For more information about this meeting, contact Ping Xu, Mathieu Stienon, Nigel Higson.

Title: | Time and almost-positive linear functions on algebras |

Seminar: | GAP Seminar |

Speaker: | Martin Bojowald, Penn State University |

Abstract: |

One of the apparent incompatibilities between quantum mechanics and general relativity is the treatment of time as an eternal parameter in the former and as a local coordinate in the latter theory. I will describe recent ideas which try to overcome this problem by taking the algebraic view of quantum states as linear functionals on the algebra of observables. A time variable may then be taken as an element of the algebra in order to describe evolution locally, while transformations between different time choices must be made for long-term evolution resembling a manifold picture. Algebraic states that include time in this sense violate the usual positivity condition, but still obey a weaker form of almost-positive linear functionals. |

### Room Reservation Information

Room Number: | MB106 |

Date: | 02 / 03 / 2015 |

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