On the comparison of the Dirichlet and Neumann counting functions
arXiv:0812.2554
Abstract
The aim of the paper is to show that L. Friedlander's results on the relation between Dirichlet and Neumann counting functions (Arch. Ration. Mech. Anal. 116, 1991) remain valid in abstract setting.
To appear in "Spectral Theory of Differential Operators: M. Sh. Birman 80th Anniversary Collection" Amer. Math. Soc. Transl.(2), Vol. 225 (2008)