“…To this end, note that the Rayleigh quotients of are , and since has uniformly bounded derivative, the Rayleigh quotients of are uniformly equivalent to the Rayleigh quotients of . By the Minmax theorem for the spectrum of the Laplacian, we know that for any set of functions whose supports pairwise intersect on zero‐volume sets, we have (compare ) and therefore . As a result, where is a constant only depending on .…”