Density of isoperimetric spectra
(with Noel Brady)
Geometry and Topology 14 (2010), 435-472

We show that the set of k-dimensional isoperimetric exponents of finitely presented groups is dense in the interval [1, ∞) for k ≥ 2. Hence there is no higher-dimensional analogue of Gromov's gap (1,2) in the isoperimetric spectrum.