Logic Seminar-Index sets, isomorphism problems, and classification

Time: Thursday, March 31, 11:00 am-12:00 noon

Place: zoom
https://gwu-edu.zoom.us/j/92174865905

Speaker:  Wesley Calvert, Southern Illinois University

http://lagrange.math.siu.edu/Calvert/

Title: Index sets, isomorphism problems, and classification

Abstract: Consider a class of computable structures, perhaps the set of models of some theory.  How hard is it to determine, from indices of diagrams of structures in this class, which structures are isomorphic to which other structures?  How hard is it to specify a particular isomorphism type from the structure?  How hard is it to classify the elements of this class up to isomorphism?  Computability has a good system for answering questions of the form, “How hard is...,” and we apply this system to these questions.