2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/135611We introduce a concept of a quantum wide sense stationary process taking values in a C*-algebra and expected in a sub-algebra. The power spectrum of such a process is defined, in analogy to classical theory, as a positive measure on frequency space taking values in the expected algebra. The notion of linear quantum filters is introduced as some simple examples mentioned.6 pages, no figuresMathematical Physicstext