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Results for "Fernando Alarid-Escudero"

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Characterization and valuation of uncertainty of calibrated parameters in stochastic decision modelsJun 11 2019We evaluated the implications of different approaches to characterize uncertainty of calibrated parameters of stochastic decision models (DMs) in the quantified value of such uncertainty in decision making. We used a microsimulation DM of colorectal cancer ... More
An improved DNN-based spectral feature mapping that removes noise and reverberation for robust automatic speech recognitionMar 23 2018Apr 03 2018Reverberation and additive noise have detrimental effects on the performance of automatic speech recognition systems. In this paper we explore the ability of a DNN-based spectral feature mapping to remove the effects of reverberation and additive noise. ... More
Calculating the Expected Value of Sample Information in Practice: Considerations from Three Case StudiesMay 28 2019Investing efficiently in future research to improve policy decisions is an important goal. Expected Value of Sample Information (EVSI) can be used to select the specific design and sample size of a proposed study by assessing the benefit of a range of ... More
Neutrino decoupling beyond the Standard Model: CMB constraints on the Dark Matter mass with a fast and precise $N_{\rm eff}$ evaluationDec 13 2018Feb 08 2019The number of effective relativistic neutrino species represents a fundamental probe of the thermal history of the early Universe, and as such of the Standard Model of Particle Physics. Traditional approaches to the neutrino decoupling are either very ... More
Hypersurfaces with many Aj-singularities: explicit constructionsMar 16 2012Jul 02 2012A construction of algebraic surfaces based on two types of simple arrangements of lines, containing the prototiles of substitution tilings, has been proposed recently. The surfaces are derived with the help of polynomials obtained from products of the ... More
More on Odd-J Pairing in NucleiDec 29 2012Apr 12 2013We point out a simplicity that arises when we use an interaction in which only an energy with odd J is non-zero. The emphasis is on J=J_{\text{max}} and in particular J=9^{+} in the g_{9/2} shell. It is noted that high overlaps can be deceptive. In many ... More
How degeneracies can obscure interesting physicsNov 16 2012We show how degeneracies, accidental or otherwise, can obscure some interesting physics. We further show how one can get around this problem.
Single j-shell studies of cross-conjugate nuclei and isomerismDec 20 2011May 09 2012It is noted that in a calculation with 4 nucleons with isospin 1 in a single j shell (f_{7/2}, g_{9/2}, h_{11/2}) the state with median angular momentum J = (J_{max}+1)/2 lies very low in energy becoming either an isomeric state or a ground state. Also ... More
Topics in Nuclear StructureJun 06 2013We consider work performed over the last decade on single-j-shell studies. We will discuss four topics.
The (2j-1) rule with other interactionsMay 11 2012Jun 24 2012We recently formulated a rule for isomeric states for a system of 4 nucleons with isospin T=1, namely that if the nucleons are in a single j shell then states with angular momenta J=2 and J=(2j-1) are either isomeric or ground states [ze12]. To show that ... More
Seniority conservation and seniority violation in the g_{9/2} shellNov 07 2005Dec 01 2005The g_{9/2} shell of identical particles is the first one for which one can have seniority-mixing effects. We consider three interactions: a delta interaction that conserves seniority, a quadrupole-quadrupole (QQ) interaction that does not, and a third ... More
Degeneracies with the Q.Q interaction in a single j shellMay 10 2016May 29 2016Previously [1] it was shown that for a configuration of 2 protons and 2 neutrons in the g_{9/2}shell there is a certain degeneracy that occurs when the quadrupole-quadrupole interaction (Q.Q) is used to to obtain the wave functions.. We here show 3 other ... More
On a family of complex algebraic surfaces of degree 3nFeb 27 2013We study a class of algebraic surfaces of degree 3n in the complex projective space with only ordinary double points. They are obtained by using bivariate polynomials with complex coefficients related to the generalized cosine associated to the affine ... More
Superconducting properties of FeSe0.5Te0.5 under high pressureJan 07 2016This work reports studies performed in the superconducting compound FeSe0:5Te0:5 under high pressure. Changes were observed in the transition temperature, superconducting critical fields,anomalous variations in the Meissner fraction, and in Ginzburg Landau ... More
The Complex Hierarchical Topology of EEG Functional ConnectivityApr 06 2016Nov 09 2016Understanding the complex hierarchical topology of functional brain networks is a key aspect of functional connectivity research. Such topics are obscured by the widespread use of sparse binary network models which are fundamentally different to the complete ... More
Weighted network estimation by the use of topological graph metricsMay 02 2017Jun 19 2018Topological metrics of graphs provide a natural way to describe the prominent features of various types of networks. Graph metrics describe the structure and interplay of graph edges and have found applications in many scientific fields. In this work, ... More
A construction of algebraic surfaces with many real nodesJul 18 2011Nov 07 2011A family of algebraic surfaces with many nondegenerate real singularities is introduced with the help of a construction, which has been used in previous works for the generation of substitution tilings.
A triple comparison between anticipating stochastic integrals in financial modelingJan 10 2018Sep 12 2018We consider a simplified version of the problem of insider trading in a financial market. We approach it by means of anticipating stochastic calculus and compare the use of the Hitsuda-Skorokhod, the Ayed-Kuo, and the Russo-Vallois forward integrals within ... More
Clifford algebras as twisted group algebras and the Arf invariantJan 22 2018Some connections between quadratic forms over the field of two elements, Clifford algebras of quadratic forms over the real numbers, real graded division algebras, and twisted group algebras will be highlighted. This allows to revisit real Clifford algebras ... More
Lepton masses and mixings in orbifold models with three Higgs familiesOct 19 2007Nov 05 2007We analyse the phenomenological viability of heterotic Z(3) orbifolds with two Wilson lines, which naturally predict three supersymmetric families of matter and Higgs fields. Given that these models can accommodate realistic scenarios for the quark sector ... More
Influence of temperature on the magnetic oscillations in graphene with spin splitting: a new approachJun 06 2018We analyze the magnetic oscillations (MO) in pristine graphene, under a perpendicular magnetic field, taking into account the Zeeman effect. We consider a constant Fermi energy, such that the valence band is always full and only the conduction band is ... More
Magnetic oscillations in siliceneJun 04 2018In this work the magnetic oscillations (MO) in pristine silicene at $T=0$ K are studied. Considering a constant electron density we obtain analytical expressions for the ground state internal energy and magnetization, under a perpendicular electric and ... More
The number of J=0 pairs in {44,46,48}TiJan 25 2005In the single j-shell, the configuration of an even-even Ti isotope consists of 2 protons and n neutrons. The I=0 wave function can be written in terms of D(J,Jv)'s, which are the probability amplitudes for the 2 protons to couple to J and the n neutrons ... More
P-V criticality in AdS black holes of massive gravityNov 16 2016In this paper we have studied the extended phase space thermodynamics in the canonical ensemble of black holes in massive gravity in AdS space. The black holes considered here belong to a theory of massive gravity where the graviton gain a mass due to ... More
An introduction to quantum plasmasJun 05 2012Shielding effects in non-degenerate and degenerate plasmas are compared. A detailed derivation of the Wigner-Poisson system is provided for electrostatic quantum plasmas where relativistic, spin and collisional effects are not essential. Later a detailed ... More
L-Borderenergetic graphsMay 14 2016The energy of a graph is defined as the sum the absolute values of the eigenvalues of its adjacency matrix. A graph G on n vertices is said to be borderenergetic if its energy equals the energy of the complete graph Kn. In this paper, we promote this ... More
Searches for Young PulsarsMay 19 2004I review the results of radio and X-ray searches for pulsations from young neutron stars, emphasizing work accomplished in the last five years. I cover undirected searches, as well as directed searches of pulsar wind nebulae, EGRET gamma-ray sources, ... More
Deep Searches for Young PulsarsOct 29 2002By 2000 there were only 10 established Galactic pulsar-supernova remnant associations. Two years later there are 16 such associations known. I discuss the work leading to this substantial increase. In particular I summarize an ongoing search project that ... More
A criterion for positive polynomialsDec 26 2003Jul 28 2004Let F be a homogeneous real polynomial of even degree in any number of variables. We consider the problem of giving explicit conditions on the coefficients so that F is positive definite or positive semi-definite. In this note we produce a necessary condition ... More
On pointed Hopf algebras associated with the Mathieu simple groupsNov 20 2007Jul 26 2008Let G be a Mathieu simple group, s in G, O_s the conjugacy class of s and \rho an irreducible representation of the centralizer of s. We prove that either the Nichols algebra B(O_s,\rho) is infinite-dimensional or the braiding of the Yetter-Drinfeld module ... More
The approach of St"ohr-Voloch to the Hasse-Weil bound with applications to optimal curves and plane arcsNov 14 2000This is an expository paper concerning topics on rational points of curves defined over finite fields based on a paper by St"ohr and Voloch.
On the constellations of Weierstrass pointsApr 04 1996We prove that the constellation of Weierstrass points characterizes the isomorphism-class of double covering of curves of genus large enough.
Homotopy theory of non-symmetric operads II: change of base category and left propernessApr 24 2013Aug 09 2013We prove, under mild assumptions, that a Quillen equivalence between symmetric monoidal model categories gives rise to a Quillen equivalence between their model categories of (non-symmetric) operads, and also between model categories of algebras over ... More
Dwyer-Kan homotopy theory of enriched categoriesJan 07 2012Mar 10 2014We construct a model structure on the category of small categories enriched over a combinatorial closed symmetric monoidal model category satisfying the monoid axiom. Weak equivalences are Dwyer-Kan equivalences, i.e. enriched functors which induce weak ... More
Dembowski-Ostram polynomials and reversed Dickson polynomialsDec 31 2018We give a complete classification of Dembowski-Ostram polynomials from reversed Dickson polynomials in odd characteristic.
A volumetric Penrose inequality for conformally flat manifoldsSep 08 2010Apr 11 2011We consider asymptotically flat Riemannian manifolds with nonnegative scalar curvature that are conformal to $\R^{n}\setminus \Omega, n\ge 3$, and so that their boundary is a minimal hypersurface. (Here, $\Omega\subset \R^{n}$ is open bounded with smooth ... More
Weak ferromagnetism in cobalt oxalate crystalsDec 28 2010Microcrystals of diaquocobalt(II) oxalate have been synthesized by the coprecipitation reaction of aqueous solutions of Cobalt (II) bromide and oxalic acid. Chemical analysis and thermal experiments revealed that there is only one phase present. X-ray ... More
Metamagnetism and Weak Ferromagnetism in Nickel (II) oxalate crystalsApr 12 2012Microcrystals of orthorhombic nickel (II) oxalate dihydrate were synthesized through a precipitation reaction of aqueous solutions of nickel chloride and oxalic acid. Magnetic susceptibility exhibits a sharp peak at 3.3 K and a broadrounded maximum near ... More
Classification of involutions on graded-division simple real algebrasJul 18 2017Feb 12 2018We classify, up to isomorphism and up to equivalence, involutions on graded-division finite-dimensional simple real (associative) algebras, when the grading group is abelian.
Hidden Sector Dark Matter and the Galactic Center Gamma-Ray Excess: A Closer LookSep 20 2017Nov 20 2017Stringent constraints from direct detection experiments and the Large Hadron Collider motivate us to consider models in which the dark matter does not directly couple to the Standard Model, but that instead annihilates into hidden sector particles which ... More
The energy gap of the compound FeSe0.5Te0.5 determined by specific heat and point contact spectroscopyJul 06 2015The superconductor $FeSe_{0.5}Te_{0.5}$ was studied with Point Contact spectroscopy and specific heat in polycrystalline samples. The transition temperature determined by magnetic measurement was $T_C =14.5$ K. The size of the energy gap measured by junctions ... More
New Parametrizations for the Photon Structure FunctionJan 07 2006In the last year four new parametrizations of the Hadronic Photon Structure Function at Next to Leading Order have appeared. In this talk, I briefly review the main features of three of them: the FFNS_CJK, CJK and AFG.
Geometric properties of RM vector fields along curves in Riemannian manifoldsSep 27 2016Rotation minimizing vector fields and frames were introduced by Bishop as an alternative to the Frenet frame. They are used in CAGD because they can be defined even the curvature vanishes. Nevertheless, many other geometric properties have not been studied. ... More
Casimir effect around disclinationsMay 05 1995This communication concerns the structure of the electromagnetic quantum vacuum in a disclinated insulator. It is shown that a nonzero vacuum energy density appears when the rotational symmetry of a continuous insulating elastic medium is broken by a ... More
Enhancement of the magnetic moment of the electron due to a topological defectMay 23 1995In the framework of the theory of defects/three-dimensional gravitation, it is obtained a positive correction to the magnetic moment of the electron bound to a disclination in a dielectric solid.
Design for a Darwinian Brain: Part 1. Philosophy and NeuroscienceMar 28 2013Physical symbol systems are needed for open-ended cognition. A good way to understand physical symbol systems is by comparison of thought to chemistry. Both have systematicity, productivity and compositionality. The state of the art in cognitive architectures ... More
Conformal covariance of massless free netsJun 16 2000In the present paper we review in a fibre bundle context the covariant and massless canonical representations of the Poincare' group as well as certain unitary representations of the conformal group (in 4 dimensions). We give a simplified proof of the ... More
Modular Theory by exampleJan 08 2009The present article contains a short introduction to Modular Theory for von Neumann algebras with a cyclic and separating vector. It includes the formulation of the central result in this area, the Tomita-Takesaki theorem, and several of its consequences. ... More
More on Equienergetic Threshold GraphsJul 02 2018The energy of a graph is defined as the sum the absolute values of the eigenvalues of its adjacency matrix. A threshold graph G on n vertices is coded by a binary sequence of length n. In this paper we answer a question posed by Jacobs et al. [Eigenvalues ... More
Geometric properties of rotation minimizing vector fields along curves in Riemannian manifoldsSep 27 2016Mar 29 2017Rotation minimizing vector fields and frames were introduced by Bishop as an alternative to the Frenet frame. They are used in CAGD because they can be defined even the curvature vanishes. Nevertheless, many other geometric properties have not been studied. ... More
A Note on Permutation Binomials and Trinomials over Finite FieldsSep 22 2016Feb 05 2017Let $p$ be an odd prime and $e$ be a positive integer. We completely explain the permutation binomials and trinomials arising from the reversed Dickson polynomials of the $(k+1)$-th kind $D_{n,k}(1,x)$ over $\mathbb{F}_{p^e}$ when $n=p^l+2$, where $l\in ... More
A triangulated category without modelsMar 11 2007We exhibit a triangulated category which is neither the stable category of a Frobenius category nor a full triangulated subcategory of the homotopy category of a stable model category.
Enhanced $A$-infinity obstruction theoryOct 01 2015Mar 12 2018We extend the Bousfield-Kan spectral sequence for the computation of the homotopy groups of the space of minimal A-infinity algebra structures on a graded projective module. We use the new part to define obstructions to the extension of truncated minimal ... More
Low Momentum Classical Mechanics with Effective Quantum PotentialsMar 02 2005A recently introduced effective quantum potential theory is studied in a low momentum region of phase space. This low momentum approximation is used to show that the new effective quantum potential induces a space-dependent mass and a smoothed potential ... More
Uncertainty, incompleteness, chance, and designJan 29 2013Apr 09 2013The 20th century has revealed two important limitations of scientific knowledge. On the one hand, the combination of Poincar\'e's nonlinear dynamics and Heisenberg's uncertainty principle leads to a world picture where physical reality is, in many respects, ... More
String black hole: Can it be a particle accelerator ?Nov 06 2013Aug 21 2014In this paper we have studied the possibility of the center-of-mass energy of two particles colliding near the horizon of a static charged black hole in string theory. Various cases corresponding to the electric charge and the angular momentum of the ... More
Clifford theory for infinite dimensional modulesApr 28 2015Dec 29 2015Clifford theory of possibly infinite dimensional modules is studied
Normal modes, and acoustic properties, of an elastic solid with line defectsSep 23 2014The normal modes of a continuum solid endowed with a random distribution of line defects that behave like elastic strings are described. These strings interact with elastic waves in the bulk, generating wave dispersion and attenuation. As in amorphous ... More
Coherent-State Overcompleteness, Path Integrals, and Weak ValuesMar 12 2014Feb 18 2016In the Hilbert space of a quantum particle the standard coherent-state resolution of unity is written in terms of a phase-space integration of the outer product $|z\rangle \langle z|$. Because no pair of coherent states is orthogonal, one can represent ... More
Regular black holes in de Sitter universe: scalar field perturbations and quasinormal modesAug 14 2015The purpose of this paper is to study quasinormal modes (QNM) of a regular black hole with a cosmological constant due to scalar perturbations. A detailed study of the QNM frequencies for the massless scalar field were done by varying the parameters of ... More
Irreducible representations of unipotent subgroups of symplectic and unitary groups defined over ringsJul 27 2015Nov 01 2016Let $A$ be a ring with $1\neq 0$, not necessarily finite, endowed with an involution~$*$, that is, an anti-automorphism of order $\leq 2$. Let $H_n(A)$ be the additive group of all $n\times n$ hermitian matrices over $A$ relative to $*$. Let ${\mathcal ... More
Local String Models and Moduli StabilisationApr 21 2014Apr 29 2014A brief overview is presented of the progress made during the past few years on the general structure of local models of particle physics from string theory including: moduli stabilisation, supersymmetry breaking, global embedding in compact Calabi-Yau ... More
The Hyperradical and The Hopkins-Levitzki Theorem for Modular LatticesSep 07 2004Many arguments in the Theory of Rings and Modules are, on close inspection, purely Lattice theoretic arguments. Calagareanu} has a long repertoire of such results in his book. The Hopkins-Levitzki Theorem is interesting from this point of view, because ... More
Web 2.0 Technologies and Social Networking Security Fears in EnterprisesApr 09 2012Web 2.0 systems have drawn the attention of corporation, many of which now seek to adopt Web 2.0 technologies and transfer its benefits to their organizations. However, with the number of different social networking platforms appearing, privacy and security ... More
Determinant of complexes and higher HessiansJan 02 1996Let $X \subset \Bbb P^r$ be a smooth algebraic curve in projective space, over an algebraically closed field of characteristic zero. For each $m \in \Bbb N$, the $m$-flexes of $X$ are defined as the points where the osculating hypersurface of degree $m$ ... More
Massless relativistic wave equations and quantum field theoryMar 12 2003Dec 16 2003We give a simple and direct construction of a massless quantum field with arbitrary discrete helicity that satisfies Wightman axioms and the corresponding relativistic wave equation in the distributional sense. We underline the mathematical differences ... More
Homotopy units in A-infinity algebrasNov 11 2011Apr 30 2014We show that the canonical map from the associative operad to the unital associative operad is a homotopy epimorphism for a wide class of symmetric monoidal model categories. As a consequence, the space of unital associative algebra structures on a given ... More
A note on the automorphism group of Schubert varietiesMay 12 2016Jan 08 2017In this work we extend some previously known results on the automorphism group of Schubert varieties. We consider the Schubert conditions which define a Schubert variety. An automorphism of the Grassmannian fixes a Schubert variety contained in it if ... More
Enveloping actions and Takai duality for partial actionsJul 17 2000We show that any continuous partial action on a topological space has a unique enveloping action, i.e. it is the restriction of a global action. In the case of C^*-algebras we prove that any partial action has an enveloping action up to Morita equivalence. ... More
Quantum MagnetohydrodynamicsMar 02 2005The quantum hydrodynamic model for charged particle systems is extended to the cases of non zero magnetic fields. In this way, quantum corrections to magnetohydrodynamics are obtained starting from the quantum hydrodynamical model with magnetic fields. ... More
On the relevance of quantum models for plasmasOct 01 2012Recently there has been a claim on the complete irrelevance of quantum modeling for plasmas. We address this subject from basic principles. Physical situations where quantum effects play a decisive role are identified.
The damped Pinney equation and its applications to dissipative quantum mechanicsDec 25 2007Dec 18 2009The work considers the damped Pinney equation, defined as the model arising when a linear in velocity damping term is included in the Pinney equation. In the general case the resulting equation does not admit Lie point symmetries or is reducible to a ... More
Aspects of quantum cooling in electron and atom systemsMay 18 2009Some features of nonadiabatic electron heat pumps are studied and connected to general questions of quantum cooling. Inelastic reflection is shown to contribute to heating if the external driving signal is time-symmetric. The quantum of cooling power, ... More
Extremal Surfaces in Asymptotically AdS Charged Boson Stars BackgroundsJan 18 2013In this paper, inspired by the holographic dual of the entanglement entropy, we consider the behaviour of extremal, codimension two, spacelike surfaces in the background of three and four dimensional charged boson stars in asymptotically anti-de Sitter ... More
Schwarzschild black hole surrounded by quintessence: Null geodesicsFeb 07 2012Aug 15 2014We have studied the null geodesics of the Schwarzschild black hole surrounded by quintessence matter. Quintessence matter is a candidate for dark energy. Here, we have done a detailed analysis of the geodesics and exact solutions are presented in terms ... More
Phase transitions of black holes in massive gravityMay 16 2016Dec 14 2016In this paper we have studied thermodynamics of a black hole in massive gravity in the canonical ensemble. The massive gravity theory in consideration here has a massive graviton due to Lorentz symmetry breaking. The black hole studied here has a scalar ... More
Counting Spanning trees in double nested graphsMay 16 2016In this paper we give a linear time algorithm for computing the number of spanninig trees in double nested graphs.
Modular reduction of the Steinberg lattice of the general linear groupAug 21 2013The modular reduction of the Steinberg lattice of the general linear group is studied
Modular representations of Heisenberg algebrasJun 18 2013Jun 20 2013Let $F$ be be an arbitrary field and let $h(n)$ be the Heisenberg algebra of dimension $2n+1$ over $F$. It was shown by Burde that if $F$ has characteristic 0 then the minimum dimension of a faithful $h(n)$-module is $n+2$. We show here that his result ... More
Remarks on numerical semigroupsDec 19 1995We extend results on Weierstrass semigroups at ramified points of double covering of curves to any numerical semigroup whose genus is large enough. As an application we strengthen the properties concerning Weierstrass weights in \cited{To}.
On certain N--sheeted coverings and numerical semigroups which cannot be realized as Weierstrass semigroupsJul 26 1994Mar 06 1995A curve $X$ is said to be of type $(N,\gamma)$ if it is an $N$--sheeted covering of a curve of genus $\gamma$ with at least one totally ramified point. A numerical semigroup $H$ is said to be of type $(N,\gamma)$ if it has $\gamma$ positive multiples ... More
Modeling of relativistic ion-acoustic waves in ultra-degenerate plasmasDec 14 2017We consider the relativistic ion-acoustic mode in a plasma composed by cold ions and an ultra-degenerate electron gas, described the relativistic Vlasov-Poisson system. A critical examination of popular fluid models for relativistic ion-acoustic waves ... More
Learning Entrepreneurship with Serious Games - A Classroom ApproachSep 18 2017The use of educational games for pedagogical practice can provide new conceptions of teaching-learning in an interactive environment stimulating the acquisition of new knowledge. The so-called serious games are focused on the goal of transmitting educational ... More
Spinning dilaton black hole in 2+1 dimensions as a particle acceleratorMar 01 2017In this paper we have studied particle collision around a spinning dilaton black hole in 2 +1 dimensions. This black hole is a solution to the low energy string theory in 2+1 dimensions. Time-like geodesics are presented in detail and the center of mass ... More
Charged dilaton black hole in 2+1 dimensions as a particle acceleratorMar 29 2017In this paper we have studied particle collisions around a charged dilaton black hole in 2+1 dimensions. This black hole is a solution to the low energy string action in 2+1 dimensions. Time-like geodesics for charged particles are studied in detail. ... More
Is String Phenomenology an Oxymoron?Dec 05 2016Dec 13 2016A brief discussion is presented assessing the achievements and challenges of string phenomenology: the subfield dedicated to study the potential for string theory to make contact with particle physics and cosmology. Building from the well understood case ... More
Moduli spaces of algebras over non-symmetric operadsDec 21 2011Aug 19 2013In this paper we study spaces of algebras over an operad (non-symmetric) in symmetric monoidal model categories. We first compute the homotopy fiber of the forgetful functor sending an algebra to its underlying object, extending a result of Rezk. We then ... More
The deterministic limit of the Moran model: a uniform central limit theoremAug 21 2015We consider a Moran model with two allelic types, mutation and selection. In this work, we study the behaviour of the proportion of fit individuals when the size of the population tends to infinity, without any rescaling of parameters or time. We first ... More
Systematic Derivation of Noether Point Symmetries in Special Relativistic Field TheoriesMar 03 2016Mar 16 2016A didactic and systematic derivation of Noether point symmetries and conserved currents is put forward in special relativistic field theories, without a priori assumptions about the transformation laws. Given the Lagrangian density, the invariance condition ... More
On the proper homotopy type of locally compact A^2_n-polyhedraMay 08 2006In this paper we address the classification problem for locally compact (n-1)-connected CW-complexes with dimension less or equal than n+2 up to proper homotopy type. We obtain complete classification theorems in terms of purely algebraic data in those ... More
Representation theory of some infinite-dimensional algebras arising in continuously controlled algebra and topologyOct 21 2003In this paper we determine the representation type of some algebras of infinite matrices continuously controlled at infinity by a compact metrizable space. We explicitly classify their finitely presented modules in the finite and tame cases. The algebra ... More
Elastic forces that do no work and the dynamics of fast cracksJul 17 1995Jul 18 1995Elastic singularities such as crack tips, when in motion through a medium that is itself vibrating, are subject to forces orthogonal to the direction of motion and thus impossible to determine by energy considerations alone. This fact is used to propose ... More
Quantum Weibel InstabilityNov 06 2007The Weibel instability is analyzed for quantum plasmas described by the Wigner-Maxwell model. For a suitable class of electromagnetic potentials, the Wigner-Maxwell system is linearized yielding a general dispersion relation for transverse electromagnetic ... More
Josephson effect between Bose condensatesOct 26 1998I present an overview of the physics of the Josephson effect between Bose condensed systems, with emphasis on the recently achieved BEC's in trapped alkali gases. I focus mostly on those physical phenomena that are likely to be observed only (or more ... More
On the scaling property in fluctuation theory for stable Lévy processesJul 22 2010We find an expression for the joint Laplace transform of the law of $(T_{[x,+\infty[},X_{T_{[x,+\infty[}})$ for a L\'evy process $X$, where $T_{[x,+\infty[}$ is the first hitting time of $[x,+\infty[$ by $X$. When $X$ is an $\alpha$-stable L\'evy process, ... More
Quasi normal modes and the area spectrum of a near extremal de Sitter black hole with conformally coupled scalar fieldApr 14 2015In this paper we have studied a black hole in de Sitter space which has a conformally coupled scalar field in the background. This black hole is also known as the $MTZ$ black hole. We have obtained exact values for the quasi normal mode frequencies under ... More
On an Inequality of Dimension-like Invariants for Finite GroupsFeb 02 2015In this paper, we introduce several notions of "dimension" of a finite group, involving sizes of generating sets and certain configurations of maximal subgroups. We focus on the inequality $m(G) \leq \mathrm{MaxDim}(G)$, giving a family of examples where ... More
Enhanced $A$-infinity obstruction theoryOct 01 2015We define a new obstruction theory for the extension of truncated A-infinity algebra structures. Obstructions lie in the new terms of a spectral sequence which extends Bousfield-Kan's fringed spectral sequence of a certain tower of fibrations. The obstructions ... More
Wave dispersion derived from the square-root Klein-Gordon-Poisson systemJul 30 2013Recently there has been great interest around quantum relativistic models for plasmas. In particular striking advances have been obtained by means of the Klein-Gordon-Maxwell system, which provides a first order approach to the relativistic regimes of ... More
On the splitting ring of a polynomialApr 04 2015Oct 16 2015Let $f(Z)=Z^n-a_{1}Z^{n-1}+\cdots+(-1)^{n-1}a_{n-1}Z+(-1)^na_n$ be a monic polynomial with coefficients in a ring~$R$ with identity, not necessarily commutative. We study the ideal $I_f$ of $R[X_1,\dots,X_n]$ generated by $\sigma_i(X_1,\dots,X_n)-a_{i}$, ... More