Organizer: Chris Laskowski
When: Tuesdays @ 3:30pm
Where: Math 1311

Archives: 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017

  • Organizational Meeting

    Speaker: Organizational Meeting () -

    When: Tue, August 29, 2017 - 3:30pm
    Where: Kirwan Hall 1311
  • Borel complexity and the Schroder-Bernstein property

    Speaker: Douglas Ulrich (UMD) -

    When: Tue, September 5, 2017 - 3:30pm
    Where: Kirwan Hall 1311

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    Abstract: We show that if a first order theory T has the Schroder-Bernstein property then it is not Borel complete, assuming some mild large cardinals.
  • Countable models of Baldwin-Shi hypergraphs

    Speaker: Danul Gunatilleka (University of Maryland, College Park) -

    When: Tue, September 12, 2017 - 3:30pm
    Where: Kirwan Hall 1311

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    Abstract: We isolate a special case of the ab initio constructions that we propose to call Baldwin-Shi hypergraphs. The theories in question are known to be either strictly stable or omega-stable and are known to have the dimensional order property. It is also known that the in case the theory is strictly stable it is not small. So we count the number of non-ismorphic countable models in the case the theory is omega-stable. We will also take a look at the regular types that arise in this case.
  • Finite-rank ordered Abelian groups

    Speaker: John Goodrick (Los Andes University) -

    When: Tue, September 19, 2017 - 3:30pm
    Where: Kirwan Hall 1311

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    Abstract: Recently there have been several advances in the study of ordered Abelian groups (OAGs) whose theories have finite dp-rank. Recall that every complete theory of OAGs has NIP (Gurevich), so it it is interesting to ask which ones are *strongly* dependent in the pure language {+, <} of ordered groups, and which ones have finite dp-rank. We will sketch a new proof of a characterization of such theories, which was discovered independently by several people in the past year.

    Next, we will consider finite dp-rank theories of ordered Abelian groups in languages expanding {+,<}. Here there is much less known, though discrete definable can be analyzed (as in work by myself and Dolich): if there is an Archimedean model, then any discrete definable set must be a finite union of arithmetic sequences. Some preliminary attempts to analyze definable sets and functions will be discussed.

    All the results presented in this talk are joint work with Alfred Dolich.
  • Coarse embeddings into superstable spaces

    Speaker: Bruno de Mendonça Braga (York University) -

    When: Tue, September 26, 2017 - 3:30pm
    Where: Kirwan Hall 1311

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    Abstract: In 1981, J. Krivine and B. Maurey introduced the definition of stable Banach spaces, and, in 1983, Y. Raynaud introduced the notion of superstability and studied uniform embeddings of Banach spaces into superstable Banach spaces. In this talk, we will talk about coarse embeddings into superstable spaces. This is a joint work with Andrew Swift.