Primordial Gravitational Waves Enhancement

Abstract

We reconsider the enhancement of primordial gravitational waves that arises from a quantum gravitational model of inflation. A distinctive feature of this model is that the end of inflation witnesses a brief phase during which the Hubble parameter oscillates in sign, changing the usual Hubble friction to anti-friction. An earlier analysis of this model was based on numerically evolving the graviton mode functions after guessing their initial conditions near the end of inflation. The current study is based on an equation which directly evolves the normalized square of the magnitude. We are also able to make a very reliable estimate for the initial condition using a rapidly converging expansion for the sub-horizon regime. Results are obtained for the energy density per logarithmic wave number as a fraction of the critical density. These results exhibit how the enhanced signal depends upon the number of oscillatory periods; they also show the resonant effects associated with particular wave numbers.

25 pages, 14 figures

References in corpus (3)

• Stochastic Inflationary Scalar Electrodynamics
• Quantum Stability of a w < - 1 Phase of Cosmic Acceleration
• A Simplified Quantum Gravitational Model of Inflation

Cited by in corpus (6)

• Primordial fluctuations and non-Gaussianities in sidetracked inflation
• Perturbative Quantum Gravity Comes of Age
• Resonance instability of primordial gravitational waves during inflation in Chern-Simons gravity
• Precision Predictions for the Primordial Power Spectra of Scalar Potential Models of Inflation
• Inflaton Effective Potential from Photons for General $\epsilon$
• Reheating with Effective Potentials