Results for "Marcelo Wu"

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Near-field tuning of optomechanical coupling in a split-beam nanocavityJul 01 2014Tunable evanescent coupling is used to modify the optomechanical interactions within a split-beam photonic crystal nanocavity. An optical fiber taper probe is used to renormalize the optical nanocavity field and introduce a dissipative optomechanical ... More
Microwave-to-optical transduction using coupled piezoelectric and optomechanical resonatorsJul 10 2019The successes of superconducting quantum circuits at local manipulation of quantum information and photonics technology at long-distance transmission of the same have spurred interest in the development of quantum transducers for efficient, low-noise, ... More
Nonlinear optomechanical paddle nanocavitiesDec 15 2014Feb 24 2015Nonlinear optomechanical coupling is the basis for many potential future experiments in quantum optomechanics (e.g., quantum non-demolition measurements, preparation of non-classical states), which to date have been difficult to realize due to small non-linearity ... More
Design and experimental demonstration of optomechanical paddle nanocavitiesSep 01 2015We present the design, fabrication and initial characterization of a paddle nanocavity consisting of a suspended sub-picogram nanomechanical resonator optomechanically coupled to a photonic crystal nanocavity. The optical and mechanical properties of ... More
Nanocavity optomechanical torque magnetometry and radiofrequency susceptometryMay 10 2016Nov 02 2016Nanophotonic optomechanical devices allow observation of nanoscale vibrations with sensitivity that has dramatically advanced metrology of nanomechanical structures [1-9] and has the potential to impact studies of nanoscale physical systems in a similar ... More
Frontiers of Condensed Matter Physics Explored with High-Field Specific HeatApr 06 2010Production of very high magnetic fields in the laboratory has relentlessly increased in quantity and quality over the last five decades, and a shift occurred from research focused in magnet technology to studies of the fundamental physics of novel materials ... More
Revisiting maximum-a-posteriori estimation in log-concave modelsDec 19 2016Jan 18 2019Maximum-a-posteriori (MAP) estimation is the main Bayesian estimation methodology in imaging sciences, where high dimensionality is often addressed by using Bayesian models that are log-concave and whose posterior mode can be computed efficiently by convex ... More
Charge Fluctuations of an Uncharged Black HoleAug 02 2016In this paper we calculate charge fluctuations of a Schwarzschild black-hole of mass $M$ confined within a perfectly reflecting cavity of radius R in thermal equilibrium with various species of radiation and fermions . Charge conservation is constrained ... More
Notes on the flexible manipulatorDec 04 2013The existence of solutions to the boundary tracking of the displacement at one end of a linear Timoshenko beam is discussed on the basis of the Cauchy problem with time and space interchanged.
Standard decomposition of expansive ergodically supported dynamicsJan 30 2012Jun 04 2014In this work we introduce the notion of weak quasigroups, that are quasigroup operations defined almost everywhere on some set. Then we prove that the topological entropy and the ergodic period of an invertible expansive ergodically supported dynamical ... More
On the Product Rule for Classification ProblemsJan 17 2013We discuss theoretical aspects of the product rule for classification problems in supervised machine learning for the case of combining classifiers. We show that (1) the product rule arises from the MAP classifier supposing equivalent priors and conditional ... More
Quantitative Logic ReasoningMay 14 2019In this paper we show several similarities among logic systems that deal simultaneously with deductive and quantitative inference. We claim it is appropriate to call the tasks those systems perform as Quantitative Logic Reasoning. Analogous properties ... More
An Equational Metalogic for Monadic Equational SystemsSep 18 2013The paper presents algebraic and logical developments. From the algebraic viewpoint, we introduce Monadic Equational Systems as an abstract enriched notion of equational presentation. From the logical viewpoint, we provide Equational Metalogic as a general ... More
A General Theory of Oscillon DynamicsOct 30 2009We present a comprehensive, nonperturbative analytical method to investigate the dynamics of time-dependent oscillating scalar field configurations. The method is applied to oscillons in a double well Klein-Gordon model in two and three spatial dimensions, ... More
Positive topological entropy for Reeb flows on 3-dimensional Anosov contact manifoldsDec 10 2015Let $(M, \xi)$ be a compact contact 3-manifold and assume that there exists a contact form $\alpha_0$ on $(M, \xi)$ whose Reeb flow is Anosov. We show this implies that every Reeb flow on $(M, \xi)$ has positive topological entropy. Our argument builds ... More
Series expansion analysis of a tetrahedral cluster spin chainSep 14 2005Using series expansion by continuous unitary transformations we study the magnetic properties of a frustrated tetrahedral spin-1/2 chain. Starting from the limit of isolated tetrahedra we analyze the evolution of the ground state energy and the elementary ... More
Efficient spectroscopy of single embedded emitters using optical fiber taper waveguidesApr 17 2009Jun 11 2009A technique based on using optical fiber taper waveguides for probing single emitters embedded in thin dielectric membranes is assessed through numerical simulations. For an appropriate membrane geometry, photoluminescence collection efficiencies in excess ... More
Igusa-Todorov functions for Artin algebrasMay 31 2016In this paper we study the behaviour of the Igusa-Todorov functions for Artin algebras A with finite injective dimension, and Gorenstein algebras as a particular case. We show that the $\phi$-dimension and $\psi$-dimension are finite in both cases. Also ... More
Re-Weighted $\ell_1$ Algorithms within the Lagrange Duality Framework: Bringing Interpretability to WeightsJun 21 2019We consider an important problem in signal processing, which consists in finding the sparsest solution of a linear system $\Phi x=b$. This problem has applications in several areas, but is NP-hard in general. Usually an alternative convex problem is considered, ... More
The Farrell-Jones Isomorphism Conjecture in K-TheoryFeb 26 2012Mar 10 2012We prove that the Farrell-Jones isomorphism conjecture for non-connective algebraic K-theory for a discrete group G and a coefficient ring R holds true if G belongs to the class of groups acting on trees, under certain conditions on G (see theorem 0.5 ... More
Legendrian contact homology and topological entropySep 12 2014Apr 23 2016In this paper we study the growth rate of a version of Legendrian contact homology, which we call strip Legendrian contact homology, in 3-dimensional contact manifolds and its relation to the topological entropy of Reeb flows. We show that: if for a pair ... More
An Objective Representation of the Gaussian IntegersNov 28 2002May 13 2004A rig is a riNg without Negatives. We analyse the free rig on a generator x subject to the equivalence x = 1 + x + x^2, showing that in it the non-constant polynomials form a ring. This ring can be identified with the Gaussian integers, which thus acquire ... More
Resonant Configurations in Scalar Field Theories: Can (Some) Oscillons Live Forever?Jun 10 2019We investigate the longevity of oscillons numerically, paying particular attention to radially-symmetric oscillons that have been conjectured to have an infinitely-long lifetime. In two spatial dimensions, oscillons have not been seen to decay. In three ... More
THERMAL EFFECTS ON THE CATALYSIS BY A MAGNETIC FIELDApr 17 1995We show that the formation of condensates in the presence of a constant magnetic field in 2+1 dimensions is extremely unstable. It disappears as soon as a heat bath is introduced with or without a chemical potential. We point out some new nonanalytic ... More
DYNAMICAL SUPERSYMMETRYApr 10 1995We show, in a simple quantum mechanical model, how a theory can become supersymmetric in the presence of interactions even when the free theory is not. This dynamical generation of supersymmetry relaxes the condition on the equality of masses of the superpartners ... More
Hybrid gap modes induced by fiber taper waveguides: application in spectroscopy of single solid-state emitters deposited on thin filmsFeb 19 2010We show, via simulations, that an optical fiber taper waveguide can be an efficient tool for photoluminescence and resonant, extinction spectroscopy of single emitters, such as molecules or colloidal quantum dots, deposited on the surface of a thin dielectric ... More
Multimodal deep learning for short-term stock volatility predictionDec 25 2018Stock market volatility forecasting is a task relevant to assessing market risk. We investigate the interaction between news and prices for the one-day-ahead volatility prediction using state-of-the-art deep learning approaches. The proposed models are ... More
A theory for combinations of risk measuresJul 05 2018Mar 18 2019We study combinations of risk measures under no restrictive assumption on the set of alternatives. The main result is the representation for resulting risk measures from the properties of both alternative functionals and combination functions. To that, ... More
Explicit Error Bounds for Carleman LinearizationNov 07 2017We revisit the method of Carleman linearization for systems of ordinary differential equations with polynomial right-hand sides. This transformation provides an approximate linearization in a higher-dimensional space through the exact embedding of polynomial ... More
Network-on-Chip with load balancing based on interleave of flits techniqueOct 23 2015This paper presents the evaluation of a Network-on-Chip (NoC) that offers load balancing for Systems-on-Chip (SoCs) dedicated for multimedia applications that require high traffic of variable bitrate communication. The NoC is based on a technique that ... More
Legendrian contact homology and topological entropySep 12 2014May 08 2017In this paper we study the growth rate of a version of Legendrian contact homology, which we call strip Legendrian contact homology, in 3-dimensional contact manifolds and its relation to the topological entropy of Reeb flows. We show that: if for a pair ... More
Quantum histories without contrary inferencesMay 20 2014In the consistent histories formulation of quantum theory it was shown that it is possible to retrodict contrary properties. We show that this problem do not appear in our formalism of generalized contexts for quantum histories.
Invited review: Epidemics on social networksDec 12 2013Since its first formulations almost a century ago, mathematical models for disease spreading contributed to understand, evaluate and control the epidemic processes.They promoted a dramatic change in how epidemiologists thought of the propagation of infectious ... More
A note on quantization in the presence of gravitational shock wavesApr 17 2013Sep 18 2013We study the quantization of a free scalar field when the background metric satisfies Einstein's equations and develops gravitational shock waves.
On the Geometry and Kinematics of Smoothly Distributed and Singular DefectsJan 14 2014A continuum mechanical framework for the description of the geometry and kinematics of defects in material structure is proposed. The setting applies to a body manifold of any dimension which is devoid of a Riemannian or a parallelism structure. In addition, ... More
Entropy of the UniverseApr 20 2009After a discussion on several limiting cases where General Relativity turns into less sophisticated theories, we find that in the correct thermodynamical and cosmological weak field limit of Einstein's field equations the entropy of the Universe is R^(3/2) ... More
A General Relativistic Rotating Evolutionary Universe - Part IIJan 13 2008Aug 06 2008As a sequel to (Berman, 2008a), we show that the rotation of the Universe can be dealt by generalised Gaussian metrics, defined in this paper. Robertson-Walker's metric has been employed with proper-time, in its standard applications; the generalised ... More
Realization of Einsteins Machian ProgramFeb 07 2013The Einsteins Machian Program is here accomplished.
Self-injective right artinian rings and Igusa Todorov functionsJan 10 2011We show that a right artinian ring $R$ is right self-injective if and only if $\psi(M)=0$ (or equivalently $\phi(M)=0$) for all finitely generated right $R$-modules $M$, where $\psi, \phi : \mod R \to \mathbb N$ are functions defined by Igusa and Todorov. ... More
Universal and deterministic manipulation of the quantum state of harmonic oscillators: a route to unitary gates for Fock State qubitsNov 10 2004We present a simple quantum circuit that allows for the universal and deterministic manipulation of the quantum state of confined harmonic oscillators. The scheme is based on the selective interactions of the referred oscillator with an auxiliary three-level ... More
The Inverse Problem for Nested Polygonal Relative EquilibriaDec 07 2017We prove that for some potentials (including the Newtonian one, and the potential of Helmholtz vortices in the plane) relative equilibria consisting of two homothetic regular polygons of arbitrary size can only occur if the masses at each polygon are ... More
A standard form for generator matrices with respect to the Niederreiter-Rosenbloom-Tsfasman metricMay 12 2011In this note, we present an analogue for codes in vector spaces with a Rosenbloom-Tsfasman metric of the well-known standard form of generator matrices for codes in spaces with the Hamming metric.
Local and global well-posedness for a quadratic Schrödinger system on spheres and Zoll manifoldsJun 07 2019We consider the initial value problem (IVP) associated to a quadratic Schr\"odinger system \begin{equation*} \begin{cases} i \partial_{t} v \pm \Delta_{g} v - v = \epsilon_{1} u \bar{v}, & t \in \mathbb{R},\; x \in M, \\[2ex] i \sigma \partial_{t} u \pm ... More
Gravitational Waves from Collapsing Vacuum DomainsJul 24 1998Nov 10 1998The breaking of an approximate discrete symmetry, the final stages of a first order phase transition, or a post-inflationary biased probability distribution for scalar fields are possible cosmological scenarios characterized by the presence of unstable ... More
Obstructions towards a generalization of no-hair theorems: I. Scalar clouds around Kerr black holesDec 14 2018We show that the integral method used to prove the no-hair theorem for Black Holes (BH's) in spherically symmetric and static spacetimes within the framework of general relativity with matter composed by a complex-valued scalar-field does not lead to ... More
Average sex ratio and population maintenance costApr 13 2010Feb 14 2017The ratio of males to females in a population is a meaningful characteristic of sexual species. The reason for this biological property to be available to the observers of nature seems to be a question never asked. Introducing the notion of historically ... More
The Apparent Fractal ConjectureSep 30 1999May 31 2000This short communication advances the hypothesis that the observed fractal structure of large-scale distribution of galaxies is due to a geometrical effect, which arises when observational quantities relevant for the characterization of a cosmological ... More
Relativistic Fractal CosmologiesOct 26 2009This article reviews an approach for constructing a simple relativistic fractal cosmology whose main aim is to model the observed inhomogeneities of the distribution of galaxies by means of the Lemaitre-Tolman solution of Einstein's field equations for ... More
On Modelling a Relativistic Hierarchical (Fractal) Cosmology by Tolman's Spacetime. II. Analysis of the Einstein-de Sitter ModelJul 07 2008This paper studies the spatially homogeneous Einstein-de Sitter cosmological model in the context of a relativistic hierarchical (fractal) cosmology as developed in paper I (0807.0866). The Einstein-de Sitter model is treated as a special case of Lemaitre-Tolman's ... More
Observations in the Einstein--de Sitter Cosmology: Dust Statistics and Limits of Apparent HomogeneityOct 07 1999The two-point correlation function for the dust distribution in the unperturbed Einstein-de Sitter cosmological model is studied along the past light cone. It was found that this function seems unable to represent the theoretical distribution of dust ... More
A type theory for cartesian closed bicategoriesApr 13 2019We construct an internal language for cartesian closed bicategories. Precisely, we introduce a type theory modelling the structure of a cartesian closed bicategory and show that its syntactic model satisfies an appropriate universal property, thereby ... More
Information-Entropic Signature of the Critical PointJan 27 2015Jun 03 2015We investigate the critical behavior of continuous phase transitions in the context of Ginzburg Landau models with a double well effective potential. In particular, we show that the recently proposed configurational entropy, a measure of spatial complexity ... More
A Dirac Morphism for the Farrell-Jones Isomorphism Conjecture in K-TheoryJan 06 2012We construct a Dirac morphism and prove that if this Dirac morphism is invertible, then the isomorphism conjecture for non-connective algebraic K-theory holds true.
A nonsmooth two-sex population modelMay 12 2013Jun 04 2014This paper considers a two-dimensional logistic model to study populations with two genders. The growth behavior of a population is guided by two coupled ordinary differential equations given by a non-differentiable vector field whose parameters are the ... More
Framization of a Temperley-Lieb algebra of type $\mathtt{B}$Aug 07 2017Oct 17 2018In this paper we first discuss a Temperley-Lieb algebra associated to the Coxeter group of type $\mathtt{B}$ which is the natural extension of the classical case, in the sense that it can be expressed as a quotient of the Hecke algebra of type B over ... More
Partial Dynamical Systems and the KMS ConditionJun 22 2000Given a countably infinite 0-1 matrix A without identically zero rows, let O_A be the Cuntz-Krieger algebra recently introduced by the authors and T_A be the Toeplitz extension of O_A, once the latter is seen as a Cuntz-Pimsner algebra, as recently shown ... More
A maximum likelihood method for the incidental parameter problemSep 03 2009This paper uses the invariance principle to solve the incidental parameter problem of [Econometrica 16 (1948) 1--32]. We seek group actions that preserve the structural parameter and yield a maximal invariant in the parameter space with fixed dimension. ... More
On the Ward Identities at Finite TemperatureJun 30 1994We show both in 1+1 and 3+1 dimensions that, contrary to the recent suggestions, the contribution of the fermion loop to the polarization tensor is manifestly transverse at finite temperature. Some subtleties associated with the Ward identities at finite ... More
Appropriate kernels for Divisive Normalization explained by Wilson-Cowan equationsApr 16 2018The interaction between wavelet-like sensors in Divisive Normalization is classically described through Gaussian kernels that decay with spatial distance, angular distance and frequency distance. However, simultaneous explanation of (a) distortion perception ... More
Density matrix for a consistent non-extensive thermodynamicsAug 08 2018Starting with the average particle distribution function for bosons and fermions for non-extensive thermodynamics , as proposed in \cite{CMP}, we obtain the corresponding density matrix operators and hamiltonians. In particular, for the bosonic case the ... More
Improved Shortest Path Maps with GPU ShadersMay 22 2018We present in this paper several improvements for computing shortest path maps using OpenGL shaders. The approach explores GPU rasterization as a way to propagate optimal costs on a polygonal 2D environment, producing shortest path maps which can efficiently ... More
Electrical Double Layer Properties of Spherical Oxide NanoparticlesDec 13 2016The accurate characterization of electrical double layer properties of nanoparticles is of fundamental importance for optimizing their physicochemical properties for specific biotechnological and biomedical applications. In this article, we use classical ... More
Revisiting Link Prediction: Evolving Models and Real Data FindingsOct 21 2016The explosive growth of Web 2.0, which was characterized by the creation of online social networks, has reignited the study of factors that could help us understand the growth and dynamism of these networks. Various generative network models have been ... More
Stability Bounds on Compact Astrophysical Objects from Information-Entropic MeasureJun 18 2015We obtain bounds on the stability of various self-gravitating astrophysical objects using a new measure of shape complexity known as configurational entropy. We apply the method to Newtonian polytropes, neutron stars with an Oppenheimer-Volkoff equation ... More
Revealing Comparative Advantages in the Backbone of ScienceSep 05 2014Mapping Science across countries is a challenging task in the field of Scientometrics. A number of efforts trying to cope with this task has been discussed in the state of the art, addressing this challenge by processing collections of scientific digital ... More
Bayesian Inference for Generalized Extreme Value Distributions via Hamiltonian Monte CarloOct 16 2014Dec 23 2014In this paper we propose to evaluate and compare Markov chain Monte Carlo (MCMC) methods to estimate the parameters in a generalized extreme value model. We employed the Bayesian approach using traditional Metropolis-Hastings methods, Hamiltonian Monte ... More
Affinity Prediction in Online Social NetworksAug 12 2014Link prediction is the problem of inferring whether potential edges between pairs of vertices in a graph will be present or absent in the near future. To perform this task it is usual to use information provided by a number of available and observed vertices/edges. ... More
A Dynamic Programming Solution to the Monotonic Path of Minimal Cost in a 3-Rows MatrixOct 16 2013We consider the problem of finding the path of minimal cost going from left to right in a 3-rows matrix, starting at the third row, and not going downwards, where there is an additional cost related to not changing rows, such that the higher the change ... More
Some a priori estimates for a critical Schrodinger-Newton equationFeb 15 2013Under natural energy and decay assumptions, we derive a priori estimates for solutions of a Schrodinger-Newton type of equation with critical exponent. On one hand, such an equation generalizes the traditional Schrodinger-Newton and Choquard equations, ... More
Geometric Aspects of Singular DislocationsAug 21 2012The theory of singular dislocations is placed within the framework of the theory of continuous dislocations using de Rham currents. For a general $n$-dimensional manifold, an $(n-1)$-current describes a local layering structure and its boundary in the ... More
On Measures and Measurements: a Fibre Bundle approach to ContextualityMar 21 2019Contextuality is the failure of "local" probabilistic models to become global ones. In this paper we introduce the notions of \emph{measurable fibre bundles}, \emph{probability fibre bundles}, and \emph{sample fibre bundle} which capture and make precise ... More
Oscillons in a Hot Heat BathFeb 13 1996In models of real scalar fields with degenerate double-well potentials, spherically symmetric, large amplitude fluctuations away from the vacuum are unstable. Neglecting interactions with an external environment, the evolution of such configurations may ... More
New models for the evolution of Post-Asymptotic Giant Branch stars and Central Stars of Planetary NebulaeDec 13 2015Jan 09 2016The Post Asymptotic Giant Branch (AGB) phase is arguably one of the least understood phases of the evolution of low- and intermediate- mass stars. The two grids of models presently available are based on outdated micro- and macro-physics and do not agree ... More
Series Expansion Analysis of a Frustrated Four-Spin-TubeJun 10 2011We study the magnetism of a frustrated four-leg spin-1/2 ladder with transverse periodic boundary conditions: the frustrated four-spin tube (FFST). Using a combination of series expansion (SE), based on the continuous unitary transformation method and ... More
The K-theory of Cuntz-Krieger algebras for infinite matricesNov 15 1998Mar 19 1999We compute the K-theory of the Cuntz-Krieger C^*-algebras associated to infinite matrices.
Existence, uniqueness and stability of equilibrium states for non-uniformly expanding mapsMar 18 2008We prove existence of finitely many ergodic equilibrium states for a large class of non-uniformly expanding local homeomorphisms on compact manifolds and Holder continuous potentials with not very large oscillation. No Markov structure is assumed. If ... More
How We Make Sense of the World: Information, Map-Making, and The Scientific NarrativeOct 26 2017Science is a constructed narrative of the natural world based on information gathering and its subsequent analysis. In this essay, we develop a novel approach to the epistemic foundations of the scientific narrative, as based on our experiential interactions ... More
Stochastic resonance in a model of opinion formation on small-world networksNov 15 2001We analyze the phenomenon of stochastic resonance in an Ising-like system on a small-world network. The system, which is subject to the combined action of noise and an external modulation, can be interpreted as a stylized model of opinion formation by ... More
Problem Solving at the Edge of Chaos: Entropy, Puzzles and the Sudoku Freezing TransitionOct 08 2018Sudoku is a widely popular $\mathcal{NP}$-Complete combinatorial puzzle whose prospects for studying human computation have recently received attention, but the algorithmic hardness of Sudoku solving is yet largely unexplored. In this paper, we study ... More
Steady flow for incompressible fluids in domains with unbounded curved channelsNov 26 2015We give an overview on the solution of the stationary Navier-Stokes equations for non newtonian incompressible fluids established by G. Dias and M.M. Santos (Steady flow for shear thickening fluids with arbitrary fluxes, J. Differential Equations 252 ... More
Simple Lyapunov spectrum for certain linear cocycles over partially hyperbolic mapsOct 17 2016Nov 06 2018Criteria for the simplicity of the Lyapunov spectra of linear cocycles have been found by Furstenberg, Guivarc'h-Raugi, Gol'dsheid-Margulis and, more recently, Bonatti-Viana and Avila-Viana. In all the cases, the authors consider cocycles over hyperbolic ... More
Quantum Phase Transitions and Bipartite EntanglementJul 07 2004Dec 17 2004We develop a general theory of the relation between quantum phase transitions (QPTs) characterized by nonanalyticities in the energy and bipartite entanglement. We derive a functional relation between the matrix elements of two-particle reduced density ... More
A priori estimates for the 3D compressible free-boundary Euler equations with surface tension in the case of a liquidAug 02 2017We derive a priori estimates for the compressible free-boundary Euler equations with surface tension in three spatial dimensions in the case of a liquid. These are estimates for local existence in Lagrangian coordinates when the initial velocity and initial ... More
A Network Perspective on Software ModularityJan 18 2012Feb 28 2013Modularity is a desirable characteristic for software systems. In this article we propose to use a quantitative method from complex network sciences to estimate the coherence between the modularity of the dependency network of large open source Java projects ... More
The outflowing disks of B[e] supergiants and unclassified B[e] starsAug 04 2004Dec 16 2004B[e] supergiants are known to possess outflowing cool disks but also some unclassified B[e] stars show clear indications for the presence of a neutral disk. We derive constraints on the disk mass loss rates, temperature distributions and disk opening ... More
Optimal Invariant Tests in an Instrumental Variables Regression With Heteroskedastic and Autocorrelated ErrorsApr 29 2017This paper uses model symmetries in the instrumental variable (IV) regression to derive an invariant test for the causal structural parameter. Contrary to popular belief, we show there exist model symmetries when equation errors are heteroskedastic and ... More
Cosmic acceleration in asymptotically Ricci flat UniverseNov 21 2017We analyze the evolution of a Friedmann-Robertson-Walker spacetime within the framework of $f(R)$ metric gravity using an exponential model. We show that $f(R)$ gravity may lead to a vanishing effective cosmological constant in the far future (i.e. $R\rightarrow ... More
Effects of immunization in small-world epidemicsSep 14 2001The propagation of model epidemics on a small-world network under the action of immunization is studied. Although the connectivity in this kind of networks is rather uniform, a vaccination strategy focused on the best connected individuals yields a considerable ... More
Nebular diagnostics for young stellar populations: Photon escape versus atmosphere blanketingNov 26 2002Emission lines in ionized nebulae can provide strong and useful constraints on the properties of both ionizing and non-ionizing stellar populations in regions with star formation, provided that stellar evolution and stellar atmosphere models can be used ... More
Thermal Fluctuations and Validity of the 1-Loop Effective PotentialNov 06 1992Nov 10 1992We examine the validity of the 1-loop approximation to the effective potential at finite temperatures and present a simple test for its reliability. As an application we study the standard electroweak potential, showing that for a Higgs mass above 70 ... More
Lattice Independent Approach to Thermal Phase MixingOct 12 1999Feb 01 2000We show how to achieve lattice-spacing independent results in numerical simulations of finite-temperature stochastic scalar field theories. We generalize the previous approach of hep-lat/9607026 by obtaining results which are independent of the renormalization ... More
A Critical Value Function Approach, with an Application to Persistent Time-SeriesJun 10 2016Aug 29 2017Researchers often rely on the t-statistic to make inference on parameters in statistical models. It is common practice to obtain critical values by simulation techniques. This paper proposes a novel numerical method to obtain an approximately similar ... More
Optimal algorithms for universal random number generation from finite memory sourcesDec 06 2014We study random number generators (RNGs), both in the fixed to variable-length (FVR) and the variable to fixed-length (VFR) regimes, in a universal setting in which the input is a finite memory source of arbitrary order and unknown parameters, with arbitrary ... More
On the well-posedness of relativistic viscous fluids with non-zero vorticityJul 25 2014Apr 07 2016We study the problem of coupling Einstein's equations to a relativistic and physically well-motivated version of the Navier-Stokes equations. Under a natural evolution condition for the vorticity, we prove existence and uniqueness in a suitable Gevrey ... More
An Extended Model for the Evolution of Prebiotic Homochirality: A Bottom-Up Approach to the Origin of LifeFeb 20 2008A generalized autocatalytic model for chiral polymerization is investigated in detail. Apart from enantiomeric cross-inhibition, the model allows for the autogenic (non-catalytic) formation of left and right-handed monomers from a substrate with reaction ... More
Toward homochiral protocells in noncatalytic peptide systemsOct 30 2008Mar 30 2009The activation-polymerization-epimerization-depolymerization (APED) model of Plasson et al. has recently been proposed as a mechanism for the evolution of homochirality on prebiotic Earth. The dynamics of the APED model in two-dimensional spatially-extended ... More
Time-Space Efficient Regression Testing for Configurable SystemsFeb 11 2017Configurable systems are those that can be adapted from a set of options. They are prevalent and testing them is important and challenging. Existing approaches for testing configurable systems are either unsound (i.e., they can miss fault-revealing configurations) ... More
Equivariant Dold-Thom topological groupsJan 29 2011Let $M$ be a covariant coefficient system for a finite group $G$. In this paper we analyze several topological abelian groups, some of them new, whose homotopy groups are isomorphic to the Bredon-Illman $G$-equivariant homology theory with coefficients ... More
Canonical characters on quasi-symmetric functions and bivariate Catalan numbersAug 04 2004Every character on a graded connected Hopf algebra decomposes uniquely as a product of an even character and an odd character (Aguiar, Bergeron, and Sottile, math.CO/0310016). We obtain explicit formulas for the even and odd parts of the universal character ... More
Promiscuity and the Evolution of Sexual Transmitted DiseasesFeb 27 2003We study the relation between different social behaviors and the onset of epidemics in a model for the dynamics of sexual transmitted diseases. The model considers the society as a system of individual sexuated agents that can be organized in couples ... More