MATHEMATICS COLLOQUIUM

When: Wednesday, December 05, 2012 3:15 PM - 4:15 PM
Where: Math Building : http://en.wikipedia.org/wiki/Hillel_Furstenberg : Colloquium Room 3206
Event Type(s): Colloquium

Speaker: Hillel Furstenberg (Hebrew University)
Title: Multiple Recurrence Phenomena for Non-amenable
Groups and A Szemeredi- like Theorem for
the Free Group
Abstract:
Szemeredi's theorem in combinatorial number theory asserts that
any subset of the integers having positive density contains arithmetic
progressions of any length. It turns out that this is equivalent to a
"multiple" recurrence statement for measure preserving transformations.
Together with Eli Glasner we show that this has an analogue for group
actions that are only measure preserving "on the average". By analogy
the case of the integers, this multiple recurrence result leads to
a theorem guaranteeing existence of geometric progressions in non-
amenable groups. The result for a finitely generated free group can
be made quite explicit.

Website: http://www-math.umd.edu/research/colloquium.html

For more information, contact:
Linette D Berry
Department of Mathematics
+1 301 405 5058

www-math.umd.edu/




Questions and/or comments about this page may be directed to the IT Help Desk at 301-405-1500.