Jonathan Cancino: On nwd-MAD families

Tuesday, April 18, 2023 17:00

Location: room A.4.1 C-19

Speaker:
Jonathan Cancino (Czech Academy of Sciences)

Title: On nwd-MAD families

Abstract: The cardinal invariant a(nwd) is defined as the minimal cardinality of an uncountable maximal antichain of the power set of the rational modulo the nowhere dense ideal. This cardinal invariant was introduced by J. Steprans, and he proved that in the Laver's model it is \(\omega_1\), and the pseudointersection number p is a lower bound for it. In this talk we will prove some related results, for example, the additivity of the meager ideal is a lower bound for a(nwd), thus improving Steprans theorem, as well as some facts about the structure of nwd-MAD families.