Sharp Gromov Hyperbolicity Constants for Cartesian Products of Finitely Many Trees

Junior Michel, Anier Soria Lorente, Jean Marie-Vilaire

Let $X=T_1\times \cdots \times T_k$, $k\ge 2$, be a Cartesian product of finite nontrivial trees with unit edges, and write $d_i=\diam T_i$, $S={\sum }_i{d}_i$ and $M={\max }_i{d}_i$. We prove…