5/3/2006

Brian Conrad
University of Michigan

It is a classical and extremely difficult problem to prove theorems about prime values of irreducible polynomials over the integers. For example, it is still not known if there are infinitely many primes of the form n² + 1. There is a long history of analogies between the integers and polynomials (in one variable) over a finite field, and so one can formulate an analogous problem in this other setting. It was discovered several years ago (joint work with K. Conrad and R. Gross) that there are some surprises. We illustrate the unexpected behavior by means of some explicit examples, and discuss theorems that predict these phenomena.  The main goal of the talk is to motivate (by examples) and (briefly!) discuss the proofs of recent asymptotic results as the finite field and polynomial being specialized are allowed to vary; these asymptotics accord well with a general philosophy of Katz concerning limiting behavior over large finite fields and behavior over number fields. The case of characteristic 2 is not suitable for a general audience, but anyone interested can ask me about it at the colloquium dinner.