{ "id": "2005.06690", "version": "v1", "published": "2020-05-14T02:13:52.000Z", "updated": "2020-05-14T02:13:52.000Z", "title": "Almost Split Triangles and Morphisms Determined by Objects in Extriangulated Categories", "authors": [ "Tiwei Zhao", "Lingling Tan", "Zhaoyong Huang" ], "journal": "Journal of Algebra 559 (2020) 346-378", "doi": "10.1016/j.jalgebra.2020.04.021", "categories": [ "math.RT", "math.RA" ], "abstract": "Let $(\\mathfrak{C},\\mathbb{E},\\mathfrak{s})$ be an Ext-finite, Krull-Schmidt and $k$-linear extriangulated category with $k$ a commutative artinian ring. We define an additive subcategory $\\mathfrak{C}_r$ (respectively, $\\mathfrak{C}_l$) of $\\mathfrak{C}$ in terms of the representable functors from the stable category of $\\mathfrak{C}$ modulo $\\mathfrak{s}$-injectives (respectively, $\\mathfrak{s}$-projectives) to $k$-modules, which consists of all $\\mathfrak{s}$-projective (respectively, $\\mathfrak{s}$-injective) objects and objects isomorphic to direct summands of finite direct sums of all third (respectively, first) terms of almost split $\\mathfrak{s}$-triangles. We investigate the subcategories $\\mathfrak{C}_r$ and $\\mathfrak{C}_l$ in terms of morphisms determined by objects, and then give equivalent characterizations on the existence of almost split $\\mathfrak{s}$-triangles.", "revisions": [ { "version": "v1", "updated": "2020-05-14T02:13:52.000Z" } ], "analyses": { "subjects": [ "18E30", "18E10", "16G70" ], "keywords": [ "split triangles", "finite direct sums", "subcategory", "objects isomorphic", "direct summands" ], "tags": [ "journal article" ], "publication": { "publisher": "Elsevier" }, "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }