For more information about this meeting, contact Stephen Simpson.
|Title:||Invariant measures, computability, and reverse mathematics|
|Speaker:||Stephen G. Simpson, Pennsylvania State University|
|Let S be the unit circle. We construct a computable homeomorphism f: S --> S such that no computable probability measure on S is invariant under f. This construction is due to Mathieu Hoyrup and Cristobal Rojas. We extend their method to prove the following result of reverse mathematics: WKL_0 is equivalent over RCA_0 to the statement that for every Z-action on a compact metric space there exists an invariant probability measure.|
Room Reservation Information
|Date:||02 / 16 / 2010|
|Time:||02:30pm - 03:45pm|