PSU Mark
Eberly College of Science Mathematics Department

Meeting Details

For more information about this meeting, contact Stephen Simpson.

Title:"Universal" Schnorr null sets
Seminar:Logic Seminar
Speaker:Nicholas Rupprecht, University of Michigan
Abstract:
A Schnorr test relative to some oracle A may informally be called "universal" if it covers all Schnorr tests. Since no true universal Schnorr test exists, such an A cannot be computable. Neither can an A with the "weakly universal" that the set of computable reals is Schnorr null relative to A. We show how tools adapted from the set theoretic study of cardinal characteristics of the continuum have been used to study these two properties, proving the former is equivalent to having high Turing degree, and the latter is strictly implied by having hyperimmune degree, and strictly implies not being computably traceable.

Room Reservation Information

Room Number:MB315
Date:01 / 26 / 2010
Time:02:30pm - 03:45pm