Penrose Limits and RG Flows

RG flows and bifurcations

Interpreting RG flows as dynamical systems in the space of couplings we produce a variety of constraints, global (topological) as well as local. These constraints, in turn, rule out some of the proposed RG flows and also predict new phases and fixed points, surprisingly, even in familiar theories such as O(N) model, QED3, or QCD4. © 2017 Published by Elsevier B.V. This is an open access article...

Penrose Limits and Spacetime

We give a covariant characterisation of the Penrose plane wave limit: the plane wave profile matrix A(u) is the restriction of the null geodesic deviation matrix (curvature tensor) of the original spacetime metric to the null geodesic, evaluated in a comoving frame. We also consider the Penrose limits of spacetime singularities and show that for a large class of black hole, cosmological and nul...

Counting RG flows

Interpreting renormalization group flows as solitons interpolating between different fixed points, we ask various questions that are normally asked in soliton physics but not in renormalization theory. Can one count RG flows? Are there different “topological sectors” for RG flows? What is the moduli space of an RG flow, and how does it compare to familiar moduli spaces of (supersymmetric) dowai...

Plane Waves and Penrose Limits

Penrose Limits and Maximal Supersymmetry

We show that the maximally supersymmetric pp-wave of IIB superstring and M-theories can be obtained as a Penrose limit of the supersymmetric AdS×S solutions. In addition we find that in a certain large tension limit, the geometry seen by a brane probe in an AdS×S background is either Minkowski space or a maximally supersymmetric pp-wave.