March 2012 arXiv papers — page 15

Philipp Schaer, Thomas Lüke, Wilko van Hoek

The problem that the same information need can be expressed in a variety of ways is especially true for scientific literature. Each scientific discipline has its own domain-specific language and vocabulary. This language is coded into documentary tools like thesauri or classifications that are used to document and describe scientific documents. When we think

Zhicheng Zhong, G. Koster, Paul J. Kelly

Competition between electronic and atomic reconstruction is a constantly recurring theme in transition-metal oxides. We use density functional theory calculations to study this competition for a model system consisting of a thin film of the polar, infinite-layer structure ACuO2 (A=Ca, Sr, Ba) grown on a nonpolar, perovskite SrTiO3 substrate. A transition fro

A. V. Geramita, B. Harbourne, J. Migliore

Star configurations are certain unions of linear subspaces of projective space. They have appeared in several different contexts: the study of extremal Hilbert functions for fat point schemes in the plane; the study of secant varieties of some classical algebraic varieties; the study of the resurgence of projective schemes. In this paper we study some algebr

Andreas Jacob, Klaus Hornberger

Recently, several laser schemes have been proposed to separate racemic mixtures of enantiomers by splitting a molecular beam into subbeams consisting of molecules of definite chirality [Y. Li, C. Bruder, and C. P. Sun, Phys. Rev. Lett. 99, 130403 (2007); X. Li and M. Shapiro, J. Chem. Phys. 132, 194315 (2010)]. These ideas rely on laser-induced effective gau

Ebru Aydin Gol, Calin Belta

In this paper, we consider the problem of controlling a dynamical system such that its trajectories satisfy a temporal logic property in a given amount of time. We focus on multi-affine systems and specifications given as syntactically co-safe linear temporal logic formulas over rectangular regions in the state space. The proposed algorithm is based on the e

S. Liu, P. E. Nissen, W. J. Schuster, G. Zhao

The differences between the neutron-capture element abundances of halo stars are important to our understanding of the nucleosynthesis of elements heavier than the iron group. We present a detailed abundance analysis of carbon and twelve neutron-capture elements from Sr up to Pb for a peculiar halo star G24-25 with [Fe/H] = -1.4 in order to probe its origin.

Z. Yoshida, Y. Yano, J. Morikawa, H. Saitoh

On a dipole plasma, we observe the generation of magnetic moment, as the movement of the levitating magnet-plasma compound, in response to electron-cyclotron heating and the increase of $β$ (magnetically-confined thermal energy). We formulate a thermodynamic model with interpreting heating as injection of microscopic magnetic moment; the corresponding chemic

Patrizia Vitale

I review the basic ingredients of discretized gravity which motivate the introduction of Group Field Theory. Thus I describe the GFT formulation of some models and conclude with a few remarks on the emergence of noncommutative structures in such models.

Mihai Turinici

Some fixed point results are given for a class of functional contractions over partial metric spaces. These extend some contributions in the area due to Ilic et al [Math. Comput. Modelling, 55 (2012), 801-809].

Michael E. Reimer, Gabriele Bulgarini, Nika Akopian, Moïra Hocevar

The ability to achieve near-unity light extraction efficiency is necessary for a truly deterministic single photon source. The most promising method to reach such high efficiencies is based on embedding single photon emitters in tapered photonic waveguides defined by top-down etching techniques. However, light extraction efficiencies in current top-down appr

Amitabha Roy

Mining large graphs for information is becoming an increasingly important workload due to the plethora of graph structured data becoming available. An aspect of graph algorithms that has hitherto not received much interest is the effect of memory hierarchy on accesses. A typical system today has multiple levels in the memory hierarchy with differing units of

L. M. Chechin

We argued that the standard field scalar potential couldn't be widely used for getting the adequate galaxies' curve lines and determining the profiles of dark matter their halo. For discovering the global properties of scalar fields that can describe the observable characteristics of dark matter on the cosmological space and time scales, we propose t

Al Kassem Jebai, François Malrait, Philippe Martin, Pierre Rouchon

Sensorless control of Permanent-Magnet Synchronous Motors at low velocity remains a challenging task. A now well-established method consists in injecting a high-frequency signal and use the rotor saliency, both geometric and magnetic-saturation induced. This paper proposes a clear and original analysis based on second-order averaging of how to recover the po

M. Jagadesh Kumar, Kanika Nadda

A distinctive approach for forming a lateral Bipolar Charge Plasma Transistor (BCPT) is explored using 2-D simulations. Different metal work-function electrodes are used to induce n- and p-type charge plasma layers on undoped SOI to form the emitter, base and collector regions of a lateral NPN transistor. Electrical characteristics of the proposed device are

Silvana Botti, José A. Flores-Livas, Maximilian Amsler, Stefan Goedecker

We present state-of-the-art first-principle calculations of the electronic and optical properties of silicon allotropes with interesting characteristics for applications in thin-film solar cells. These new phases consist of distorted sp$^3$ silicon networks and have a lower formation energy than other experimentally produced silicon phases. Some of these str

Dalene Stangl, Lurdes Y. T. Inoue, Telba Z. Irony

Donald (Don) Arthur Berry, born May 26, 1940 in Southbridge, Massachusetts, earned his A.B. degree in mathematics from Dartmouth College and his M.A. and Ph.D. in statistics from Yale University. He served first on the faculty at the University of Minnesota and subsequently held endowed chair positions at Duke University and The University of Texas M.D. Ande

Frederic Campana, Fei Wang, De-Qi Zhang

We prove two results about the natural representation of a group G of automorphisms of a normal projective threefold X on its second cohomology. We show that if X is minimal then G, modulo a normal subgroup of null entropy, is embedded as a Zariski-dense subset in a semi-simple real linear algebraic group of real rank < 3. Next, we show that X is a complex t

Simone Scotti

We study the effect of parameter uncertainty on a stochastic diffusion model, in particular the impact on the pricing of contingent claims, using methods from the theory of Dirichlet forms. We apply these techniques to hedging procedures in order to compute the sensitivity of SDE trajectories with respect to parameter perturbations. We show that this analysi

Paul Broussous

We show that almost all (Bushnell and Kutzko) types of PGL(2,F), F a non-Archimedean locally compact field of odd residue characteristic, naturally appear in the cohomology of finite graphs.

Brecht Verstichel

In this thesis the variational optimisation of the density matrix is discussed as a method in many-body quantum mechanics. This is a relatively unknown technique in which one tries to obtain the two-particle reduced density matrix directly in a variational approach. In the first Chapter we introduce the subject in the broader context of many-body quantum mec

Subhamoy Ghatak, Atindra Nath Pal, Arindam Ghosh

We present low temperature electrical transport experiments in five field effect transistor devices consisting of monolayer, bilayer and trilayer MoS2 films, mechanically exfoliated onto Si/SiO2 substrate. Our experiments reveal that the electronic states in all films are localized well up to the room temperature over the experimentally accessible range of g

Medini Padmanabhan, Kallol Roy, Gopalakrishnan Ramalingam, Srinivasan Raghavan

We present an electrochemical route for the integration of graphene with light sensitive copper-based alloys used in optoelectronic applications. Graphene grown using chemical vapor deposition (CVD) transferred to glass is found to be a robust substrate on which photoconductive Cu_{x}S films of 1-2 um thickness can be deposited. The effect of growth paramete

Mario Gai, Alberto Vecchiato, Sebastiano Ligori, Alessandro Sozzetti

The Gravitation Astrometric Measurement Experiment (GAME) is a mission concept based on astronomical techniques (astrometry and coronagraphy) for Fundamental Physics measurements, namely the γ and β parameters of the Parametrized Post-Newtonian formulation of gravitation theories extending the General Relativity. The science case also addresses cosmology, ex

Jakob Jonsson

J. L. Andersen proved that there is 5-torsion in the bottom nonvanishing homology group of the simplicial complex of graphs of degree at most two on seven vertices. We use this result to demonstrate that there is 5-torsion also in the bottom nonvanishing homology group of the matching complex $M_{14}$ on 14 vertices. Combining our observation with results du

Severino Melo, Elmar Schrohe, Thomas Schick

Boutet de Monvel&#39;s calculus provides a pseudodifferential framework which encompasses the classical differential boundary value problems. In an extension of the concept of Lopatinski and Shapiro, it associates to each operator two symbols: a pseudodifferential principal symbol, which is a bundle homomorphism, and an operator-valued boundary symbol. Ellip

Rawane Samb

This manuscript is a supplemental document providing the omitted material for our paper entitled &#34;Nonparametric kernel estimation of the probability density function of regression errors using estimated residuals&#34; [arXiv:1010.0439]. The paper is submitted to Journal of Nonparametric Statistics.

Péter Kövesárki

This paper describes a novel method to approximate the polynomial coefficients of regression functions, with particular interest on multi-dimensional classification. The derivation is simple, and offers a fast, robust classification technique that is resistant to over-fitting.

Maciej Matyka, Zbigniew Koza

Tortuosity is one of the key parameters describing the geometry and transport properties of porous media. It is defined either as an average elongation of fluid paths or as a retardation factor that measures the resistance of a porous medium to the flow. However, in contrast to a retardation factor, an average fluid path elongation is difficult to compute nu

Jakob Jonsson

Let $1 \le m \le n$. We prove various results about the chessboard complex $M_{m,n}$, which is the simplicial complex of matchings in the complete bipartite graph $K_{m,n}$. First, we demonstrate that there is nonvanishing 3-torsion in $H_d(M_{m,n};Z)$ whenever $\frac{m+n-4}{3} \le d \le m-4$ and whenever $6 \le m < n$ and $d=m-3$. Combining this result with

Jakob Jonsson

Building on work by Bouc and by Shareshian and Wachs, we provide a toolbox of long exact sequences for the reduced simplicial homology of the matching complex $M_n$, which is the simplicial complex of matchings in the complete graph $K_n$. Combining these sequences in different ways, we prove several results about the 3-torsion part of the homology of $M_n$.

J. Cleymans

A discussion is presented of results with identified particles at the Large Hadron Collider. Possible deviations from the standard statistical distributions are investigated by considering in detail results obtained using the Tsallis distribution. Matter-antimatter production is discussed within the framework of chemical equilibrium in \pp and heavy ion coll

Tetsuichi Kishishita, Aya Bamba, Yasunobu Uchiyama, Yasuyuki Tanaka

We report on the results from {\it Suzaku} X-ray observations of the radio complex region called Kookaburra, which includes two adjacent TeV $γ$-ray sources HESS J1418-609 and HESS J1420-607. The {\it Suzaku} observation revealed X-ray diffuse emission around a middle-aged pulsar PSR J1420-6048 and a plausible PWN Rabbit with elongated sizes of $σ_{\rm X}=1^

Ronit Bustin, Miquel Payaro, Daniel Palomar, Shlomo Shamai

The scalar additive Gaussian noise channel has the &#34;single crossing point&#34; property between the minimum-mean square error (MMSE) in the estimation of the input given the channel output, assuming a Gaussian input to the channel, and the MMSE assuming an arbitrary input. This paper extends the result to the parallel MIMO additive Gaussian channel in th

E. Yu. Petrov, A. V. Kudrin

Many intriguing properties of driven nonlinear resonators, including the appearance of chaos, are very important for understanding the universal features of nonlinear dynamical systems and can have great practical significance. We consider a cylindrical cavity resonator driven by an alternating voltage and filled with a nonlinear nondispersive medium. It is

Itsuhiro Kakeya, Yuta Omukai, Minoru Suzuki, Takashi Yamamoto

Terahertz radiation from the mesa structures of Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ is detected in samples with thin electrodes $< 100$ nm. In samples with thick electrodes $\simeq$ 400 nm, neither radiations nor voltage jumps in current-voltage characteristics are detected. This suggests that the thin electrode helps excite the Josephson plasma oscillation as a r

Juan Rojo

A precision measurement of the LHC luminosity is a key ingredient for its physics program. In this contribution first of all we review the theoretical accuracy in the computation of LHC benchmark processes. Then we discuss the impact of available and future LHC data in global analysis of parton distributions, with emphasis on the treatment of normalization u

V. A. Yuryev, L. V. Arapkina, M. S. Storozhevykh, V. A. Chapnin

Issues of Ge hut cluster nucleation and growth at low temperatures on the Ge/Si(001) wetting layer are discussed on the basis of explorations performed by high resolution STM and in-situ RHEED. Data of HRTEM investigations of Ge/Si heterostructures are presented with the focus on low-temperature formation of perfect multilayer films. Exploration of the photo

Marius V. Costache, German Bridoux, Ingmar Neumann, Sergio O. Valenzuela

Thermoelectric effects in spintronics are gathering increasing attention as a means of managing heat in nanoscale structures and of controlling spin information by using heat flow. Thermal magnons (spin-wave quanta) are expected to play a major role, however, little is known about the underlying physical mechanisms involved. The reason is the lack of informa

Luigi Del Debbio, Enrico Rinaldi

We explore the phase diagram of the SU(2) Yang-Mills theory in 5 dimensions by numerical simulations. The lattice system shows a dimensionally-reduced phase where the extra dimension is small compared to the four dimensional correlation length. In the low-energy regime of this phase, the system behaves like a four-dimensional gauge theory coupled to an adjoi

Michael D. Perlman, Sanjay Chaudhuri

The Reverse Stein Effect is identified and illustrated: A statistician who shrinks his/her data toward a point chosen without reliable knowledge about the underlying value of the parameter to be estimated but based instead upon the observed data will not be protected by the minimax property of shrinkage estimators such as that of James and Stein, but instead

Nicolas Boizot, Jean-Paul Gauthier

In this paper, we present a general theory of motion planning for kinematic systems. This theory has been developed for long by one of the authors in a previous series of papers. It is mostly based upon concepts from subriemannian geometry. Here, we summarize the results of the theory, and we improve on, by developping in details an intricated case: the ball

Corsin Pfister

In order to find a physical axiomatization of quantum theory, physical theories are often considered as a special case of a much more general framework of generalized probabilistic theories. We first present a detailed introduction to generalized probabilistic theories before we examine new approaches towards a physical axiomatization of quantum theory. The

Pierre Le Doussal, Aleksandra Petkovic, Kay Jörg Wiese

We study the motion of an elastic object driven in a disordered environment in presence of both dissipation and inertia. We consider random forces with the statistics of random walks and reduce the problem to a single degree of freedom. It is the extension of the mean field ABBM model in presence of an inertial mass m. While the ABBM model can be solved exac

Omar Dzagnidze

Motivated by the general problem of extending the classical theory of holomorphic functions of a complex variable to the case of quater- nion functions, we give a notion of an H-derivative for functions of one quaternion variable. We show that the elementary quaternion func- tions introduced by Hamilton as well as the quaternion logarithm function possess su

Edward I. George, Feng Liang, Xinyi Xu

In a remarkable series of papers beginning in 1956, Charles Stein set the stage for the future development of minimax shrinkage estimators of a multivariate normal mean under quadratic loss. More recently, parallel developments have seen the emergence of minimax shrinkage estimators of multivariate normal predictive densities under Kullback--Leibler risk. We

Chung-Chieh Fang

A general critical condition of subharmonic oscillation in terms of the loop gain is derived. Many closed-form critical conditions for various control schemes in terms of converter parameters are also derived. Some previously known critical conditions become special cases in the generalized framework. Given an arbitrary control scheme, a systematic procedure

Carl N. Morris, Martin Lysy

This review traces the evolution of theory that started when Charles Stein in 1955 [In Proc. 3rd Berkeley Sympos. Math. Statist. Probab. I (1956) 197--206, Univ. California Press] showed that using each separate sample mean from $k\ge3$ Normal populations to estimate its own population mean $μ_i$ can be improved upon uniformly for every possible $μ=(μ_1,...,

Amel Atallah-Baraket, Clotilde Fermanian Kammerer

In this paper, we study a system of thermoelasticity with a degenerated second order operator in the Heat equation. We analyze the evolution of the energy density of a family of solutions. We consider two cases: when the set of points where the ellipticity of the Heat operator fails is included in a hypersurface and when it is an open set. In the first case

N. Ben Bekhti, B. Winkel, P. Richter, J. Kerp

We aim at analysing systematically the distribution and physical properties of neutral and mildly ionised gas in the Milky Way halo, based on a large absorption-selected data set. Multi-wavelength studies were performed combining optical absorption line data of CaII and NaI with follow-up HI 21-cm emission line observations along 408 sight lines towards low-

Peng Xu, Zhiguo Ding, and Xuchu Dai, Kin Leung

In this paper, we consider the design of a new secrecy transmission scheme for a four-node relay-eavesdropper channel. The key idea of the proposed scheme is to combine noisy network coding with the interference assisted strategy for wiretap channel with a helping interferer. A new achievable secrecy rate is characterized for both discrete memoryless and Gau

X. -L. Liu, J. -J. Wang

IRAS22475+5939 has been well researched by previous astronomers. But we still get some new characteristics about it, using the first observations in lines of CO J=2-1,13CO J=2-1,13CO J=3-2 by the KOSMA 3 m telescope. The mapping of the intensity ratio of 13CO J=3-2 and 13CO J=2-1 shows the distribution of the temperature with two peaks, which don&#39;t coinc

G. Contopoulos, N. Delis, C. Efthymiopoulos

A usual assumption in the so-called {\it de Broglie - Bohm} approach to quantum dynamics is that the quantum trajectories subject to typical `guiding&#39; wavefunctions turn to be quite irregular, i.e. {\it chaotic} (in the dynamical systems&#39; sense). In the present paper, we consider mainly cases in which the quantum trajectories are {\it ordered}, i.e.

Ugo Bertello

Numerical N-body simulations of large scale structure formation in the universe are based on Newtonian gravity. However, according to our current understanding, the most correct theory of gravity is general relativity. It is therefore important to understand which degrees of freedom and which features are lost when the relativistic universe is approximated,

Bernard Teissier

This is the LaTeX version of the handwritten notes of a lecture at the Kyoto Singularities Symposium held at the RIMS in April 1978. It presents the relationship of various invariants of isolated singularities of complex analytic hypersurfaces with the jacobian Newton polygon built from the polar curves. An appendix presents features of the semiring of Newto

Yue-Yue Zhao, Ya-Bo Wu, Jianbo Lu, Zhuo Zhang

A modified f(G) gravity model with coupling between matter and geometry is proposed, which is described by the product of the Lagrange density of the matter and an arbitrary function of the Gauss-Bonnet term. The field equations and the equations of motion corresponding to this model show the non-conservation of the energy-momentum tensor, the presence of an

J. C. Berengut, V. V. Flambaum

In their Letter, Kentosh and Mohageg [Phys. Rev. Lett. 108, 110801 (2012)] seek to use data from clocks aboard global positioning system (GPS) satellites to place limits on local position invariance (LPI) violations of Planck&#39;s constant, h. It is the purpose of this comment to show that discussing limits on variation of dimensional constants (such as h)

Song Wang, Jun Ma

In this paper, we present internal surface brightness profiles, using images in the F606W and F814W filter bands observed with the Advanced Camera for Surveys on the {\it Hubble Space Telescope}, for ten globular clusters (GCs) in the outer halo of M31. Standard King models are fitted to the profiles to derive their structural and dynamical parameters. The r

Jose A. Diaz-Garcia, Jose E. Rodriguez, Rogelio Ramos-Quiroga

Sensitivity analysis of the optimal solution in response surface methodology is studied and an explicit form of the effect of perturbation of the regression coefficients on the optimal solution is obtained. The characterisation of the critical point of the convex program corresponding to the optimum of a response surface model is also studied. The asymptotic

A. G. Afonin, V. T. Baranov, M. K. Bulgakov, Yu. A. Chesnokov

Recently it was proposed to apply a bent single crystal with decreasing curvature instead of uniform bending for improvement of extraction and collimation of a circulating beam in particle accelerators. In the given paper created crystal devices with a variable curvature, realizing this idea are described. Results of measurement of curvature along a crystal

Xiaomeng Liu, Hai Lin, Ben M. Chen

This paper considers the controllability problem for multi-agent systems. In particular, the structural controllability of multi-agent systems under switching topologies is investigated. The structural controllability of multi-agent systems is a generalization of the traditional controllability concept for dynamical systems, and purely based on the communica

G. P. Pavlos, L. P. Karakatsanis, M. N. Xenakis, A. E. G. Pavlos

In this study the q-statistics of Tsallis theory is testified in various complex physical systems. Especially the Tsallis q-triplet is estimated for space plasmas atmospheric dynamics and seismogenesis as well as for the brain and cardiac activity. The coincidence of theoretical predictions following after Tsallis theory and experimental estimations were fou

Jongwook Kim, Teppei Okumura

We propose a stochastic process driven by the memory effect with novel distributions which include both exponential and leptokurtic heavy-tailed distributions. A class of the distributions is analytically derived from the continuum limit of the discrete binary process with the renormalized auto-correlation. The moment generating function with a closed form i

Seth Olsen, Ross H. McKenzie

We propose a single effective Hamiltonian to describe the low-energy electronic structure of a series of symmetric cationic diarylmethanes, which are all bridge-substituted derivatives of Michler&#39;s Hydrol Blue. Three-state diabatic Hamiltonians for the dyes are calculated using four-electron three-orbital state-averaged complete active space self-consist

L. Ghezzi, S. Goto, J. Hong, W. V. Vasconcelos

For a Noetherian local ring $(\RR, \m)$, the first two Hilbert coefficients, $e_0$ and $e_1$, of the $I$-adic filtration of an $\m$-primary ideal $I$ are known to code for properties of $\RR$, of the blowup of $\spec(\RR)$ along $V(I)$, and even of their normalizations. We give estimations for these coefficients when $I$ is enlarged (in the case of $e_1$ in

Rahul Gupta, Bharat Baldewa, Yogesh M. Joshi

Soft glassy materials are out of thermodynamic equilibrium and show time dependent slowing down of the relaxation dynamics. Under such situation these materials follow Boltzmann superposition principle only in the effective time domain, wherein time dependent relaxation processes are scaled by a constant relaxation time. In this work we extend effective time

Bharat Baldewa, Yogesh M Joshi

In this work we investigate creep flow of aqueous suspension of Laponite, a model soft glassy material, at different aging times and stresses. We observe that this system shows time - aging time - stress superposition over a range of aging times and stresses when real time scale is transformed into effective time scale. Existence of superposition in an effec

Manish Kaushal, Yogesh M. Joshi

In this work we study creep flow behavior of suspension of Polyaniline (PANI) particles in silicone oil under application of electric field. Suspension of PANI in silicone oil, a model electrorheological fluid, shows enhancement in elastic modulus and yield stress with increase in the magnitude of electric field. Under creep flow field, application of greate

Pierre-Olivier Amblard, Olivier J. J. Michel

The paper investigates the link between Granger causality graphs recently formalized by Eichler and directed information theory developed by Massey and Kramer. We particularly insist on the implication of two notions of causality that may occur in physical systems. It is well accepted that dynamical causality is assessed by the conditional transfer entropy,

Vitri Tundjungsari, Jazi Eko Istiyanto, Edi Winarko, Retantyo Wardoyo

This paper proposes a new consensus model in participatory decision making. The model employs advice centrality approach by electing a leader and recommender named as Supra Decision Maker (SDM). A SDM has a role as a decision bench-marker to other decision makers in evaluating each alternative with respect to given criteria. The weighting value for each alte

Zhe Chang, Xin Li, Sai Wang

Recently, Cohen and Glashow [A.G. Cohen, S.L. Glashow, Phys. Rev. Lett. {\bf 107}, 181803 (2011)] pointed out that the superluminal neutrinos reported by the OPERA would lose their energy rapidly via the Cherenkov-like process. The Cherenkov-like process for the superluminal particles would be forbidden if the principle of special relativity holds in any fra

Akito Tajitsu, Wako Aoki, Tomoyasu Yamamuro

We report on the design, manufacturing, and performance of the image slicer for the High Dispersion Spectrograph (HDS) on the Subaru Telescope. This instrument is a Bowen-Walraven type image slicer providing five 0.3 arcsec x 1.5 arcsec images with a resolving power of R= 110,000. The resulting resolving power and line profiles are investigated in detail, in

Mahouton Norbert Hounkonnou, Dine Ousmane Samary

This paper stands for an application of the noncommutative (NC) Noether theorem, given in our previous work [AIP Proc 956 (2007) 55-60], for the NC complex Grosse-Wulkenhaar model. It provides with an extension of a recent work [Physics Letters B 653 (2007) 343-345]. The local conservation of energy-momentum tensors (EMTs) is recovered using improvement proc

Xiaoguang Wang

In 1980s, Thurston established a topological characterization theorem for postcritically finite rational maps. In this paper, a decomposition theorem for a class of postcritically infinite branched covering termed `Herman map&#39; is developed. It&#39;s shown that every Herman map can be decomposed along a stable multicurve into finitely many Siegel maps and

Jing Li, Tin Cheung Au Yeung, Chan Hin Kam

In this work, we employed non-equilibrium Green&#39;s function to investigate the electron transport properties in the nanowire with the presence of scatterings. The scattering mechanism is modelled by using the concept of Büttiker probe. The effect of electron scattering is analyzed under three conditions: absence of external field; with a bias voltage; and

T. Vasyunina, A. I. Vasyunin, E. Herbst, H. Linz

We simulate the chemistry of infrared dark clouds (IRDCs) with a model in which the physical conditions are homogeneous and time-independent. The chemistry is solved as a function of time with three networks: one purely gas-phase, one that includes accretion and desorption, and one, the complete gas-grain network, that includes surface chemistry in addition.

G. P. Pavlos

This study was announced for the first time in Greek language in 1988 in the National Observatory of Athens, in the conference of the 1st Panhellenic Symposium entitled &#34;Solar and Space Research in Greece Today - Basic Research, Technology and Applications&#34; organized by the National Observatory of Athens, in Penteli (Athens) in 1988. It was also repu

G. P. Pavlos

The results of this study were announced and published in Greek in the Fifth Panhellenic Conference Proceedings of the Hellenic Physical Society. It is the sequel of a previous study (Pavlos, 1988), in which it was introduced the hypothesis of magnetospheric chaos for the interpretation of magnetic substorms. In this study it is described the possibility of

Michael Eisermann

Sturm&#39;s theorem (1829/35) provides an elegant algorithm to count and locate the real roots of any real polynomial. In his residue calculus (1831/37) Cauchy extended Sturm&#39;s method to count and locate the complex roots of any complex polynomial. For holomorphic functions Cauchy&#39;s index is based on contour integration, but in the special case of po

L. P. Karakatsanis, G. P. Pavlos, M. N. Xenakis

In the second part of this study and similarly with part one, the nonlinear analysis of the solar flares index is embedded in the non-extensive statistical theory of Tsallis [1]. The triplet of Tsallis, as well as the correlation dimension and the Lyapunov exponent spectrum were estimated for the SVD components of the solar flares timeseries. Also the multif

Mikhail A. Vasiliev

Holographic duality is argued to relate classes of models that have equivalent unfolded formulation, hence exhibiting different space-time visualizations for the same theory. This general phenomenon is illustrated by the $AdS_4$ higher-spin gauge theory shown to be dual to the theory of 3d conformal currents of all spins interacting with 3d conformal higher-

Ehsan Hatefi, I. Y. Park

In our continued efforts of matching full string computations with the corresponding effective field theory computations, we evaluate string theory correlators in closed forms. In particular, we consider a correlator between three SYM vertex operators and one Ramond-Ramond $C$-field vertex operator: $<V_{C}V_ϕ V_AV_A>$. We show that the infinite number of ma

Karthik H. Shankar, Anand Balaraman, Kameshwar C. Wali

We consider a theory of gravity with a hidden extra-dimension and metric-dependent torsion. A set of physically motivated constraints are imposed on the geometry so that the torsion stays confined to the extra-dimension and the extra-dimension stays hidden at the level of four dimensional geodesic motion. At the kinematic level, the theory maps on to General

Zejun Huang, Chi-Kwong Li, Edward Poon, Nung-Sing Sze

Given two sets of quantum states {A_1, ..., A_k} and {B_1, ..., B_k}, represented as sets of density matrices, necessary and sufficient conditions are obtained for the existence of a physical transformation T, represented as a trace-preserving completely positive map, such that T(A_i) = B_i for i = 1, ..., k. General completely positive maps without the trac

Rui Sá Pereira, Evelina Shamarova

Recent developments on financial markets have revealed the limits of Brownian motion pricing models when they are applied to actual markets. Lévy processes, that admit jumps over time, have been found more useful for applications. Thus, we suggest a Lévy model based on Forward-Backward Stochastic Differential Equations (FBSDEs) for option pricing in a Lévy-t

Ivan Losev

This paper continues the study of highest weight categorical sl_2-actions started in part I. We start by refining the definition given there and showing that all examples considered in part I are also highest weight categorifications in the refined sense. Then we prove that any highest weight sl_2-categorification can be filtered in such a way that the succe

Achim Rosch

We show that a topological superconductor made of four chains of superconducting spinless fermions characterized by four Majorana edge states can adiabatically be deformed into a trivial band insulator. To unwind this time-reversal invariant topological superconductor, interactions to spinful fermions are switched on along an adiabatic path. Thereby, we coup

Rebekah I. Dawson, John Asher Johnson

Exoplanet orbital eccentricities offer valuable clues about the history of planetary systems. Eccentric, Jupiter-sized planets are particularly interesting: they may link the &#34;cold&#34; Jupiters beyond the ice line to close-in hot Jupiters, which are unlikely to have formed in situ. To date, eccentricities of individual transiting planets primarily come

Xinguo Ren, Patrick Rinke, Christian Joas, Matthias Scheffler

The random-phase approximation (RPA) as an approach for computing the electronic correlation energy is reviewed. After a brief account of its basic concept and historical development, the paper is devoted to the theoretical formulations of RPA, and its applications to realistic systems. With several illustrating applications, we discuss the implications of R

Jason Rute

Unlike Martin-Löf randomness and Schnorr randomness, computable randomness has not been defined, except for a few ad hoc cases, outside of Cantor space. This paper offers such a definition (actually, several equivalent definitions), and further, provides a general method for abstracting &#34;bit-wise&#34; definitions of randomness from Cantor space to arbitr

Bruno Scherrer

We consider infinite-horizon $γ$-discounted Markov Decision Processes, for which it is known that there exists a stationary optimal policy. We consider the algorithm Value Iteration and the sequence of policies $π_1,...,π_k$ it implicitely generates until some iteration $k$. We provide performance bounds for non-stationary policies involving the last $m$ gen

Manda Banerji, Richard G. McMahon, Paul C. Hewett, Susannah Alaghband-Zadeh

We present a new sample of purely near infra-red selected KVega<16.5 extremely red ((J-K)>2.5) quasar candidates at z~2 from 900 sq deg of data in the UKIDSS Large Area Survey (LAS). Five of these are spectroscopically confirmed to be heavily reddened Type 1 AGN with broad emission lines bringing our total sample of reddened quasars from the UKIDSS-LAS to 12

V. Bosch-Ramon, M. V. Barkov, D. Khangulyan, M. Perucho

The winds from a non-accreting pulsar and a massive star in a binary system collide forming a bow-shaped shock structure. The Coriolis force induced by orbital motion deflects the shocked flows, strongly affecting their dynamics. We study the evolution of the shocked stellar and pulsar winds on scales in which the orbital motion is important. Potential sites

Paul Balança, Erick Herbin

The purpose of this article is a set-indexed extension of the well-known Ornstein-Uhlenbeck process. The first part is devoted to a stationary definition of the random field and ends up with the proof of a complete characterization by its $L^2$-continuity, stationarity and set-indexed Markov properties. This specific Markov transition system allows to define

Francesco Fidaleo

We investigate the Bose-Einstein Condensation on non homogeneous non amenable networks for the model describing arrays of Josephson junctions on perturbed Cayley Trees. The resulting topological model has also a mathematical interest in itself. The present paper is then the application to the Bose-Einstein Condensation phenomena, of the harmonic analysis asp

Florent Krzakala, Marc Mézard, Lenka Zdeborová

We study the random K-satisfiability problem using a partition function where each solution is reweighted according to the number of variables that satisfy every clause. We apply belief propagation and the related cavity method to the reweighted partition function. This allows us to obtain several new results on the properties of random K-satisfiability prob

R. Kumar, S. Krishna, A. Shukla, R. P. Malik

Taking the simple examples of an Abelian 1-form gauge theory in two (1 + 1)-dimensions, a 2-form gauge theory in four (3 + 1)-dimensions and a 3-form gauge theory in six (5 + 1)-dimensions of spacetime, we establish that such gauge theories respect, in addition to the gauge symmetry transformations that are generated by the first-class constraints of the the

Davide Gaiotto, Shlomo S. Razamat

Recently a prescription to compute the superconformal index for all theories of class S was proposed. In this paper we discuss some of the physical information which can be extracted from this index. We derive a simple criterion for the given theory of class S to have a decoupled free component and for it to have enhanced flavor symmetry. Furthermore, we est

E. S. Vernova, M. I. Tyasto, D. G. Baranov

Photospheric magnetic fields were studied using the Kitt Peak synoptic maps for 1976-2003. Only strong magnetic fields (B>100 G) of the equatorial region were taken into account. The north-south asymmetry of the magnetic fluxes was considered as well as the imbalance between positive and negative fluxes. The north-south asymmetry displays a regular alternati

Alessandro Gnoatto

We consider a short rate model, driven by a stochastic process on the cone of positive semidefinite matrices. We derive sufficient conditions ensuring that the model replicates normal, inverse or humped yield curves.

Chaoyu He, L. Z. Sun, C. X. Zhang, K. W. Zhang

Two new carbon allotropes (H-carbon and S-carbon) are proposed, as possible candidates for the intermediate superhard phases between graphite and diamond obtained in the process of cold compressing graphite, based on the results of first-principles calculations. Both H-carbon and S-carbon are more stable than previously proposed M-carbon and W-carbon and the