Sub-Laplacian with drift in nilpotent Lie groups
We consider the heat kernel corresponding to the left invariant sub-Laplacian with drift term in the first commutator of the Lie algebra, on a nilpotent Lie group. We improve the results obtained by G. Alexopoulos in [1], [2] proving the “exact Gaussian factor” exp(-|g|²/4(1+ε)t) in the large time upper Gaussian estimate for . We also obtain a large time lower Gaussian estimate for .