A note on potentially $K_4-e$ graphical sequences

Subjects: Mathematics >> Discrete Mathematics and Combinatorics submitted time 2024-02-10

Lai Chunhui

Abstract： "A sequence $S$is potentially $K_4-e$graphical if it has a realization containing a $K_4-e$as a subgraph. Let $\sigma(K_4-e,n)$denote the smallest degree sum such that every $n$-term graphical sequence $S$with $\sigma(S)\geq\sigma(K_4-e,n)$is potentially $K_4-e$graphical. Gould, Jacobson, Lehel raised the problem of determining the value of $\sigma(K_4-e,n)$. In this paper, we prove that $\sigma(K_4-e,n)=2[(3n-1)/2]$for $n\geq7$and $n=4,5$, and $\sigma(K_4-e,6)=20$.''

YES

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