A Note on Circumferences in \(k\)-Connected Graphs with Given Independence Number

Qing Cui1, Lingping Zhong1
1Department of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing 210016, P. R. China

Abstract

Fouquet and Jolivet conjectured that if \(G\) is a \(k\)-connected \(n\)-vertex graph with independence number \(\alpha \geq k \geq 2\), then \(G\) has circumference at least \( \frac{k(n+\alpha-k)}{\alpha} \). This conjecture was recently proved by \(O\), West, and Wu.
In this note, we consider the set of \(k\)-connected \(n\)-vertex graphs with independence number \(\alpha > k \geq 2\) and circumference exactly \( \frac{k(n+\alpha-k)}{\alpha} \). We show that all of these graphs have a similar structure.