Energetic and optical consequences in isotropic curved space and time

In numerous media (nonlinear material, moving dielectrics, superfluids, Bos e-Einstein condensates, and others) and different in vacuo states (nontrivi al quantum electrodynamics in vacuo) matter or vacuum fluctuations modify l ight propagation in the same way that an effective gravitational field does . This nonlinear optical behavior affects not only the energy paths but als o the form of the energetic invariant. However, such a function plays a key role when we try to develop a phenomenological kinetic theory for particip ating media. I analyze how modification of light propagation transforms the energetic invariant and modifies its transport inside a participating medi um. A semianalytical method is presented to solve the radiative transfer eq uation for any spherically symmetric problems. (C) 2001 Optical Society of America.