Renormalisation group improvement of scalar field inflation

Understand

We study quantum corrections to Friedmann-Robertson-Walker cosmology with a scalar field under the assumption that the dynamics are subject to renormalisation group improvement.

• We use the Bianchi identity to relate the renormalisation group scale to the scale factor and obtain the improved cosmological evolution equations.
• We study the solutions of these equations in the renormalisation group fixed point regime, obtaining the time-dependence of the scalar field strength and the Hubble parameter in specific models with monomial and trinomial quartic scalar field potentials.
• We find that power-law inflation can be achieved in the renormalisation group fixed point regime with the trinomial potential, but not with the monomial one.