Pure Geometric Branes and Mass Hierarchy

TL;DR

This paper introduces a geometric brane model in a 5D Weyl manifold, revealing how graviton localization and mass spectrum can address the hierarchy problem while remaining consistent with low-energy experiments.

Contribution

It presents a novel brane configuration using Weyl geometry, showing the localization of massless gravitons on negative tension branes and implications for the hierarchy problem.

Findings

Massless graviton localized on negative tension brane

Massive gravitons are weakly coupled and hidden at low energies

Positive tension brane is necessary for realistic cosmology

Abstract

We consider a toy model with flat thin branes embedded in a 5-dimensional Weyl integrable manifold, where the geometric Weyl scalar provides the material that constitute the brane configurations. The brane configuration is similar to the Randall-Sundrum model. However, it is found that the massless graviton is localized on the brane with negative tension. So in order to solve the gauge hierarchy problem our world should be confined on the positive tension brane, and this is crucial to reproduce a correct Friedmann-like equation on the brane. The spacings of graviton mass spectrum are very tiny, but these massive gravitons are hidden in low energy experiments because they are weakly coupled with matter on the brane.