Results for "Silvio C. Ferreira"

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Eden clusters in three-dimensions and the Kardar-Parisi-Zhang universality classSep 19 2012Oct 25 2012We present large-scale simulations of radial Eden clusters in three-dimensions and show that the growth exponent is in agreement with the value $\beta=0.242$ accepted for the Kardar-Parisi-Zhang (KPZ) universality class. Our results refute a recent assertion ... More
Griffiths effects of the susceptible-infected-susceptible epidemic model on random power-law networksDec 16 2015Mar 28 2016We provide numerical evidence for slow dynamics of the susceptible-infected-susceptible model evolving on finite-size random networks with power-law degree distributions. Extensive simulations were done by averaging the activity density over many realizations ... More
Scaling, cumulant ratios and height distribution of the ballistic deposition in 3+1 and 4+1 dimensionsMar 28 2016Apr 07 2016We investigate the origin of the scaling corrections in ballistic deposition models in high dimensions using the method proposed by Alves \textit{et al}. [Phys Rev. E \textbf{90}, 052405 (20014)] in $d=2+1$ dimensions, where the intrinsic width associated ... More
Non-universal parameters, corrections and universality in Kardar-Parisi-Zhang growthFeb 15 2013Apr 12 2013We present a comprehensive numerical investigation of non-universal parameters and corrections related to interface fluctuations of models belonging to the Kardar-Parisi-Zhang (KPZ) universality class, in d=1+1, for both flat and curved geometries. We ... More
On the origins of scaling corrections in ballistic growth modelsSep 08 2014We study the ballistic deposition and the grain deposition models on two-dimensional substrates. Using the Kardar-Parisi-Zhang (KPZ) ansatz for height fluctuations, we show that the main contribution to the intrinsic width, which causes strong corrections ... More
Scaling laws in the diffusion limited aggregation of persistent random walkersJul 27 2011We investigate the diffusion limited aggregation of particles executing persistent random walks. The scaling properties of both random walks and large aggregates are presented. The aggregates exhibit a crossover between ballistic and diffusion limited ... More
Kardar-Parisi-Zhang universality class in 2+1 dimensions: Universal geometry-dependent distributions and finite-time correctionsFeb 15 2013Apr 12 2013The dynamical regimes of models belonging to the Kardar-Parisi-Zhang (KPZ) universality class are investigated in d=2+1 by extensive simulations considering flat and curved geometries. Geometry-dependent universal distributions, different from their Tracy-Widom ... More
Sampling methods for the quasistationary regime of epidemic processes on regular and complex networksMay 31 2016A major hurdle in the simulation of the steady state of epidemic processes is that the system will unavoidably visit an absorbing, disease-free state at sufficiently long times due to the finite size of the networks where epidemics evolves. In the present ... More
Universality of fluctuations in the Kardar-Parisi-Zhang class in high dimensions and its upper critical dimensionMay 05 2014Jul 30 2014We show that the theoretical machinery developed for the Kardar-Parisi-Zhang (KPZ) class in low dimensions are obeyed by the restricted solid-on-solid (RSOS) model for substrates with dimensions up to $d=6$. Analyzing different restriction conditions, ... More
Quantifying echo chamber effects in information spreading over political communication networksJan 11 2019Echo chambers in online social networks, in which users prefer to interact only with ideologically-aligned peers, are believed to facilitate misinformation spreading and contribute to radicalize political discourse. In this paper, we gauge the effects ... More
Multiscale model for the effects of adaptive immunity suppression on the viral therapy of cancerFeb 15 2013Oncolytic virotherapy - the use of viruses that specifically kill tumor cells - is an innovative and highly promising route for treating cancer. However, its therapeutic outcomes are mainly impaired by the host immune response to the viral infection. ... More
Optimal detrended fluctuation analysis as a tool for the determination of the roughness exponent of the mounded surfacesDec 15 2016Mar 22 2017We present an optimal detrended fluctuation analysis (DFA) and applied it to evaluate the local roughness exponent in non-equilibrium surface growth models with mounded morphology. Our method consists in analyzing the height fluctuations computing the ... More
Spectral properties and the accuracy of mean-field approaches for epidemics on correlated networksJul 03 2019Jul 05 2019We present a comparison between stochastic simulations and mean-field theories for the epidemic threshold of the susceptible-infected-susceptible (SIS) model on correlated networks (both assortative and disassortative) with power-law degree distribution ... More
Towards Automated Verification of Web ServicesNov 11 2011This paper proposes the use of model-checking software technology for the verification of workflows and business processes behaviour based on web services, namely the use of the SPIN model checker. Since the specification of a business process behaviour ... More
Quantum field theory on rotating black hole spacetimesSep 25 2015This thesis is concerned with the development of a general method to compute renormalised local observables for quantum matter fields, in a given quantum state, on a rotating black hole spacetime. The rotating black hole may be surrounded by a Dirichlet ... More
The cardinality of the set of real numbersAug 17 2001Jul 15 2013A proof that the set of real numbers is denumerable is given.
On the cardinality of the set of the real numbersMar 20 2001Nov 06 2001It is shown that any denumerable list L to which Cantor's diagonal method was applied is incomplete. However, this doesn't allow us to affirm that the cardinality of the real numbers of the interval [0, 1] is greater than the cardinality of the finite ... More
On the $3 \times 3$ magic square constructed with nine distinct square numbersApr 24 2015Jun 26 2015A proof that there is no $3 \times 3$ magic square constructed with nine distinct square numbers is given.
Observational limits on the spin-down torque of Accretion Powered Stellar WindsDec 15 2010The rotation period of classical T Tauri stars (CTTS) represents a longstanding puzzle. While young low-mass stars show a wide range of rotation periods, many CTTS are slow rotators, spinning at a small fraction of break-up, and their rotation period ... More
The Antinomy of the Liar and ProvabilityJun 03 2008This work evidences that a sentence cannot be denominated by P and written as P IS NOT TRUE. It demonstrates that in a system in which Q denominates the sentence Q IS NOT PROVABLE it is not provable that Q is true and not provable.
Renormalized vacuum polarization of rotating black holesFeb 04 2015May 05 2015Quantum field theory on rotating black hole spacetimes is plagued with technical difficulties. Here, we describe a general method to renormalize and compute the vacuum polarization of a quantum field in the Hartle-Hawking state on rotating black holes. ... More
How do scalar-field dark matter haloes react to orbiting bodies?Apr 24 2019Low-energy, self-gravitating solutions of a scalar field coupled to gravity, described by the Schrodinger-Poisson system, are good candidates for realistic astrophysical structures, being particularly suited to describe dark matter halos. In this work ... More
Williams and Bjerknes model with growth limitationNov 19 2001Williams and Bjerknes proposed a simple stochastic growth model to describe the tumor growth in the basal layer of an epithelium. In this work we generalize this model by including the possibility of saturation in the tumor growth as it is clinically ... More
The non-trivial zeros of Riemann's zeta-functionMay 27 2004Apr 26 2015A proof of the Riemann hypothesis using the reflection principle is presented.
A proof of the non existence of Frey curves without using TSW theoremNov 19 2002Jul 19 2013Fermat's Last Theorem (FLT) implies that the Frey curves do not exist. A proof of FLT independent of proved Taniyama-Shimura-Weil conjecture is presented.
On Goldbach's ConjectureSep 18 2002It is shown that if every odd integer $n > 5$ is the sum of three primes, then every even integer $n > 2$ is the sum of two primes. A conditional proof of Goldbach's conjecture, based on Cram\'er's conjecture, is presented. Theoretical and experimental ... More
Infinite and natural numbersFeb 14 2002The infinite numbers of the set M of finite and infinite natural numbers are defined starting from the sequence 0\Phi, where 0 is the first natural number, \Phi is a succession of symbols S and xS is the successor of the natural number x. The concept ... More
Critical behavior of the contact process on small-world networksJul 23 2013Nov 11 2013We investigate the role of clustering on the critical behavior of the contact process (CP) on small-world networks using the Watts-Strogatz (WS) network model with an edge rewiring probability p. The critical point is well predicted by a homogeneous cluster-approximation ... More
Weak Compactness and Fixed Point Property for Affine Bi-Lipschitz MapsOct 18 2016Mar 22 2018In this paper we show that if $(y_n)$ is a seminormalized sequence in a Banach space which does not have any weakly convergent subsequence, then it contains a wide-$(s)$ subsequence $(x_n)$ which admits an equivalent convex basic sequence. This fact is ... More
Modelling of epitaxial film growth with a Ehrlich-Schwoebel barrier dependent on the step heightJun 30 2011The formation of mounded surfaces in epitaxial growth is attributed to the presence of barriers against interlayer diffusion in the terrace edges, known as Ehrlich-Schwoebel (ES) barriers. We investigate a model for epitaxial growth using a ES barrier ... More
Universality of the contact process with random dilutionJan 05 2011We present quasi-stationary simulations of the two-dimensional contact process with quenched disorder included through the random dilution of a fraction of the lattice sites (these sites are not susceptible to infection). Our results strongly indicate ... More
Pair quenched mean-field theory for the susceptible-infected-susceptible model on complex networksMay 22 2013Sep 10 2013We present a quenched mean-field (QMF) theory for the dynamics of the susceptible-infected-susceptible (SIS) epidemic model on complex networks where dynamical correlations between connected vertices are taken into account by means of a pair approximation. ... More
Multiple phase transitions of the susceptible-infected-susceptible epidemic model on complex networksMar 26 2014Jan 09 2015The epidemic threshold of the susceptible-infected-susceptible (SIS) dynamics on random networks having a power law degree distribution with exponent $\gamma>3$ has been investigated using different mean-field approaches, which predict different outcomes. ... More
Critical behavior of the contact process in a multiscale networkJan 06 2011Inspired by dengue and yellow fever epidemics, we investigated the contact process (CP) in a multiscale network constituted by one-dimensional chains connected through a Barab\'asi-Albert scale-free network. In addition to the CP dynamics inside the chains, ... More
Eden model with nonlocal growth rules and the kinetic roughening in biological systemsMay 28 2018Aug 22 2018We investigate an off-lattice Eden model where the growth of new cells is performed with a probability dependent on the availability of resources coming externally towards the growing aggregate. Concentration of nutrients necessary for replication is ... More
Activation thresholds in epidemic spreading with motile infectious agents on scale-free networksAug 02 2018Dec 11 2018We investigate a fermionic susceptible-infected-susceptible model with mobility of infected individuals on uncorrelated scale-free networks with power-law degree distributions $P (k) \sim k^{-\gamma}$ of exponents $2<\gamma<3$. Two diffusive processes ... More
Principal Schottky Bundles over Riemann surfacesDec 27 2016Oct 02 2018We introduce and study (strict) Schottky G-bundles over a compact Riemann surface X, where G is a connected reductive algebraic group. Strict Schottky representations are shown to be related to branes in the moduli space of G-Higgs bundles over X, and ... More
Quasi-stationary analysis of the contact process on annealed scale-free networksMay 17 2011We present an analysis of the quasi-stationary (QS) state of the contact process (CP) on annealed scale-free networks using a mapping of the CP dynamics in a one-step processes and analyzing numerically and analytically the corresponding master equation. ... More
Faceted anomalous scaling in the epitaxial growth of semiconductor filmsJan 07 2011May 17 2011We apply the generic dynamical scaling theory (GDST) to the surfaces of CdTe polycrystalline films grown in glass substrates. The analysed data were obtained with a stylus profiler with an estimated resolution lateral resolution of $l_c=0.3 \mu$m. Both ... More
Heterogeneous pair-approximation for the contact process on complex networksFeb 12 2014May 07 2014Recent works have shown that the contact process running on the top of highly heterogeneous random networks is described by the heterogeneous mean-field theory. However, some important aspects as the transition point and strong corrections to the finite-size ... More
ALGORAND: The Efficient and Democratic LedgerJul 05 2016Aug 24 2016Algorand is a truly decentralized, new, and secure way to manage a shared ledger. Unlike prior approaches based on {\em proof of work}, it requires a negligible amount of computation, and generates a transaction history that does not fork with overwhelmingly ... More
ALGORAND: The Efficient and Democratic LedgerJul 05 2016Oct 03 2016Algorand is a truly decentralized, new, and secure way to manage a shared ledger. Unlike prior approaches based on {\em proof of work}, it requires a negligible amount of computation, and generates a transaction history that does not fork with overwhelmingly ... More
The distribution of symmetry of a naturally reductive nilpotent Lie groupOct 13 2017We show that the distribution of symmetry of a naturally reductive nilpotent Lie group coincides with the invariant distribution induced by the set of fixed vectors of the isotropy. This extends a known result on compact naturally reductive spaces. We ... More
The index of symmetry of three-dimensional Lie groups with a left-invariant metricApr 17 2016Jul 11 2016We determine the index of symmetry of 3-dimensional unimodular Lie groups with a left-invariant metric. In particular, we prove that every 3-dimensional unimodular Lie group admits a left-invariant metric with positive index of symmetry. We also study ... More
Manifolds admitting a metric with co-index of symmetry 4Dec 12 2018Jul 22 2019By a recent result, it is known that compact homogeneous spaces with co-index of symmetry 4 are quotients of a semisimple Lie group of dimension at most 10. In this paper we determine exactly which ones of these spaces actually admit such a metric. For ... More
A Berger-type theorem for metric connections with skew-symmetric torsionNov 21 2011Dec 14 2012We prove a Berger-type theorem which asserts that if the orthogonal subgroup generated by the torsion tensor (pulled back to a point by parallel transport) of a metric connection with skew-symmetric torsion is not transitive on the sphere, then the space ... More
On the 3D Euler equations with Coriolis force in borderline Besov spacesJun 24 2017Jul 19 2017We consider the 3D Euler equations with Coriolis force (EC) in the whole space. We show long-time solvability in Besov spaces for high speed of rotation $\Omega $ and arbitrary initial data. For that, we obtain $\Omega$-uniform estimates and a blow-up ... More
Gravitational field around a screwed superconducting cosmic string in scalar-tensor theoriesNov 19 2001We obtain the solution that corresponds to a screwed superconducting cosmic string (SSCS) in the framework of a general scalar-tensor theory including torsion. We investigate the metric of the SSCS in Brans-Dicke theory with torsion and analyze the case ... More
$r$-skeletons on the Alexandroff duplicateApr 04 2018An $r$-skeleton on a compact space is a family of continuous retractions having certain rich properties. The $r$-skeletons have been used to characterized the Valdivia compact spaces and the Corson compact spaces. Here, we characterized a compact space ... More
Hadamard states for a scalar field in anti-de Sitter spacetime with arbitrary boundary conditionsOct 04 2016Dec 16 2016We consider a real, massive scalar field on ${\rm PAdS}_{d+1}$, the Poincar\'e domain of the $(d+1)$-dimensional anti-de Sitter (AdS) spacetime. We first determine all admissible boundary conditions that can be applied on the conformal boundary, noting ... More
On the algebraic quantization of a massive scalar field in anti-de-Sitter spacetimeJan 25 2017Feb 16 2017We discuss the algebraic quantization of a real, massive scalar field in the Poincar\'e patch of the (d+1)-dimensional anti-de Sitter spacetime, with arbitrary boundary conditions. By using the functional formalism, we show that it is always possible ... More
Global existence for Schrodinger-Debye system for initial data with infinite massSep 07 2010Feb 07 2013We obtain global existence results for the Cauchy problem associated to the Schrodinger-Debye system for a class of data with infinite mass (L2-norm). A smallness condition on data is assumed. Our results include data such as singular-homogeneous functions ... More
On the Schrödinger equation with singular potentialsJul 25 2013We study the Cauchy problem for the non-linear Schr\"odinger equation with singular potentials. For point-mass potential and nonperiodic case, we prove existence and asymptotic stability of global solutions in weak-L^{p} spaces. Specific interest is give ... More
Global well-posedness and asymptotic behavior in Besov-Morrey spaces for chemotaxis-Navier-Stokes fluidsNov 07 2018Jun 17 2019In this work we consider the Keller-Segel system coupled with Navier-Stokes equations in $\mathbb{R}^{N}$ for $N\geq2$. We prove the global well-posedness with small initial data in Besov-Morrey spaces. Our initial data class extends previous ones found ... More
Global well-posedness and asymptotic behavior for Navier-Stokes-Coriolis equations in homogeneous Besov spacesNov 08 2017We are concerned with the $3$D-Navier-Stokes equations with Coriolis force. Existence and uniqueness of global solutions in homogeneous Besov spaces are obtained for large speed of rotation. In the critical case of the regularity, we consider a suitable ... More
Is it really possible to grow isotropic on-lattice diffusion-limited aggregates?Mar 08 2006In a recent paper (Bogoyavlenskiy V A 2002 \JPA \textbf{35} 2533), an algorithm aiming to generate isotropic clusters of the on-lattice diffusion-limited aggregation (DLA) model was proposed. The procedure consists of aggregation probabilities proportional ... More
Large scale magnetic fields in viscous resistive accretion disks. I. Ejection from weakly magnetized disksMar 23 2010Cold steady-state disk wind theory from near Keplerian accretion disks requires a large scale magnetic field at near equipartition strength. However the minimum magnetization has never been tested. We investigate the time evolution of an accretion disk ... More
Exactly Solvable Interacting Spin-Ice Vertex ModelAug 23 2006A special family of solvable five-vertex model is introduced on a square lattice. In addition to the usual nearest neighbor interactions, the vertices defining the model also interact alongone of the diagonals of the lattice. Such family of models includes ... More
Anomalous tag diffusion in the asymmetric exclusion model with particles of arbitrary sizesApr 03 2002Anomalous behavior of correlation functions of tagged particles are studied in generalizations of the one dimensional asymmetric exclusion problem. In these generalized models the range of the hard-core interactions are changed and the restriction of ... More
Existence and stability of global large strong solutions for the Hall-MHD systemDec 30 2014Apr 26 2015We consider the 3D incompressible Hall-MHD system and prove a stability theorem for global large solutions under a suitable integrable hypothesis in which one of the parcels is linked to the Hall term. As a byproduct, a class of global strong solutions ... More
Renormalizability of Nonrenormalizable Field TheoriesDec 04 1998We give a simple and elegant proof of the Equivalence Theorem, stating that two field theories related by nonlinear field transformations have the same S matrix. We are thus able to identify a subclass of nonrenormalizable field theories which are actually ... More
Temporal Network Analysis of Literary TextsFeb 22 2016We study temporal networks of characters in literature focusing on "Alice's Adventures in Wonderland" (1865) by Lewis Carroll and the anonymous "La Chanson de Roland" (around 1100). The former, one of the most influential pieces of nonsense literature ... More
Effects of local population structure in a reaction-diffusion model of a contact process on metapopulation networksMay 21 2013Nov 08 2013We investigate the effects of local population structure in reaction-diffusion processes representing a contact process (CP) on metapopulations represented as complex networks. Considering a model in which the nodes of a large scale network represent ... More
Effects of a kinetic barrier on limited-mobility interface growth modelsFeb 08 2019Feb 13 2019The role played by a kinetic barrier originated by out-of-plane step edge diffusion, introduced in [Leal \textit{et al.}, \href{https://doi.org/10.1088/0953-8984/23/29/292201}{J. Phys. Condens. Matter \textbf{23}, 292201 (2011)}], is investigated in the ... More
Quasi-stationary simulations of the directed percolation universality class in d = 3 dimensionsJan 05 2011Jan 07 2011We present quasi-stationary simulations of three-dimensional models with a single absorbing configuration, namely the contact process (CP), the susceptible-infected-susceptible (SIS) model and the contact replication process (CRP). The moment ratios of ... More
Phase transitions with infinitely many absorbing states in complex networksSep 28 2012Feb 08 2013We instigate the properties of the threshold contact process (TCP), a process showing an absorbing-state phase transition with infinitely many absorbing states, on random complex networks. The finite size scaling exponents characterizing the transition ... More
Collective versus hub activation of epidemic phases on networksDec 01 2015Feb 19 2016We consider a general criterion to discern the nature of the threshold in epidemic models on scale-free (SF) networks. Comparing the epidemic lifespan of the nodes with largest degrees with the infection time between them, we propose a general dual scenario, ... More
Effects of a kinetic barrier on limited-mobility interface growth modelsFeb 08 2019The role played by a kinetic barrier originated by out-of-plane step edge diffusion, introduced in [Leal \textit{et al.}, \href{https://doi.org/10.1088/0953-8984/23/29/292201}{J. Phys. Condens. Matter \textbf{23}, 292201 (2011)}], is investigated in the ... More
Continuous and discontinuous absorbing-state phase transitions on Voronoi-Delaunay random latticesSep 17 2015Dec 18 2015We study absorbing-state phase transitions in two-dimensional Voronoi-Delaunay (VD) random lattices with quenched coordination disorder. Quenched randomness usually changes the criticality and destroys discontinuous transitions in low-dimensional nonequilibrium ... More
Epidemic thresholds of the Susceptible-Infected-Susceptible model on networks: A comparison of numerical and theoretical resultsJun 28 2012Oct 16 2012Recent work has shown that different theoretical approaches to the dynamics of the Susceptible-Infected-Susceptible (SIS) model for epidemics lead to qualitatively different estimates for the position of the epidemic threshold in networks. Here we present ... More
Effects of a kinetic barrier on limited-mobility interface growth modelsFeb 08 2019Mar 27 2019The role played by a kinetic barrier originated by out-of-plane step edge diffusion, introduced in [Leal \textit{et al.}, \href{https://doi.org/10.1088/0953-8984/23/29/292201}{J. Phys. Condens. Matter \textbf{23}, 292201 (2011)}], is investigated in the ... More
Sampling methods for the quasistationary regime of epidemic processes on regular and complex networksMay 31 2016Oct 14 2016A major hurdle in the simulation of the steady state of epidemic processes is that the system will unavoidably visit an absorbing, disease-free state at sufficiently long times due to the finite size of the networks where epidemics evolves. In the present ... More
Existence and symmetry for elliptic equations in R^n with arbitrary growth in the gradientJul 24 2013Feb 13 2014We study the semilinear elliptic equation $\Delta u + g(x,u,Du) = 0$ in $\R^n$. The nonlinearities $g$ can have arbitrary growth in $u$ and $Du$, including in particular the exponential behavior. No restriction is imposed on the behavior of $g(x,z,p)$ ... More
Global smoothness for a 1D supercritical transport model with nonlocal velocitySep 12 2018We are concerned with a nonlocal transport 1D-model with supercritical dissipation $\gamma\in(0,1)$ in which the velocity is coupled via the Hilbert transform. This model arises in fluid mechanics linked to vortex-sheet problems, and as a lower dimensional ... More
A mass-transportation approach to a one dimensional fluid mechanics model with nonlocal velocityOct 29 2011We consider a one dimensional transport model with nonlocal velocity given by the Hilbert transform and develop a global well-posedness theory of probability measure solutions. Both the viscous and non-viscous cases are analyzed. Both in original and ... More
Gradient flows of time-dependent functionals in metric spaces and applications for PDEsSep 14 2015We develop a gradient-flow theory for time-dependent functionals defined in abstract metric spaces. Global well-posedness and asymptotic behavior of solutions are provided. Conditions on functionals and metric spaces allow to consider the Wasserstein ... More
Anomalous scaling and super-roughness in the growth of CdTe polycrystalline filmsJan 06 2011CdTe films grown on glass substrates covered by fluorine doped tin oxide by Hot Wall Epitaxy (HWE) were studied through the interface dynamical scaling theory. Direct measures of the dynamical exponent revealed an intrinsically anomalous scaling characterized ... More
Quasi-stationary simulations of the contact process on quenched networksJul 01 2011Nov 17 2011We present high-accuracy quasi-stationary (QS) simulations of the contact process in quenched networks, built using the configuration model with both structural and natural cutoffs. The critical behavior is analyzed in the framework of the anomalous finite ... More
Addendum to "Anomalous scaling and super-roughness in the growth of CdTe polycrystalline films"Jan 10 2011The scaling of the growth of CdTe films on glass substrates was investigated by Mata \textit{et al.} [Phys. Rev. B \textbf{78}, 115305 (2008)]. Part of the analysis consisted of the estimation of the correlation length $\xi$ using the decay in the height-height ... More
Exact Exchange: a pathway for a Density Functional Theory of the Integer Quantum Hall EffectOct 13 2017It is shown here that the Exact Exchange (EE) formalism provides a natural and rigorous approach for a Density Functional Theory (DFT) of the Integer Quantum Hall Effect (IQHE). Application of a novel EE method to a quasi two-dimensional electron gas ... More
Curves orthogonal to a vector field in Euclidean spacesAug 07 2019A curve is rectifying if it lies on a moving hyperplane orthogonal to its curvature vector. In this work, we extend the main result of [B.-Y. Chen, Tamkang J. Math. $\mathbf{48}$ (2017) 209-214] to any space dimension: we prove that rectifying curves ... More
Strategies for Optimize Off-Lattice Aggregate SimulationsApr 13 2008We review some computer algorithms for the simulation of off-lattice clusters grown from a seed, with emphasis on the diffusion-limited aggregation, ballistic aggregation and Eden models. Only those methods which can be immediately extended to distinct ... More
Universal fluctuations in KPZ growth on one-dimensional flat substratesDec 09 2011We present a numerical study of the evolution of height distributions (HDs) obtained in interface growth models belonging to the Kardar-Parisi-Zhang (KPZ) universality class. The growth is done on an initially flat substrate. The HDs obtained for all ... More
Accretion funnels onto weakly magnetized young starsDec 18 2007Aims : We re-examine the conditions required to steadily deviate an accretion flow from a circumstellar disc into a magnetospheric funnel flow onto a slow rotating young forming star. Methods : New analytical constraints on the formation of accretion ... More
Inverse Magnetic Catalysis in hot quark matter within (P)NJL modelsApr 06 2015Apart from Magnetic Catalysis at low temperatures, recent LQCD studies have shown the opposite effect at temperatures near the transition region: instead of enhancing, the magnetic field suppresses the quark condensates (Inverse Magnetic Catalysis). In ... More
Kinetic modelling of epitaxial film growth with up- and downward step barriersAug 23 2011The formation of three-dimensional structures during the epitaxial growth of films is associated to the reflection of diffusing particles in descending terraces due to the presence of the so-called Ehrlich-Schwoebel (ES) barrier. We generalize this concept ... More
Cardinality of the Ellis semigroup on compact metric countable spacesNov 24 2016Let $E(X,f)$ be the Ellis semigroup of a dynamical system $(X,f)$ where $X$ is a compact metric space. We analyze the cardinality of $E(X,f)$ for a compact countable metric space $X$. A characterization when $E(X,f)$ and $E(X,f)^* = E(X,f) \setminus \{ ... More
Unconstrained steepest descent method for multicriteria optimization on Riemmanian manifoldsOct 29 2010In this paper we present a steepest descent method with Armijo's rule for multicriteria optimization in the Riemannian context. The well definedness of the sequence generated by the method is guaranteed. Under mild assumptions on the multicriteria function, ... More
An Existence Result for the Generalized Vector Equilibrium Problem on Hadamard ManifoldJun 19 2014Jun 28 2014A sufficient condition for the existence of a solution for generalized vector equilibrium problem (GVEP) on Hadamard manifold, by using a version of KKM lemma on this context, is presented in this paper. It is worth to point out that, in particular, existence ... More
A Global Energetic Model for Microquasars (GEMM): A rich and consistent disk+jet solutionOct 01 2008Based on a dynamical model describing how stationary, powerful and self-collimated jets are being launched from a magnetized disk, we build a consistent disk+jet microquasar picture. Our disk is a new type of disk solution called the Jet Emitting Disk ... More
Universal fluctuations in radial growth models belonging to the KPZ universality classSep 22 2011We investigate the radius distributions (RD) of surfaces obtained with large-scale simulations of radial clusters that belong to the KPZ universality class. For all investigated models, the RDs are given by the Tracy-Widom distribution of the Gaussian ... More
Effects of the mean free path and relaxation in a model for the aggregation of particles in superfluid mediaJan 05 2011In this paper, we study a two-dimensional model for the growth of molecular clusters in superfluid helium at low temperature. In the model, particles of diameter a follow random ballistic moves of length \delta = a-256a. Upon attachment on the cluster ... More
Improving the Redundancy of the Knuth Balancing Scheme for Packet Transmission SystemsNov 09 2017Nov 15 2017A simple scheme was proposed by Knuth to generate balanced codewords from a random binary in- formation sequence. However, this method presents a redundancy which is twice that of the full sets of bal- anced codewords, that is the minimal achievable redun- ... More
Isoperimetric problems of the calculus of variations with fractional derivativesMay 11 2011In this paper we study isoperimetric problems of the calculus of variations with left and right Riemann-Liouville fractional derivatives. Both situations when the lower bound of the variational integrals coincide and do not coincide with the lower bound ... More
Iteration-complexity of gradient, subgradient and proximal point methods on Riemannian manifoldsSep 15 2016This paper considers optimization problems on Riemannian manifolds and analyzes iteration-complexity for gradient and subgradient methods on manifolds with non-negative curvature. By using tools from the Riemannian convex analysis and exploring directly ... More
An approach without using Hardy inequality for the linear heat equation with singular potentialJul 24 2013The aim of this paper is to employ a strategy known from fluid dynamics in order to provide results for the linear heat equation $u_{t}-\Delta u-V(x)u=0$ in $\mathbb{R}^{n}$ with singular potentials. We show well-posedness of solutions, without using ... More
Self-similar solutions for active scalar equations in Fourier-Besov-Morrey spacesSep 20 2013Feb 13 2014We are concerned with a family of dissipative active scalar equation with velocity fields coupled via multiplier operators that can be of high-order. We consider sub-critical values for the fractional diffusion and prove global well-posedness of solutions ... More
On nonlinear Schrödinger equations with random potentials: existence and probabilistic propertiesApr 09 2013In this paper we are concerned with nonlinear Schr\"odinger equations with random potentials. Our class includes continuum and discrete potentials. Conditions on the potential $V_{\omega}$ are found for existence of solutions almost sure $\omega $. We ... More
Global well-posedness and symmetries for dissipative active scalar equations with positive-order couplingsMay 14 2013Jan 02 2014We consider a family of dissipative active scalar equations outside the $L^{2}$-space. This was introduced in [D. Chae, P. Constantin, J. Wu, to appear in IUMJ (2014)] and its velocity fields are coupled with the active scalar via a class of multiplier ... More
Besov-weak-Herz spaces and global solutions for Navier-Stokes equationsApr 24 2017We consider the incompressible Navier-stokes equations (NS) in $\mathbb{R}^{n}$ for $n\geq2$. Global well-posedness is proved in critical Besov-weak-Herz spaces (BWH-spaces) that consist in Besov spaces based on weak-Herz spaces. These spaces are larger ... More