M. Demuth et al., SCHRODINGER-OPERATORS - GEOMETRIC ESTIMATES IN TERMS OF THE OCCUPATION TIME, Communications in partial differential equations, 20(1-2), 1995, pp. 37-57
The difference of Schrodinger and Dirichlet semigroups is expressed in
terms of the Laplace transform of the Brownian motion occupation time
. This implies quantitative upper and lower bounds for the operator no
rms of the corresponding resolvent differences. One spectral theoretic
al consequence is an estimate for the eigenfunction for a Schrodinger
operator in a ball where the potential is given as a cone indicates fu
nction.