For more information about this meeting, contact Stephen Simpson.

Title: | Measure-theoretic regularity and LR-reducibility |

Seminar: | Logic Seminar |

Speaker: | Stephen G. Simpson, Pennsylvania State University |

Abstract Link: | http://www.math.psu.edu/simpson/papers/massmtr.pdf |

Abstract: |

Let S be a Lebesgue measurable set in Euclidean space. It is well known that we can find closed sets C included in S such that the measure of S minus the measure of C is as small as desired. This phenomenon is known as measure-theoretic regularity. Using tools from the theory of computability and algorithmic randomness, we analyze the "descriptive complexity" or "logical strength" of the closed sets which are needed in order to implement measure-theoretic regularity. One of the tools is Nies's notion of LR-reducibility. |

### Room Reservation Information

Room Number: | MB315 |

Date: | 10 / 27 / 2009 |

Time: | 02:30pm - 03:45pm |