Braneworlds in $f(Q)$ gravity

Abstract

We propose a braneworld scenario in a modified symmetric teleparallel gravitational theory, where the dynamics for the gravitational field is encoded in the nonmetricity tensor rather than in the curvature. Assuming a single real scalar field with a sine-Gordon self-interaction, the generalized quadratic nonmetricity invariant Q controls the brane width while keeping the shape of the energy density. By considering power corrections of the invariant Q in the gravitational Lagrangian, the sine-Gordon potential is modified exhibiting new barriers and false vacuum. As a result, the domain wall brane obtains an inner structure, and it undergoes a splitting process. In addition, we also propose a non-minimal coupling between a bulk fermion field and the nonmetricity invariant Q. Such geometric coupling leads to a massless chiral fermion bound to the 3-brane and a stable tower of non-localized massive states.

Braneworlds in warped Einsteinian cubic gravity

“…A similar behavior was found in symmetric teleparallel braneworld [56]. The energy density is sketched in the figure 2-a, the warp function is shown in figure 2-b and the scalar field profile is ploted in figure 2-c.…”

Sound from extra dimension: quasinormal modes of thick brane

“…In order to recover the physics in our four-dimensional world, the zero modes of various fields should be confined on the brane. In previous literatures, some thick brane models and the localization of various matter fields on the brane were investigated [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42]. Besides these zero modes, there are massive Kaluza-Klein (KK) modes which might propagate along extra dimensions.…”