CAPITAL REGION ALGEBRA/NUMBER THEORY SEMINAR 


Speaker:     Robert G. Underwood, Auburn University Montgomery 

Time:        Wednesday, April 10, at 4:30pm, 

Place:       Bailey Hall, Room 100, Union College, Schenectady  

Title:       Cyclic Hopf Orders Defined by Isogenies of Formal Groups 

Abstract: 

Let $R$ be the valuation ring of a local number field $K$. Let
$C_{p^n}$ denote the cyclic group of order $p^n$. We describe a
construction of $R$-Hopf orders in $KC_{p^n}$ which represent kernels of
isogenies of degree $2$, dimension $n$ polynomial formal groups defined
over $R$.

We examine how this new class of Hopf orders relates to known classes
of Hopf orders in $KC_{p^n}$, for $n=2$ and $n=3$.

This is joint work with Lindsay Childs of the University at Albany.