Piotr Borodulin-Nadzieja: On P-measures in random model

Tuesday, October 26, 2021 17:00

Location: room 605, Mathematical Institute, University of Wroclaw

Speaker:
Piotr Borodulin-Nadzieja


Title: On P-measures in random model

Abstract: We consider compact spaces which can be embedded into a product of real lines so that the support of every element is of size \(<\kappa\); here \(\kappa\) is a fixed cardinal number. We discuss measure-theoretic properties of such spaces and related properties of Banach spaces of continuous functions.

Alberto Salguero Alarcón: A twisted sum of \(C(K)\)-spaces not isomorphic to any \(C(K)\)-space

Tuesday, October 19, 2021 17:00

Location: room 605, Mathematical Institute, University of Wroclaw

Speaker:
Alberto Salguero Alarcón (Universidad de Extremadura, Badajoz, Spain)


Title: A twisted sum of \(C(K)\)-spaces not isomorphic to any \(C(K)\)-space

Abstract: A twisted sum of two Banach spaces \(X\) and \(Y\) is another space \(Z\) containing \(Y\) as a closed subspace so that \(Z/Y=X\). In this talk we focus on twisted sums of spaces of continuous functions on compact spaces. It has been known for some time that a twisted sum of two \(C(K)\)-spaces does not need to be isomorphic to a \(C(K)\)-space. We will focus on one recent and singular construction which serves as an example: a twisted sum of \(c_0\) and \(c_0(\mathfrak c)\) which is not isomorphic to any \(C(K)\)-space. This is part of a joint work with Grzegorz Plebanek.

Aleksander Cieślak: Full-splitting Miller trees and Cohen reals

Tuesday, October 12, 2021 17:00

Location: Zoom.us: if you want to participate please contact organizers

Speaker:
Aleksander Cieślak

Title: Full-splitting Miller trees and Cohen reals

Abstract: We will investigate tree ideal \(fm_0\) related to certain widening of Miller trees. This - so called - full Miller trees consist in taking the entire omega on split nodes instead of just its infinite subset. We will investigate cardinal invariants of \(fm_0\) and its relation to meager sets.