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From quantum to classical modelling of radiation reaction: a focus on the radiation spectrumFeb 08 2018Soon available multi petawatt ultra-high-intensity (UHI) lasers will allow us to probe high-amplitude electromagnetic fields interacting with either ultra-relativistic electron beams or hot plasmas in the so-called moderately quantum regime. The correct ... More

Pair creation in collision of $γ$--ray beams produced with high intensity lasersApr 29 2015Oct 23 2015Direct production of electron--positron pairs in two photon collisions, the Breit--Wheeler process, is one of the basic processes in the Universe. However, it has never been observed in laboratory because of absence of the intense gamma-ray sources. Laser ... More

Controlling the generation of high frequency electromagnetic pulses with relativistic flying mirrors using an inhomogeneous plasmaSep 18 2012A method for the controlled generation of intense high frequency electromagnetic fields by a breaking Langmuir wave (relativistic flying mirrors) in a gradually inhomogeneous plasma is proposed. The wave breaking threshold depends on the local plasma ... More

Carpet cloaking on a dielectric half-spaceApr 04 2010Apr 29 2010Carpet cloaking is proposed to hide an object on a dielectric half-space from electromagnetic (EM) detection. A two-dimensional conformal transformation specified by an analytic function is utilized for the design. Only one nonsingular material parameter ... More

Plasmon hybridization in pyramidal metamaterials: a route towards ultra-broadband absorptionApr 07 2014Pyramidal metamaterials are currently developed for ultra-broadband absorbers. They consist of periodic arrays of alternating metal/dielectric layers forming truncated square-based pyramids. The metallic layers of increasing lengths play the role of vertically ... More

Generation of high-energy electron-positron beams in the collision of a laser-accelerated electron beam and a multi-petawatt laserOct 08 2015Oct 12 2015Generation of antimatter via the multiphoton Breit-Wheeler process in an all-optical scheme will be made possible on forthcoming high-power laser facilities through the collision of wakefield-accelerated GeV electrons with a counter-propagating laser ... More

Modeling of radiative and quantum electrodynamics effects in PIC simulations of ultra-relativistic laser-plasma interactionNov 05 2013Nov 06 2013Next generation of ultra-intense laser facilities will lead to novel physical conditions ruled by collective and quantum electrodynamics effects, such as synchrotron-like emission of high-energy photons and electron-positron pair generation. In view of ... More

Probing graphene χ(2) using a gold photon sieveDec 21 2015Nonlinear second harmonic optical activity of graphene covering a gold photon sieve was determined for different polarizations. The photon sieve consists of a subwavelength gold nanohole array placed on glass. It combines the benefits of efficient light ... More

Enhancing laser-driven proton acceleration by using micro-pillar arrays at high drive energySep 19 2017The interaction of micro- and nano-structured target surfaces with high-power laser pulses is being widely investigated for its unprecedented absorption efficiency. We have developed vertically aligned metallic micro-pillar arrays for laser-driven proton ... More

Parton Model in Lorentz Invariant Non-Commutative SpaceMay 26 2004Aug 22 2004We consider the Lorentz invariant non-commutative QED and complete the Feynman rules for the theory up to the order $\theta^2$. In the Lorentz invariant version of the non-commutative QED the particles with fractional charges can be also considered. We ... More

Electromagnetic Response of Weyl SemimetalsMar 22 2013Jun 27 2013It has been suggested recently, based on subtle field-theoretical considerations, that the electromagnetic response of Weyl semimetals and the closely related Weyl insulators can be characterized by an axion term E.B with space and time dependent axion ... More

The Charm Quark Contribution to the Proton Structure FunctionOct 14 2006Dec 27 2006The charm quark structure function $F^c_2$ and the longitudinal structure function $F_l^p$ are directly sensitive to the gluon content of proton and therefore are crucial in understanding of proton structure function, in particular at low momentum transfer ... More

Production and Decay of Scalar Stoponium Bound StatesDec 02 1993In this paper we discuss possible signatures for the production of scalar \stst\ (stoponium) bound states \sigst\ at hadron colliders, where \st\ is the lighter scalar top eigenstate. We first study the decay of \sigst; explicit expressions are given ... More

The decay of singlet scalar dark matter to unparticle and photonMay 06 2008We consider the unparticle physics introduced by Georgi and show that if the standard model is extended to include a singlet scalar as a dark matter candidate, there is a channel which leads to its decay to photon and unparticle. We calculate the decay ... More

On the effect of the thermal gas component to the stability of vortices in trapped Bose-Einstein condensatesMar 12 2002We study the stability of vortices in trapped single-component Bose-Einstein condensates within self-consistent mean-field theories--especially we consider the Hartree-Fock-Bogoliubov-Popov theory and its recently proposed gapless extensions. It is shown ... More

Quantum information processing: The case of vanishing interaction energyOct 27 2002We investigate the rate of operation of quantum "black boxes" ("oracles") and point out the possibility of performing an operation by a quantum "oracle" whose average energy equals zero. This counterintuitive result not only presents a generalization ... More

Self-Organized Topological State with Majorana FermionsJul 08 2013Nov 06 2013Topological phases, quite generally, are difficult to come by. They either occur under rather extreme conditions (e.g. the quantum Hall liquids, which require high sample purity, strong magnetic fields and low temperatures) or demand fine tuning of system ... More

Spin Response of Electrons on the Surface of a Topological InsulatorJan 11 2012The surface of a topological insulator hosts a very special form of a quasi-two dimensional metallic system when it is embedded in a topologically trivial medium like the vacuum. The electronic properties of this unusual 2D metal are distinct in many ... More

Neutralino-Nucleon Scattering RevisitedJul 01 1993We present a detailed discussion of the elastic scattering of a supersymmetric neutralino off a nucleon or nucleus, with emphasis on the spin--independent interaction. We carefully treat QCD effects on the squark exchange contribution. In particular, ... More

Data mining for cones of metrics, quasi-metrics, hemi-metrics and super-metricsJan 02 2002Dec 27 2002Using some adaptations of the adjacency decomposition method \cite{CR} and the program {\it cdd} (~\cite{Fu}), we compute the first computationally difficult cases of convex cones of $m$-ary and oriented analogs of semi-metrics and cut semi-metrics, which ... More

Dyadic shift randomization in classical discrepancy theorySep 06 2014Nov 16 2014Dyadic shifts of point distributions in the multi-dimensional unit cube are considered as a randomization. Explicit formulas for the discrepancies of such randomized distributions are given in the paper in terms of Rademacher functions. Relaying on the ... More

Holographic entanglement entropy of the BTZ black holeJul 09 2009Jul 22 2009We investigate quantum entanglement of gravitational configurations in 3D AdS gravity using the AdS/CFT correspondence. We derive explicit formulas for the holographic entanglement entropy (EE) of the BTZ black hole, conical singularities and regularized ... More

Pair excitations and the mean field approximation of interacting Bosons, IISep 19 2015Jul 31 2016We consider a large number of Bosons with interaction potential $v_N(x)=N^{3 \beta}v(N^{\beta}x)$. In earlier papers we considered a set of equations for the condensate $\phi$ and pair excitation function $k$ and proved that they provide a Fock space ... More

Singlet particles as cold dark matter in noncommutative space-timeMar 10 2009We extend the noncommutative (NC) standard model to incorporate singlet particles as cold dark matter. In the NC space-time, the singlet particles can be coupled to the U(1) gauge field in the adjoint representation. We Study the relic density of the ... More

Contractions on a manifold polarized by an ample vector bundleOct 27 1994A complex manifold $X$ of dimension $n$ together with an ample vector bundle $E$ on it will be called a {\sf generalized polarized variety}. The adjoint bundle of the pair $(X,E)$ is the line bundle $K_X + det(E)$. We study the positivity (the nefness ... More

On the twisted cohomology of arrangements of linesJul 07 2015Let $\A$ be an affine line arrangement in $\C^2,$ with complement $\M(\A).$ The twisted (co)homology of $\M(\A)$ is an interesting object which has been considered by many authors, strictly related to the (co)homology of the Milnor fibre associated to ... More

Scalar transport in compressible flowNov 29 1996Transport of scalar fields in compressible flow is investigated. The effective equations governing the transport at scales large compared to those of the advecting flow are derived by using multi-scale techniques. Ballistic transport generally takes place ... More

Color superconductivity in two- and three-flavor systems at moderate densitiesMay 02 2002May 06 2002Basic features of color superconductivity are reviewed, focusing on the regime of ``moderate densities'', which is not accessible by perturbation theory. We discuss the standard picture of two- and three flavor color superconductors and study the color-flavor ... More

Color-Flavor Unlocking and Phase Diagram with Self-Consistently Determined Strange Quark MassesSep 11 2001Dec 17 2001The phase diagram of strongly interacting matter at non-zero temperature and baryon chemical potential is calculated within a 3-flavor NJL-type quark model with realistic quark masses. The model exhibits spontaneous chiral symmetry breaking as well as ... More

Biorthogonal Laurent polynomials, Toeplitz determinants, minimal Toda orbits and isomonodromic tau functionsMar 23 2005We consider the class of biorthogonal polynomials that are used to solve the inverse spectral problem associated to elementary co-adjoint orbits of the Borel group of upper triangular matrices; these orbits are the phase space of generalized integrable ... More

Fractional supersymmetric Quantum Mechanics as a set of replicas of ordinary supersymmetric Quantum MechanicsDec 06 2003A connection between fractional supersymmetric quantum mechanics and ordinary supersymmetric quantum mechanics is established in this Letter.

Modeling the Spectral Energy Distribution and Variability of 3C 66A during the WEBT campaign of 2003 -- 2004Apr 03 2007The BL Lac object 3C 66A was observed in an extensive multiwavelength monitoring campaign from July 2003 till April 2004. The spectral energy distribution (SED) was measured over the entire electromagnetic spectrum, with flux measurements from radio to ... More

High confidence AGN candidates among unidentified Fermi-LAT sources via statistical classificationJun 27 2013The second Fermi-LAT source catalog (2FGL) is the deepest survey of the gamma-ray sky ever compiled, containing 1873 sources that constitute a very complete sample down to an energy flux of about 10^(-11) erg cm^(-2) s^(-1). While counterparts at lower ... More

Reliability of astrophysical jet simulations in 2D: On inter-code reliability and numerical convergenceOct 22 2001In the present paper, we examine the convergence behavior and inter-code reliability of astrophysical jet simulations in axial symmetry. We consider both, pure hydrodynamic jets and jets with a dynamically significant magnetic field. The setups were chosen ... More

Longitudinal top quark polarizationApr 20 2001Longitudinal polarization of the top quark, averaged over the production angle, is discussed for the top quark produced in e+e- annihilation near its production threshold. It is demonstrated that Coulomb type corrections and rescattering corrections are ... More

A new class of solutions of the DMPK equationMar 17 2003Sep 03 2003We introduce and discuss a new class of solutions of the DMPK equation in which some of the eigenvalues are grouped into clusters which are conserved in the asymptotic large distance limit (i.e. as the length of the wire increases). We give an explicit ... More

Wilson renormalization group and improved perturbation theoryMay 20 1997We discuss a resummed perturbation theory based on the Wilson renormalization group. In this formulation the Wilsonian flowing couplings, which generalize the running coupling, enter directly into the loop expansion. In the case of an asymptotically free ... More

An improvement of the BeppoSAX LECS and MECS positioning accuracyOct 04 2002We present a study of the source positioning accuracy of the LECS and MECS instruments on-board BeppoSAX. From the analysis of a sample of archival images we find that a systematic error, which depends on the spacecraft roll angle and has an amplitude ... More

J/psi Production via Fragmentation at the TevatronMay 06 1994May 31 1994The production of $\jpsi$ at large transverse momenta ($\pt > M_\jpsi$) in $p\bar p$ collisions is considered by including the mechanism of fragmentation. Both contributions of fragmentation to $\jpsi$ and of fragmentation to $\chi$ states followed by ... More

Floquet states and persistent currents transitions in a mesoscopic ringJul 10 2002We consider the effect of an oscillating potential on the single-particle spectrum and the time-averaged persistent current of a one-dimensional phase-coherent mesoscopic ring with a magnetic flux. We show that in a ring with an even number of spinless ... More

Scattering Theory of Dynamic Electrical TransportFeb 09 2005We have developed a scattering matrix approach to coherent transport through an adiabatically driven conductor based on photon-assisted processes. To describe the energy exchange with the pumping fields we expand the Floquet scattering matrix up to linear ... More

The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodogramsJan 16 2009The Lomb-Scargle periodogram is a common tool in the frequency analysis of unequally spaced data equivalent to least-squares fitting of sine waves. We give an analytic solution for the generalisation to a full sine wave fit, including an offset and weights ... More

Chiral symmetries associated with angular momentumNov 29 2013In beginning quantum mechanics courses, symmetries of a physical system are usually introduced as operators which commute with the Hamiltonian. In this article we will consider chiral symmetries which anticommute with the Hamiltonian. Typically, introductory ... More

Smooth Manifolds vs Differential triadsNov 25 2013We consider differentiable maps in the setting of Abstract Differential Geometry and we study the conditions that ensure the uniqueness of differentials in this setting. In particular, we prove that smooth maps between smooth manifolds admit a unique ... More

Quasilocal Energy in FRW CosmologyMar 23 2009Oct 03 2009This paper presents a calculation of the quasilocal energy of a generic FRW model of the universe. The results have the correct behavior in the small-sphere limit and vanish for the empty Milne universe. Higher order corrections are found when comparing ... More

Polynomial Differential Equations with Small coefficientsApr 17 2009Classes of polynomial differential equations of degree n are considered. An explicit upper bound on the size of the coefficients are given which implies that each equation in the class has exactly n complex periodic solutions. In most of the classes the ... More

Ultrahigh energy neutrino interactions and weak-scale string theoriesMay 15 2000Oct 05 2000It has been suggested that ultrahigh energy neutrinos can acquire cross-sections approaching hadronic size if the string scale is as low as 1-10 TeV. In this case, the vertical air showers observed with energies above the Greisen-Zatsepin-Kuzmin cutoff ... More

Nonreciprocal Dispersion of Spin Waves in Ferromagnetic Thin Films Covered with a Finite-Conductivity MetalJan 29 2014We study the effect of one-side metallization of a uniform ferromagnetic thin film on its spin-wave dispersion relation in the Damon-Eshbach geometry. Due to the finite conductivity of the metallic cover layer on the ferromagnetic film the spin-wave dispersion ... More

Color fluctuation effects in proton-nucleus collisionsJan 04 2013Mar 21 2013Color fluctuations in hadron-hadron collisions are responsible for the presence of inelastic diffraction and lead to distinctive differences between the Gribov picture of high energy scattering and the low energy Glauber picture. We find that color fluctuations ... More

Mobile Phone Faraday CageDec 23 2011A Faraday cage is an interesting physics phenomena where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to ... More

The Wonders of LevitationOct 27 2010I discuss some interesting classroom demonstrations of diamagnetism and how this effect can produce levitation. The possibilities for hands-on demonstrations of diamagnetic and superconducting levitation are discussed. To conclude I discuss some practical ... More

Kinetic theory of cluster impingement in the framework of statistical mechanics of rigid disksJul 09 2005The paper centres on the evaluation of the function n(theta)=N(theta)/N0, that is the normalized number of islands as a function of coverage 0<theta<1, given N0 initial nucleation centres (dots) having any degree of spatial correlation. A mean field approach ... More

Fractional Spin through Quantum Affine Algebra $\hat A(n)$ and quantum affine superalgebra $\hat A(n,m)$Oct 29 2000Using the splitting of a $Q$-deformed boson, in the $Q \to q= e^{\frac{\rm 2\pi i}{\rm k}}$ limit, the fractional decomposition of the quantum affine algebra $\hat A(n)$ and the quantum affine superalgebra $\hat A(n,m)$ are found. This decomposition is ... More

Sterile neutrino dark matter as a consequence of nuMSM-induced lepton asymmetryApr 29 2008Jun 29 2008It has been pointed out in ref.[1] that in the nuMSM (Standard Model extended by three right-handed neutrinos with masses smaller than the electroweak scale), there is a corner in the parameter space where CP-violating resonant oscillations among the ... More

Thermodynamics of Non-Topological SolitonsApr 06 1998In theories with low energy supersymmetry breaking, the effective potential for squarks and sleptons has generically nearly flat directions, V(phi) ~ M^4 (log(phi/M))^n. This guarantees the existence of stable non-topological solitons, Q-balls, that carry ... More

Diffraction for non-believersNov 04 2005Diffractive reactions involving a hard scale can be understood in terms of quarks and gluons. These reactions have become a valuable tool for investigating the low-x structure of the proton and the behavior of QCD in the high-density regime, and they ... More

Signal and noise simulation of CUORE bolometric detectorsJun 20 2011Jul 18 2011Bolometric detectors are used in particle physics experiments to search for rare processes, such as neutrinoless double beta decay and dark matter interactions. By operating at cryogenic temperatures, they are able to detect particle energies from a few ... More

Fine structure of two-electron states in single and double quantum dotsAug 21 2009Aug 22 2009Energy spectrum fine structure of triplet two-electron states is investigated theoretically. Spin-orbit interaction induced terms in the effective Hamiltonian of electron-electron interaction are derived for zinc-blende lattice semiconductor nanostructures: ... More

Magnetic field effects on spin relaxation in heterostructuresJun 16 2004Effect of magnetic field on electron spin relaxation in quantum wells is studied theoretically. We have shown that Larmor effect and cyclotron motion of carriers can either jointly suppress D'yakonov-Perel' spin relaxation or compensate each other. The ... More

K-minus Estimator Approach to Large Scale StructureAug 01 2007Self similar 3D distributions of point-particles, with a given quasifractal dimension D, were generated on a Menger sponge model and then compared with \textit{2dfGRS} and \textit{Virgo project} data \footnote{http://www.mso.anu.edu.au/2dFGRS/, http://www.mpa-garching.mpg.de/Virgo/}. ... More

Systematic study of longitudinal and transverse helicity amplitudes in the hypercentral Constituent Quark ModelJun 19 2015The predictions of the hypercentral Consituent Quark Model for the nucleon helicity amplitudes are briefly reported. Some future perspectives are also discussed.

Introduction: GDH and related topicsJan 07 2003The formulation of the Gerasimov-Drell-Hearn sum rule is revisited, showing its connection with other sum rules occurring in electron scattering and discussing the problem of its saturation, both from the theoretical and experimental point of v iew. The ... More

Multiparameter quantum function algebra at roots of 1Oct 15 1994We study the theory of representations of a multiparameter deformation of the function algebra of a simple algebraic group (as defined by Reshetikhin) when the quantum parameter is a root of unity. We extend the technics of De Concini-Lyubashenko in the ... More

Multiflavor QCD* on R_3 x S_1: Studying Transition From Abelian to Non-Abelian ConfinementJan 23 2009The center-stabilized multiflavor QCD* theories formulated on R_3 x S_1 exhibit both Abelian and non-Abelian confinement as a function of the S_1 radius, similar to the Seiberg-Witten theory as a function of the mass deformation parameter. For sufficiently ... More

Confinement in Yang--Mills: Elements of a Big PictureOct 21 2008Nov 12 2008We present a nontechnical review of the current understanding of the phenomenon of color confinement. The emphasis is put on recent advances. This is a combined and slightly expanded version of talks delivered at 14th International QCD Conference "QCD ... More

String vacua with flux from freely-acting obifoldsOct 27 2003Jan 12 2004A precise correspondence between freely-acting orbifolds (Scherk-Schwarz compactifications) and string vacua with NSNS flux turned on is established using T-duality. We focus our attention to a certain non-compact Z_2 heterotic freely-acting orbifold ... More

Junction conditions for F(R)-gravity and their consequencesMar 06 2013Jun 04 2013I present the junction conditions for F(R) theories of gravity and their implications: the generalized Israel conditions and equations. These junction conditions are necessary to construct global models of stars, galaxies, etc., where a vacuum region ... More

Report on workshop A1: Exact solutions and their interpretationOct 29 2007Nov 29 2007I report on the communications and posters presented on exact solutions and their interpretation at the GRG18 Conference, Sydney.

Symmetric hyperbolic systems for a large class of fields in arbitrary dimensionJul 26 2006Symmetric hyperbolic systems of equations are explicitly constructed for a general class of tensor fields by considering their structure as r-fold forms. The hyperbolizations depend on 2r-1 arbitrary timelike vectors. The importance of the so-called "superenergy" ... More

General Electric-Magnetic decomposition of fields, positivity and Rainich-like conditionsOct 25 2000Oct 29 2000We show how to generalize the classical electric-magnetic decomposition of the Maxwell or the Weyl tensors to arbitrary fields described by tensors of any rank in general $n$-dimensional spacetimes of Lorentzian signature. The properties and applications ... More

New conservation laws for electromagnetic fields in gravityNov 10 2003A recently found (gr-qc/0303036) 2-index, symmetric, trace-free, divergence-free tensor is introduced for arbitrary source-free electromagnetic fields. The tensor can be constructed for any test Maxwell field in Einstein spaces (including proper vacuum), ... More

Novel results on trapped surfacesNov 03 2003A unifying definition of trapped submanifold for arbitrary codimension by means of its mean curvature vector is presented. Then, the interplay between (generalized) symmetries and trapped submanifolds is studied, proving in particular that (i) stationary ... More

Adiabatic theory of off-center vibronic polarons: Local dynamics and itinerant features along a linear chainJan 18 2006The vibronic mixing by an odd-parity vibrational mode of two opposite-parity nearly-degenerate electronic states at a molecular site may drive the small polaron off-center. An associated electric dipole may occur due to broken inversion symmetry which ... More

The long wavelength view of GG Tau A: Rocks in the Ring WorldJul 19 2013We present the first detection of GG Tau A at centimeter-wavelengths, made with the Arcminute Microkelvin Imager Large Array (AMI-LA) at a frequency of 16 GHz ({\lambda} = 1.8 cm). The source is detected at > 6 {\sigma}_{rms} with an integrated flux density ... More

Precise predictions for Higgs production at e+ e- colliders and Numerical calculation of one-loop integralsOct 12 2004Some of the most interesting Higgs-production processes at future e+ e- colliders are of the type e+ e- -> f anti-f H. We present a calculation of the complete O(alpha) corrections to these processes in the Standard Model for final-state neutrinos and ... More

Existence of Multiagent Equilibria with Limited AgentsJun 30 2011Multiagent learning is a necessary yet challenging problem as multiagent systems become more prevalent and environments become more dynamic. Much of the groundbreaking work in this area draws on notable results from game theory, in particular, the concept ... More

Ideal quantum glass transitions: many-body localization without quenched disorderSep 04 2013Nov 06 2013We explore the possibility for translationally invariant quantum many-body systems to undergo a dynamical glass transition, at which ergodicity and translational invariance break down spontaneously, driven entirely by quantum effects. In contrast to analogous ... More

Topological Terms in String Theory on OrbifoldsSep 21 1994We study toroidal orbifold models with topologically invariant terms in the path integral formalism and give physical interpretations of the terms from an operator formalism point of view. We briefly discuss a possibility of a new class of modular invariant ... More

Complete Resolution of the Quantum Zeno Paradox for Outside ObserversJan 27 2004The quantum Zeno paradox is fully resolved for purely indirect and incomplete measurements performed by the detectors outside the system. If the outside detectors are prepared to observe propagating signals of a decay event of an excited state in the ... More

The relativistic nuclear dynamics for the SU(3) Goldstone bosons of chiral QCDDec 04 2002In this habilitation theses the chiral SU(3) Lagrangian is applied to antikaon and hyperon propagation in cold nuclear matter. The self consistent many-body dynamics relies on a detailed analysis of the pion, kaon and antikaon-nucleon scattering data ... More

Migdal's short range correlations in a covariant modelOct 26 2002Aug 13 2003We construct a covariant model for short range correlations of a pion emerged in nuclear matter. Once the delta-hole contribution is considered an additional and so far neglected channel opens that leads to significant modifications in the vicinity of ... More

Umbilical-Type Surfaces in SpacetimeNov 29 2011Apr 19 2012A spacelike surface S immersed in a 4-dimensional Lorentzian manifold will be said to be umbilical along a direction N normal to S if the second fundamental form along N is proportional to the first fundamental form of S. In particular, S is pseudo-umbilical ... More

Resolution of Verb Ellipsis in Japanese Sentence using Surface Expressions and ExamplesDec 13 1999Verbs are sometimes omitted in Japanese sentences. It is necessary to recover omitted verbs for purposes of language understanding, machine translation, and conversational processing. This paper describes a practical way to recover omitted verbs by using ... More

Higgs PhysicsJan 27 2015Feb 23 2015We discuss the interpretation of the LHC Higgs data and the test of the Higgs mechanism. This is done in a more model-independent approach relying on an effective Lagrangian, as well as in specific models like composite Higgs models and supersymmetric ... More

The dynamical disconnection of sunspots from their magnetic rootsJun 27 2005After a dynamically active emergence phase, magnetic flux at the solar surface soon ceases to show strong signs of the subsurface dynamics of its parent magnetic structure. This indicates that some kind of disconnection of the emerged flux from its roots ... More

Boundary layer emission and Z-track in the color-color diagram of luminous LMXBsJun 01 2005Mar 09 2006We demonstrate that Fourier-frequency resolved spectra of atoll and Z- sources are identical, despite significant difference in their average spectra and luminosity (by a factor of ~10-20). This result fits in the picture we suggested earlier, namely ... More

Statistical Mechanics of the Hyper Vertex Cover ProblemJul 02 2007Jul 03 2007We introduce and study a new optimization problem called Hyper Vertex Cover. This problem is a generalization of the standard vertex cover to hypergraphs: one seeks a configuration of particles with minimal density such that every hyperedge of the hypergraph ... More

The Earliest Epoch of Reionisation in the Standard $Λ$CDM ModelMar 06 2003Jul 15 2003We show that the earliest possible reionisation of the Universe is approximately at $z\simeq 13.5$ and the optical depth is $\tau\simeq 0.17$ in the conventionally accepted $\Lambda$ cold dark matter ($\Lambda$CDM) model with adiabatic fluctuations of ... More

On the Location of the 1-particle Branch of the Spectrum of the Disordered Stochastic Ising ModelNov 07 2003Mar 09 2011We analyse the lower non trivial part of the spectrum of the generator of the Glauber dynamics, which we consider a positive operator, for a d-dimensional nearest neighbour Ising model with a bounded random potential. We prove conjecture 1 in a paper ... More

Consistency of Microcanonical and Canonical Finite-Size ScalingAug 07 2000Typically, in order to obtain finite-size scaling laws for quantities in the microcanonical ensemble, an assumption is taken as a starting point. In this paper, consistency of such a Microcanonical Finite-Size Scaling Assumption with its commonly accepted ... More

Grothendieck rings of o-minimal expansions of ordered abelian groupsMay 16 2005We will calculate completely the Grothendieck rings, in the sense of first order logic, of o-minimal expansions of ordered abelian groups by introducing the notion of the bounded Euler characteristic.

Neutron $2p$ and $1f$ spin--orbit splittings in $^{40}$Ca, $^{36}$S, and $^{34}$Si $N=20$ isotones: tensor--induced and pure spin--orbit effectsNov 04 2015Neutron $2p$ and $1f$ spin--orbit splittings were recently measured in the isotones $^{37}$S and $^{35}$Si by $(d,p)$ transfer reactions. Values were reported by using the major fragments of the states. An important reduction of the $p$ splitting was ... More

The central charge in three dimensional anti-de Sitter spaceJun 11 1998This paper collects the various ways of computing the central charge $c=3l/2G$ arising in 3d asymptotically anti-de Sitter spaces, in the Chern-Simons formulation. Their similarities and differences are displayed.

A Robust Scheme for PSS Detection and Integer Frequency Offset Recovery in LTE SystemsMay 12 2015Before establishing a communication link in a cellular network, the user terminal must activate a synchronization procedure called initial cell search in order to acquire specific information about the serving base station. To accomplish this task, the ... More

Analysis of $f(R)$ Theory Corresponding to NADE and NHDEOct 14 2013We develop the connection of $f(R)$ theory with new agegraphic and holographic dark energy models. The function $f(R)$ is reconstructed, regarding the $f(R)$ theory as an effective description for these dark energy models. We show the future evolution ... More

Cosmology of Holographic and New Agegraphic $f(R,T)$ ModelsAug 29 2013We consider the $f(R,T)$ theory, where $R$ is the scalar curvature and $T$ is the trace of energy-momentum tensor, as an effective description for the holographic and new agegraphic dark energy and reconstruct the corresponding $f(R,T)$ functions. In ... More

Stability of Thin-Shell Wormholes in Nonlinear ElectrodynamicsJun 17 2013In this paper, we construct thin-shell wormholes by applying the cut and paste procedure to a regular charged black hole in nonlinear electrodynamics field. We discuss different physical aspects of wormholes such as, the possible equation of state to ... More

The Stability of a Shearing Viscous Star with Electromagnetic FieldDec 04 2013We analyze the role of electromagnetic field for the stability of shearing viscous star with spherical symmetry. Matching conditions are given for the interior and exterior metrics. We use perturbation scheme to construct the collapse equation. The range ... More

Mechanical Stability of Cylindrical Thin-Shell WormholesJul 31 2013Aug 07 2013In this paper, we apply the cut and paste procedure to charged black string for the construction of thin-shell wormhole. We consider the Darmois-Israel formalism to determine the surface stresses of the shell. We take Chaplygin gas to deal with the matter ... More

Stability of Anisotropic Cylinder with Zero ExpansionMay 24 2013We study the dynamical instability of anisotropic collapsing cylinder with the expansion-free condition, which generates vacuum cavity within fluid distribution. The perturbation scheme is applied to distinguish Newtonian, post-Newtonian and post-post ... More