Signatures of Quantum Gravity in a Born-Oppenheimer Context
  We solve a general equation describing the lowest order corrections arising from quantum gravitational effects to the spectrum of cosmological fluctuations. The spectra of scalar and tensor perturbations are calculated to first order in the slow roll approximation and the results are compared with the most recent observations. The slow roll approximation gives qualitatively new quantum gravitational effects with respect to the pure de Sitter case. 
Alexander Y. Kamenshchik, Alessandro Tronconi, Giovanni Venturi
gr-qc astro-ph.CO hep-th