{ "id": "2012.06098", "version": "v2", "published": "2020-12-11T03:37:52.000Z", "updated": "2022-03-22T13:42:46.000Z", "title": "Co-$t$-structures on derived categories of coherent sheaves and the cohomology of tilting modules", "authors": [ "Pramod N. Achar", "William Hardesty" ], "comment": "40 pages. v2: extensive corrections; added details in some proofs", "categories": [ "math.RT", "math.CT", "math.GR" ], "abstract": "We construct a co-$t$-structure on the derived category of coherent sheaves on the nilpotent cone $\\mathcal{N}$ of a reductive group, as well as on the derived category of coherent sheaves on any parabolic Springer resolution. These structures are employed to show that the push-forwards of the \"exotic parity objects\" along the (classical) Springer resolution give indecomposable objects inside the coheart of the co-$t$-structure on $\\mathcal{N}$. We also demonstrate how the various parabolic co-$t$-structures can be related by introducing an analogue to the usual translation functors. As an application, we give a proof of a scheme-theoretic formulation of the relative Humphreys conjecture on support varieties of tilting modules in type $A$ for $p>h$.", "revisions": [ { "version": "v2", "updated": "2022-03-22T13:42:46.000Z" } ], "analyses": { "keywords": [ "coherent sheaves", "derived category", "tilting modules", "cohomology", "parabolic springer resolution" ], "note": { "typesetting": "TeX", "pages": 40, "language": "en", "license": "arXiv", "status": "editable" } } }