Poincaré's recurrence theorem is a fundamental result, but only of qualitative nature. This drawback was partly surpassed with the ergodic theorem that however only considers one quantitative aspect of recurrence. More recently, there has been a growing interest in the area, starting with the works of Boshernitzan, Ornstein and Weiss. I will present sharp descriptions of quantitative recurrence and in particular the curious coincidence of the recurrence rate with the pointwise dimension.
Speaker:
Luis Barreira (Instituto Superior Técnico)