21/Apr/2014: Grigor Sargsyan and Joel Hamkins

All talks are in Hill

DST Seminar at 3:20 Room 525

Monday 04/21 — Grigor Sargsyan (Rutgers)
Title: Stability and Morley rank IX

Logic Seminar at 5:00 Room 705

Monday 04/21 — Joel Hamkins (College of Staten Island)
Title: Large cardinals need not be large in HOD
Abstract: I will show that large cardinals, such as measurable, strong and supercompact cardinals, need not exhibit their large cardinal nature in HOD. It is relatively consistent that a supercompact cardinal is not weakly compact in HOD, and one may construct models with a proper class of supercompact cardinals, none of them weakly compact in HOD. This is current joint work with Cheng Yong.

Bakhadyr Khoussainov: Algorithmically random algebraic structures

Invitation to the Logic Seminar at the National University of Singapore

Date: Wednesday, 16 April 2014, 17:00 hrs

Room: S17#04-05, Department of Mathematics, NUS

Speaker: Bakhadyr Khoussainov, University of Auckland

Title: Algorithmically random algebraic structures

URL: http://www.comp.nus.edu.sg/~fstephan/logicseminar.html

Abstract: In this talk we introduce the concept of algorithmically
random algebraic structure. In particular, we construct
algorithmically random structures in the classes of graphs, trees,
universal algebras, and monoids. We prove that there exist computably
enumerable algorithmically random trees. We also build algorithmically
random universal algebras and graphs computable in the halting set.

Rodrigo R. Dias: Supertightness and point-picking games

Boise Set Theory Seminar
Tuesday, April 15 from 2 to 3pm
Room: Mathematics 136
Speaker: Rodrigo Roque Dias (BSU and São Paulo)
Title: Supertightness and point-picking games

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. This conference aims to bring together the different areas of research relating to Professor Dow’s work on compactness, convergence, and their relation to set theory and forcing.

This is a special meeting of the Mid-Atlantic Mathematical Logic Seminar (MAMLS). Support for the meeting is provided by the National Science Foundation.

Plenary Speakers

  • Alexander Arhangelskii, Ohio University
  • Todd Eisworth, Ohio University
  • Klaas Pieter Hart, Delft University of Technology
  • Istvan Juhasz, Alfréd Rényi Institute of Mathematics
  • Piotr Koszmider, Polish Academy of Sciences
  • Arnold Miller, University of Wisconsin
  • Juris Steprans, York University
  • Stevo Todorcevic, University of Toronto and University of Paris VII
  • Jan van Mill, Vrije Universiteit

Organizers

  • Michael Hrusak, Universidad Nacional Autónoma de México
  • Justin Moore, Cornell University

Jan Grebík: Extending the Density Function II

Wednesday, April 16, 2014, 11:00
Prague – CTS

Speaker: Jan Grebík

Title: Extending the Density Function II

Marion Scheepers: Box powers of Baire spaces

11 April 2014, 13:30–15:00

Fields institute, Room 210

Speaker: Marion Scheepers

Title: Box powers of Baire spaces

Abstract: A topological space is a Baire space if any countable sequence of dense open subsets has a non-empty intersection. In this talk we discuss an elegant (consistent module large cardinals) characterization of spaces that have the Baire property in all powers, considered in the box topology.

Nam Trang: Guessing models II

Speaker: Nam Trang

Title: Guessing models II

Abstract: We define a class of guessing models, introduced by Viale and
Weiss. The existence of guessing models is equivalent to the principle:
every slender list has an ineffable branch. The latter, captures many
combinatorial structures of supercompactness and yet can hold at successor
cardinals, was isolated and studied by Weiss. We discuss consistency
strength and prove some combinatorial consequences of the existence of
guessing models.

Jan Grebík: Extending the Density Function on P(omega)

Wednesday, April 9, 2014, 11:00
Prague – CTS

Speaker: Jan Grebík

Title: Extending the Density Function on P(omega)

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 FS-sets (where FS(X) is the set of all possible sums of finitely many elements from X (you can only add each element once)). I will show two little results (with nice little neat proofs!) about these: first, that every strongly summable ultrafilter on the countable Boolean group is rapid. Second, that there is a model where strongly summable ultrafilters (on any abelian group really, but without loss of generality on the countable Boolean group) exist yet Martin’s axiom for countable forcing notions fails (up until now, these ultrafilters were only known to exist under this hypothesis).

Wu Guohua: On a theorem of Seetapun

Invitation to the Logic Seminar at the National University of Singapore

Date: Wednesday, 09 April 2014, 17:00 hrs

Room: S17#04-05, Department of Mathematics, NUS

Speaker: Wu Guohua

Title: On a theorem of Seetapun

URL: http://www.comp.nus.edu.sg/~fstephan/logicseminar.html

Abstract:
In this talk, we will consider local noncappability property of
recursively enumerable degrees, which was proposed by Seetapun in his
thesis in 1991. We will give an improvement of this theorem, which
will have several known results as direct corollaries. This talk
is based on joint work with Frank Stephan.