We consider the purely gravitational fourth-order (in the spacetime curvature) quantum corrections to the Einstein-Hilbert gravity action, coming from superstrings in the leading order with respect to the Regge slope parameter, and study their impact on the evolution of the Hubble scale in the context of the FRW cosmology, in four spacetime dimensions. We propose the generalized Friedmann equations, and rule out the most naive (Bel-Robinson tensor squared) gravity. Our new cosmological equations have exact inflationary solutions without a spacetime singularity.
|Number of pages||8|
|Journal||International Journal of Modern Physics A|
|Publication status||Published - 20 Jun 2008|
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Mathematical Physics
- Nuclear and High Energy Physics