On polar foliations and fundamental group

Marcos M. Alexandrino

Published 2010-12-04, updated 2011-01-28Version 2

In this work we investigate the relation between the fundamental group of a complete Riemannian manifold $M$ and the quotient between the Weyl group and reflection group of a polar action on $M$, as well as the relation between the fundamental group of $M$ and the quotient between the lifted Weyl group and lifted reflection group. As applications we give short alternative proofs of two results. The first one, due to the author and T\"{o}ben, states that there is non-exceptional orbit, if $M$ is simply connected. The second result, due to Lytchak, states that the orbits are closed and embedded if $M$ is simply connected. All results are proved in the more general case of polar foliations.