PALESTRA: On the denseness of finitude of sinks
Resumo: In 1995, Jacob Palis stated an ambitious conjecture on denseness of finitude of attractors for diffeomorphisms in arbitrary dimensions. Before that, Newhouse proved the existence of residual sets of surface diffeomorphisms (in certain nonempty open sets) in the C² topology displaying infinitely many sinks (hyperbolic periodic attractors), and Bonatti and Diaz did the same in the C¹ topology in higher dimensions. We will discuss the problem of proving the denseness (in the C¹ topology) of diffeomorphisms (in arbitrary dimensions) displaying only a finite number of sinks. This is a joint work with Fernando Lenarduzzi and Jacob Palis.
PALESTRA: Uniqueness of u-Gibbs measures for hyperbolic skew products
Resumo: Studying the ergodic and topological properties of the invariant foliations of partially hyperbolic diffeomorphism is useful to understand its dynamical properties, such as transitivity, statistical behavior, ergodicity etc. We study the strong unstable foliation of a certain class of uniformly hyperbolic skew products on T4. These systems have a strong unstable and a weak unstable directions. We show that Cr-dense and C2-open in this set every u-Gibbs measure is SRB, in particular, there is only one such measure. As an application of this, we can obtain the minimality of the strong unstable foliation. This is a joint work with Sylvain Crovisier and Davi Obata.
PALESTRA: Positividade da dimensão de Hausdorff de espectros de Markov e Lagrange dinâmicos genéricos
Resumo: Os espectros de Markov e Lagrange dinâmicos são subconjuntos de números reais que descrevem o comportamento assintótico das órbitas de um sistema com respeito a um potencial. Motivados por versões clássicas desses espectros, que têm origens relacionadas a problemas de teoria dos números, tais conjuntos podem ajudar a entender o comportamento a longo prazo das órbitas de sistemas genéricos. Nesta palestra discutiremos sobre a positividade da dimensão de Hausdorff destes espectros para dinâmicas genéricas possuindo interseção homoclínica transversal em variedades compactas com dimensões maiores ou igual a 2.
PALESTRA: Polynomial decay of correlations of geodesic flows on some nonpositively curved surfaces
Resumo: In a joint work with Carlos Matheus and Ian Melbourne, we consider a class of nonpositively curved surfaces and show that their geodesic flows have polynomial decay of correlations.
Horário:
Sandoel Vieira: 14:30 - 15:15
Mauricio Poletti: 15:30 - 16:15
Yuri Lima: 16:45 - 17:30
Carlos Gustavo Moreira: 17:45 - 18:30