### K_0-theory of n-potents in rings and algebras, by Efton Park and Jody Trout

Let n be an integer greater than or equal to 2. An n-potent is an element e of
a ring R such that e^n = e. In this paper, we study n-potents in matrices over
R and use them to construct an abelian group K_0^n(R). If A is a complex
algebra, there is a group isomorphism from K_0^n(A) to (K_0(A))^(n-1) for all n
greater than or equal to 2. However, for algebras over cyclotomic fields, this
is not true in general. We consider K_0^n as a covariant functor, and show that
it is also functorial for a generalization of homomorphism called an
n-homomorphism.

Efton Park <e.park@tcu.edu>

Jody Trout <John.D.Trout@dartmouth.edu>