Fake Supergravity and Domain Wall Stability
D. Z. Freedman, C. Nunez, M. Schnabl, K. Skenderis
TL;DR
The paper develops a generalized, non-supersymmetric stability framework for domain-wall solutions (fake supergravity) and extends it to AdS_d-sliced geometries using an su(2) matrix superpotential. It demonstrates non-perturbative stability for the Gutperle-Janus solution and its deformations, and provides a constructive approach to stability with multiple scalars via a Boucher-style composite superpotential. A concrete explicit construction of fake Killing spinors and the corresponding W for Janus solidify the stability arguments, while a simple linear-dilaton solution serves as a useful byproduct and consistency check. Together, these results bolster the non-perturbative stability of non-supersymmetric holographic domain walls in Type IIB and related theories, with implications for AdS/CFT and brane-world scenarios.
Abstract
We review the generalized Witten-Nester spinor stability argument for flat domain wall solutions of gravitational theories. Neither the field theory nor the solution need be supersymmetric. Nor is the space-time dimension restricted. We develop the non-trivial extension required for AdS-sliced domain walls and apply this to show that the recently proposed "Janus" solution of Type IIB supergravity is stable non-perturbatively for a broad class of deformations. Generalizations of this solution to arbitrary dimension and a simple curious linear dilaton solution of Type IIB supergravity are byproducts of this work.
