Combinatorial intersection cohomology for fans
Combinatorial intersection cohomology for fans
We investigate minimal extension sheaves on arbitrary (possibly non-rational) fans as an approach toward a combinatorial "virtual'' intersection cohomology. These are flabby sheaves of graded modules over a sheaf of polynomial rings, satisfying three relatively simple axioms that characterize the equivariant intersection cohomology sheaves on toric varieties. As in "classical'' …