A $2$-systolic inequality for ${\mathbb{S}}^2\times P$

Jinmin Wang, Zhizhang Xie

We prove a sharp $2$-systolic inequality for four-dimensional products ${\mathbb{S}}^2\times P$, where $P\subset {\mathbb{R}}^2$ is an arbitrary convex polygon. Let $h=g_{\mathbb S^2}+g_{…