Domain Wall from Gauged d=4, N=8 Supergravity: Part I

TL;DR

This paper investigates domain-wall solutions in gauged N=8 supergravity in four dimensions, analyzing various gaugings and scalar potentials, and finds explicit flow equations and solutions related to the superpotential.

Contribution

It introduces new domain-wall solutions from extremization of energy density in non-semi-simple and non-compact gaugings of N=8 supergravity, extending previous classifications.

Findings

Existence of first-order domain-wall solutions in certain gaugings.

Scalar potential expressed as difference of positive definite terms.

Flow equations derived from superpotential eigenvalues.

Abstract

By studying already known extrema of non-semi-simple Inonu-Wigner contraction CSO(p, q)^{+} and non-compact SO(p, q)^{+}(p+q=8) gauged N=8 supergravity in 4-dimensions developed by Hull sometime ago, one expects there exists nontrivial flow in the 3-dimensional boundary field theory. We find that these gaugings provide first-order domain-wall solutions from direct extremization of energy-density. We also consider the most general CSO(p, q, r)^{+} with p+q+r=8 gauging of N=8 supergravity by two successive SL(8,R) transformations of the de Wit-Nicolai theory, that is, compact SO(8) gauged supergravity. The theory found earlier has local SU(8)x CSO(p, q, r)^{+} gauge symmetry as well as local N=8 supersymmetry. The gauge group CSO(p, q, r)^{+} is spontaneously reduced to its maximal compact subgroup SO(p)^{+} x SO(q)^{+} x U(1)^{+r(r-1)/2}. The T-tensor we obtain describes a two-parameter family of gauged N=8 supergravity from which one can construct A_1 and A_2 tensors. The effective nontrivial scalar potential can be written as the difference of positive definite terms. We examine the scalar potential for critical points at which the expectation value of the scalar field is SO(p)^{+} x SO(q)^{+} x SO(r)^{+} invariant. It turns out that there is no new extra critical point. However, we do have flow equations and domain-wall solutions for the scalar fields are the gradient flow equations of the superpotential that is one of the eigenvalues of A_1 tensor.