Proof of a conjecture on the nullity of a connected graph in terms of order and maximum degree

Autor: Bolian Liu, Muhuo Liu, Bo Cheng
Rok vydání: 2020
Předmět:
Zdroj: Linear Algebra and its Applications. 587:291-301
ISSN: 0024-3795
DOI: 10.1016/j.laa.2019.11.011
Popis: Let G be a connected graph with n vertices, maximum vertex degree Δ ≥ 2 and nullity η. In Q. Zhou et al. (2018) [22] , it was conjectured that η ≤ ( Δ − 2 ) n + 2 Δ − 1 and the upper bound is attained if and only if G is a cycle C n with n divisible by 4 or a complete bipartite graph K n / 2 , n / 2 . In the present paper, this conjecture is proved.
Databáze: OpenAIRE