June 7, 2022
Title: Computing endomorphism rings and Frobenius matrices of Drinfeld modules
Speaker: Mihran Papikian (Pennsylvania State University)
Let $mathbb{F}_q[T]$ be the polynomial ring over a finite field $mathbb{F}_q$. We study the endomorphism rings of Drinfeld $mathbb{F}_q[T]$-modules of arbitrary rank over finite fields. We compare the endomorphism rings to their subrings generated by the Frobenius endomorphism and deduce from this a reciprocity law for the division fields of Drinfeld modules. We then use these results to give an efficient algorithm for computing the endomorphism rings and discuss some interesting examples produced by our algorithm. This is joint work with Sumita Garai.