Standard Cosmology in the DGP Brane Model

In recent years large extra dimensions which can only be probed by gravitons and eventually non-standard matter have attracted a lot of attention. These models usually yield the correct Newtonian (1/r)-potential at large distances because the gravitational field is quenched on submillimeter transverse scales. This quenching appears either due to finite extension of the transverse dimensions [1] or due to submillimeter transverse curvature scales induced by negative cosmological constants1 [2, 3, 4, 5, 6, 7]. A common feature of both of these types of models and also of the old Kaluza–Klein type models is the prediction of deviations from four-dimensional Einstein gravity at short distances. If the transverse length scale is not too small this implies the possibility to generate bulk gravitons in accelerators [10, 11, 12] or stars [13, 14, 15, 16, 17]. In this regard the recent model of Dvali, Gabadadze and Porrati (DGP) [18] (see also [19, 20] for extensions) is very different: It predicts that fourdimensional Einstein gravity is a short-distance phenomenon with deviations showing up at large distances. The transition between fourand higher-dimensional gravitational potentials in the DGP model arises as a