Gravity Localization on Intersecting Thick Braneworlds

TL;DR

This paper investigates gravity localization in intersecting thick braneworld models, demonstrating that gravity is confined to the brane with various mode spectra, and discusses phenomenological implications for spherical internal spaces.

Contribution

It provides a comprehensive analysis of gravity localization in multiple intersecting thick brane models, including the explicit determination of zero and massive modes, and explores their phenomenological consequences.

Findings

Gravity is localized on the brane in all models studied.

Models IV and V have discrete massive graviton spectra, with implications for gravity propagation.

Sphere models derived from these configurations can reproduce Newtonian gravity.

Abstract

The localization of gravity for (5 + 1)-dimensional intersecting thick braneworld models is thoroughly investigated. Departing from preliminary results for five independent proposals, from I to V, gravity is shown to be localized in the brane. In particular, for models from I to III, only the zero modes are analytically determined. On the other hand, for models IV and V, massive modes are all obtained: a finite number of massive states is identified for model IV, while an infinite but discrete number of massive states bounded from below is exhibited by model V. Considering that the discreteness of the graviton modes implies that gravity does not propagate in the co-dimensions, the naked singularities of models IV and V, at edges of space, are made harmless. To conclude, the phenomenological implications for sphere models, constructed out of models III and IV, are also discussed. According to such an overall classification, if the internal space is a sphere, model IV is shown to exhibit normalizable modes. More relevantly, for the sphere model assembled out of model III, the subtle property of reproducing a consistent Newtonian limit is identified.