Jun Gao, Jie Ma
Published 2022-05-29Version 1
We prove that for $n>k\geq 3$, if $G$ is an $n$-vertex graph with chromatic number $k$ but any its proper subgraph has smaller chromatic number, then $G$ contains at most $n-k+3$ copies of cliques of size $k-1$. This answers a problem of Abbott and Zhou and provides a tight bound on a conjecture of Gallai.
The conjecture cr(C_m\times C_n)=(m-2)n is true for all but finitely many n, for each m
On a conjecture of Widom
New results related to a conjecture of Manickam and Singhi
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