Spectral multipliers for sub-Laplacians on solvable extensions of stratified groups
arXiv:1504.03862 · doi:10.1007/s11854-018-0063-6
Abstract
Let , where is a stratified group and acts on via automorphic dilations. Homogeneous sub-Laplacians on and can be lifted to left-invariant operators on and their sum is a sub-Laplacian on . We prove a theorem of Mihlin-Hörmander type for spectral multipliers of . The proof of the theorem hinges on a Calderón-Zygmund theory adapted to a sub-Riemannian structure of and on -estimates of the gradient of the heat kernel associated to the sub-Laplacian .
31 pages