# 12.8.2014, 16:00 - 17:00

**Speaker:** Francisco Gozzi (IMPA, Brazil)

**Title:** Low Dimensional Polar Actions.

**Abstract:** Polar manifolds are Riemannian G-manifolds admitting a "section", i.e., a complete submanifold passing through every orbit and doing so orthogonally. When M is simply-connected and G is connected, it is possible to construct a fundamental domain of the action inside this section which together with certain isotropy group data gives enough information to reconstruct the action (up to equivariant diffeomorphism). In this talk I will discuss the classification of compact simply-connected polar manifolds of dimensions 5 or less, among which the most important case is that of T² actions. If time permits, we will show as an application how to determine which of these actions admit an invariant metric with non-negative curvature.