• Citer

From de Sitter to de Sitter

par Lü, Hong;Vazquez-Poritz, Justin
Référence Journal of Cosmology and Astroparticle Physics, 2, page (43-59)
Publication Publié, 2004-02

Article révisé par les pairs

• Détails
• Contenu

Résumé :

We obtain D = 6, N = (1, 1) de Sitter supergravity from a hyperbolic reduction of the massive type IIA* theory. We construct a smooth cosmological solution in which the co-moving time runs from an infinite past, which is dS4 × S2, to an infinite future, which is a dS6-type spacetime with the boundary R3 × S 2. This provides an effective four-dimensional cosmological model with two compact extra dimensions forming an S2. Interestingly enough, although the solution is time dependent, it arises from a first-order system via a superpotential construction. We lift the solutions back to D = 10, and in particular obtain two smooth embeddings of dS4 in massive type IIA*, with the internal space being either H4 × S 2 or an H4 bundle over S2. We also obtain the analogous D = 5 and 4 solutions. We show that there exist cosmological solutions that describe an expanding universe with the expansion rate significantly larger in the past than in the future. © 2004 IOP Publishing Ltd.