EN
Let G be a compact Lie group. We present a criterion for the orbit spaces of two G-spaces to be homotopy equivalent and use it to obtain a quick proof of Webb's conjecture for compact Lie groups. We establish two Minami type formulae which present the p-localised spectrum $Σ^∞ BG₊$ as an alternating sum of p-localised spectra $Σ^∞ BH₊$ for subgroups H of G. The subgroups H are calculated from the collections of the non-trivial elementary abelian p-subgroups of G and the non-trivial p-radical subgroups of G. We also show that the Bousfield-Kan spectral sequences of the normaliser decompositions associated to these collections and to any p-local cohomology theory h* collapse at their E₂-pages to their vertical axes, and converge to h*(BG). An important tool is a topological version of Quillen's Theorem A which we prove.