{ "id": "2111.04869", "version": "v3", "published": "2021-11-08T23:27:18.000Z", "updated": "2022-01-25T07:40:31.000Z", "title": "Lin-Lu-Yau curvature and diameter of amply regular graphs", "authors": [ "Xintian Li", "Shiping Liu" ], "comment": "5 pages", "journal": "J. Univ. Sci. Tech. China 51 (2021), no. 12, 889-893", "doi": "10.52396/JUST-2021-0232", "categories": [ "math.CO", "math.DG" ], "abstract": "By Hall's marriage theorem, we study lower bounds of the Lin-Lu-Yau curvature of amply regular graphs with girth $3$ or $4$ under different parameter restrictions. As a consequence, we show that each conference graph has positive Lin-Lu-Yau curvature. Our approach also provides a geometric proof of a classical diameter estimate for amply regular graphs in the case of girth $4$ and some special cases of girth $3$.", "revisions": [ { "version": "v3", "updated": "2022-01-25T07:40:31.000Z" } ], "analyses": { "keywords": [ "amply regular graphs", "halls marriage theorem", "study lower bounds", "conference graph", "classical diameter estimate" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable" } } }