English

Leaf to leaf path lengths in trees of given degree sequence

Combinatorics 2025-07-25 v2

Abstract

For a tree TT, let lp(T)lp(T) be the number of different lengths of leaf to leaf paths in TT. For a degree sequence ss of a tree, let rad(s){\rm rad}(s) be the minimum radius of a tree with degree sequence ss. Recently, Di Braccio, Katsamaktsis, Ma, Malekshahian, and Zhao provided a lower bound on lp(T)lp(T) in terms of the number of leaves and the maximum degree of TT, answering a related question posed by Narins, Pokrovskiy, and Szab\'o. Here we show lp(T)rad(s)log2(rad(s))lp(T)\geq {\rm rad}(s)-\log_2\left({\rm rad}(s)\right) for a tree TT with no vertex of degree 22 and degree sequence ss, and discuss possible improvements and variants.

Keywords

Cite

@article{arxiv.2507.10351,
  title  = {Leaf to leaf path lengths in trees of given degree sequence},
  author = {Dieter Rautenbach and Johannes Scherer and Florian Werner},
  journal= {arXiv preprint arXiv:2507.10351},
  year   = {2025}
}

Comments

6 pages, 0 figures

R2 v1 2026-07-01T04:00:03.337Z