{ "id": "2305.12688", "version": "v1", "published": "2023-05-22T03:53:18.000Z", "updated": "2023-05-22T03:53:18.000Z", "title": "Testing Isomorphism of Graphs in Polynomial Time", "authors": [ "Rui Xue" ], "categories": [ "math.CO", "cs.CC", "cs.DM" ], "abstract": "Given a graph $G$, the graph $[G]$ obtained by adding, for each pair of vertices of $G$, a unique vertex adjacent to both vertices is called the binding graph of $G$. In this work, we show that the class of binding graphs is graph-isomorphism complete and that the stable partitions of binding graphs by the Weisfeiler-Lehman (WL) algorithm produce automorphism partitions. To test the isomorphism of two graphs $G$ and $H$, one computes the stable graph of the binding graph $[G\\uplus H]$ for the disjoint union graph $G\\uplus H$. The automorphism partition reveals the isomorphism of $G$ and $H$. Because the WL algorithm is a polynomial-time procedure, the claim can be made that the graph-isomorphism problem is in complexity class $\\mathtt{P}$.", "revisions": [ { "version": "v1", "updated": "2023-05-22T03:53:18.000Z" } ], "analyses": { "keywords": [ "polynomial time", "testing isomorphism", "binding graph", "algorithm produce automorphism partitions", "disjoint union graph" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }