Mass gap for gravity localized on Weyl thick branes

TL;DR

This paper investigates gravity localization on Weyl thick branes, revealing a mass gap in the graviton spectrum, with exact solutions for the effective potential, and discusses implications for the hierarchy problem and Newtonian gravity corrections.

Contribution

It introduces a new class of Weyl thick brane models with a mass gap in the graviton spectrum, providing exact solutions and analyzing their phenomenological implications.

Findings

Existence of a mass gap separating the 4D graviton from KK modes.

Exact solvability of the Schrödinger-like equation with a modified Pöschl-Teller potential.

Explicit computation of Newton's law corrections in the thin brane limit.

Abstract

We study the properties of a previously found family of thick brane configurations in a pure geometric Weyl integrable 5D space time, a non-Riemannian generalization of Kaluza-Klein (KK) theory involving a geometric scalar field. Thus the 5D theory describes gravity coupled to a self-interacting scalar field which gives rise to the structure of the thick branes. Analyzing the graviton spectrum for this class of models, we find that a particularly interesting situation arises for a special case in which the 4D graviton is separated from the KK gravitons by a mass gap. The corresponding effective Schroedinger equation has a modified Poeschl-Teller potential and can be solved exactly. Apart from the massless 4D graviton, it contains one massive KK bound state, and the continuum spectrum of delocalized KK modes. We discuss the mass hierarchy problem, and explicitly compute the corrections to Newton's law in the thin brane limit.