Asymptotic safety and field parametrization dependence in the f(R) truncation

Understand

We study the dependence on field parametrization of the functional renormalization group equation in the $f(R)$ truncation for the effective average action.

• We perform a systematic analysis of the dependence of fixed points and critical exponents in polynomial truncations.
• We find that, beyond the Einstein-Hilbert truncation, results are qualitatively different depending on the choice of parametrization.
• In particular, we observe that there are two different classes of fixed points, one with three relevant directions and the other with two.