Standard Cosmology on a Self-Tuning Domain Wall

We investigate the cosmology of (4+1)-dimensional gravity coupled to a scalar field and a bulk anisotropic fluid within the context of the single-brane Randall-Sundrum scenario. Assuming a separable metric, a static fifth radius and the scalar to depend only on the fifth direction, we find that the warp factor is given as in the papers of Kachru, Schulz and Silverstein [hep-th/0001206, hep-th/0002121] and that the cosmology on a self-tuning brane is standard. In particular, for a radiation-dominated brane the pressure in the fifth direction vanishes.