Speaker
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.
