{ "id": "2003.06033", "version": "v1", "published": "2020-03-12T21:56:23.000Z", "updated": "2020-03-12T21:56:23.000Z", "title": "Smooth approximation for classifying spaces of diffeomorphism groups", "authors": [ "Yong-Geun Oh", "Hiro Lee Tanaka" ], "comment": "17 pages. Comments welcome! Portions of this work previously appeared in arXiv:1911.00349v2; that previous work has been split into multiple papers (including this one) to better explicate the ingredients", "categories": [ "math.AT", "math.DG", "math.SG" ], "abstract": "We prove a smooth approximation theorem for classifying spaces of certain infinite-dimensional smooth groups. More precisely, using the framework of diffeological spaces, we show that the smooth singular complex of a classifying space BG is weakly homotopy equivalent to the (continuous) singular complex of BG when G is a diffeomorphism group of a compact smooth manifold. In particular, the smooth homotopy groups of BG are naturally isomorphic to the usual (continuous) homotopy groups of BG. On top of a computation of homotopy groups, our methods yield a way to construct homotopically coherent actions of G using infinity-categorical techniques. We discuss some generalizations and consequences of this result with an eye toward [OT19], where we show that higher homotopy groups of symplectic automorphism groups map to Fukaya-categorical invariants, and where we prove a conjecture of Teleman from the 2014 ICM in the Liouville and monotone settings.", "revisions": [ { "version": "v1", "updated": "2020-03-12T21:56:23.000Z" } ], "analyses": { "keywords": [ "classifying space", "diffeomorphism group", "symplectic automorphism groups map", "infinite-dimensional smooth groups", "smooth homotopy groups" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }