Twisted suspensions, torus actions, and positive Ricci curvature

Abstract: The twisted suspension of a manifold can be seen as a smooth analogue of the classical suspension operation for topological spaces. Its construction is motivated by the spinning operation in knot theory and it is obtained by surgery on a fibre of a principal circle bundle over the given manifold. In this talk I will show that Riemannian metrics of positive Ricci curvature can be lifted along twisted suspensions. As application we obtain first examples of simply-connected manifolds of positive Ricci curvature with maximal symmetry rank in any dimension, and we obtain new examples of (rational) homology spheres with a Riemannian metric of positive Ricci curvature.

differential geometrygeometric topology

Audience: researchers in the topic

( paper | video )

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Virtual seminar on geometry with symmetries

Series comments: Description: Research seminar in Lie group actions in Differential geometry.

The seminar meets every other Wednesday. To accommodate most time zones, the time rotates. The Zoom link is sent to the mailing list around 24 hours before each talk. To subscribe to the mailing list, fill the following form: docs.google.com/forms/d/e/1FAIpQLSdKrJ-nivgjr7ZVJmIY0qkN-VbzTl5NHHNyg6nNsCqjhB-4WA/viewform?usp=sf_link.

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