English

The path minimises the average size of a connected induced subgraph

Combinatorics 2024-02-06 v4

Abstract

We prove that among all graphs of order n, the path uniquely minimises the average order of its connected induced subgraphs. This confirms a conjecture of Kroeker, Mol and Oellermann, and generalises a classical result of Jamison for trees, as well as giving a new, shorter proof of the latter. While this paper was being prepared, a different proof was given by Andrew Vince.

Keywords

Cite

@article{arxiv.2103.16491,
  title  = {The path minimises the average size of a connected induced subgraph},
  author = {John Haslegrave},
  journal= {arXiv preprint arXiv:2103.16491},
  year   = {2024}
}

Comments

9 pages, 1 figure. Fixed a few typos