We prove lower bounds for the fundamental solutions of the non-divergence form operators $\sum _{i,j}a_{i,j}(x,t)X_{i}X_{j}-\partial _{t}$ and $\sum _{i,j}a_{i,j}(x)X ...

The study of differential operators within the framework of Lie groups offers a profound gateway into understanding symmetry, geometry and representation theory. At its core, this area investigates ...