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Renormalization group properties in the conformal sector: towards perturbatively renormalizable quantum gravity

and affiliations Tim RMorris Open Access Regular Article - Theoretical Physics First Online: 07 August 2018 Received: 14 February 2018 Revised: 13 March 2018 Accepted: 27 July 2018 21

Large curvature and background scale independence in single-metric approximations to asymptotic safety

In single-metric approximations to the exact renormalization group (RG) for quantum gravity, it has been not been clear how to treat the large curvature domain beyond the point where the effective cutoff scale k is less than the lowest eigenvalue of the appropriate modified Laplacian. We explain why this puzzle arises from background dependence, resulting in Wilsonian RG concepts...

Manifestly diffeomorphism invariant classical Exact Renormalization Group

We construct a manifestly diffeomorphism invariant Wilsonian (Exact) Renor-malization Group for classical gravity, and begin the construction for quantum gravity. We demonstrate that the effective action can be computed without gauge fixing the diffeo-morphism invariance, and also without introducing a background space-time. We compute classical contributions both within a...

Solutions to the reconstruction problem in asymptotic safety

Starting from a full renormalised trajectory for the effective average action (a.k.a. infrared cutoff Legendre effective action) Γ k , we explicitly reconstruct corresponding bare actions, formulated in one of two ways. The first step is to construct the corresponding Wilsonian effective action S k through a tree-level expansion in terms of the vertices provided by Γ k . It forms...

Background independent exact renormalization group for conformally reduced gravity

Within the conformally reduced gravity model, where the metric is parametrised by a function f (ϕ) of the conformal factor ϕ, we keep dependence on both the background and fluctuation fields, to local potential approximation and \( \mathcal{O}\left({\partial}^2\right) \) respectively, making no other approximation. Explicit appearances of the background metric are then dictated...

The local potential approximation in the background field formalism

I. Hamzaan Bridle 0 Juergen A. Dietz 0 Tim R. Morris 0 0 School of Physics and Astronomy, University of Southampton , Highfield, Southampton, SO17 1BJ, U.K Working within the familiar local