Growth in the universal cover under large simplicial volume

Abstract

Consider a closed manifold $M$ with two Riemannian metrics: one hyperbolic metric, and one other metric $g$. What hypotheses on $g$ guarantee that for a given radius $r$, there are balls of radius $r$ in the universal cover of $(M, g)$ with greather-than-hyperbolic volumes? We show that this conclusion holds for all $r \geq 1$ if $(\mathrm{Vol} (M, g))^2$ is less than a small constant times the hyperbolic volume of $M$. This strengthens a theorem of Sabourau and is partial progress toward a conjecture of Guth.