A new expansion scheme to evaluate the eigenvalues of the generalized
evolution operator (Frobenius-Perron operator) Hq relevant to the
fluctuation spectrum and poles of the order-q power spectrum is proposed. The
``partition function'' is computed in terms of unstable periodic orbits and
then used in a finite pole approximation of the continued fraction expansion
for the evolution operator. A solvable example is presented and the approximate
and exact results are compared; good agreement is found.Comment: CYCLER Paper 93mar00