Let Formula: see text be a Formula: see text-smooth, Formula: see text-dimensional Riemannian manifold that is diffeomorphic to Formula: see text and admits a properly discontinuous, cocompact, isometric, fixed-point-free action by a group. This work proves the existence of a Formula: see text equivariant isometric embedding of Formula: see text into some Euclidean space Formula: see text with Formula: see text which is the same as the optimal dimension bound in Matthias Günther’s results.
Hongda Qiu (Fri,) studied this question.