January 2021
Marton Elekes: Games, their values, and Baire class 1 functions
28/01/21 11:27
Tuesday, Fabruary 2, 2021 17:00
Location: Zoom.us: if you want to participate please contact organizers
Speaker: Marton Elekes (Alfred Renyi Institute)
Title: Games, their values, and Baire class 1 functions
Abstract: We consider interesting descriptive set-theoretic problems emerging from theoretical economics. First, we investigate a certain two-player game coming from gambling theory. Then, as a by-product, we obtain a novel game that characterizes the Baire class 1 functions. Finally, we determine the exact complexity of the so-called value of the above game, which turns out to be a less well-known class, namely analytic-inductive.
Location: Zoom.us: if you want to participate please contact organizers
Speaker: Marton Elekes (Alfred Renyi Institute)
Title: Games, their values, and Baire class 1 functions
Abstract: We consider interesting descriptive set-theoretic problems emerging from theoretical economics. First, we investigate a certain two-player game coming from gambling theory. Then, as a by-product, we obtain a novel game that characterizes the Baire class 1 functions. Finally, we determine the exact complexity of the so-called value of the above game, which turns out to be a less well-known class, namely analytic-inductive.
Grzegorz Plebanek: A connected version of Kunen's compact L-space
20/01/21 16:57
Tuesday, January 26, 2021 17:00
Location: Zoom.us: if you want to participate please contact organizers
Speaker: Grzegorz Plebanek
Title: A connected version of Kunen's compact L-space
Abstract: Modifying Kunen's construction from 1981, we show that under CH there is a compact connected space K that carries a regular normal probability measure (normal = `all Borel sets with empty interior have measure zero'). Then we show that the Banach space C(K) of continuous functions is isomorphic to no space of the form C(L) with L compact and zero-dimensional.
Location: Zoom.us: if you want to participate please contact organizers
Speaker: Grzegorz Plebanek
Title: A connected version of Kunen's compact L-space
Abstract: Modifying Kunen's construction from 1981, we show that under CH there is a compact connected space K that carries a regular normal probability measure (normal = `all Borel sets with empty interior have measure zero'). Then we show that the Banach space C(K) of continuous functions is isomorphic to no space of the form C(L) with L compact and zero-dimensional.
Michael Hrusak: Invariant Ideal Axiom
12/01/21 10:08
Tuesday, January 19, 2021 17:00
Location: Zoom.us: if you want to participate please contact organizers
Speaker: Michael Hrusak (National Autonomous University of Mexico)
Title: Invariant Ideal Axiom
Abstract: We shall introduce a consistent set-theoretic axiom IIA which has a profound impact on convergence properties in topological groups. As an application we show that consistently (consequence of IIA) every countable sequential group is either metrizable or \(k_\omega\).
Location: Zoom.us: if you want to participate please contact organizers
Speaker: Michael Hrusak (National Autonomous University of Mexico)
Title: Invariant Ideal Axiom
Abstract: We shall introduce a consistent set-theoretic axiom IIA which has a profound impact on convergence properties in topological groups. As an application we show that consistently (consequence of IIA) every countable sequential group is either metrizable or \(k_\omega\).