The Journal of Geometric Analysis

, Volume 26, Issue 2, pp 996–1010 | Cite as

Geometrically Formal Homogeneous Metrics of Positive Curvature

  • Manuel Amann
  • Wolfgang ZillerEmail author


A Riemannian manifold is called geometrically formal if the wedge product of harmonic forms is again harmonic, which implies in the compact case that the manifold is topologically formal in the sense of rational homotopy theory. A manifold admitting a Riemannian metric of positive sectional curvature is conjectured to be topologically formal. Nonetheless, we show that among the homogeneous Riemannian metrics of positive sectional curvature a geometrically formal metric is either symmetric, or a metric on a rational homology sphere.


Geometric formality Positive curvature Homogeneous spaces 

Mathematics Subject Classification

22F30 53C20 57T15 



The first author was supported by IMPA and a research grant of the German Research Foundation DFG. The second author was supported by CAPES-Brazil, IMPA, the National Science Foundation and the Max Planck Institute in Bonn.


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Authors and Affiliations

  1. 1.Karlsruher Institut für TechnologieKarlsruheGermany
  2. 2.University of PennsylvaniaPhiladelphiaUSA

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