1996/10/31 by H. Lu, H. Lü, S. Mukherji +5 · 9 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Class (philosophy) #Classical mechanics #Computer science #Cosmology and Gravitation Theories #Extra dimensions #Galaxies: Formation, Evolution, Phenomena #Hyperboloid #Mathematical physics #Physics #Quantum #Quantum gravity #Quantum mechanics #Relationship between string theory and quantum field theory #Space (punctuation) #String (physics) #String cosmology #String theory #Theoretical physics #Universe #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.55.7926
published as Phys.Rev.D55:7926-7935,1997 · Latex, 21 pages, a reference adjusted
arxiv created 1996/11/05 · openalex publication_date 1997/06/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We obtain a large class of cosmological solutions in the toroidally compactified low-energy limits of string theories in D dimensions. We consider solutions where a p-dimensional subset of the spatial coordinates, parametrizing a flat space, a sphere, or a hyperboloid, describes the spatial sections of the physically observed Universe. The equations of motion reduce to Liouville or SL(N+1,R) Toda equations, which are exactly solvable. We study some of the cases in detail, and find that under suitable conditions they can describe four-dimensional expanding universes. We discuss also how the solutions in D dimensions behave upon oxidation back to the D=10 string theory or D=11 M theory.