{ "id": "1906.10989", "version": "v1", "published": "2019-06-26T11:44:28.000Z", "updated": "2019-06-26T11:44:28.000Z", "title": "Proper classes and Gorensteinness in extriangulated categories", "authors": [ "Jiangsheng Hu", "Dongdong Zhang", "Panyue Zhou" ], "comment": "32pages", "categories": [ "math.RT" ], "abstract": "Extriangulated categories were introduced by Nakaoka and Palu as a simultaneous generalization of exact categories and triangulated categories. A notion of proper class in an extriangulated category is defined in this paper. Let $\\mathcal{C}$ be an extriangulated category and $\\xi$ a proper class in $\\mathcal{C}$. We prove that $\\mathcal{C}$ admits a new extriangulated structure. This construction gives extriangulated categories which are neither exact categories nor triangulated categories. Moreover, we introduce and study $\\xi$-Gorenstein projective objects in $\\mathcal{C}$ and demonstrate that $\\xi$-Gorenstein projective objects share some basic properties with Gorenstein projective objects in module categories or in triangulated categories. In particular, we refine a result of Asadollahi and Salarian [Gorenstein objects in triangulated categories, J. Algebra 281(2004), 264-286]. As an application, the $\\xi$-$\\mathcal{G}$projective model structures on extriangulated categories are obtained.", "revisions": [ { "version": "v1", "updated": "2019-06-26T11:44:28.000Z" } ], "analyses": { "subjects": [ "18E30", "18E10", "16E05", "18G20", "18G35" ], "keywords": [ "extriangulated category", "proper class", "triangulated categories", "exact categories", "gorensteinness" ], "note": { "typesetting": "TeX", "pages": 32, "language": "en", "license": "arXiv", "status": "editable" } } }