{ "id": "1706.03387", "version": "v1", "published": "2017-06-11T18:23:16.000Z", "updated": "2017-06-11T18:23:16.000Z", "title": "Gerbe patching and a Mayer-Vietoris sequence over arithmetic curves", "authors": [ "Bastian Haase" ], "categories": [ "math.AG" ], "abstract": "We discuss patching techniques and local-global principles for gerbes over arithmetic curves. Our patching setup is that introduced by Harbater, Hartmann and Krashen. Our results for gerbes can be viewed as a 2-categorical analogue on their results for torsors. Along the way, we also discuss bitorsor patching and local-global principles for bitorsors. As an application of these results, we obtain a Mayer-Vietoris sequence with respect to patches for non-abelian hypercohomology sets with values in the crossed module G->Aut(G) for G a linear algebraic group. Using local-global principles for gerbes, we also prove local-global principles for points on homogeneous spaces under linear algebraic groups H that are special (e.g. SL_n and Sp_2n) for certain kind of stabilizers.", "revisions": [ { "version": "v1", "updated": "2017-06-11T18:23:16.000Z" } ], "analyses": { "subjects": [ "14H25", "18G50", "14M17" ], "keywords": [ "mayer-vietoris sequence", "arithmetic curves", "local-global principles", "gerbe patching", "linear algebraic group" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }