# Piotr Borodulin-Nadzieja: Tunnels through topological spaces

Tuesday, April 17, 2018 17:15

Room: D1-215

Speaker:

Title: Tunnels through topological spaces

Abstract. I will show a ZFC example of a compact space (without isolated points) through which one cannot drill a tunnel. I will discuss when and when not $$\omega^*$$ has a tunnel.

# Piotr Borodulin-Nadzieja: Mathias forcings for slaloms

Tuesday, March 8, 2016 17:15

Room: D1-215

Speaker:

Title: Mathias forcings for slaloms

Abstract. We will show an example of a Boolean algebra which is not sigma-centered but sigma-n-linked. Moreover, it has property (*) of Fremlin. Such examples were known before. We will construct our algebra using Mathias forcing for something resembling the density filter.

# Piotr Borodulin-Nadzieja: Analytic P-ideals and Banach spaces

Tuesday, November 4, 2014 17:15

Room: D1-215

Speaker: