Integral homology of PGL_2 over elliptic curves,
by Kevin P. Knudson, Northwestern University

Suppose that E is an elliptic curve with a unique point at infinity,
and denote by A the coordinate algebra of E (we assume the ground field
k is infinite).  In this note, we compute
the integral homology of PGL_2(A).  The answer consists of a number
of direct summands of the form H_i(PGL_2(k)) and H_i(k^*), and
some additional factors in certain cases.  As a corollary, we obtain
a rigidity result.