Positive tension 3-branes in an $AdS_{5}$ bulk

TL;DR

This paper explores conditions for positive tension 3-branes in an AdS5 bulk within Brans-Dicke theory, highlighting the role of scalar fields and dynamic brane tension in stabilizing braneworld models.

Contribution

It extends consistency conditions for braneworlds in Brans-Dicke gravity and demonstrates the feasibility of positive tension branes in AdS5 without unstable objects.

Findings

Positive tension branes can exist in AdS5 with Brans-Dicke scalar fields.

Brane tension can change sign depending on the bulk cosmological constant.

Scalar fields help avoid unstable objects in compactification schemes.

Abstract

In this work, we review and extend the so-called consistency conditions for the existence of a braneworld scenario in arbitrary dimensions in the Brans-Dicke (BD) gravitational theory. After that, we consider the particular case of a five-dimensional scenario which seems to have phenomenological interesting implications. We show that, in the BD framework, it is possible to achieve necessary conditions pointing to the possibility of accommodating branes with positive tensions in an AdS bulk by the presence of the additional BD scalar field, avoiding in this way the necessity of including unstable objects in the compactification scheme. Furthermore, in the context of time variable brane tension, it is shown that the brane tension may change its sign, following the bulk cosmological constant sign.