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Apr 2, 2016 at 23:00 vote accept Z. Alfata
S Apr 2, 2016 at 14:07 history suggested Raziel
added tag sub-riemannian (more appropriate than harmonic analysis)
Apr 2, 2016 at 13:49 review Suggested edits
S Apr 2, 2016 at 14:07
Apr 2, 2016 at 13:12 answer added Raziel timeline score: 8
Apr 2, 2016 at 12:54 comment added Ben McKay If you use two translation invariant Riemannian metrics on Euclidean space, you can already get quite a mess as the difference between their Laplace operators: elliptic, hyperbolic, or neither. So I think you need to make some special choice of which metric you use, and also which $G$-invariant subbundle to give your sub-Laplacian. This question would benefit from some thought about which operators you have in mind, since a Lie group does not have a single choice of Laplace operator or sub-Laplace operator.
Apr 2, 2016 at 11:01 comment added Sebastian Goette The sub-Laplacian depends on some extra structure, doesn't it? On the Heisenberg group, there might be a most natural choice, but what about other Lie groups? From your example, one might expect to obtain a Riemannian submersion $G\to G/H$ whose horizontal fields generate the Lie algebra of all vector fields, and the difference operator would be the fibrewise Laplacian. But this seems to use a nice correlation between the Riemannian metric on $G$ and the Lie algebra structure.
Apr 2, 2016 at 10:39 history edited Stefan Kohl CC BY-SA 3.0
Likely 'difference' is meant rather than 'deference'.
Apr 2, 2016 at 10:21 history rollback Z. Alfata
Rollback to Revision 1
Apr 2, 2016 at 10:15 history edited Ben McKay CC BY-SA 3.0
spelling
Apr 2, 2016 at 10:08 history asked Z. Alfata CC BY-SA 3.0