13 May 2014, Logic Tea, Zhenhao Li

Abstract

I will talk on a problem that I worked on but did not fully solve in 2013 when I was visiting Berkeley.
The goal of the talk is to give the backgrounds and the motivations of the problem, present my results on this problem, and to encourage ambitious master students and early stage PhD students at the ILLC to work on this beautiful problem.
I will assume only a basic understanding of relative computability and Turing degree from the audience.

The problem is to characterize those countable structures, e.g., the countable dense linear ordering without endpoints, which have representations (in the Cantor space) having minimal Turing degrees.
Note that for each signature (of a structure) we can fix a Gödel's arithmeticalization to talk about representations in the Cantor space of structures having that signature.

For more information, please visit the website http://www.illc.uva.nl/logic_tea/. or contact Guus Eelink (guuseelink at gmail.com), Johannes Marti (johannes.marti at gmail.com) or Masa Mocnik (masa.mocnik at gmail.com).