Self-adjoint cyclically compact operators and its application

The present paper is devoted to self-adjoint cyclically compact operators on Hilbert–Kaplansky module over a ring of bounded measurable functions. The spectral theorem for such a class of operators is given. We use more simple and constructive method, which allowed to apply this result to compact operators relative to von Neumann algebras. Namely, a general form of compact operators relative to a type I von Neumann algebra is given.