Recent and upcoming talks by Juris Steprans

Juris Steprans: Groups with sub exponential growth and actions on the integers with unique invariant means in the Cohen model

Place: BA6183, Bahen Centre Date: August 11, 2017 (13:30-15:00) Speaker: Juris Steprans Title: Groups with sub exponential growth and actions on the integers with unique invariant means in the Cohen model Abstract: It will be shown that the objects mentioned in the title do not exist. continue reading…

Juris Steprans: Automorphisms of $P(\omega)/fin$

Place: Fields Institute (Room 210) Date: November 25th, 2016 (13:30-15:00) Speaker: Juris Steprans, York University Title: Automorphisms of $P(\omega)/fin$ Abstract: The question of whether all automorphisms of $P(\kappa)/fin$ are trivial has been settled in the following cases: – For $\kappa =\omega$ by Rudin and Shelah – For $\kappa$ between $\omega_2$ and the first inaccessible by work of Larson & McKenney and Shelah and me. continue reading…

Set Theory and its Applications in Topology, September 11-16, 2016

The meeting took place in Oaxaca, Mexico. The slides may be found below. 08:45 – 09:00 Introduction and Welcome (Conference Room San Felipe) 09:00 – 10:00 Alan Dow: The even numbered problems (Conference Room San Felipe) 10:00 – 10:30 Rodrigo Jesus Hernandez Gutierrez: Spaces discretely generated at infinity (Conference Room San Felipe) 10:30 – 11:00 Coffee Break (Conference Room San Felipe) 11:00 – 11:30 Isván Juhász: Lindelöf spaces of countable pseudocharacter (Conference Room San Felipe) 11:30 – 12:00 Juris Steprans: PID and universal graphs (Conference Room San Felipe) 13:20 – 13:30 Group Photo (Hotel Hacienda Los Laureles) 13:30 – 15:00 Lunch (Restaurant Hotel Hacienda Los Laureles) 15:00 – 16:00 Itay Neeman: Forcing one instance of the Moore-Todorcevic principle (Conference Room San Felipe) 16:00 – 16:30 Coffee Break (Conference Room San Felipe) 16:30 – 17:00 James Cummings: Dowker and super-Dowker filters (Conference Room San Felipe) 17:00 – 17:30 Assaf Rinot: The $\omega_2$-Souslin problem (Conference Room San Felipe) 19:00 – 21:00 Dinner (Restaurant Hotel Hacienda Los Laureles) Tuesday, September 13 07:30 – 09:00 Breakfast (Restaurant at your assigned hotel) 09:00 – 10:00 Christina Brech: Bases of Homogeneous families bellow the first Mahlo cardinal (Conference Room San Felipe) 10:30 – 11:00 Coffee Break (Conference Room San Felipe) 11:00 – 11:30 Piotr Koszmider: A non-commutative Mrówka’s $\Psi$-space (Conference Room San Felipe) 11:30 – 12:00 Asger Tornquist: Invariant descriptive set theory and almost disjointness modulo an ideal (Conference Room San Felipe) 13:30 – 15:00 Lunch (Restaurant Hotel Hacienda Los Laureles) 15:00 – 16:00 Alexander Shibakov: Sequential groups: large and small (Conference Room San Felipe) 16:00 – 16:30 Coffee Break (Conference Room San Felipe) 16:30 – 17:00 Jindrich Zapletal: Strong measure zero sets in Polish groups (Conference Room San Felipe) 17:00 – 17:30 Marcin Sabok: On hyperfiniteness of boundary actions of hyperbolic groups (Conference Room San Felipe) 19:00 – 21:00 Dinner (Restaurant Hotel Hacienda Los Laureles) Wednesday, September 14 07:30 – 09:00 Breakfast (Restaurant at your assigned hotel) 09:00 – 09:30 Joerg Brendle: Q (Conference Room San Felipe) 09:30 – 10:00 Dilip Raghavan: More on the density zero ideal (Conference Room San Felipe) 10:00 – 10:30 Osvaldo Guzmán: Combinatorial properties of MAD families (Conference Room San Felipe) 10:30 – 11:00 Coffee Break (Conference Room San Felipe) 11:00 – 11:30 Victor Torres-Perez: Constructions with oppositions: Cardinal invariants and games (Conference Room San Felipe) 11:30 – 12:00 David Fernández Bretón: Strong failures of higher analogs of Hindman’s theorem (Conference Room San Felipe) 12:00 – 12:30 Natasha Dobrinen: Topological Ramsey spaces in some creature forcings (Conference Room San Felipe) 12:30 – 13:30 Lunch (Restaurant Hotel Hacienda Los Laureles) 13:30 – 17:30 Free Afternoon (Oaxaca) 19:00 – 21:00 Dinner (Restaurant Hotel Hacienda Los Laureles) Thursday, September 15 07:30 – 09:00 Breakfast (Restaurant at your assigned hotel) 09:00 – 10:00 Slawomir Solecki: Monoid actions on left-topological compact semigroups (Conference Room San Felipe) 10:30 – 11:00 Coffee Break (Conference Room San Felipe) 11:00 – 11:30 Aleksandra Kwiatkowska: The Ramsey degree of the pre-pseudoarc (Conference Room San Felipe) 11:30 – 12:00 Dana Bartosova: Ultrafilter combinatorics in topological dynamics (Conference Room San Felipe) 13:30 – 15:00 Lunch (Restaurant Hotel Hacienda Los Laureles) 15:00 – 16:00 Jan van Mill: Erdős spaces (Conference Room San Felipe) 16:00 – 16:30 Coffee Break (Conference Room San Felipe) 16:30 – 17:00 Anush Tserunyan: Topological dimension and Baire category (Conference Room San Felipe) 17:00 – 17:30 Yinhe Peng: Weak network and the basis problem (Conference Room San Felipe) 19:00 – 21:00 Dinner (Restaurant Hotel Hacienda Los Laureles) Friday, September 16 07:30 – 09:00 Breakfast (Restaurant at your assigned hotel) 09:00 – 09:30 Jeffrey Bergfalk: Walks… (Conference Room San Felipe) 09:30 – 10:00 Iian Smythe: A local Ramsey theory for block sequences (Conference Room San Felipe) 10:00 – 10:30 Noé de Rancourt: Ramsey theory with and without the pigeonhole principle (Conference Room San Felipe) 10:30 – 11:00 Coffee Break (Conference Room San Felipe) 11:00 – 11:30 Claribet Piña: Topological partition relations for $\omega^2$ (Conference Room San Felipe) 11:30 – 12:00 Carlos Uzcategui: Bases and selectors for cofinal families of countable sets (Conference Room San Felipe) 12:00 – 12:30 Carlos Di Prisco: Graphs on the Cantor set (Conference Room San Felipe) 12:30 – 14:30 Lunch (Restaurant Hotel Hacienda Los Laureles)   continue reading…

Juris Steprans: Graph embedding and the P-ideal dichotomy

Place: Fields Institute (Room 210) Date: April 22nd , 2016 (13:30-15:00) Speaker: Juris Steprans Title: Graph embedding and the P-ideal dichotomy Abstract: I will discuss a family of proofs of the consistency of a universal graph on $\omega_1$ with the failure of CH that rely on iterating reals and using the P-ideal dichotomy. continue reading…

Juris Steprans: Universal functions

Place: Fields Institute (Room 210) Date: July 10, 2015 (13:30-15:00) Speaker: Juris Steprans Title: Universal functions Abstract: Universality has various interpretations and it will be the purpose of this talk to establish that many of these are provably different. continue reading…

Juris Steprans: The descriptive set theoretic complexity of the weakly almost periodic functions in the dual of the group algebra

Place: Fields Institute,  Steart Library Date and time : 7 November 2014,  13:30-15:00 Speaker:  Juris Steprans Title: The descriptive set theoretic complexity of the weakly almost periodic functions in the dual of the group algebra Abstract: The almost periodic functions on a group G are those functions F from G to the complex number such that the uniform norm closure of all shifts of F is compact in the uniform norm. continue reading…

Alan Dow Conference, December 6–9, 2014

60 years of Dow celebrating the mathematics of Alan Dow December 6–9, 2014 Alan Dow has made deep contributions to set-theoretic topology and has been one of few researchers to pioneer new techniques in set theory which were directly motivated by fundamental topological problems. continue reading…

Juris Steprans: Non-trivial automorphisms of $P(\omega_1)/fin$

7 March 2014, 13:30–15:00 Fields institute, Room 210 Speaker:  Juris Steprans Title:  Non-trivial automorphisms of $P(\omega_1)/fin$ Abstract: Just as in the case of automorphisms of $P(\omega)/fin$, an automorphism of $P(\omega_1)/fin$ will be called trivial if it is induced by a bijection between cofinite subsets of $\omega_1$. continue reading…

Workshop on Forcing Axioms and their Applications, October 22-26, 2012

This workshop will take place at the Fields institute, as a part of the 2012 Thematic Program on Forcing and its Applications. Organizing Committee: Jordi Lopez Abad Justin Tatch Moore Stevo Todorcevic Show Schedule Monday, October 22 9:30 Justin Tatch Moore, Cornell University Martin’s Maximum, a tutorial 1 The purpose of these talks will be to survey the consequences of Martin’s Maximum. continue reading…

2011 CMS Winter Meeting, December 10 – 12, 2011

Saturday December 10 10:00 – 10:25 Slawomir Solecki 10:30 – 10:55 Aleksandra Kwiatkowska 11:00 – 11:25 Samuel Coskey 14:00 – 14:25 Martin Zeman 14:30 – 14:55 Grigor Sargsyan 16:00 – 16:25 James Cummings 16:30 – 16:55 Dima Sinapova 17:00 – 17:25 John Krueger Sunday December 11 8:30 – 8:55 Claude Laflamme 9:00 – 9:25 Assaf Rinot 9:30 – 9:55 Juris Steprans 14:00 – 14:25 Asger Tornquist 16:00 – 16:25 Itay Neeman 16:30 – 16:55 Sean Cox 17:00 – 17:25 Justin Moore Additional two events for Friday, December 9th: ** 9am-12pm: CMS meeting mini course Bahen, room 1240 Speaker: Dima Sinapova (Irvine) Tittle: Large cardinals and Prikry type forcing (outline attached) ** 1:30pm-3pm: Toronto set theory seminar Fields, room 210 Speaker: Hugh Woodin (Berkeley) Title: The HOD Conjecture Sinapova minicourse outline.pdf continue reading…