Equivariant prime ideals for infinite dimensional supergroups

Let A be a commutative algebra equipped with an action of a group G. The socalled G-primes of A are the equivariant analogs of prime ideals, and of central importance in equivariant commutative algebra. When G is an infinite dimensional group, these ideals can be very subtle: for instance, distinct G-primes can have the same radical. In previous work, the second author showed that if G = GL∞ and A is a polynomial representation, then these pathologies disappear when G is replaced with the supergroup GL∞|∞ and A with a corresponding algebra; this leads to a geometric description of G-primes of A. In the present paper, we construct an abstract framework around this result, and apply the framework to prove analogous results for other (super)groups. We give some applications to the isomeric determinantal ideals (commonly known as “queer determinantal ideals”).