On the K-theory of the coordinate axes in the plane
Let k a regular Fp-algebra, let A = k[x,y]/(xy) be
the coordinate ring of the coordinate axes in the affine k-plane, and
let I = (x,y) be the ideal that defines the intersection point. We
evaluate the relative K-groups Kq(A,I) completely in terms
of the groups of big de Rham-Witt forms of k. This generalizes a
formula for K1 and K2 by Dennis and Krusemeyer.