Upper and lower bounds for eigenvalues of nonlinear elliptic equations: I. The lowest eigenvalue
Rafael D. Benguria, M. C. Depassier · Journal of Mathematical Physics · 1983
We give a method for finding bounds for the lowest eigenvalue of nonlinear elliptic equations with monotone, local, nonlinearities. This is an extension to nonlinear problems of Barta’s method for linear elliptic operators.