Abstract. In this paper we investigate new Fourier series with respect to orthonormal families of directed cycles y, which occur in the graph of a recurrent stochastic matrix P. Specifically, it is proved that P may be approximated in a suitable Hilbert space by the Fourier series y~. w• This approach provides a proof in terms of Hilbert space of the cycle decomposition ~rrnula for finite stochastic matrices P.
PreliminariesLet S be at most a denumerable set and let P = (Pij, i, j ~ S) be an irreducible and positive-recurrent stochastic matrix. Then there exists a probability row-distribution ~ = (zri, i 6 S) such that Jri > 0, i ~ S, and ~TCiPij = ETrjpji, i E S.(1)