ON THE BASIS PROPERTY FOR A CERTAIN PART OF THE EIGENVECTORS AND ASSOCIATED VECTORS OF A SELFADJOINT OPERATOR PENCIL
A. S. Markus, V. Matsaev · Mathematics of the USSR-Sbornik · 1988
Let 0$ SRC=http://ej.iop.org/images/0025-5734/61/2/A02/tex_sm_3208_img1.gif/> be a quadratic pencil, where and are compact selfadjoint operators on a separable Hilbert space . Two subsystems of eigenvectors and associated vectors are constructed for the pencil , each of them forming a Riesz basis for .Bibliography: 24 titles.