Probing the Fundamental Nature of Spacetime with the Renormalization Group

Mar 23 – 27, 2015
Nordita, Stockholm
Europe/Stockholm timezone

Background independent exact renormalization group for conformally reduced gravity

Mar 23, 2015, 11:10 AM
50m
FB 54 (Nordita, Stockholm)

Tim Morris

Description

Within the conformally reduced gravity model, where the metric is parametrised by a function of the conformal factor field, we keep dependence on both the background and fluctuation fields, to local potential approximation and order derivative-squared respectively, making no other approximation. The functional dependence on the background field is then dictated by realising a remnant diffeomorphism invariance. The standard non-perturbative Renormalization Group (RG) scale is inherently background dependent, which we show in general forbids the existence of RG fixed points. By combining the flow equations with the modified split Ward identity, we uncover a unique background independent notion of RG scale. The corresponding RG flow equations are then not only explicitly background independent along the entire RG flow but also explicitly independent of the way the conformal factor is parametrised.

 Slides