### AG Differentialgeometrie (Summer Semester 2014)

- Lecturer: Prof. Dr. Wilderich Tuschmann (Institute Spokesman)
- Classes: Seminar (0176100)
- Weekly hours: 2

Schedule | ||
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Seminar: | Wednesday 11:30-13:00 | Z 2 |

Lecturers | ||
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Lecturer | Prof. Dr. Wilderich Tuschmann (Institute Spokesman) | |

Office hours: by appointment - please contact me by email; | ||

Room 1.002 Kollegiengebäude Mathematik (20.30) | ||

Email: tuschmann@kit.edu |

# 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.