Number Theory seminar

Thursday, April 11, 2013 3:30 pm - 3:30 pm EDT (GMT -04:00)

Rahim Moosa, Pure Mathematics, University of Waterloo

"Twisted Lang-Weil and the elementary theory of the Frobenius automorphism"

I will give an expository talk on a theorem of Ehud Hrushovski that is as yet unpublished, though an early draft dates back at least to 1998. It is a generalisation of a celebrated classical theorem of Ax on the elementary theory of finite fields. Where Ax’s theorem relied heavily on the Lang-Weil estimates for the number of rational points on varieties over finite fields,
Hrushovski requires a significantly stronger intersection-theoretic twisted form of Lang-Weil.  Besides motivation and precise statements, I will also discuss some application of Hrushovski’s work to algebraic dynamics (results of Amerik and Fakhruddin). The material from this talk is drawn from various lectures given two weeks ago at CIRM (Luminy).