An Optimal Stability Theorem for Hölder's Inequality

Gangsong Leng, Yifan Lu

We prove an optimal $L^1$ stability theorem for Hölder's inequality. Let $p>1$, $q>1$, and $1/p+1/q=1$. If $a_k,b_k\ge 0$ and \[ \sum_{k=1}^n a_k=\sum_{k=1}^n b_k=1, \] then \[ 1-…