PGMAT-UFAL PROGRAMA DE PÓS-GRADUAÇÃO EM MATEMÁTICA (PGMAT-UFAL) INSTITUTO DE MATEMÁTICA E ESTATÍSTICA Téléphone/Extension: (71) 98189-2295
Dissertation/Thèse

Clique aqui para acessar os arquivos diretamente da Biblioteca Digital de Teses e Dissertações da UFBA

2023
Thèses
1
  • AFONSO FERNANDES DA SILVA
  • Contributions To Phase Transition Of Intermittent Skew-Product And Piecewise Monotone Dynamics On The Circle

  • Leader : THIAGO BOMFIM SAO LUIZ NUNES
  • MEMBRES DE LA BANQUE :
  • THIAGO BOMFIM SAO LUIZ NUNES
  • VITOR DOMINGOS MARTINS DE ARAUJO
  • PAULO CESAR RODRIGUES PINTO VARANDAS
  • ANDERSON REIS DA CRUZ
  • RICARDO TUROLLA BORTOLOTTI
  • Data: 7 mars 2023


  • Afficher le Résumé
  • It is well known that all transitive uniformly expanding or hyperbolic dynamics have no phase transition with respect to H\"older continuous potentials. For more general dynamics, It is still an open question to classify all the dynamics having phase transition with respect to a certain class of regular potential. In dimension one, due to the work of Bomfim-Victor \cite{BC21}, it was proved that for all transitive $C^{1+\alpha}-$local diffeomorphism $f$ on the circle that is neither a uniformly expanding map nor invertible, has an unique thermodynamic phase transition with respect to the geometric potential, in other words, the topological pressure function $\R \ni t \mapsto P_{top}(f,-t\log|Df|)$ is analytic except in a point $t_{0} \in (0 , 1]$. Furthermore, they proved spectral phase transitions, more specific, the transfer operator $\Lo_{f,-t\log|Df|}$ acting on the space of H\"older continuous functions, has the spectral gap property for all $t<t_0$ and does not have the spectral gap property for all $t\geq t_0$. We aim to prove similar results for two special cases of dynamics: a co-dimension $1$ partially hyperbolic endomorphism and transitive piecewise monotone on the circle. For the higher dimension, endomorphisms, we prove that thermodynamic and spectral phase transition lead to multifractal analysis of the Lyapunov spectrum, in particular we exhibit a class of partially hyperbolic endomorphism having phase transition with respect to the geometric potential in the central direction and describe the multifractal analysis of the central Lyapunov spectrum. For transitive piecewise monotone maps, we prove that the set of Hölder continuous potentials which doesn't have spectral and thermodynamic phase transition is dense in the uniform topology and the set of Hölder continuous potentials that has phase transition are not dense. Furthermore, we provide a description of phase transition based on the properties of the transfer operator and the type of convexity of the topological pressure function. In particular, we describe the behavior of the topological pressure function and the transfer operator associated.

2
  • Paulo Cesar Cerqueira dos Santos Júnior
  • Virtual braid groups, virtual twin groups and crystallographic groups

  • Leader : OSCAR EDUARDO OCAMPO URIBE
  • MEMBRES DE LA BANQUE :
  • OSCAR EDUARDO OCAMPO URIBE
  • CAROLINA DE MIRANDA E PEREIRO
  • DACIBERG LIMA GONÇALVES
  • JOHN GUASCHI
  • DANIEL JUAN PINEDA
  • Data: 11 juil. 2023


  • Afficher le Résumé
  • Let $n\ge 2$. Let $VB_n$ (resp. $VP_n$) be the virtual braid group (resp. the pure virtual braid group), and let $VT_n$ (resp. $PVT_n$) be the virtual twin group (resp. the pure virtual twin group).
    Let $\Pi$ be one of the following quotients: $VB_n/\Gamma_2(VP_n)$ or $VT_n/\Gamma_2(PVT_n)$ where $\Gamma_2(H)$ is the commutator subgroup of $H$. In this thesis, we show that $\Pi$ is a crystallographic group and we characterize the elements of finite order and the conjugacy classes of elements in $\Pi$.
    Furthermore, we realize explicitly some Bieberbach groups and infinite virtually cyclic groups in $\Pi$.
    Finally, we also study other braid-like groups (welded, unrestricted, flat virtual, flat welded and Gauss virtual braid group) modulo the respective commutator subgroup in each case. Even more, we show that the groups $B_n(M)/\Gamma_k(P_n(M))$, where $M$ is the finitely punctured sphere, $VB_n/\Gamma_3(VP_n)$, $VT_n/\Gamma_k(PVT_n)$ and $UVB_n/\Gamma_k(UVP_n)$ are almost-crystallographic group.

2022
Thèses
1
  • VICTOR BORGES CARNEIRO
  • Thermodynamical and spectral phase transitions for local diffeomorphisms on the circle

  • Leader : THIAGO BOMFIM SAO LUIZ NUNES
  • MEMBRES DE LA BANQUE :
  • AUGUSTO ARMANDO DE CASTRO JUNIOR
  • DANIEL SMANIA BRANDAO
  • LEANDRO MARTINS CIOLETTI
  • PAULO CESAR RODRIGUES PINTO VARANDAS
  • THIAGO BOMFIM SAO LUIZ NUNES
  • Data: 23 mars 2022


  • Afficher le Résumé
  • It is known that all uniformly expanding dynamics have no phase transition with respect to H\"older continuous potentials. In this work we show that given a local diffeomorphism $f$ on the circle, that is neither a uniformly expanding dynamics nor invertible, the topological pressure function $\R \ni t \mapsto P_{top}(f,-t\log|Df|)$ is not analytical. In other words, $f$ has a thermodynamic phase transition with respect to geometric potential. Assuming that $f$ is transitive and that $Df$ is Hölder continuous, we show that there exists $t_0 \in (0,1]$ such that the transfer operator $\Lo_{f,-t\log|Df|}$ acting on the space of H\"older continuous functions, has the spectral gap property for all $t<t_0$ and has not the spectral gap property for all $t\geq t_0$. Similar results are also obtained when the transfer operator acts on the space of bounded variations functions and smooth functions. In particular, we show that in the transitive case $f$ has a unique thermodynamic phase transition and it occurs in $t_0$. In addition, if the loss of expansion of the dynamics occurs because of an indifferent fixed point or the dynamics admits an absolutely continuous invariant probability with positive Lyapunov exponent then $t_0=1$. As a consequence of thermodynamical and spectral phase transition, we obtain applications on multifractal analysis for the Lyapunov spectrum.

2
  • CARLOS ALBERTO DA SILVA NONATO
  • Recent advances in delay dissipative systems governed by partial differential equations

  • Leader : CARLOS ALBERTO RAPOSO DA CUNHA
  • MEMBRES DE LA BANQUE :
  • ANDERSON DE JESUS ARAÚJO RAMOS
  • CARLOS ALBERTO RAPOSO DA CUNHA
  • JOILSON OLIVEIRA RIBEIRO
  • KLEYBER MOTA DA CUNHA
  • SEBASTIÃO MARTINS SIQUEIRA CORDEIRO
  • Data: 24 nov. 2022


  • Afficher le Résumé
  • This work deals with the global existence of solution and the asymptotic behavior for three distinct models: The wave equation, swelling of porous elastic soils with a saturation of fluid, and the laminated beams model. For all models, is applied the semigroup theory to prove the global existence of the solution. In the analysis of the asymptotic behavior, are applied distinct technics. In the first two models cited above, is considered the action of weights and non-constants delay. The exponential decay is proved by using the multipliers method. For the laminated beams model, is take into account
    the action of viscoelastic damping and a strong time delay, two situations are observed: Exponential stability if the propagation speed of the waves is the same, otherwise, the polynomial decay with rate t^{1/2}.

3
  • PEDRO HENRIQUE MARTINS DE MORAIS
  • Gradings, graded polynominal identities and Specht Property for the Lie algebra of triangular superior matrices of order 2x2 in characteristic 2
  • Leader : MANUELA DA SILVA SOUZA
  • MEMBRES DE LA BANQUE :
  • MANUELA DA SILVA SOUZA
  • VIVIANE RIBEIRO TOMAZ DA SILVA
  • PLAMEN EMILOV KOCHLOUKOV
  • DIOGO DINIZ PEREIRA DA SILVA E SILVA
  • LUCIO CENTRONE
  • Data: 29 nov. 2022


  • Afficher le Résumé
  • In this paper, we present some recent results in PI-theory about gradings and graded polynomial
    identities for the algebra of triangular superior matrices of order 2 when it is defined as a Lie algebra.
    More precisely, fixed a field
    K of characteristic 2 (finite or infinite), we present a classification of the
    gradings on
    (UT2(K ),), the algebra of triangular superior matrices of order 2 over K endowed with
    the product defined by
    x y = x y + yx. We also show generators for the TG-ideals of these gradings
    as well give a positive answer to the Specht problem for the variety of Lie algebras generated by
    UT2(K ) for each of these gradings.

2021
Thèses
1
  • DIEGO DALTRO CONCEIÇÃO
  • Gibbs measures for suspension semiflows over C1+α piecewise expanding maps: the absence of the Federer property and their exponential decay of correlations

  • Leader : PAULO CESAR RODRIGUES PINTO VARANDAS
  • MEMBRES DE LA BANQUE :
  • CARLOS MATHEUS SILVA SANTOS
  • OLIVER BUTTERLEY
  • PAULO CESAR RODRIGUES PINTO VARANDAS
  • VILTON JEOVAN VIANA PINHEIRO
  • VITOR DOMINGOS MARTINS DE ARAUJO
  • Data: 25 mai 2021


  • Afficher le Résumé
  • We study the decay of correlations for Gibbs measures associated to codimension one Axiom A attractors for flows. We prove that a codimension one Axiom A attractors whose strong stable foliation is C1+α either have exponential decay of correlations with respect to all Gibbs measures associated to Holder continuous potentials or their stable and unstable bundles are jointly integrable. As a consequence, there exist C1-open sets of C3-vector fields generating Axiom A flows having attractors so that it mix exponentially with respect to equilibrium states associated with Holder continuous potentials.

2
  • ADRIANO PEDREIRA CATTAI
  • Existence of solution and asymptotic behavior of some dissipative models involving the monotono p-Laplacian operator

  • Leader : CARLOS ALBERTO RAPOSO DA CUNHA
  • MEMBRES DE LA BANQUE :
  • CARLOS ALBERTO RAPOSO DA CUNHA
  • JOILSON OLIVEIRA RIBEIRO
  • SEBASTIÃO MARTINS SIQUEIRA CORDEIRO
  • DUCIVAL CARVALHO PEREIRA
  • OCTAVIO PAULO VERA VILLAGRAN
  • HUY HOANG NGUYEN
  • Data: 11 déc. 2021


  • Afficher le Résumé
  • We study the existence of solution and the asymptotic behavior for four specific models: wave equation with memory; coupled system of wave equations; coupled system of wave equation with heat equation (thermo-elastic system) and thermo-elastic system with external source. We analyze these problems under the interference of the monotono p-Laplacian operator. Our approach presents the recent aspects in the treatment of these models, in the scope of Partial Differential Equations. In this sense, we highlight our thermo-elastic model with p-Laplacian, as far as we know, it was presented for the first time in the literature precisely in this thesis. For the existence of a solution weuse the Faedo-Galerkin Method. For the analysis of the asymptotic behavior we used different andrecent techniques: in the stability analysis, the Theorem of M. Nakao and H. Kuwahara (1987) was used, and also the Theorem of P. Martinez (1999), based on a new inequality that generalizes the previous results of A. Haraux (1985) and M. Nakao (1978); for the finite time “Blow-up” analysis weused the Lemma de Y. Qin and J. Rivera (2004).

2020
Thèses
1
  • FABRICIO ANTONIO OLIVEIRA DOS SANTOS
  • Contributions to the theory of coherence and compatibility

  • Leader : JOILSON OLIVEIRA RIBEIRO
  • MEMBRES DE LA BANQUE :
  • JOILSON OLIVEIRA RIBEIRO
  • VLADIMIR PESTOV
  • DANIEL MARINHO PELLEGRINO
  • GERALDO MARCIO DE AZEVEDO BOTELHO
  • JAMILSON RAMOS CAMPOS
  • Data: 6 mars 2020


  • Afficher le Résumé
  • In this work, we will present contributions to the coherence and compatibility theories already established in the literature, passing through the newly introduced sequence classes and generalizing them. We will also present an abstract approach to absolutely summing polynomials and to summing multiple multilinear applications, leading us to establish concepts that generalize the sequence classes. We have established a new concept of stricter coherence and compatibility by testing its limits on some ideal generator methods and presenting some of its properties.
     
    Finally, we present a new approach for newly introduced multipolinomials in order to allow us to establish a new concept for coherence and compatibility in the multipolinomial context.
2
  • FABÍOLA DE OLIVEIRA PEDREIRA
  • ON THE BEHAVIOUR OF THE SINGULAR VALUES OF EXPANDING LORENZ MAPS

  • Leader : VILTON JEOVAN VIANA PINHEIRO
  • MEMBRES DE LA BANQUE :
  • ALBERTO ADREGO PINTO
  • MANUEL STADLBAUER
  • MARIA JOSÉ PACÍFICO
  • PAULO CESAR RODRIGUES PINTO VARANDAS
  • VILTON JEOVAN VIANA PINHEIRO
  • Data: 2 juil. 2020


  • Afficher le Résumé
  • In this work we study one-dimensional expanding Lorenz maps f with the same singular point c. We show that if the orbits of singular values satisfy a condition of slow recurrence, then every ergodic invariant probability has slow recurrence to the singularity and it has finite Lyapunov exponent. Moreover, we show that generically the singular values do not belong to the basin of its SRB measure. Also, we show that singularity allows the existence of many ergodic invariant measures with full support, having positive entropy, fast recurrence to the singular region and infinite Lyapunov exponent. Furthermore, we consider a two-parameter standard family of these maps and prove that there is a cone in the parameter space, in which we find sets of points on the curves, which has positive Hausdorff dimension, so that the maps associated to these points have finite Lyapunov exponent for every ergodic invariant probability, and there is one and only one equilibrium state for a given H¨older potential.
    Keywords: Expanding Lorenz, Lyapunov exponent, slow recurrence, two-parameter
    family, Hausdorff dimension.

3
  • FABÍOLA DE OLIVEIRA PEDREIRA
  • ON THE BEHAVIOUR OF THE SINGULAR VALUES OF EXPANDING LORENZ MAPS

  • Leader : VILTON JEOVAN VIANA PINHEIRO
  • MEMBRES DE LA BANQUE :
  • VILTON JEOVAN VIANA PINHEIRO
  • PAULO CESAR RODRIGUES PINTO VARANDAS
  • ALBERTO ADREGO PINTO
  • MANUEL STADLBAUER
  • MARIA JOSÉ PACÍFICO
  • Data: 2 juil. 2020


  • Afficher le Résumé
  • In this work we study one-dimensional expanding Lorenz maps f with the same singular point c. We show that if the orbits of singular values satisfy a condition of slow recurrence, then every ergodic invariant probability has slow recurrence to the singularity and it has finite Lyapunov exponent. Moreover, we show that generically the singular values do not belong to the basin of its SRB measure. Also, we show that singularity allows the existence of many ergodic invariant measures with full support, having positive entropy, fast recurrence to the singular region and infinite Lyapunov exponent. Furthermore, we consider a two-parameter standard family of these maps and prove that there is a cone in the parameter space, in which we find sets of points on the curves, which has positive Hausdorff dimension, so that the maps associated to these points have finite Lyapunov exponent for every ergodic invariant probability, and there is one and only one equilibrium state for a given H¨older potential.
    Keywords: Expanding Lorenz, Lyapunov exponent, slow recurrence, two-parameter
    family, Hausdorff dimension.

4
  • DIOGO SOARES DOREA DA SILVA
  • The Slow Bond Random Walk and the Snapping Out Brownian Motion

  • Leader : TERTULIANO FRANCO SANTOS FRANCO
  • MEMBRES DE LA BANQUE :
  • TERTULIANO FRANCO SANTOS FRANCO
  • DIRK ERHARD
  • VITOR DOMINGOS MARTINS DE ARAUJO
  • MARCELO RICHARD HILÁRIO
  • RENATO SOARES DOS SANTOS
  • Data: 31 juil. 2020


  • Afficher le Résumé
  • We consider the continuous time symmetric random walk with a slow bond on Z, which rates are equal to 1/2 for all bonds, except for the bond of vertices {−1, 0}, which associated rate is given by αn −β /2, where α > 0 and β ∈ [0, ∞] are the parameters of the model. We prove here a functional central limit theorem for the random walk with a slow bond: if β ∈ [0, 1), then it converges to the usual Brownian motion. If β ∈ (1, ∞], then it converges to the reflected Brownian motion. And at the critical value β = 1, it converges to the snapping out Brownian motion (SNOB) of parameter κ = 2α, which is a Brownian type-process recently constructed in 2016 by A. Lejay. We also provide Berry-Esseen estimates in the dual bounded Lipschitz metric for the weak convergence of one-dimensional distributions, which we believe to be sharp.

5
  • EDVAN SANTOS DA TRINDADE
  • Robust Exponential Mixing and Convergence to Equilibrium for Singular Hyperbolic Attracting Sets.

  • Leader : VITOR DOMINGOS MARTINS DE ARAUJO
  • MEMBRES DE LA BANQUE :
  • AUGUSTO ARMANDO DE CASTRO JUNIOR
  • DANIEL SMANIA BRANDAO
  • PAULO CESAR RODRIGUES PINTO VARANDAS
  • VITOR DOMINGOS MARTINS DE ARAUJO
  • YURI GOMES LIMA
  • Data: 30 nov. 2020


  • Afficher le Résumé
  • We extend results on robust exponential mixing for geometric Lorenz attractors,
    with a dense orbita and a unique singularity, to singular-hyperbolic attracting sets with
    any number of (either Lorenz- or non-Lorenz-like) singularities and finitely many ergodic
    physical/SRB invariant probability measures, whose basins cover a full Lebesgue measure
    subset of the trapping region of the attracting set.
    We obtain exponential mixing for any physical probability measure supported in
    the trapping region and also exponential convergence to equilibrium, for a C 2 open subset
    of vector fields in any d-dimensional compact manifold (d ≥ 3).

2019
Thèses
1
  • MARIANA TAVARES DE AGUIAR
  • SCALING LIMITS FOR SLOWED EXCLUSION PROCESS

  • Leader : TERTULIANO FRANCO SANTOS FRANCO
  • MEMBRES DE LA BANQUE :
  • CLAUDIO LANDIM
  • DIRK ERHARD
  • MILTON DAVID JARA VALENZUELA
  • PAULO CESAR RODRIGUES PINTO VARANDAS
  • TERTULIANO FRANCO SANTOS FRANCO
  • Data: 28 janv. 2019


  • Afficher le Résumé
  • The aim of the present study was to study the following problems: Hydrodynamic Limit for SSEP with a slow membrane and Out of Balance Fluctuations for SSEP with a slow link. More precisely, the hydrodynamic boundary study model is the symmetric simple exclusion process (SSEP) in the d-dimensional torus, which has a membrane whose passage rate $? / (N ^?) $, $? > 0 $, is lower than the rate in other links. Due to the existence of this slow membrane, depending on the regimen of the parameter that regulates the slowness of this membrane, border conditions appear at macroscopic level. For $ \ beta \ in [0, 1) $, the hydrodynamic equation is given by the heat equation in the continuous torus, meaning that the slow membrane has no effect on the boundary. For $ \ in \ (1, \ infty) $, the hydrodynamic equation is given by the heat equation with Neumann edge conditions, meaning that the membrane divides the torus into two isolated regions. And, for the critical value $ \ beta = 1 $, the hydrodynamic equation is given by the heat equation with Robin boundary conditions, related to Fick's law. In the case of Fluctuations, the model under study is the one-dimensional SSEP that has a slow link. The great difficulty in the work of the Fluctuations was to obtain accurate estimates of transition probabilities of random walks of dimensions 1 and 2.
2
  • ADRIANA COUTINHO DOS SANTOS
  • Asymptotic probabilistic properties of orbits: return times and shortest distance

  • Leader : JEROME FRANCOIS ALAIN JEAN ROUSSEAU
  • MEMBRES DE LA BANQUE :
  • BENOIT SAUSSOL
  • JEROME FRANCOIS ALAIN JEAN ROUSSEAU
  • MIGUEL NATALIO ABADI
  • PAULO CESAR RODRIGUES PINTO VARANDAS
  • RODRIGO LAMBERT
  • Data: 15 févr. 2019


  • Afficher le Résumé
  • This work provides some original contributions to the study of large deviation for return times and the asymptotic behavior of the shortest distance between observed orbits. In the first part, we prove a large deviation result for return time of the orbits of a dynamical system in a r-neighbourhood of an initial point x. Our first result may be seen as a differentiable version of the work by Jain and Bansal, who considered the return time of a stationary and ergodic process defined in the space of infinite sequences. We obtain large deviation estimates for dynamical systems in general and in the case of conformal repellers we compute the rate functions in terms of HP-spectrum for dimensions of multifractal analysis. In the second part of this work, we investigate the shortest distance between two observed orbits and its asymptotic behavior. The main result is a strong law of large numbers for a re-scaled version of this quantity, which presents an explicit relation with the correlation dimension of the pushforward measure. We apply this result to study the shortest distance between orbits of a random dynamical system. In the symbolic case, this problem corresponds to the longest common substring problem for encoded sequences and its limiting relationship with the R´enyi entropy. We apply this results to the zero-inflated contamination model and to the stochastic scrabble.

3
  • GERALDO DE ASSIS JUNIOR
  • ON MINIMALITY OF THE SYMMETRICAL AND STANDARD POLYNOMONES IN ALGEBRAS VERBALLY PRIMAS.
  • Leader : THIERRY CORREA PETIT LOBAO
  • MEMBRES DE LA BANQUE :
  • FERNANDA GONÇALVES DE PAULA
  • KARINA KFOURI SARTORI
  • MANUELA DA SILVA SOUZA
  • SÉRGIO MOTA ALVES
  • THIERRY CORREA PETIT LOBAO
  • Data: 4 avr. 2019


  • Afficher le Résumé
  • The present work brings as an object of study the minimality of the degree of symmetric and standard polynomials in verbal raw algebras. That said, we determine the minimal degree of the symmetric polynomial that makes it a polynomial identity for the algebras M_n (E), M_ (a, b) (E), and A_ (a, b) (E). For the standard polynomial, we determine its minimal degree in the ideal T-algebra M_ (n, n) (E) and set altitudes for the algebras M_n (E), M_ (a, b) (E), and A_ (a, b) (E) advanced the results of papers already published (ALVES; SARTORI, 2015, 2017; ALVES; ASSIS, 2017). We also study the minimal degree of the symmetric and standard polynomials in the tensor power of Grassmann's algebra E ^ (⊗ ^ n) = E ⊗ ⋯ ⊗E (n factors), generalizing a result of Gaimbruno and Koshlukov (2001). Then, the minimal degree of the symmetric polynomial in the ideal T-T of E ^ (⊗ ^ n) and the minimal degree of the standard polynomial in the ideal T of E ^ (⊗ ^ 2n) were determined, and finally we determined the degrees minimal of the standard polynomial so that it belongs to the ideal T of E ^ (⊗ ^ (2n + 1)).


4
  • ELEN DEISE ASSIS BARBOSA
  • The Isomorphism Problem (Iso) consists of verifying whether two groups will be isomorphic whenever their group rings are. This issue has been
    studied considering integral group rings since the works of Higman, in 1940, when it was conjectured if Z≃ ZH, then ≃ H.  The search for classes of groups that satisfy such problem is intense.
     
    In this work, we show the validity of (Iso) for groups classes given by the wreath product of a $p$-group by a nilpotent group and we generalize this result ensuring
    the validity of (Iso) for the group class given by the wreath product of nilpotent groups.
  • Leader : THIERRY CORREA PETIT LOBAO
  • MEMBRES DE LA BANQUE :
  • CARMELA SICA
  • KISNNEY EMILIANO DE ALMEIDA
  • PAULA MURGEL VELOSO
  • Rodrigo Lucas Rodrigues
  • THIERRY CORREA PETIT LOBAO
  • Data: 5 avr. 2019


  • Afficher le Résumé
  • The Isomorphism Problem (Iso) consists of verifying whether two groups will be isomorphic whenever their group rings are. This issue has been
    studied considering integral group rings since the works of Higman, in 1940, when it was conjectured if Z≃ ZH, then ≃ H.  The search for classes of groups that satisfy such problem is intense.
     
    In this work, we show the validity of (Iso) for groups classes given by the wreath product of a $p$-group by a nilpotent group and we generalize this result ensuring
    the validity of (Iso) for the group class given by the wreath product of nilpotent groups.
5
  • VINICIUS COELHO DOS SANTOS
  • Some topics about singular hyperbolicity and invariant measures

  • Leader : LUCIANA SILVA SALGADO
  • MEMBRES DE LA BANQUE :
  • LUCIANA SILVA SALGADO
  • VILTON JEOVAN VIANA PINHEIRO
  • VITOR DOMINGOS MARTINS DE ARAUJO
  • FELIPE FONSECA DOS SANTOS
  • MANUEL STADLBAUER
  • Data: 18 avr. 2019


  • Afficher le Résumé
  • We showed the existence of singular adapted metrics for any  codimension one singular hyperbolic set  with respect to a $C^1 vector field on finite dimensional compact manifolds without using quadradic forms. Looking at the measures of a system,  we  provided a Kingman-like Theorem for an arbitrary finite measure  assuming some conditions in any metric space, and we give necessary conditions to guarantee  the existence of invariant measures in locally compact and separable metric spaces for continuous proper maps. Moreover, we use the Perron-Frobenius operator and the techniques developed here to obtain other criteria to guarantee  the existence of invariant measures for continuous maps (not necessarily a proper maps) in  locally compact separable metric spaces. 
6
  • JUNILSON CERQUEIRA DA SILVA
  • Komuro-expansiveness for sectional-hyperbolic attracting sets

  • Leader : VITOR DOMINGOS MARTINS DE ARAUJO
  • MEMBRES DE LA BANQUE :
  • VITOR DOMINGOS MARTINS DE ARAUJO
  • VILTON JEOVAN VIANA PINHEIRO
  • AUGUSTO ARMANDO DE CASTRO JUNIOR
  • LUCIANA SILVA SALGADO
  • FELIPE FONSECA DOS SANTOS
  • Data: 6 juin 2019


  • Afficher le Résumé
  • In this work we prove the expansiveness according to Komuro for hyperbolic-sectional measures for a variety of dimension d ≥ 3. For this we present two results, the first is restricted to the case in that d_cu = 2, that is, the center-unstable subfibre of the sink has dimensions are 2 and the second is for the case d_cu> 2. In the latter case we will see that it is necessary to assume that the sink is 1-strongly dissipative. However, Poincaré, our main tool for study of expansivity, and we used stable foliation throughout the region trap containing the sink to analyze expansion of distances. We also present some consequences of these results.


7
  • ELAINE FERREIRA ROCHA
  • Extension of Kesten's criterion on amenity for extensions by Gibbs-Markov application graph

  • Leader : AUGUSTO ARMANDO DE CASTRO JUNIOR
  • MEMBRES DE LA BANQUE :
  • ALBERT MEADS FISHER
  • MANUEL STADLBAUER
  • TERTULIANO FRANCO SANTOS FRANCO
  • VILTON JEOVAN VIANA PINHEIRO
  • VITOR DOMINGOS MARTINS DE ARAUJO
  • Data: 24 sept. 2019


  • Afficher le Résumé
  • This paper provides some original contributions to the study of the relationships between graph amenity and Dynamic Systems. In the first main result of the work, we characterize graph amenity through the extension by graph of a complete Markov application, inspired by the works of Stadlbauer and Jaerisch for extension by group. We saw that under soft hypotheses, the graph is mild if, and only if, the spectral radius of the Transfer operator associated with graph extension is equal to 1. In addition, we have defined graph extension of Markov applications with embedded Gibbs Markov structure and non-uniformly expandable applications, and we show the graph amenity characterization through graph extension for these classes of dynamic systems. We conclude with two non-trivial applications. First, we show that Schreier's graph is mild, if the decay rate of the graph extension of a Markov application with embedded Gibbs-Markov structure is equal to 1, while in the other application, we consider an extension of a complete Markov application by a semigroup. In this scenario, the amenity of the semigroup is equivalent to the spectral radius of the Transfer operator equal to 1.

8
  • SARA RUTH PIRES BISPO
  • Martin's frontier of an extension by a hyperbolic group
  • Leader : AUGUSTO ARMANDO DE CASTRO JUNIOR
  • MEMBRES DE LA BANQUE :
  • LEANDRO MARTINS CIOLETTI
  • MANUEL STADLBAUER
  • TERTULIANO FRANCO SANTOS FRANCO
  • VILTON JEOVAN VIANA PINHEIRO
  • VITOR DOMINGOS MARTINS DE ARAUJO
  • Data: 12 nov. 2019


  • Afficher le Résumé

  • Ancona-Gouëzel uniform inequalities established for random walk in hyperbolic groups were extended to extension by hyperbolic group. As application, we obtained the identification of the minimum conforming measures with the visual border of the hyperbolic group. In the first main result of the work, these inequalities were established. For this purpose, it was necessary to generalize Green's functions to the extensions by hyperbolic groups, through Green's family of operators. As an application, a Hölder function was obtained from the visual boundary to the Martin boundary. In order to obtain an analogous function in the reverse direction, proving that both boundaries are homeomorph bi-Hölder, a family of conforming and minimal measures was defined. Martin's border has been shown to coincide with this set of measures.

2018
Thèses
1
  • HEIDES LIMA DE SANTANA
  • On rotation sets of homeomorphisms and flows on tori

  • Leader : PAULO CESAR RODRIGUES PINTO VARANDAS
  • MEMBRES DE LA BANQUE :
  • PAULO CESAR RODRIGUES PINTO VARANDAS
  • THIAGO BOMFIM SAO LUIZ NUNES
  • CRISTINA LIZANA ARANEDA
  • RODRIGO LAMBERT
  • WESCLEY BONOMO
  • Data: 17 déc. 2018


  • Afficher le Résumé
  • We study the rotation sets for homeomorphisms homotopic to the identity on the torus T d , d ≥ 2. In the conservative setting, we prove that there exists a Baire residual subset of the set Homeo0,λ(T 2 ) of conservative homeomorphisms homotopic to the identity so that the set of points with wild pointwise rotation set is a Baire residual subset in T 2 , and that it carries full topological pressure and full metric mean dimension. Moreover, we prove that, for every d ≥ 2, the rotation set of C 0 -generic conservative homeomorphisms on T d is convex. Related results are obtained in the case of dissipative homeomorphisms on tori. The previous results rely on the description of the topological complexity of the set of points with wild historic behavior and on the denseness of periodic measures for continuous maps with the gluing orbit property (on chain recurrent classes).

2
  • JACQUELINE COSTA CINTRA
  • The Normalizer Property in Edge Extensions of Nilpotent Groups.
  • Leader : THIERRY CORREA PETIT LOBAO
  • MEMBRES DE LA BANQUE :
  • CARMELA SICA
  • GEORG WILHELM KLEIN
  • OSCAR EDUARDO OCAMPO URIBE
  • Rodrigo Lucas Rodrigues
  • THIERRY CORREA PETIT LOBAO
  • Data: 21 déc. 2018


  • Afficher le Résumé
  • The determination of the normalizer of the group generating a group ring in its group of units is a matter that is naturally imposed. In integral group rings, in particular, it was observed that, for important classes of finite groups, this normalizer is minimal, that is, N_U (G) = G. Z (U (ZG)). When this occurs, the group in question and its integral group ring are said to satisfy the Normalizer Property. also known as (Nor). In this thesis, we use the structure of the automorphism group of an edge product and techniques developed for such actions to show, in an equivalent way, the validity of (Nor) for certain bounded extensions involving nilpotent groups.
SIGAA | STI/SUPAC - - | Copyright © 2006-2024 - UFBA