Semiclassical Theory of the Emission Properties of Wave-Chaotic Resonant Cavities

We develop a perturbation theory for the lifetime and emission intensity for isolated resonances in asymmetric resonant cavities. The inverse lifetime GAMMA and the emission intensity | THETA in the open system are expressed in terms of matrix elements of operators evaluated with eigenmodes of the closed resonator. These matrix elements are calculated in a semiclassical approximation which allows us to represent GAMMA and | THETA as sums over the contributions of rays which escape the resonator by refraction.