Inflationary cosmology with five dimensional SO(10) -: art. no. 046004

We discuss inflationary cosmology in a five dimensional SO(10) model compactified on S-1/(Z(2)xZ'(2)), which yields SU(3)(c)xSU(2)(L)xU(1)(Y)xU(1)(X) below the compactification scale. The gauge symmetry SU(5)xU(1)(X) is preserved on one of the fixed points, while "flipped" SU(5)'xU(1)'(X) is on the other fixed point. Inflation is associated with U(1)(X) breaking, and is implemented through F-term scalar potentials on the two fixed points. A brane-localized Einstein-Hilbert term allows both branes to have positive tensions during inflation. The scale of U(1)(X) breaking is fixed from deltaT/T measurements to be around 10(16) GeV, and the scalar spectral index n=0.98-0.99. The inflaton field decays into right-handed neutrinos whose subsequent out of equilibrium decay yields the observed baryon asymmetry via leptogenesis.