{ "id": "1603.09379", "version": "v1", "published": "2016-03-30T20:55:20.000Z", "updated": "2016-03-30T20:55:20.000Z", "title": "Co-t-structures: The First Decade", "authors": [ "Peter Jorgensen" ], "comment": "12 pages", "categories": [ "math.RT", "math.RA" ], "abstract": "Co-t-structures were introduced about ten years ago as a type of mirror image of t-structures. Like t-structures, they permit to divide an object in a triangulated category T into a \"left part\" and a \"right part\", but there are crucial differences. For instance, a bounded t-structure gives rise to an abelian subcategory of T, while a bounded co-t-structure gives rise to a so-called silting subcategory. This brief survey will emphasise three philosophical points. First, bounded t-structures are akin to the canonical example of \"soft\" truncation of complexes in the derived category. Secondly, bounded co-t-structures are akin to the canonical example of \"hard\" truncation of complexes in the homotopy category. Thirdly, a triangulated category T may be skewed towards t-structures or co-t-structures, in the sense that one type of structure is more useful than the other for studying T. In particular, we think of derived categories as skewed towards t-structures, and of homotopy categories as skewed towards co-t-structures.", "revisions": [ { "version": "v1", "updated": "2016-03-30T20:55:20.000Z" } ], "analyses": { "subjects": [ "18E30" ], "keywords": [ "first decade", "homotopy category", "bounded co-t-structure", "derived category", "canonical example" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160309379J" } } }