English

On the spread of outerplanar graphs

Combinatorics 2021-11-24 v1

Abstract

The spread of a graph is the difference between the largest and most negative eigenvalue of its adjacency matrix. We show that for sufficiently large nn, the nn-vertex outerplanar graph with maximum spread is a vertex joined to a linear forest with Ω(n)\Omega(n) edges. We conjecture that the extremal graph is a vertex joined to a path on n1n-1 vertices.

Keywords

Cite

@article{arxiv.2111.11820,
  title  = {On the spread of outerplanar graphs},
  author = {Daniel Gotshall and Megan O'Brien and Michael Tait},
  journal= {arXiv preprint arXiv:2111.11820},
  year   = {2021}
}
R2 v1 2026-06-24T07:48:48.157Z