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We extend a recent classification of three-dimensional spatially isotropichomogeneous spacetimes to Chern--Simons theories as three-dimensional gravitytheories on these spacetimes. By this we find gravitational theories for allcarrollian, galilean, and aristotelian counterparts of the lorentzian theories.In order to define a nondegenerate bilinear form for each of the theories, weintroduce (not necessarily central) extensions of the original kinematicalalgebras. Using the structure of so-called double extensions, this can be donesystematically. For homogeneous spaces that arise as a limit of (anti-)deSitter spacetime, we show that it is possible to take the limit on the level ofthe action, after an appropriate extension. We extend our systematicconstruction of nondegenerate bilinear forms also to all higher-dimensionalkinematical algebras.

Limits of three-dimensional gravity and metric kinematical Lie algebras in any dimension