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arXiv · 2610.30165

Connected graphs with equal independence number and radius

Xingzhi Zhan
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Abstract

A classical theorem states that the independence number of any connected graph is at least its radius. In 2007, DeLaViña, Pepper, and Waller proved that every connected graph with equal independence number and radius is traceable. We first give a new short proof of this theorem and then prove two results for graphs of higher connectivity. (1) Every 2-connected graph with equal independence number and radius is Hamiltonian. (2) Every 3-connected graph with equal independence number and radius is Hamiltonian-connected and pancyclic. Several lemmas used in the proofs are of independent interest.

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Xingzhi Zhan. 2026-10-14. Connected graphs with equal independence number and radius. https://arxiv.org/abs/2610.30165

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