There will be a logic seminar next Wednesday, September 21, from 4 to 5:30, in 3096 East Hall.
Peter Krautzberger will speak on “Flat Ultrafilters”. Here’s an abstract of his talk:
“On a recent visit to Toronto, Ilijas Farah introduced me to the somewhat mysterious notion of “flat ultrafilter”. These are ultrafilters on $omega$ that have found interesting applications in Farah, Steprans and Philips “The commutant of L( H ) in its ultrapower may or may not be trivial “, Mathematische Annalen, 2009.
In my talk, I will only outline the main results from the above paper but mostly focus on the actual definition and open questions regarding the existence of (non-)flat ultrafilters.”
The talk will be recorded; I will update this post as soon as the video is available.