Seminars

Seminar series

DYNAMICAL SYSTEMS Seminar

Informal/working seminar of the Lisbon dynamical systems group.
Suggestions to speakers:

  • well-organized lectures with many pictures are always appreciated
  • also detailed and simple examples
  • encourage naive questions
  • allow occasional access to blackboard
  • break after one hour, followed by no-time-constrained discussion

Organized by Pedro Duarte.

Past seminars Signup mailing list Usual time: Wed 15h Usual room: Sala Delta, ISEG

Upcoming seminars


Wednesday, May 25, 2022, 14h. Online seminar.

Location: TBA. Poster Email
Some more questions and remarks about $SL(2,R)$-cocycles.
Paulo Varandas (CMUP-Universidade do Porto, Universidade Federal da Bahia).
Abstract: Linear dynamical systems in finite dimension are well understood, and their stability relies on the eigenvalues of a representation matrix. This allows to describe some properties (e.g. hyperbolicity or ellipticity) of matrices $A$ in the space $SL(2, R)$ in terms of their eigenvalues. The situation becomes immediately non-trivial when one considers random products of two matrices $A,B$ in $SL(2, R)$, which determine a linear cocycle over the shift. In the paper “Some questions and remarks about $SL(2,R)$-cocycles”, J.-C. Yoccoz initiated the study of the hyperbolicity and ellipticity locus for such cocycles. In this talk I will recall some results by Yoccoz and subsequent work, and show how the a good understanding of the space of linear cocycle impacts in other problems, including a characterization of the space of cocycles whose Lyapunov exponents are everywhere well defined. Join via https://videoconf-colibri.zoom.us/j/96003557028
toni v.1 MMXV