Arturo Antonio Martínez Celis Rodríguez
Arturo Antonio Martínez Celis Rodríguez: Some combinatorics related to the Michael space problem II
21/11/22 09:09
Tuesday, November 22, 2022 17:00
Location: room C11-3.11
Speaker: Arturo Antonio Martínez Celis Rodríguez
Title: Some combinatorics related to the Michael space problem II
Abstract: In this talk we will continue the construction of a Michael space from an ultrafilter. The main goal is to show that the existence of a selective ultrafilter (plus \(\varepsilon\ge 0\)) is enough to construct a Michael space. If the time allows it, we will show a model of ZFC without Michael ultrafilters.
Location: room C11-3.11
Speaker: Arturo Antonio Martínez Celis Rodríguez
Title: Some combinatorics related to the Michael space problem II
Abstract: In this talk we will continue the construction of a Michael space from an ultrafilter. The main goal is to show that the existence of a selective ultrafilter (plus \(\varepsilon\ge 0\)) is enough to construct a Michael space. If the time allows it, we will show a model of ZFC without Michael ultrafilters.
Arturo Antonio Martínez Celis Rodríguez: Rosenthal Families
10/03/21 15:24
Tuesday, March 16, 2021 17:00
Location: Zoom.us: if you want to participate please contact organizers
Speaker: Arturo Antonio Martínez Celis Rodríguez (University of Wroclaw)
Title: Rosenthal Families
Abstract: A collection of infinite subsets of the natural numbers is a Rosenthal family if it can replace the family of all infinite subsets in a classical Lemma by Rosenthal concerning sequences of measures on pairwise disjoint sets. In this talk we will show that every ultrafilter is a Rosenthal family and that the minimal size of a Rosenthal family is the reaping number. We will also try to show some connections to functional analysis.
Location: Zoom.us: if you want to participate please contact organizers
Speaker: Arturo Antonio Martínez Celis Rodríguez (University of Wroclaw)
Title: Rosenthal Families
Abstract: A collection of infinite subsets of the natural numbers is a Rosenthal family if it can replace the family of all infinite subsets in a classical Lemma by Rosenthal concerning sequences of measures on pairwise disjoint sets. In this talk we will show that every ultrafilter is a Rosenthal family and that the minimal size of a Rosenthal family is the reaping number. We will also try to show some connections to functional analysis.