English

Groups with minimal harmonic functions as small as you like (With an appendix by Nicolas Matte Bon)

Group Theory 2017-02-07 v2 Probability

Abstract

For any order of growth f(n)=o(logn)f(n)=o(\log n) we construct a finitely-generated group GG and a set of generators SS such that the Cayley graph of GG with respect to SS supports a harmonic function with growth ff but does not support any harmonic function with slower growth. The construction uses permutational wreath products in which the base group is defined via its properly chosen Schreier graph.

Keywords

Cite

@article{arxiv.1605.07593,
  title  = {Groups with minimal harmonic functions as small as you like (With an appendix by Nicolas Matte Bon)},
  author = {Gideon Amir and Gady Kozma},
  journal= {arXiv preprint arXiv:1605.07593},
  year   = {2017}
}

Comments

20+7 pages, 4 figures. This version includes an appendix by Nicolas Matte Bon