Speaker
Dr
Max Niedermaier
(Department of Physics and Astronomy, University of Pittsburgh)
Description
In QFT an Anti-Newtonian expansion perturbs around decoupled copies of a self-interacting quantum mechanical system, with subsequent coupling induced by spatial hopping terms. Such an expansion is developed for the effective action of 1+d dimensional scalar QFTs. A Functional Renormalization Group in the hopping parameter leads to a recursion for which an exact solution in terms of combinatorial graph rules is presented.
Upon coupling to gravity a coordinated gravitational expansion is needed to account for the classical backreaction of scalar field inhomogeneities. In Einstein gravity, the Anti-Newtonian limit has no dynamical spatial gradients, yet remains fully diffeomorphism invariant and propagates the original number of dofs. A canonical transformation (trivialization map) is constructed, in powers of a fractional inverse of Newton's constant that maps the ADM action into its Anti-Newtonian limit. Its inverse restores dynamical spatial gradients and provides classically the coordinated gravitational expansion. We outline the prospects of an associated trivializing flow in the quantum theory.
