Ana Rechtman

  1. The Weinstein conjecture in the presence of submanifolds having a Legendrian foliation.

    Authors: Ana Rechtman, Klaus Niederkrüger
    Subjects: Dynamical Systems
    Abstract

    Helmut Hofer introduced in '93 a novel technique based on holomorphic curves
    to prove the Weinstein conjecture. Among the cases where these methods apply
    are all contact 3--manifolds $(M,\xi)$ with $\pi_2(M) \ne 0$. We modify Hofer's
    argument to prove the Weinstein conjecture for some examples of higher
    dimensional contact manifolds. In particular, we are able to show that the
    connected sum with a real projective space always has a closed contractible
    Reeb orbit.

  2. Minimal F{\o}lner foliations are amenable.

    Authors: Fernando Alcalde Cuesta, Ana Rechtman
    Subjects: Dynamical Systems
    Abstract

    For finitely generated groups, amenability and F{\o}lner properties are
    equivalent. However, contrary to a widespread idea, Kaimanovich showed that F\o
    lner condition does not imply amenability for discrete measured equivalence
    relations. He also gave an example of a $C^\infty$ foliation that is F{\o}lner
    and non-amenable with respect to a non-finite transverse invariant measure. In
    this paper, we exhibit two examples of $C^\infty$ foliations of closed
    manifolds satisfying the same properties with respect to a finite transverse
    invariant measure and a transverse invariant volume.

Syndicate content