar, Mohd. Dilshad Ansari

Now-a-days internet has become a vast source of entertainment & new services are available in quick succession which provides entertainment to the users. One of this service i.e. Video-on-Demand is most hyped service in this context. Transferring the video over the network with less error is the main objective of the service providers. In this paper we prese

D. G. Yakovlev, M. Beard, L. R. Gasques, M. Wiescher

We propose a physically transparent analytic model of astrophysical S-factors as a function of a center-of-mass energy E of colliding nuclei (below and above the Coulomb barrier) for non-resonant fusion reactions. For any given reaction, the S(E)-model contains four parameters [two of which approximate the barrier potential, U(r)]. They are easily interpolat

Kh. Saaidi, S. Ziaee

We study the anisotropic Big Bang cosmology for a general non-linear equation of state (EoS) in standard general relativity cosmology in early times. According to brane world cosmology and loop quantum gravity which introduce a quadratic term in the energy density, we study a non-linear EoS with a general nonlinear term in the energy density. We show that th

Thomas Thiemann

In a series of seminal papers, Laddha and Varadarajan have developed in depth the quantisation of Parametrised Field Theory (PFT) in the kind of discontinuous representations that are employed in Loop Quantum Gravity (LQG). In one spatial dimension (circle) PFT is very similar to the closed bosonic string and the constraint algebra is isomorphic to two mutua

Konstadinos Siampos

In this dissertation, we review the study of quark and monopole bound-state potentials within the gauge/gravity correspondence. Their behaviors often differ from what is expected on general physical grounds and field-theory considerations. We identify the configurations of physical interest by examining the stability of the string (brane) solutions dual to t

T. Bäckdahl, J. A. Valiente Kroon

In this article we construct a geometric invariant for initial data sets for the vacuum Einstein field equations $(\mathcal{S},h_{ab},K_{ab})$, such that $\mathcal{S}$ is a 3-dimensional manifold with an asymptotically Euclidean end and an inner boundary $\partial \mathcal{S}$ with the topology of the 2-sphere. The hypersurface $\mathcal{S}$ can be though of

Alexandre Gabard, David Gauld

We show that both, the Jordan curve theorem and the Schoenflies theorem extend to non-metric manifolds (at least in the two-dimensional context), and conclude by some dynamical applications à la Poincaré-Bendixson.

P. Van Isacker

The use of the seniority quantum number in many-body systems is reviewed. A brief summary is given of its introduction by Racah in the context of atomic spectroscopy. Several extensions of Racah's original idea are discussed: seniority for identical nucleons in a single-$j$ shell, its extension to the case of many, non-degenerate $j$ shells and to system

A. Zenesini, D. Ciampini, O. Morsch, E. Arimondo

We report the experimental observation of Stückelberg oscillations of matter waves in optical lattices. Extending previous work on Landau-Zener tunneling of Bose-Einstein condensates in optical lattices, we study the effects of the accumulated phase between two successive crossings of the Brillouin zone edge. Our results agree well with a simple model for mu

Petr N. Vabishchevich

Rapid processes of heat transfer are not described by the standard heat conduction equation. To take into account a finite velocity of heat transfer, we use the hyperbolic model of heat conduction, which is connected with the relaxation of heat fluxes. In this case, the mathematical model is based on a hyperbolic equation of second order or a system of equat

Kh. Saaidi, S. Ziaee

Using non-linear equation of state for pressure and density energy, we show that the universe is began with a smooth and isotropic bounce. We use a non-linear equation of state which is a binary mixture of perfect fluid and dark energy. We show that in order to preserve a smooth and isotropic bounce, the source for contraction before the bounce, must have an

J. N. Reeves, J. Gofford, V. Braito, R. Sambruna

We present evidence for X-ray line emitting and absorbing gas in the nucleus of the Broad-Line Radio Galaxy (BLRG), 3C 445. A 200ks Chandra LETG observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft X-ray spectrum, primarily from the He and H-like ions of O, Ne, Mg and Si. Radiative recombination emission is detected

Jiayu Li, Yunyan Yang

Nonexistence of quasi-harmonic spheres is necessary for long time existence and convergence of harmonic map heat flows. Let $(N,h)$ be a complete noncompact Riemannian manifolds. Assume the universal covering of $(N,h)$ admits a nonnegative strictly convex function with polynomial growth. Then there is no quasi-harmonic spheres $u:\mathbb{R}^n\ra N$ such tha

Justin D. Yeakel, Dirk Stiefs, Mark Novak, Thilo Gross

Over the past years several authors have used the approach of generalized modeling to study the dynamics of food chains and food webs. Generalized models come close to the efficiency of random matrix models, while being as directly interpretable as conventional differential-equation-based models. Here we present a pedagogical introduction to the approach of

Yangbo Xie, Huanyang Chen, Yadong Xu, Lin Zhu

In this paper, we use the parameter retrieval method together with an analytical effective medium approach to design a well-performed invisible cloak, which is based on an empirical revised version of the reduced cloak. The designed cloak can be implemented by silver nanowires with elliptical cross-sections embedded in a polymethyl methacrylate host. This cl

Aditi Mitra, Achim Rosch

The properties of a local spin S=1/2 coupled to K independent wires is studied in the presence of bias voltages which drive the system out of thermal equilibrium. For K >> 1, a perturbative renormalization group approach is employed to construct the voltage dependent scaling function for the conductance and the T-matrix. In contrast to the single-channel cas

Kh. Saaidi, A. Aghamohammadi

We investigate the corresponding relation between $f(R)$ gravity and holographic dark energy. We introduce a kind of energy density from $f(R)$ which has role of the same as holographic dark energy. We obtain the differential equation that specify the evolution of the introduced energy density parameter based on varying gravitational constant. We find out a

Robert Cauty

A topological space is locally equiconnected if there exists a neighborhood $U$ of the diagonal in $X\times X$ and a continuous map $λ:U\times[0,1]\to X$ such that $λ(x,y,0)=x$, $λ(x,y,1)=y$ et $λ(x,x,t)=x$ for $(x,y)\in U$ and $(x,t)\in X\times[0,1]$. This class contains all ANRs, all locally contractible topological groups and the open subsets of convex su

Johannes S. Seldenthuis, Ferry Prins, Joseph M. Thijssen, Herre S. J. van der Zant

Many types of molecular motors have been proposed and synthesized in recent years, displaying different kinds of motion, and fueled by different driving forces such as light, heat, or chemical reactions. We propose a new type of molecular motor based on electric field actuation and electric current detection of the rotational motion of a molecular dipole emb

Matthias Schroeder

We prove that the Kleene-Kreisel space $N^N^N$ does not satisfy Normann's condition. A topological space $X$ is said to fulfil Normann's condition, if every functionally closed subset of $X$ is an intersection of clopen sets. The investigation of this property is motivated by its strong relationship to a problem in Computable Analysis. D. Normann has

O. Tibolla, K. Mannheim, D. Elsässer

Recently, two nearby prominent starburst galaxies, M82 and NGC253, have been detected as point-like sources with gamma-ray telescopes at TeV energies [1] [2]. It has been claimed that these detections show that the cosmic ray intensity in the starburst galaxies is three orders of magnitude higher than in the Milky Way galaxy, assuming that the observed gamma

Frank-Peter Schilling

Studies are presented of the selection of events consistent with top quark pair production in data recorded by the CMS detector at the LHC, corresponding to an integrated luminosity of 0.84+/-0.09 1/pb and at center-of-mass energy sqrt{s}=7 TeV. Results are presented for the lepton+jets as well as dilepton channels. Event yields in data are compared to those

F. T. Vasko

The transient response of an intrinsic graphene, which is caused by the ultrafast interband transitions, is studied theoretically for the range of pumping correspondent to the saturated absorption regime. Spectral and temporal dependencies of the photoexcited concentration as well as the transmission and relitive absotption coefficients are considered for mi

B. B. Brandt, S. Capitani, M. Della Morte, D. Djukanovic

We present an update on our on-going project to compute hadronic observables for Nf=2 flavours of O(a) improved Wilson fermions at small lattice spacings. The procedure to determine the lattice scale via the mass of the Omega baryon is described. Furthermore we present preliminary results for the pion form factor computed using twisted boundary conditions, a

Shoko Jin, Nicolas F. Martin

We investigate the possibility that Hercules, a recently discovered Milky Way (MW) satellite, is a stellar stream in the process of formation. This hypothesis is motivated by Hercules' highly elongated shape as well as the measurement of a tentative radial velocity gradient along its body. The application of simple analytical techniques on radial velocit

Nataliya M. Ivanova, C. Sophocleous

Nonclassical symmetries of a class of generalized Huxley equations of form $u_t=u_{xx}+k(x)u^2(1-u)$ are found. More precisely, for the class under consideration we completely classify reduction operators with $τ=1$ and give a wide number of examples of equations admitting reduction operators with $τ=0$.

Piotr T. Chruściel, Roger Tagne Wafo

We prove propagation of weighted Sobolev regularity for solutions of the hyperboloidal Cauchy problem for a class of quasi-linear symmetric hyperbolic systems, under structure conditions compatible with the Einstein-Maxwell equations in space-time dimensions $n+1\ge 7$. Similarly we prove propagation of polyhomogeneity in dimensions $n+1\ge 9$. As a byproduc

Peter Vermeire

Under an explicit positivity condition, we show the first secant variety of a linearly normal smooth variety is projectively normal, give results on the regularity of the ideal of the secant variety, and give conditions on the variety that are equivalent to the secant variety being arithmetically Cohen-Macaulay. Under this same condition, we then show that i

Mihaiela Lupea, Doina Tatar, Zsuzsana Marian

In this paper the problems of deriving a taxonomy from a text and concept-oriented text segmentation are approached. Formal Concept Analysis (FCA) method is applied to solve both of these linguistic problems. The proposed segmentation method offers a conceptual view for text segmentation, using a context-driven clustering of sentences. The Concept-oriented C

Y. Azizi

We employ the charge neutrality condition in the form of zero vorticity for a Josephson junction lattice in calculating its ground state. We consider a Fibonacci ladder and the Penrose lattice to test our method. We also compare the results with those of the model that treats the plaquettes independently. We show that the zero vorticity condition improves on

B. Ghosh, M. Sardar, S. Banerjee

In this paper we have tried to understand the precise nature of magnetism in ZnO nanoparticles. Cooling field dependence of magnetic hysteresis and coercive field was observed for high temperature annealed sample indicating cooperative magnetic correlation and ordering within the agglomerated nanograins. The increasing induced internal magnetic field along t

James P. Cossey, Mark L. Lewis

Suppose $G$ is a $p$-solvable group, where $p$ is odd. We explore the connection between lifts of Brauer characters of $G$ and certain local objects in $G$, called vertex pairs. We show that if $χ$ is a lift, then the vertex pairs of $χ$ form a single conjugacy class. We use this to prove a sufficient condition for a given pair to be a vertex pair of a lift

Thimo Petri

In this thesis we discuss the decays of the pseudoscalar mesons (the neutral pion, the eta and eta-prime) which are governed by the chiral anomaly. Some of these decays are of special interest because their study permits a deep insight into aspects of modern physics. The decays can be classified according to the type of the anomaly (triangle or box) that gov

L. Szunyogh, L. Udvardi, J. Jackson, U. Nowak

In order to derive tensorial exchange interactions and local magnetic anisotropies in itinerant magnetic systems, an approach combining the Spin-Cluster Expansion with the Relativistic Disordered Local Moment scheme is introduced. The theoretical background and computational aspects of the method are described in detail. The exchange interactions and site re

Jakub Cieslak, Stanislaw M. Dubiel, Michael Reissner

Neutron diffraction technique was used to study distribution of Co and Cr atoms over different lattice sites as well as lattice paramaters in sigma-phase Co100-xCrx compounds with x = 57.0, 62.7 and 65.8. From the diffractograms recorded in the temperature range of 4.2 - 300 K it was found that all five sites A, B, C, D and E are populated by both kinds of a

Andrea Campagna, Rasmus Pagh

While there has been a lot of work on finding frequent itemsets in transaction data streams, none of these solve the problem of finding similar pairs according to standard similarity measures. This paper is a first attempt at dealing with this, arguably more important, problem. We start out with a negative result that also explains the lack of theoretical up

V. S. Usatyuk

This article presets a review of lattice problems. Paper contains the main eighteen problems with their reductions and referents to his cryptography application. As an example of reduction, we detail analyze connection between SVP and CVP. Moreover, we give an Ajtai theorem and demonstrate its role in lattice based cryptography.

Thomas Brougham, Vojtech Kost'ak, Igor Jex, Erika Andersson

We investigate the entanglement produced by a multi-path interferometer that is composed of two symmetric multiports, with phase shifts applied to the output of the first multiport. Particular attention is paid to the case when we have a single photon entering the interferometer. For this situation we derive a simple condition that characterize the types of

Lorenzo Zaninetti

The asymmetric shape of the nebula around $η$-Carinae (Homunculus) can be explained by a spherical expansion in a non-homogeneous medium. Two models are analyzed: an exponential and an inverse power law dependence for the density as a function of distance from the equatorial plane. The presence of a medium with variable density along the polar direction prog

Anirudh Pradhan, Hassan Amirhashchi

A new dark energy model in anisotropic Bianchi type-III space-time with variable equation of state (EoS) parameter has been investigated in the present paper. To get the deterministic model, we consider that the expansion $θ$ in the model is proportional to the eigen value $σ^{2}_{~2}$ of the shear tensor $σ^{j}_~i$. The EoS parameter $ω$ is found to be time

Altug Arda, Ramazan Sever

The one-dimensional effective-mass Klein-Gordon equation for the real, and non-\textrm{PT}-symmetric/non-Hermitian generalized Morse potential is solved by taking a series expansion for the wave function. The energy eigenvalues, and the corresponding eigenfunctions are obtained. They are also calculated for the constant mass case.

Andrea Campagna, Rasmus Pagh

Given a directed acyclic graph with labeled vertices, we consider the problem of finding the most common label sequences ("traces") among all paths in the graph (of some maximum length m). Since the number of paths can be huge, we propose novel algorithms whose time complexity depends only on the size of the graph, and on the frequency epsilon of the

J. Theodore Cox

We consider the stepping stone model on the torus of side $L$ in $\mathbb{Z}^2$ in the limit $L\to\infty$, and study the time it takes two lineages tracing backward in time to coalesce. Our work fills a gap between the finite range migration case of [Ann. Appl. Probab. 15 (2005) 671--699] and the long range case of [Genetics 172 (2006) 701--708], where the m

Siim Karus, Marlon Dumas

This paper studies the problem of predicting the coding effort for a subsequent year of development by analysing metrics extracted from project repositories, with an emphasis on projects containing XML code. The study considers thirteen open source projects and applies machine learning algorithms to generate models to predict one-year coding effort, measured

Carlos Hoyos, Mark den Brok, Gijs Verdoes Kleijn, David Carter

We present a catalogue of structural parameters for 8814 galaxies in the 25 fields of the HST/ACS Coma Treasury Survey. Parameters from Sérsic fits to the two-dimensional surface brightness distributions are given for all galaxies from our published Coma photometric catalogue with mean effective surface brightness brighter than 26.0 mag/sq. arcsec and bright

Saidakhmat N. Lakaev, Shohruh Yu. Holmatov

The Hamiltonian of a system of two quantum mechanical particles moving on the $d$-dimensional lattice $\Z^d$ and interacting via zero-range attractive pair potentials is considered. For the two-particle energy operator $H_μ(K),$ $K\in \T^d=(-π,π]^d$ -- the two-particle quasi-momentum, the existence of a unique positive eigenvalue $z(μ, K)$ above the upper ed

Anjan S. Joshipura, Bhavik P. Kodrani

The charged fermion mass matrices are invariant under $U(1)^3$ symmetry linked to the fermion number transformation. Under the condition that the definition of this symmetry in arbitrary weak basis does not depend upon Higgs parameters such as ratio of vacuum expectation values, a class of two Higgs doublet models (2HDM) can be identified in which tree level

Riccardo Albertoni, Monica De Martino

This paper deals with the semantic interpretation of information resources (e.g., images, videos, 3D models). We present a case study of an approach based on semantic and context dependent similarity applied to the industrial design. Different application contexts are considered and modelled to browse a repository of 3D digital objects according to different

Marcus N. Bannerman, Jonathan E. Kollmer, Achim Sack, Michael Heckel

The response of an oscillating granular damper to an initial perturbation is studied using experiments performed in microgravity and granular dynamics mulations. High-speed video and image processing techniques are used to extract experimental data. An inelastic hard sphere model is developed to perform simulations and the results are in excellent agreement