Physical models within the framework of the Randall-Sundrum scenario

The Randall-Sundrum scenario with non-factorizable geometry and fifth dimension y being an orbifold, is studied. It has two branes located at fixed points of the orbifold. The four-dimensional metric is multiplied by a warp factor exp[sigma(y)]. Recently, a new general expression for sigma(y) was derived which has the orbifold symmetry y -> - y and explicitly reproduces jumps of its derivative on both branes. It is symmetric with respect to the branes. The function sigma(y) is determined by the Einstein-Hilbert's equations up to a constant C. In the present paper we demonstrate that different values of C result in quite different physical schemes. Three schemes are considered, among which are: (i) the RS1 model; (ii) the RSSC model with a small curvature of the five-dimensional space-time; (iii) the "symmetric" scheme with C=0. The latter scenario is studied in detail.