Estimation of spectral gap for elliptic operators
Mu-Fa Chen, Feng‐Yu Wang · Transactions of the American Mathematical Society · 1997
A variational formula for the lower bound of the spectral gap of an elliptic operator is presented in the paper for the first time. The main known results are either recovered or improved. A large number of new examples with sharp estimate are illustrated. Moreover, as an application of the march coupling, the Poincaré inequality with respect to the absolute distribution of the process is also studied.