Speaker: Kostas Beros (U. North Texas)

Title: Normal numbers and a completeness result in the difference hierarchy

Abstract: In this talk I consider a natural set of real numbers, arising in ergodic theory, and show that it is Wadge-complete for the class of differences of $F_{\sigma\delta}$ sets. I will recall basic definitions and motivate my result with a discussion of related theorems from the past twenty years.

Logic seminar

Keller Hall 401

Achilles Beros will
speak on “Algorithmic learning and the arithmetic hierarchy”

Summary:

I will present a theorem from my thesis that establishes the arithmetic
complexity of a well-known learning criterion. Two other papers have
been published since then that continue the line of research. I will
discuss the newer papers as well as broader connections between
recursion theory and learning theory.

Keller Hall 303