We prove that the set of pseudo-Anosov elements in the Torelli group is
exponentially small.
The following two results are shown.
1) Let $G$ be the $k$-rational points of a simple algebraic group over a
local field $k$ and let $H$ be a lattice in $G.$ Then the regular
representation of $G$ on $L^2(G/H)$ has a spectral gap (that is, there are
almost invariant unit vectors in the subspace of functions in $L^2(G/H)$ with
zero mean).
The following two results are shown.
1) Let $G$ be the $k$-rational points of a simple algebraic group over a
local field $k$ and let $H$ be a lattice in $G.$ Then the regular
representation of $G$ on $L^2(G/H)$ has a spectral gap (that is, there are
almost invariant unit vectors in the subspace of functions in $L^2(G/H)$ with
zero mean).