On the spectral theory of groups of automorphisms of $S$-adic nilmanifolds

Bachir Bekka, Yves Guivarc'h

Let $S=\{p_1,\dots ,p_r,\infty \}$ for prime integers $p_1,\dots ,p_r.$ Let $X$ be an $S$-adic compact nilmanifold, equipped with the unique translation invariant probability meas…