University Seminar- Computability, Complexity, and Algebraic Structure-Relativizing categoricity and low computably enumerable sets

Time: Wednesday, February 18, 5:00–6:00 pm

Place: Phillips Hall, Room 108

Speaker:  Java Villano, University of Toronto

Title: Relativizing categoricity and low computably enumerable sets

Abstract: In computable structure theory, we say that a computable structure A is computably categorical if for every computable copy B of it, there exists a computable isomorphism between A and B. We can relativize this notion to a specific Turing degree d by asking that for every d-computable copy, there exists a d-computable isomorphism. This notion of relativized categoricity has interesting behavior in the Turing degrees, and in this talk, we will discuss its behavior in particular to low computably enumerable. degrees. This is a joint ongoing project with D. Gonzalez and J. Valenzuela Morales.