Series: Penn State Logic Seminar

Date: Tuesday, February 15, 2005

Time: 2:30 - 3:45 PM

Place: 103 Pond Laboratory

Speaker: John Clemens, Penn State, Mathematics

Title: Fixed Points of Isometries of the Urysohn Space


  A current area of research is investigating the isometry group of
  Urysohn's universal metric space.  In particular, the complexity of
  classifying isometries up to conjugacy is unknown.  I will show that
  one potential invariant turns out to be very weak in this regard,
  namely: Given an isometry of Urysohn's space with at least one fixed
  point, the set of fixed points is in fact isometric to the entire
  space.  I will discuss other possibilities for finding better