Mundo-Brana tipo-corda em uma gravidade f(T)

Abstract

In order to understand how a modified teleparallel gravity f (T) where f (T) = T + kT^n, behaves in a braneworld scenario, we obtain the tetrad fields, the Weitzenböck connection, the torsion tensor, the contortion and the torsional dual relating to a space-time of a string-like braneworld. We observe either asymptotically, the geometry of the bulk converges to a space-time AdS_6, whose cosmological constant is produced by k and n torsion parameters. By varying the torsion parameters, the brane undergoes a phase transition, from a single brane to sub-branes, which leads to the formation of ring-like structures. The analysis of the stress energy condition reveals a splitting brane process satisfying the weak and strong energy conditions for some values of the parameters. In addition, we investigate the behaviour of the gravitational perturbations in this scenario. We note that the gravitational spectrum is modified by the torsion parameters. Inside the brane core, the twist produces new barriers and potential wells, leading to a massless mode located in the vicinity of the brane. We observed that inside the brane core, the torsion produces an internal structure even for a single scalar field. By assuming a global vortex as the source, we found a α = 0 vortex solution that yields to a thick string-like brane, but in the case of α ≠ 0 no topological solutions are generated.