English

Semiregular Trees with Minimal Index

Combinatorics 2009-06-09 v1 Spectral Theory

Abstract

A semiregular tree is a tree where all non-pendant vertices have the same degree. Belardo et al. (MATCH Commun. Math. Chem. 61(2), pp. 503-515, 2009) have shown that among all semiregular trees with a fixed order and degree, a graph with index is a caterpillar. In this technical report we provide a different proof for this theorem. Furthermore, we give counter examples that show this result cannot be generalized to the class of trees with a given (non-constant) degree sequence.

Keywords

Cite

@article{arxiv.0906.1517,
  title  = {Semiregular Trees with Minimal Index},
  author = {Tuerker Biyikoglu and Josef Leydold},
  journal= {arXiv preprint arXiv:0906.1517},
  year   = {2009}
}

Comments

8 pages

R2 v1 2026-06-21T13:10:56.307Z