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Results for "Ulisses Braga-Neto"

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Scalable optimal Bayesian classification of single-cell trajectories under regulatory model uncertaintyFeb 08 2019Single-cell gene expression measurements offer opportunities in deriving mechanistic understanding of complex diseases, including cancer. However, due to the complex regulatory machinery of the cell, gene regulatory network (GRN) model inference based ... More
Control of Gene Regulatory Networks with Noisy Measurements and Uncertain InputsFeb 24 2017This paper is concerned with the problem of stochastic control of gene regulatory networks (GRNs) observed indirectly through noisy measurements and with uncertainty in the intervention inputs. The partial observability of the gene states and uncertainty ... More
Particle Filters for Partially-Observed Boolean Dynamical SystemsFeb 23 2017Partially-observed Boolean dynamical systems (POBDS) are a general class of nonlinear models with application in estimation and control of Boolean processes based on noisy and incomplete measurements. The optimal minimum mean square error (MMSE) algorithms ... More
Rank discriminants for predicting phenotypes from RNA expressionJan 07 2014Nov 21 2014Statistical methods for analyzing large-scale biomolecular data are commonplace in computational biology. A notable example is phenotype prediction from gene expression data, for instance, detecting human cancers, differentiating subtypes and predicting ... More
Learning Maximum Entropy Models from finite size datasets: a fast Data-Driven algorithm allows sampling from the posterior distributionJul 15 2015Sep 08 2016Maximum entropy models provide the least constrained probability distributions that reproduce statistical properties of experimental datasets. In this work we characterize the learning dynamics that maximizes the log-likelihood in the case of large but ... More
A variational principle for hardening elastoplasticityOct 12 2007We present a variational principle governing the quasistatic evolution of a linearized elastoplastic material. In case of linear hardening, the novel characterization allows to recover and partly extend some known results and proves itself to be especially ... More
Sequential Experimental Design for Optimal Structural Intervention in Gene Regulatory Networks Based on the Mean Objective Cost of UncertaintyMay 30 2018Scientists are attempting to use models of ever increasing complexity, especially in medicine, where gene-based diseases such as cancer require better modeling of cell regulation. Complex models suffer from uncertainty and experiments are needed to reduce ... More
M31-RV evolution and its alleged multi-outburst patternFeb 12 2004The photometric evolution of M31-RV has been investigated on 1447 plates of the Andromeda galaxy obtained over half a century with the Asiago telescopes. M31-RV is a gigantic stellar explosion that occurred during 1988 in the Bulge of M31 and that was ... More
Finite thermoelastoplasticity and creep under small elastic strainsApr 16 2018A mathematical model for an elastoplastic continuum subject to large strains is presented. The inelastic response is modeled within the frame of rate-dependent gradient plasticity for nonsimple materials. Heat diffuses through the continuum by the Fourier ... More
Spectroscopy, Photometry and Micro-arcsec Astrometry of Binaries with the GAIA Space Mission and with the RAVE ExperimentJun 01 2003GAIA astrometric mission of ESA will be very efficient in discovering binary and multiple stars with any orbital period, from minutes to millions of years. Main parameters of the revised mission design are presented. Next we estimate the fraction of binary ... More
UBVRI photometric sequences for symbiotic starsAug 16 2002Deep, wide-range and accurate UBVRI photometric sequences have been established around more than 80 symbiotic stars, to assist current photometry as well as measurement of old photographic plates. Sequences for 40 symbiotic stars have already been published; ... More
Photometry of the progenitor of Nova Del 2013 (V339 Del) and calibration of a deep BVRI photometricDec 20 2013The Asiago plate archive has been searched for old plates covering the region of the sky containing Nova Del 2013 (V339 Del). The brightness of the progenitor was measured against a deep BVRI photometric sequence that we calibrated on purpose. The mean ... More
Thermodynamics of elastoplastic porous rocks at large strains towards earthquake modelingJul 02 2018Jul 05 2018A mathematical model for an elastoplastic porous continuum subject to large strains in combination with reversible damage (aging), evolving porosity, water and heat transfer is advanced. The inelastic response is modeled within the frame of plasticity ... More
Finite plasticity in $P^T P$Sep 29 2015We discuss a finite-plasticity model based on the symmetric tensor $P^T P$ instead of the classical plastic strain $P$. Such a model structure arises from assuming that the material behavior is invariant with respect to frame transformations of the intermediate ... More
Symbiotic stars on Asiago archive plates. IIFeb 06 2002The Asiago photographic archive has been searched for plates containing the symbiotic stars Hen 2-468, QW Sge, LT Del, V407 Cyg, K 3-9, V335 Vul, FG Ser and Draco C-1. A total of 635 plates imaging the program stars have been found and the brightness ... More
Existence results for incompressible magnetoelasticityNov 16 2013Nov 29 2013We investigate a variational theory for magnetoelastic solids under the incompressibility constraint. The state of the system is described by deformation and magnetization. While the former is classically related to the reference configuration, magnetization ... More
A Simple Method to Test for Energy-Dependent Dispersion in High Energy Light-Curves of Astrophysical SourcesApr 10 2012In this paper we discuss a simple method of testing for the presence of energy-dependent dispersion in high energy data-sets. It uses the minimisation of the Kolmogorov distance between the cumulative distribution of two probability functions as the statistical ... More
The geometry of C_60: a rigorous approach via Molecular MechanicsApr 07 2016Molecular Mechanics describes molecules as particle configurations interacting via classical potentials. These {\it configurational energies} usually consist of the sum of different phenomenological terms which are tailored to the description of specific ... More
Optimal control of a rate-independent evolution equation via viscous regularizationJul 04 2016We study the optimal control of a rate-independent system that is driven by a convex, quadratic energy. Since the associated solution mapping is non-smooth, the analysis of such control problems is challenging. In order to derive optimality conditions, ... More
Quasistatic evolution of magnetoelastic thin films via dimension reductionMay 27 2014A rate-independent model for the quasistatic evolution of a magnetoelastic thin film is advanced and analyzed. Starting from the three-dimensional setting, we present an evolutionary $\Gamma$-convergence argument in order to pass to the limit in one of ... More
Attractors for gradient flows of non convex functionals and applicationsMay 31 2007This paper addresses the long-time behavior of gradient flows of non convex functionals in Hilbert spaces. Exploiting the notion of generalized semiflows by J. M. Ball, we provide some sufficient conditions for the existence of a global attractor. The ... More
The geometry of C_60: a rigorous approach via Molecular MechanicsApr 07 2016Jan 09 2017Molecular Mechanics describes molecules as particle configurations interacting via classical potentials. These {\it configurational energies} usually consist of the sum of different phenomenological terms which are tailored to the description of specific ... More
Random versus maximum entropy models of neural population activityDec 08 2016The principle of maximum entropy provides a useful method for inferring statistical mechanics models from observations in correlated systems, and is widely used in a variety of fields where accurate data are available. While the assumptions underlying ... More
UBVRI photometry and spectroscopy of the young open cluster Haffner 18Dec 19 1997UBVRI CCD photometry of a $2.^{\prime}1 \times 3.^{\prime}3$ field centered on the young open cluster Haffner~18 is presented and discussed. Spectroscopic classification of seven stars is also provided. 44 clusters members are identified, the earliest ... More
Observational studies of early-type binary stars: VV OrionisOct 06 2006New and previously published observations of the bright eclipsing binary VV Orionis are analyzed. We present new radial velocities and interstellar reddening measurements from high-resolution spectra of this detached, short-period (P=1.48 d) binary. We ... More
The maximum time of 2-neighbor bootstrap percolation: complexity resultsAug 27 2015In 2-neighborhood bootstrap percolation on a graph G, an infection spreads according to the following deterministic rule: infected vertices of G remain infected forever and in consecutive rounds healthy vertices with at least 2 already infected neighbors ... More
Acquisition and use of knowledge over a restricted domain by intelligent agentsMay 06 2018This short paper provides a description of an architecture to acquisition and use of knowledge by intelligent agents over a restricted domain of the Internet Infrastructure. The proposed architecture is added to an intelligent agent deployment model over ... More
Heavy meson dissociation in a plasma with magnetic fieldsFeb 06 2018The fraction of heavy vector mesons detected after a heavy ion collision provides information about the possible formation of a plasma state. An interesting framework for estimating the degree of dissociation of heavy mesons in a plasma is the holographic ... More
Constructive Setting of the Density Ratio Estimation Problem and its Rigorous SolutionJun 03 2013Jun 15 2013We introduce a general constructive setting of the density ratio estimation problem as a solution of a (multidimensional) integral equation. In this equation, not only its right hand side is known approximately, but also the integral operator is defined ... More
Thermal width of heavy quarkonia from an AdS/QCD modelJun 30 2016We estimate the thermal width of a heavy quark anti-quark pair inside a strongly coupled plasma using a holographic AdS/QCD model. The imaginary part of the quark potential that produces the thermal width appears in the gravity dual from quantum fluctuations ... More
COUPLING CHIRAL BOSONS TO GRAVITYJan 18 1995The chiral boson actions of Floreanini and Jackiw (FJ), and of McClain,Wu and Yu (MWY) have been recently shown to be different representations of the same chiral boson theory. MWY displays manifest covariance and also a (gauge) symmetry that is hidden ... More
Chiral Bosons as solutions of the BV master equation 2D chiral gauge theoriesFeb 25 1994We construct the chiral Wess-Zumino term as a solution for the Batalin-Vilkovisky master equation for anomalous two-dimensional gauge theories, working in an extended field-antifield space, where the gauge group elements are introduced as additional degrees ... More
Towards the Modular Specification and Validation of Cyber-Physical SystemsMar 08 2018Cyber-Physical Systems (CPS) are systems controlled by one or more computer-based components tightly integrated with a set of physical components, typically described as sensors and actuators, that can either be directly attached to the computer components, ... More
Positronium Portal into Hidden Sector: A new Experiment to Search for Mirror Dark MatterMay 26 2010Jul 19 2010The understanding of the origin of dark matter has great importance for cosmology and particle physics. Several interesting extensions of the standard model dealing with solution of this problem motivate the concept of hidden sectors consisting of SU(3)xSU(2)_LxU(1)_Y ... More
Characterization of optimal carbon nanotubes under stretching and validation of the Cauchy-Born ruleJun 05 2017Carbon nanotubes are modeled as point configurations and investigated by minimizing configurational energies including two- and three-body interactions. Optimal configurations are identified with local minima and their fine geometry is fully characterized ... More
Polarimetric Tomography of Blazar JetsApr 16 2014In this paper we propose a way to use optical polarisation observations to provide independent constraints and guide to the modelling of the spectral energy distribution (SED) of blazars, which is particularly useful when two-zone models are required ... More
A phase-field approach to Eulerian interfacial energiesMay 11 2018We analyze a phase-field approximation of a sharp-interface model for two- phase materials proposed by M. Silhavy [32, 33]. The distinguishing trait of the model resides in the fact that the interfacial term is Eulerian in nature, for it is defined on ... More
A shortest-path based clustering algorithm for joint human-machine analysis of complex datasetsDec 31 2018Clustering is a technique for the analysis of datasets obtained by empirical studies in several disciplines with a major application for biomedical research. Essentially, clustering algorithms are executed by machines aiming at finding groups of related ... More
Axial Anomaly from the BPHZ regularized BV master equationAug 06 1997Aug 07 1997A BPHZ renormalized form for the master equation of the field antifiled (or BV) quantization has recently been proposed by De Jonghe, Paris and Troost. This framework was shown to be very powerful in calculating gauge anomalies. We show here that this ... More
Superspace Formulation for the BRST Quantization of the Chiral Schwinger ModelSep 16 1996It has recently been shown that the Field Antifield quantization of anomalous irreducible gauge theories with closed algebra can be represented in a BRST superspace where the quantum action at one loop order, including the Wess Zumino term, and the anomalies ... More
Comparison between Laplace-Lagrange Secular Theory and Numerical SimulationJun 08 2018The large increase in exoplanet discoveries in the last two decades showed a variety of systems whose stability is not clear. In this work we chose the $\upsilon$ Andromedae system as the basis of our studies in dynamical stability. This system has a ... More
Dynamical Casimir effect with cylindrical waveguidesAug 03 2004I consider the quantum electromagnetic field in a coaxial cylindrical waveguide, such that the outer cylindrical surface has a time-dependent radius. The field propagates parallel to the axis, inside the annular region between the two cylindrical surfaces. ... More
Moduli of Legendrian CurvesOct 29 2009We construct the generic component of the moduli space of the germs of Legendrian curves with generic plane projection topologicaly equivalent to a curve y^n = x^m, (n,m)=1.
Pairing, Stripes, Lattice Distortions and Superconductivity in Cuprate OxidesJul 27 2000We propose a model for a spatially modulated collective state of superconducting cuprates in which the electronic properties vary locally in space. In this model the regions of higher hole density (called stripes) are described as Luttinger liquids and ... More
Microlocal Versal Deformations of Plane CurvesDec 04 2009We introduce the notion of microlocal versal deformation of a plane curve. We construct equisingular versal deformations of Legendrian curves that are the conormal of a semi-quasi-homogeneous branch.
The Gauge Unfixing Formalism and the Solutions of the Dirac Bracket CommutatorsApr 29 2009Sep 04 2009We propose a systematic procedure that solves the Dirac bracket commutators. The method is based on the Gauge Unfixing formalism, a procedure that converts second class systems into first class ones without the enlargement of the original phase space ... More
Fundamental Constants, Entropic Gravity and Nonextensive Equipartition TheoremJan 14 2011Apr 23 2012By using the Verlinde's formalism[1], we propose that the positive numerical factor, in which Klinkhamer[2] states that it is necessary to define the fundamental length, can be associated to the parameter q of the Tsallis' nonextensive statistical mechanics[3]. ... More
Nonhomogeneous Cooling, Entropic Gravity and MOND TheorySep 24 2010Jun 20 2011In this paper, by using the holographic principle, a modified equipartition theorem where we assume that below a critical temperature the energy is not equally divided on all bits, and the Unruh temperature, we derive MOND theory and a modified Friedmann ... More
Gauging by Stückelberg field-shifting symmetryMay 14 2003Aug 13 2003We embed second class constrained systems by a formalism that combines concepts of the BFFT method and the unfixing gauge formalism. As a result, we obtain a gauge-invariant system where the introduction of the Wess-Zumino (WZ) field is essential. The ... More
Theory of tangential idealizers and tangentially free idealsAug 06 2009Jun 20 2017We generalize the theory of logarithmic derivations through a self-contained study of modules here dubbed tangential idealizers. We establish reflexiveness criteria for such modules, provided the ring is a factorial domain. As a main consequence, necessary ... More
Using permutations to detect, quantify and correct for confounding in machine learning predictionsMay 18 2018Nov 27 2018Clinical machine learning applications are often plagued with confounders that are clinically irrelevant, but can still artificially boost the predictive performance of the algorithms. Confounding is especially problematic in mobile health studies run ... More
Detecting Learning vs Memorization in Deep Neural Networks using Shared Structure Validation SetsFeb 21 2018The roles played by learning and memorization represent an important topic in deep learning research. Recent work on this subject has shown that the optimization behavior of DNNs trained on shuffled labels is qualitatively different from DNNs trained ... More
Strong correlations and the anisotropy of acceptor states in insulating La(2-x)Sr(x)CuO(4)Dec 15 2010We use the Green's function formalism to discuss the role of strong correlations to the spatial structure of acceptor states doped into a two-dimensional Mott-Hubbard antiferromagnetic insulator. When the scattering between doped carriers, at the nesting ... More
From cool pions to the chiral phase transitionMar 12 2000Using the ideas of effective field theory and dimensional reduction, we relate the parameters of two low energy models of QCD: the O(N) nonlinear sigma model in D=3+1, which describes the dynamics of cool pions, and the O(N) Heisenberg magnet in D=3+0, ... More
Limits of Tangents of SurfacesNov 25 2015We compute the limit of tangents of an arbitrary surface. We obtain as a byproduct an embedded version of Jung's desingularization theorem for surface singularities with finite limits of tangents.
Limits of Tangents of a Quasi-Ordinary HypersurfaceMar 24 2010We compute explicitly the limits of tangents of a quasi-ordinary singularity in terms of its special monomials. We show that the set of limits of tangents of Y is essentially a topological invariant of Y .
Direct off-line robot programming via a common CAD packageSep 09 2013This paper focuses on intuitive and direct off-line robot programming from a CAD drawing running on a common 3-D CAD package. It explores the most suitable way to represent robot motion in a CAD drawing, how to automatically extract such motion data from ... More
On the topology of families of isolated singularitiesNov 27 2014Dec 03 2014We study the topology of analytic families of $n$-dimensional complex hypersurfaces having an isolated singularity at the origin. We prove that such a family is $\mu$-constant if and only if it admits an uniform Milnor radius, which happens if and only ... More
Lê's polyhedron for line singularitiesFeb 05 2012Nov 27 2014We study the topology of a line singularity, which is a complex hypersurface with non-isolated singularity given by a complex line. We describe the degeneration of its Milnor fibre to the singular hypersurface by means of a pair of polyhedra, one in the ... More
Non-Fermi liquid behavior in U and Ce intermetallicsNov 06 1999Dec 06 1999In this paper we review the current experimental and theoretical situation of the description of non-Fermi liquid behavior (NFL) in U and Ce intermetallics. We focus on the magnetic and thermodynamic properties. We also discuss a recent theoretical interpretation ... More
Stripes, Vibrations and SuperconductivityFeb 15 2001Mar 20 2001We propose a model of a spatially modulated collective charge state of superconducting cuprates. The regions of higher carrier density (stripes) are described in terms of Luttinger liquids and the regions of lower density as a two-dimensional interacting ... More
NON-POLYNOMIAL LAGRANGIANS IN THE SKYRME MODELApr 03 1995We choose three different coupling constants for a particular higher-derivative term in the Skyrme model that allows the total Lagrangian to converge in a binomial, geometric and a logarithmic form. Improved numerical results are obtained.
Remarks on the Collective Quantization of the SU(2) Skyrme ModelJan 03 1994We point out the question of ordering momentum operator in the canonical \break quantization of the SU(2) Skyrme Model. Thus, we suggest a new definition for the momentum operator that may solve the infrared problem that appears when we try to minimize ... More
Solar observations with Rio de Janeiro Danjon astrolabe: diameter variations and its correlations (1998-2000)Jan 14 2013This work has aimed to analyze the 1998 to 2000 campaign of solar diameter surveying. The employed instrument was a Danjon astrolabe, at the Observat\'orio Nacional campus, and specially modified for the solar observations. During the time lapse, 10807 ... More
On Stable Hypersurfaces with Vanishing Scalar CurvatureMay 24 2013Jan 07 2015We will prove that \emph{there are no stable complete hypersurfaces of $\mathbb{R}^4$ with zero scalar curvature, polynomial volume growth and such that $\dfrac{(-K)}{H^3}\geq c>0$ everywhere, for some constant $c>0$}, where $K$ denotes the Gauss-Kronecker ... More
A Many-Core Overlay for High-Performance Embedded Computing on FPGAsAug 21 2014In this work, we propose a configurable many-core overlay for high-performance embedded computing. The size of internal memory, supported operations and number of ports can be configured independently for each core of the overlay. The overlay was evaluated ... More
Magneto-elastic coupling between copper spin configurations and oxygen octahedra in La(2-x)Sr(x)CuO(4). Untwinning, Raman (phonon) spectrum, and neutron responseFeb 21 2006Jun 12 2006We reinterpret neutron scattering and Raman spectroscopy experiments in La(2-x)Sr(x)CuO(4), showing modulation of spin and lattice degrees of freedom both in the low-temperature orthorhombic and tetragonal phases, in terms of a magneto-elastic coupling ... More
Selected Topics in Graphene physicsApr 19 2010Graphene research is currently one of the largest fields in condensed matter. Due to its unusual electronic spectrum with Dirac-like quasiparticles, and the fact that it is a unique example of a metallic membrane, graphene has properties that have no ... More
CDW, Superconductivity and Anomalous Metallic Behavior in 2D Transition Metal DichalcogenidesDec 08 2000We propose a theory for quasi-two-dimensional transition metal dichalcogenides that provides a unified microscopic picture of the charge density wave (CDW) and superconducting phases. We show, based on the electron-phonon coupling and Fermi surface topology, ... More
Non-Linear Waves in Fermi LiquidsDec 09 1994I show that when non-linearities are taken into account the Landau theory of Fermi liquids predicts the existence of hyperbolic waves in fermionic systems. The zero sound is described by a infinite set of coupled non-linear partial differential equations, ... More
An improved Gauge Unfixing formalism and the Abelian Pure Chern Simons TheorySep 29 2006Jul 05 2007We propose a variant scheme of the Gauge Unfixing formalism which modifies directly the original phase space variables of a constrained system. These new variables are gauge invariant quantities. We apply our procedure in a mixed constrained system that ... More
Using instrumental variables to disentangle treatment and placebo effects in blinded and unblinded randomized clinical trials influenced by unmeasured confoundersJun 15 2016Jun 21 2016Clinical trials traditionally employ blinding as a design mechanism to reduce the influence of placebo effects. In practice, however, it can be difficult or impossible to blind study participants and unblinded trials are common in medical research. Here ... More
Inhomogeneous Hopf-Oleĭnik Lemma and Applications. Part IV: Sharp Krylov Boundary Gradient Type Estimates for Solutions to Fully Nonlinear Differential Inequalities with unbounded coefficients and $C^{1,Dini}$ boundary dataAug 08 2016In this paper we provide another application of the Inhomogeneous Hopf-Ole\u{i}nik Lemma (IHOL) proved in \cite{BM-IHOL-PartI}. As a matter of fact, we also provide a new and simpler proof of IHOL with unbounded coefficients but only for the the fully ... More
Lyapunov Coefficients for Degenerate Hopf BifurcationsSep 25 2007In this paper are studied the codimensions one, two, three and four Hopf bifurcations and the pertinent Lyapunov stability coefficients. Algebraic expressions obtained with computer assisted calculations are displayed.
Hopf Bifurcations in a Watt Governor With a SpringFeb 29 2008Mar 04 2008This paper pursues the study carried out by the authors in "Stability and Hopf bifurcation in a hexagonal governor system", focusing on the codimension one Hopf bifurcations in the hexagonal Watt governor differential system. Here are studied the codimension ... More
A SUPERSPACE FORMULATION FOR THE BATALIN VILKOVISKY FORMALISM WITH EXTENDED BRST INVARIANCEMay 02 1995A superspace formulation for the Batalin Vilkovisky formalism (also called field-antifield quantization ) with extended BRST invariance (BRST and anti-BRST invariance ) for gauge theories with closed algebra is presented. In contrast to a recent formulation, ... More
Glueball Regge trajectories from gauge/string duality and the PomeronJul 06 2005Dec 29 2005The spectrum of light baryons and mesons has been reproduced recently by Brodsky and Teramond from a holographic dual to QCD inspired in the AdS/CFT correspondence. They associate fluctuations about the AdS geometry with four dimensional angular momenta ... More
Charge stripe order from antiphase spin spirals in the spin-Fermion modelSep 21 2006We revisit the ground state of the spin-Fermion model within a semiclassical approximation. We demonstrate that antiphase spin spirals, or pi-spirals, whose chirality alternates between consecutive rows (or columns) of local moments, have, for sufficiently ... More
Theory of tangential idealizers and tangentially free idealsAug 06 2009Oct 07 2009We generalize the theory of logarithmic derivations through a self-contained study of modules here dubbed tangential idealizers. We establish reflexiveness criteria for such modules, provided the ring is a factorial domain. As a main consequence, necessary ... More
Nonlinear Pendulum: A Simple GeneralizationJul 22 2010In this work we solve the nonlinear second order differential equation of the simple pendulum with a general initial angular displacement ($\theta(0)=\theta_0$) and velocity ($\dot{\theta}(0)=\phi_0$), obtaining a closed-form solution in terms of the ... More
Removing the Wess Zumino fields in the BFFT formalismNov 29 2004Jun 09 2005In this paper we give some prescriptions in order to remove the Wess Zumino fields of the BFFT formalism and, consequently, we derive a gauge invariant system written only in terms of the original second class phase space variables. Here, the Wess Zumino ... More
A Note in the Skyrme Model with Higher Derivative TermsFeb 09 1994Another stabilizer term is used in the classical Hamiltonian of the Skyrme Model that permits in a much simple way the generalization of the higher-order terms in the pion derivative field. Improved numerical results are obtained.
The role of magnetic field for quiescence-outburst models in CVsDec 19 2014In this paper we present the elementary assumptions of our research on the role of the magnetic field in modelling the quiescence-outbursts cycle in Cataclysmic Variables (CVs). The behaviour of the magnetic field is crucial not only to integrate the ... More
Casimir force between $δ-δ^{\prime}$ mirrors transparent at high frequenciesJul 21 2016Aug 14 2016We investigate, in the context of a real massless scalar field in $1+1$ dimensions, models of partially reflecting mirrors simulated by Dirac $\delta-\delta^{\prime}$ point interactions. In the literature, these models do not exhibit full transparency ... More
Decay Properties of the Connectivity for Mixed Long Range Percolation Models on $\Z^d$May 15 2006Sep 10 2007In this short note we consider mixed short-long range independent bond percolation models on $\Z^{k+d}$. Let $p_{uv}$ be the probability that the edge $(u,v)$ will be open. Allowing a $x,y$-dependent length scale and using a multi-scale analysis due to ... More
DnaA and the timing of chromosome replication in Escherichia coli as a function of growth rateJan 04 2012Background: In Escherichia coli, overlapping rounds of DNA replication allow the bacteria to double in faster times than the time required to copy the genome. The precise timing of initiation of DNA replication is determined by a regulatory circuit that ... More
Continuity of Lyapunov Exponents for Random 2D MatricesDec 04 2010The Lyapunov exponents of locally constant GL(2;C)-cocycles over Bernoulli shifts depend continuously on the cocycle and on the invariant probability. The Oseledets decomposition also depends continuously on the cocycle, in measure.
The degeneration of the boundary of the Milnor fibre to the link of complex and real non-isolated singularitiesSep 05 2012We study the boundary of the Milnor fibre of real analytic singularities $f: (\bR^m,0) \to (\bR^k,0)$, $m\geq k$, with an isolated critical value and the Thom $a_f$-property. We define the vanishing zone for $f$ and we give necessary and sufficient conditions ... More
Deformations of Legendrian CurvesJul 11 2016We construct versal and equimultiple versal deformations of the parametrization of a Legendrian curve.
Metallic Continuum Quantum Ferromagnets at Finite TemperatureAug 08 2002May 28 2003We study via renormalization group (RG) and large N methods the problem of continuum SU(N) quantum Heisenberg ferromagnets (QHF) coupled to gapless electrons. We establish the phase diagram of the dissipative problem and investigate the changes in the ... More
Finite size corrections to disordered systems on Erdös-Rényi random graphsMay 14 2013Oct 01 2013We study the finite size corrections to the free energy density in disorder spin systems on sparse random graphs, using both replica theory and cavity method. We derive an analytical expressions for the $O(1/N)$ corrections in the replica symmetric phase ... More
Extended supersymmetry in D=1+1May 19 1999Jul 15 1999We extend superspace by introducing an antisymmetric tensorial coordinate. The resulting theory presents a supersymmetry with central charge. After integrating over the tensorial coordinate, an effective action describing massive bosons and fermions is ... More
Functional versus canonical quantization of a nonlocal massive vector-gauge theoryFeb 01 1999It has been shown in literature that a possible mechanism of mass generation for gauge fields is through a topological coupling of vector and tensor fields. After integrating over the tensor degrees of freedom, one arrives at an effective massive theory ... More
Axial and gauge anomalies in a theory with one and two-form gauge fieldsMar 20 1998We study the problem of axial and gauge anomalies in a reducible theory involving vector and tensor gauge fields coupled in a topological way. We consider that vector and axial fermionic currents couple with the tensor field in the same topological manner ... More
Poincaré and mean value inequalities for hypersurfaces in Riemannian manifolds and applicationsFeb 05 2015Feb 04 2016In the first part of this paper we prove some new Poincar\'e inequalities, with explicit constants, for domains of any hypersurface of a Riemannian manifold with sectional curvatures bounded from above. This inequalities involve the first and the second ... More
Numerical analysis of semilinear elliptic equations with finite spectral interactionJul 28 2011We present an algorithm to solve $- \lap u - f(x,u) = g$ with Dirichlet boundary conditions in a bounded domain $\Omega$. The nonlinearities are non-resonant and have finite spectral interaction: no eigenvalue of $-\lap_D$ is an endpoint of $\bar{\partial_2f(\Omega,\RR)}$, ... More
The Batalin-Tyutin Formalism on the Collective Coordinates Quantisation of the SU(2) Skyrme ModelSep 25 1995We apply The Batalin-Tyutin constraint formalism of converting a second class system into a first class system for the rotational quantisation of the SU(2) Skyrme model. We obtain the first class constraint and the Hamiltonian in the extended phase space. ... More
Mass generation for gauge fields in the Salam-Weinberg theory without HiggsJan 15 1996We consider the Salam-Weinberg theory by introducing tensor gauge fields. When these fields are coupled in a topological way with the vector ones, the resulting system constitutes an alternative mechanism of mass generation for vector fields without the ... More
Forest-Fire Model with Resistant TreesFeb 09 2011Aug 02 2011The role of forest heterogeneity in the long-term, large-scale dynamics of forest fires is investigated by means of a cellular automata model and mean field approximation. Heterogeneity was conceived as trees (or acres of forest) with distinct strengths ... More
Dynamical Model for Virus SpreadNov 29 1995Dec 01 1995The steady state properties of the mean density population of infected cells in a viral spread is simulated by a general forest fire like cellular automaton model with two distinct populations of cells ( permissive and resistant ones) and studied in the ... More