Springer fibers and the Delta Conjecture at t=0

We introduce a family of varieties Yn,lambda,s, which we call the Delta-Springer varieties, that generalize the type A Springer fibers. We give an explicit presentation of the cohomology ring H*(Yn,lambda,s) and show that there is a symmetric group action on this ring generalizing the Springer action on the cohomology of a Springer fiber. In particular, the top cohomology groups are induction products of Specht modules with trivial modules. The lambda = (1k) case of this construction gives a compact geometric realization for the expression in the Delta Conjecture at t = 0. Finally, we generalize results of De Concini and Procesi on the scheme of diagonal nilpotent matrices by constructing an ind-variety Yn,lambda whose cohomology ring is isomorphic to the coordinate ring of the