Bulk Supersymmetry and Brane Cosmological Constant

TL;DR

This paper explores how bulk supersymmetry in brane world models with infinite extra dimensions can protect against a non-zero brane cosmological constant, using a scalar field profile to connect AdS and Minkowski vacua without violating energy conditions.

Contribution

It proposes a novel setup where bulk supersymmetry safeguards the brane cosmological constant through a scalar potential and domain wall configuration.

Findings

Bulk supersymmetry can remain unbroken despite brane supersymmetry breaking.

The scalar field profile leads to a domain wall connecting AdS and Minkowski vacua.

The model avoids violating the weak energy condition.

Abstract

We consider a recent proposal to solve the cosmological constant problem within the context of brane world scenarios with infinite volume extra dimensions. In such theories bulk can be supersymmetric even if brane supersymmetry is completely broken. We propose a setup where unbroken bulk supersymmetry appears to protect the brane cosmological constant. This is due to a non-trivial scalar potential in the bulk which implies a non-trivial profile for a bulk scalar field. In the presence of the latter bulk supersymmetry appears to be incompatible with non-vanishing brane cosmological constant. Moreover, in this setup the corresponding domain wall interpolates between an AdS and the Minkowski vacua, so that the weak energy condition is not violated.