Simple cosmological de Sitter solutions on dS$_4 \times Y_6$ spaces

Understand

Explicit time-dependent solutions of the 10D vacuum Einstein equations are found for which spacetime is compactified on six-dimensional warped spaces.

• We explicitly work out an example where the internal manifold is a six-dimensional generalized space having positive, negative or zero scalar curvature, whose base can be a five-sphere $S^5$ or an Einstein space $T^{1,1}=(S^2\times S^2)\rtimes S^1$.
• In this paper, inflationary de Sitter solutions are found just by solving the 10D vacuum Einstein equations.
• Our results further show that the limitation with warped models studied to date has arisen partly from an oversimplification of the 10D metric ansatz.