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Recent seminar announcements
 Simon Cho: A Category Theoretic Perspective on Continuous Logic Michigan Logic Seminar
 Garrett Ervin: The Cube Problem for linear orders Carnegie Mellon Logic Seminar
 Marcos Mazari Armida: Introduction to good frames in Abstract Elementary Classes Carnegie Mellon Logic Seminar
 Yuan Yuan Zheng: Moderatelyabstract parametrized Ellentuck theorem Toronto Set Theory Seminar
 Miha Habič: The grounded Martin’s axiom Prague Set Theory Seminar
 Micheal Pawliuk: The Perfect Expansion Property Toronto Set Theory Seminar
 Andy Zucker: A direct solution to the Generic Point Problem II Carnegie Mellon Logic Seminar
 Stefan Hoffelner: NS saturated and Δ_1definable Prague Set Theory Seminar
 Andy Zucker: A direct solution to the Generic Point Problem Carnegie Mellon Logic Seminar
 Juris Steprans: Groups with sub exponential growth and actions on the integers with unique invariant means in the Cohen model Toronto Set Theory Seminar
Upcoming conferences
 October 18: On the Infinite, Paris, October 18 – 21, 2017
 November 20: Ultrafilters, Ramsey Theory and Dynamics, Villeurbanne, November 2024, 2017
 January 27: Winter School, Hejnice, Jan 27 – Feb 3, 2018
 April 22: Set Theory, Model Theory and Applications (In memory of Mati Rubin), Eilat, April 2226, 2018

Talks by venue
 Barcelona Set Theory Seminar (RSS)
 Boise Set Theory Seminar (RSS)
 Bonn Logic Seminar (RSS)
 Bristol Logic Seminar (RSS)
 Budapest Logic Seminar (RSS)
 Carnegie Mellon Logic Seminar (RSS)
 Dartmouth Logic Seminar (RSS)
 Israeli Logic Talks (RSS)
 Kurt Godel Research Center (RSS)
 Logic Seminar in Turin (RSS)
 Michigan Logic Seminar (RSS)
 Morelia Topology and Set Theory Seminar (RSS)
 New York Logic Seminars (RSS)
 NUS logic seminar (RSS)
 Prague Set Theory Seminar (RSS)
 Rutgers Logic Seminar (RSS)
 Toronto Set Theory Seminar (RSS)
 UC Irvine Set Theory Seminar (RSS)
 Wrocław University of Technology (RSS)
Talks by speaker
Alan Dow Alekos Kechris Aleksander Cieślak Aleksandra Kwiatkowska Alessandro Vignati Alex Usvyatsov Alexei Kolesnikov Andreas Blass Andrés Caicedo Andrés Villaveces Andrew BrookeTaylor Andrew Marks Andrew Toms Andy Zucker Antonio Avilés Anush Tserunyan Ari Brodsky Arthur Apter Asaf Karagila Asger Tornquist Ashutosh Kumar Assaf Hasson Assaf Rinot Barnabas Farkas Benjamin Miller Bill Chen Bill Mitchell Boban Velickovic Boris Zilber Borisa Kuzeljevic Brent Cody Burak Kaya Carlos Di Prisco Carlos MartinezRanero Chris Eagle Chris LambieHanson Christina Brech Clinton Conley Daisuke Ikegami Dana Bartošová Daniel Rodriguez Daniel Soukup David Aspero David Chodounsky David J. Fernández Bretón David Marker David Milovich David Schrittesser Diana Ojeda Diego Alejandro Mejia Dikran Dikranjan Dilip Raghavan Dima Sinapova Dimitrios Vlitas Egbert Thümmel Erez Shochat Erin Carmody François Dorais Frank Stephan Franklin Tall Gregory Cherlin Grigor Sargsyan Grzegorz Plebanek Gunter Fuchs Heike Mildenberger Hiroshi Sakai Hugh Woodin Ilijas Farah Ioannis Souldatos Isaac Goldbring István Juhász Itay Neeman James Cummings Jan Grebík Jan van Mill Janusz Pawlikowski Jay Williams Jean Larson Jindra Zapletal Joan Bagaria Joel David Hamkins John Baldwin John Clemens John Krueger John Steel Jonathan Verner Jordi LopezAbad Jörg Brendle Jose Iovino Jouko Väänänen Julien Melleray Juliette Kennedy Juris Steprans Justin Moore K. P. Hart Kaethe Minden Katharina Dupont Konstantinos Tyros Lajos Soukup Laura Fontanella Liljana Babinkostova Liuzhen Wu Luca Motto Ros Luz María García Ávila Lynn Scow Lyubomyr Zdomskyy Marcin Michalski Marcin Sabok Marion Scheepers Martin Goldstern Martin Zeman Martino Lupini Maryanthe Malliaris Masaru Kada Matteo Viale Matthew D. Foreman Melvin Fitting Menachem Kojman Menachem Magidor Merlin Carl Michael Hrusak Michal Doucha Miguel Angel Mota Miha Habic Mikhail Tkachenko Miodrag Sokic Mirna Džamonja Miyamoto Tadatoshi Monroe Eskew Moti Gitik Nadav Meir Nam Trang Natasha Dobrinen Norman Perlmutter Omer Ben Neria Omer Mermelstein Osvaldo Guzmán González Paul Larson Paul McKenney Peng Yinhe Peter Holy Peter Koellner Peter Koepke Peter Komjath Peter Krautzberger Petr Simon Philip Welch Philipp Lücke Philipp Schlicht Pierre Simon Piotr BorodulinNadzieja Piotr Koszmider Ralf Schindler Randall Holmes Rick Statman Robert Ralowski Robin TuckerDrob Rodrigo R. Dias Roman Kossak Saharon Shelah Sakaé Fuchino Salma Kuhlmann Samuel Coskey Scott Cramer Scott Schneider Sean Cox Sebastien Vasey Sergei Artemov Shehzad Ahmed Simon Thomas Slawomir Solecki Spencer Breiner Spencer Unger Stefan Geschke Stevo Todorcevic Su Gao Sy David Friedman Szymon Zeberski Taras Banakh Teruyuki Yorioka Thilo Weinert Timothy Trujillo Todd Eisworth Todor Tsankov Tomek Bartoszynski Toshimichi Usuba Trevor Wilson Tristan Bice Uri Abraham Vera Fischer Victor Torres Perez Victoria Gitman Vincenzo Dimonte Wieslaw Kubis Will Boney Wojciech Stadnicki Wolfgang Wohofsky Yair Hayut Yizheng Zhu Yurii KhomskiiCategories
Recent discussions
 10th Young Set Theory Workshop, Edinburgh, July 1014, 2017  Set Theory Talks on 6th Young Set Theory Workshop, June 1014, 2013
 10th Young Set Theory Workshop, Edinburgh, July 1014, 2017  Set Theory Talks on 9th Young Set Theory Workshop, Copenhagen, June 1317, 2016
 10th Young Set Theory Workshop, Edinburgh, July 1014, 2017  Set Theory Talks on 8th Young Set Theory Workshop, Jerusalem, October 2530, 2015
 1st Irvine Conference on Descriptive Inner Model Theory and HOD Mice, July 1829 2016  Set Theory Talks on Inner Model Theory events in California, June, 2014
 saf on Assaf Rinot: The strength of the generalized Souslin hypothesis
 10th Young Set Theory Workshop, Edinburgh, July 1014, 2017  Set Theory Talks on 6th Young Set Theory Workshop, June 1014, 2013
Seminar organizer’s toolbox
David Fernández Bretón earned a Ph.D. from the Department of Mathematics and Statistics of York University in Toronto, under the supervision of Juris Steprāns.
My main interests are Logic and Set Theory, especially Forcing and Large Cardinals (although my knowledge of the latter is not as deep as I would like), and their applications to Algebra and Analysis. I am currently working on the algebra and topology of the StoneČech compactification of groups, notably Abelian groups, and with idempotents in said compactification. I have also been interested in the Cardinal Invariants of the Continuum for a while.
In a much more informal fashion (pretty much as a hobby), I also like to look at alternative axiomatizations of set theory, such as NFU, and some (very basic) category theory. I am also interested in the Philosophy of Mathematics and in Ludwig Wittgenstein’s life and work.
Recent and upcoming talks by David J. Fernández Bretón
David Fernández Bretón: Gruff ultrafilters in the Random model
Thursday, January 28, 4:005:30 PM at CC Little 2502 (note the nonstandard building/room!!!):
A gruff ultrafilter (a concept introduced by van Douwen) is an ultrafilter on the rational numbers with a base of perfect subsets (where perfect means both closed (in the topology inherited from the usual Euclidean one from the reals) and crowded (without isolated points)). continue reading…
David Fernández Bretón: An introduction to weak diamonds, II
Thursday, November 19, 2015; 16:0017:30; East Hall 3096
After having introduced the basics of weak diamond principles, we will show their usage with some examples: construction of a Suslin tree, of strongly summable ulrafilters, and of gruff ultrafilters. continue reading…
David Fernández Bretón: An introduction to weak diamonds
Thursday, November 5, 2015, 16:0017:30, 3096 East Hall.
I will introduce the basics of weak diamond principles, and show their usage with a couple of examples (construction of a Suslin tree and of a Ppoint). continue reading…
David Fernandez Breton: All that there is to know about gruff ultrafilters, II
Wednesday, September 23, 2015 — 16:00 to 17:30 — 3096 East Hall
An ultrafilter on the rational numbers is gruff if it has a base of perfect (this is, closed and without isolated points) sets. continue reading…
David Fernández Bretón: All that there is to know about gruff ultrafilters
Wednesday, September 16, 2015
3096 East Hall
16:0017:30.
Gruff ultrafilters are ultrafilters on the rational numbers that have a basis of perfect sets (according to the usual Euclidean topology). I will explain what is known about their existence, and hopefully (if there’s enough time) finish with a theorem of M. continue reading…
David Fernandez: A model of ZFC with strongly summable ultrafilters, small covering of meagre and large dominating number
Place: Fields Institute, Room 210
Date and time: Friday 23 January 2015 (13:3015:00)
Speaker: David Fernandez
Title: A model of ZFC with strongly summable ultrafilters, small covering of meagre and large dominating number. continue reading…
David Fernandez: Two microcontributions to the theory of Strongly Summable Ultrafilters
4 April 2014, 13:30–15:00
Fields institute, Room 210
Speaker: David Fernandez
Title: Two microcontributions to the theory of Strongly Summable Ultrafilters
Strongly Summable Ultrafilters are those generated by FSsets (where FS(X) is the set of all possible sums of finitely many elements from X (you can only add each element once)). continue reading…
David Fernandez: Strongly Productive Ultrafilters
04/October/2013, 13:30–15:00
Fields institute, Room 210
Speaker: David Fernandez (York University)
Title: Strongly Productive Ultrafilters
Abstract: The concept of a Strongly Productive Ultrafilter on a semigroup (known as a “strongly summable ultrafilter” when the semigroup is additively denoted) constitute an important concept ever since Hindman defined it, while trying to prove the theorem that now bears his name. continue reading…
David Fernández: Strongly summable ultrafilters and union ultrafilters are not the same thing
21/June/2013, 13:30–15:00
Fields institute,Room 210
Speaker: David J. Fernández Bretón
Title: Strongly summable ultrafilters and union ultrafilters are not the same thing
Abstract: This is, in some sense, a continuation of my previous talk (though of course selfcontained). continue reading…
David Fernández: Every strongly summable ultrafilter is sparse
24/May/2013, 13:30–15:00
Fields institute,Room 210
Speaker: David J. Fernández Bretón
Title: “Every strongly summable ultrafilter is sparse!”
Abstract: The concept of a Strongly Summable Ultrafilter was born from Hindman’s efforts for proving the theorem that now bears his name (which at the time was known as GrahamRothschild’s conjecture), although later on it got a life of its own and started to be studied for its own sake, mostly because of its nice algebraic properties. continue reading…