{ "id": "2107.14767", "version": "v1", "published": "2021-07-30T17:19:13.000Z", "updated": "2021-07-30T17:19:13.000Z", "title": "Distinguishing threshold of graphs", "authors": [ "Mohammad Hadi Shekarriz", "Bahman Ahmadi", "Seyed Alireza Talebpoor Shirazi Fard", "Mohammad Hasan Shirdareh Haghighi" ], "comment": "19 pages, 6 figures", "categories": [ "math.CO" ], "abstract": "A vertex coloring of a graph $G$ is called distinguishing if no non-identity automorphisms of $G$ can preserve it. The distinguishing number of $G$, denoted by $D(G)$, is the minimum number of colors required for such coloring. The distinguishing threshold of $G$, denoted by $\\theta(G)$, is the minimum number $k$ of colors such that every $k$-coloring of $G$ is distinguishing. In this paper, we study $\\theta(G)$, find its relation to the cycle structure of the automorphism group and prove that $\\theta(G)=2$ if and only if $G$ is isomorphic to $K_2$ or $\\overline{K_2}$. Moreover, we study graphs that have the distinguishing threshold equal to 3 or more and prove that $\\theta(G)=D(G)$ if and only if $G$ is asymmetric, $K_n$ or $\\overline{K_n}$. Finally, we consider Johnson scheme graphs for their distinguishing number and threshold concludes the paper.", "revisions": [ { "version": "v1", "updated": "2021-07-30T17:19:13.000Z" } ], "analyses": { "subjects": [ "05C09", "05C15", "05C25", "05C30" ], "keywords": [ "minimum number", "johnson scheme graphs", "distinguishing number", "cycle structure", "threshold concludes" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }