TITLE: Characterizing  Separating Invariants 
AUTHORS: Mara D.~Neusel and M\"uf\.it Sezer
ABSTRACT:
We study separating algebras for rings of invariants of finite groups. 
We give an algebraic characterization for these. Furthermore, we describe 
a particularly nice separating subalgebra for rings of invariants of p-groups 
in characteristic p. This leads to a characterization of subalgebras such 
that their p-root and integral closure is equal to the ring of invariants. 
Finally, we present separating sets for invariants rings of nonmodular 
representations of abelian groups whose size depends only on the degree of 
the representation.