Recent and upcoming talks by John Clemens

John Clemens: The recursion theorem in set theory

Tuesday, September 27 from 3 to 4pm Room: MB 124 Speaker: John Clemens (BSU) Title: The Recursion Theorem in Set Theory Abstract: Kleene’s Recursion Theorem is a simple yet powerful result about computable functions, which asserts the existence of functions which “know their own code” in some suitably nice enumeration of the computable functions. continue reading…

BEST 2016 slides

The 23rd BEST conference was held June 15–16 in San Diego, CA. Shehzad Ahmed – Jonsson cardinals and pcf theory Liljana Babinkostova – A weakening of the closure operator Kyle Beserra – On the conjugacy problem for automorphisms of countable regular trees Erin Carmody – Killing them softly William Chan – Every analytic equivalence relation with all Borel classes is Borel somewhere John Clemens – Relative primeness of equivalence relations Paul Corazza – The axiom of infinity, quantum field theory, and large cardinals Cody Dance – Indiscernibles for $L[T_2,x]$ Natasha Dobrinen – Ramsey spaces coding universal triangle-free graphs and applications to Ramsey degrees Paul Ellis – A Borel amalgamation property Monroe Eskew – Rigid ideals Daniel Hathaway – Disjoint Borel functions Jared Holshouser – Partition properties for non-ordinal sets under the axiom of determinacy Paul McKenney – Automorphisms of $\mathcal P(\lambda)/\mathcal I_\kappa Kaethe Minden – Subcomplete forcing and trees Daniel Soukup – Orientations of graphs with uncountable chromatic number Simon Thomas – The isomorphism and bi-embeddability relations for finitely generated groups Douglas Ulrich – A new notion of cardinality for countable first order theories Kameryn Williams – Minimal models of Kelley-Morse set theory Martin Zeman – Master conditions from huge embeddings continue reading…

John Clemens: Relative primeness of equivalence relations

Wednesday, November 11 from 3 to 4pm Room: MP 207 Speaker: John Clemens (BSU) Title: Relative primeness of equivalence relations Abstract: Let $E$ and $F$ be equivalence relations on the spaces $X$ and $Y$. continue reading…

John Clemens: Isomorphism of homogeneous structures

Wednesday, September 16 from 3 to 4pm Room: MP 207 Speaker: John Clemens (BSU) Title: Isomorphism of homogeneous structures Abstract: The theory of Borel reducibility of equivalence relations can be used to gauge the complexity of the isomorphism problem for a collection of countable structures. continue reading…

6th Descriptive Set Theory in Paris, December 16 – 17, 2013

The sixth meeting Descriptive Set Theory in Paris  organized by the Equipe d’Analyse Fonctionnelle will be held on December 16 and 17, 2013 at the Institut de Mathématique de Jussieu. List Of Speakers Itai BEN YAACOV John CLEMENS Sy FRIEDMAN Vassilis GREGORIADES Adriane KAÏCHOUH David KERR Aleksandra KWIATKOWSKA François LE MAITRE Luca MOTTO ROS Lionel NGUYEN VAN THE Marcin SABOK Omar SELIM Konstantin SLUTSKY Slawomir SOLECKI Asger TORNQUIST Anatoly VERSHIK Titles and Abstracts continue reading…

John Clemens: Treeable equivalence relations and descriptive complexity

Monday, May 14, 2012, 16.30 Speaker: John Clemens (University of Münster) Title: Treeable equivalence relations and descriptive complexity Abstract: The property of treeability has been well-studied in the context of countable Borel equivalence relations, but has been little studied up to now in the uncountable case. continue reading…