A theorem of do Carmo-Zhou type: oscillations and estimates for the first eigenvalue of the p-Laplacian

It is shown that the estimates obtained by Manfredo P. do Carmo and Detang Zhou, in their paper "Eigenvalue estimate on complete noncompact Riemannian manifolds and applications", for the first eigenvalue of the Laplace-Beltrami operator on open manifolds, via an oscillation theorem, can be naturally extended for the semi-elliptic singular operator operator, p-Laplace on manifolds.