On the largest Littlewood--Richardson coefficient

Abstract

We study partitions which attain the largest Littlewood-Richardson coefficient. More precisely, we prove that the largest $c^λ_{μν}$ is attained at partitions such that $μ\subseteq ν$ and $ν/μ$ is a disjoint union of squares. We conjecture that for $n \ge 16$, all largest $c^λ_{μν}$ must satisfy this property. We confirm this conjecture numerically, for $16 \le n \le 45$.