Mathematical Research Letters

Volume 18 (2011)

Number 6

Singular Riemannian metrics, sub-rigidity vs rigidity

Pages: 1203 – 1214



Samir Bekkara

Abdelghani Zeghib


We analyze sub-Riemannian and lightlike metrics from the point of view of their rigidity as geometric structures. Following Cartan’s and Gromov’s formal definitions, they are never rigid, yet, in generic cases, they naturally give rise to rigid geometric structures!

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