News & Events » Talk » Valuations, Newton Polygons, and an Eisenstein Criterion for Ordinary Linear Differential Operators
Valuations, Newton Polygons, and an Eisenstein Criterion for Ordinary Linear Differential Operators
Submitted by ppaterso on Mon, 08/10/2009 - 3:15pm.
Aug 17 2009 - 2:00pm
Aug 17 2009 - 3:00pm
Speaker:
Rick Churchill
Professor of Mathematics, Hunter College and the Graduate Center
of CUNY (The City University of New York)
Adjunct Professor of Mathematics, University of Calgary
Location:
MS 431
Number Theory/Applied Math Talk
Eisenstein's criterion is a classical irreducibility test for
polynomials in Z[x]. One of the first applications encountered in
number theory is a proof of the irreducibility of the p^th cyclotomic
polynomial for any rational integer prime p. In this talk we cast the
proof in geometric terms and use that approach to generalize the result
to skew-polynomials, which include ordinary linear differential operators.
The talk is aimed at an elementary level, and prior acquaintance with
valuations and/or Newton polygons is not assumed. Technical details
will be kept to a minimum.
The results cover a portion of recent joint work of the speaker and Yang
Zhang of the University of Manitoba.