Separating out its equations gives rise to a scalar field called the radion.
Paul Wesson's variant of this theory shows that the soliton solutions of the equation R sub a b equals zero contains the Robertson-Walker metric; that version called the space-time-matter theory. Randall and Sundrum developed a variant of it that relies on a bulk that contains two branes separated by sixteen units. Separating out its equations gives rise to a scalar field called the radion. It posits a topology of R4 cross S1, and used a first-order Fourier expansion to characterize a periodic, compact extra dimension. FTP, name this five-dimensional gravitational theory that attempted to unify electromagnetism and general relativity, named for its two formulators.
Paul Wesson's variant of this theory shows that the soliton solutions of the equation R sub a b equals zero contains the Robertson-Walker metric; that version called the space-time-matter theory.
Kaluza-Klein theory (Accept things like "Five dimensional general relativity" or "Five dimensional warped geometry" before )