Dana Bartosova: Lelek fan via the projective Fraïssé theory

Data: sexta-feira, 16 de maio de 2014, às 14h

Sala: 243-A

Palestrante: Dana Bartosova, IME-USP

Título: Lelek fan via the projective Fraïssé theory

Resumo: This is going to be part 1 of the series whose part 2 was presented last week. We describe a well-known continuum called the Lelek fan as a natural quotient of a projective Fraïssé limit of finite ordered trees.This model-theoretic approach allowed us to get new results about the Lelek fan and its group of homeomorphisms (e.g. the group of homeomorphisms has a dense conjugacy class). Some results are however purely topological, for instance simplicity of the group of homeomorphisms. At the end, we make the connection between the dynamics of the group of homeomoprhisms and the Gowers' Theorem, which will be the content of part 3. This is a joint work with Aleksandra Kwiatkowska.