Organizers

prof. dr hab. Witold Marciszewski
prof. dr hab. Piotr Zakrzewski

Information

Wednesdays, 4:15 p.m. , room: 5050

Research fields

Topology and Set Theory

List of talks

Dec. 7, 2016, 4:15 p.m.
Maciej Malicki (Warsaw School of Economics)
Groups of measurable functions - part 2.
Nov. 30, 2016, 4:15 p.m.
Maciej Malicki (Warsaw School of Economics)
Groups of measurable functions
Let G be a Polish group, and let m be a non-atomic probability measure on the interval [0,1]. We define L_0(G) to be the Polish group of all m-equivalence classes of m -measurable functions with …
Nov. 23, 2016, 4:15 p.m.
Tomasz Weiss (Cardinal Stefan Wyszyński University in Warsaw)
More remarks on the intersection ideal M /\ N - part 2.
Nov. 16, 2016, 4:15 p.m.
Tomasz Weiss (Cardinal Stefan Wyszyński University in Warsaw)
More remarks on the intersection ideal M /\ N
We prove in ZFC that every (M /\ N)-additive set is N-additive.
Nov. 9, 2016, 4:15 p.m.
Martin Dolezal (Uniwersytet Warszawski)
Haar meager sets - part 2.
Oct. 26, 2016, 4:15 p.m.
Martin Dolezal (Uniwersytet Warszawski)
Haar meager sets
The notion of Haar meager sets in abelian Polish groups was introduced by Darji. Haar meager sets form a topological counterpart to Haar null sets defined by Christensen. We show some analogies of Haar meager …
Oct. 19, 2016, 4:15 p.m.
Tomasz Cieśla (doktorant UW)
An example of Eberlein compact that is not bisequential
Peter Nyikos gave an example of Eberlein compact that is not bisequential during his talk on Eighth Summer Conference on General Topology and its Applications (over 20 years ago). According to my knowledge he never …
Oct. 12, 2016, 4:15 p.m.
Adam Krawczyk (Uniwersytet Warszawski)
Gry Banacha - Mazura na strukturach relacyjnych
June 8, 2016, 4:15 p.m.
Saeed Ghasemi (IMPAN)
Non-trivially isomorphic corona algebras
It is well-known that there are Cech-Stone remainders (corona spaces) of locally compact spaces for which the question of whether they are homeomorphic is independent from ZFC (e.g., the Cech-Stone remainders of the ordinals \omega …
June 1, 2016, 4:15 p.m.
Piotr Koszmider (IMPAN)
Scattered C*-algebras: A case study in noncommutative set-theoretic topology
The passage from commutative to noncommutative mathematics has stimulated a big part of mathematical research since the mid 20th century which resulted the unprecedented impact of this programme on the shape of today's mathematics. Quite …
May 25, 2016, 4:15 p.m.
Piotr Borodulin-Nadzieja (Uniwersytet Wrocławski)
Measures and slaloms
We construct several examples of spaces supporting measures using a technique developed by Todorcevic. In particular, we show that there is a ZFC example of non-separable growth of omega supporting a measure and that consistently …
May 11, 2016, 4:15 p.m.
Witold Marciszewski (Uniwersytet Warszawski)
On continuous images of compact spaces of finite sets
April 27, 2016, 4:15 p.m.
Wiesław Kubiś (Cardinal Stefan Wyszyński University in Warsaw)
Abstract Banach-Mazur game
We shall present a generalization of the Banach-Mazur game in the setting of partially ordered sets. This approach leads to significant simplifications of arguments showing uniqueness and universality of certain objects related to Fraisse limits. …
April 13, 2016, 4:15 p.m.
Tomasz Weiss (UKSW)
O translacjach zbioru domknietego miary zero w R
Opowiem o łatwiejszym przykładzie (pochodzącym od Elekesa i Totha) zbioru domkniętego miary zero w przestrzeni Cantora, którego mniej niż continuum translacji pokrywa całą przestrzeń. Przedstawię również ciekawy problem B.Tsabana dotyczący translacji zbioru domkniętego miary zero.
April 6, 2016, 4:15 p.m.
Todor Tsankov (Université Paris Diderot)
Metric Scott analysis
Back-and-forth equivalence relations have been an important tool in model theory and descriptive set theory since their advent in the fifties. They provide Borel approximations to the isomorphism relation that are useful in a variety …