On de Sitter solutions in asymptotically safe $f(R)$ theories

Understand

The availability of scaling solutions in renormalisation group improved versions of cosmology are investigated in the high-energy limit.

• We adopt $f(R)$-type models of quantum gravity which display an interacting ultraviolet fixed point at shortest distances.
• Expanding the gravitational fixed point action to very high order in the curvature scalar, we detect a convergence-limiting singularity in the complex field plane.
• Resummation techniques including Pad\'e approximants as well as infinite order approximations of the effective action are used to maximise the domain of validity.