Thick brane in f(T,B) gravity

TL;DR

This paper studies a five-dimensional modified gravity model in a brane-world scenario, analyzing the geometry, energy conditions, and gravitational perturbations, revealing stable massive modes and localized gravity under certain parameter conditions.

Contribution

It introduces a novel f(T,B) gravity model in five dimensions with specific functional forms, analyzing its geometric, energetic, and perturbative properties in a brane context.

Findings

Bulk geometry approaches AdS_5 spacetime.

Energy conditions allow brane splitting for certain parameters.

Localized massless graviton mode exists under specific conditions.

Abstract

In this paper, we explore the five-dimensional f(T,B) teleparallel modified gravity with f_1(T,B)=T+k_1B^{n_1} and f_2(T,B)=B+k_2T^{n_2} in the brane scenario. Asymptotically, the bulk geometry converges to an AdS_5 spacetime whose cosmological constant is produced by parameters that control torsion and boundary term. The analysis of the energy density condition reveals a splitting brane process satisfying the weak and strong energy conditions for some values of the parameters n_{1,2} and k_{1,2}. In addition, we investigate the behavior of the gravitational perturbations in this scenario. In the bulk, the torsion keeps a gapless non-localizable, and stable tower of massive modes. Inside the brane core, the torsion produces new barriers and potential wells, leading to small amplitude massive modes and a massless mode localized for some values of the parameters n_{1,2} and k_{1,2}.