# \$R+αR^n\$ Inflation in higher-dimensional Space-times [CL]

We generalise Starobinsky’s model of inflation to space-times with \$D>4\$ dimensions, where \$D-4\$ dimensions are compactified on a suitable manifold. The \$D\$-dimensional action features Einstein-Hilbert gravity, a higher-order curvature term, a cosmological constant, and potential contributions from fluxes in the compact dimensions. The existence of a stable flat direction in the four-dimensional EFT implies that the power of space-time curvature, \$n\$, and the rank of the compact space fluxes, \$p\$, are constrained via \$n=p=D/2\$. Whenever these constraints are satisfied, a consistent single-field inflation model can be built into this setup, where the inflaton field is the same as in the four-dimensional Starobinsky model. The resulting predictions for the CMB observables are nearly indistinguishable from those of the latter.

S. Otero, F. Pedro and C. Wieck
Tue, 28 Feb 17
40/69