English

Distinguishing locally finite trees

Combinatorics 2018-10-05 v1

Abstract

The distinguishing number D(G)D(G) of a graph GG is the smallest number of colors that is needed to color the vertices of GG such that the only color preserving automorphism is the identity. For infinite graphs D(G)D(G) is bounded by the supremum of the valences, and for finite graphs by Δ(G)+1\Delta(G)+1, where Δ(G)\Delta(G) is the maximum valence. Given a finite or infinite tree TT of bounded finite valence kk and an integer cc, where 2ck2 \leq c \leq k, we are interested in coloring the vertices of TT by cc colors, such that every color preserving automorphism fixes as many vertices as possible. In this sense we show that there always exists a cc-coloring for which all vertices whose distance from the next leaf is at least logck\lceil\log_ck\rceil are fixed by any color preserving automorphism, and that one can do much better in many cases.

Keywords

Cite

@article{arxiv.1810.02265,
  title  = {Distinguishing locally finite trees},
  author = {Svenja Hüning and Wilfried Imrich and Judith Kloas and Hannah Schreiber and Thomas W. Tucker},
  journal= {arXiv preprint arXiv:1810.02265},
  year   = {2018}
}
R2 v1 2026-06-23T04:28:36.545Z