{ "id": "1910.12107", "version": "v1", "published": "2019-10-26T17:28:25.000Z", "updated": "2019-10-26T17:28:25.000Z", "title": "Bounds for Distinguishing Invariants of Infinite Graphs", "authors": [ "Wilfried Imrich", "Rafał Kalinowski", "Monika Pilśniak", "Mohammad H. Shekarriz" ], "journal": "The electronic journal of combinatorics 24(3) (2017), #P3.6", "categories": [ "math.CO" ], "abstract": "We consider infinite graphs. The distinguishing number $D(G)$ of a graph $G$ is the minimum number of colours in a vertex colouring of $G$ that is preserved only by the trivial automorphism. An analogous invariant for edge colourings is called the distinguishing index, denoted by $D'(G)$. We prove that $D'(G)\\leq D(G)+1$. For proper colourings, we study relevant invariants called the distinguishing chromatic number $\\chi_D(G)$, and the distinguishing chromatic index $\\chi'_D(G)$, for vertex and edge colourings, respectively. We show that $\\chi_D(G)\\leq 2\\Delta(G)-1$ for graphs with a finite maximum degree $\\Delta(G)$, and we obtain substantially lower bounds for some classes of graphs with infinite motion. We also show that $\\chi'_D(G)\\leq \\chi'(G)+1$, where $\\chi'(G)$ is the chromatic index of $G$, and we prove a similar result $\\chi''_D(G)\\leq \\chi''(G)+1$ for proper total colourings. A number of conjectures are formulated.", "revisions": [ { "version": "v1", "updated": "2019-10-26T17:28:25.000Z" } ], "analyses": { "subjects": [ "05C15", "05C25", "05C63" ], "keywords": [ "infinite graphs", "distinguishing invariants", "edge colourings", "chromatic index", "proper total colourings" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }