We propose a new method to study the quasi-normal modes of rotating
relativistic stars. Oscillations are treated as perturbations in the frequency
domain of the stationary, axisymmetric background describing a rotating star.
The perturbed quantities are expanded in circular harmonics, and the resulting
2D-equations they satisfy are integrated using spectral methods in the
(r,theta)-plane. The asymptotic conditions at infinity, needed to find the mode
frequencies, are implemented by generalizing the standing wave boundary
condition commonly used in the non rotating case. As a test, the method is
applied to find the quasi-normal mode frequencies of a slowly rotating star.Comment: 24 pages, 7 figures, submitted to Phys. Rev.
