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arXiv · 2609.35862

Five-dimensional thick branes in the scalar representation of $f(Q,B)$ gravity

F. C. E. Lima·F. M. Belchior·C. A. S. Almeida
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Abstract

One examines a codimension-one thick braneworld in the scalar representation of $f(Q,B)$ gravity, where $Q$ is the nonmetricity scalar, and $B$ is the boundary term satisfying $R=Q-B$. We write the gravitational sector in terms of two auxiliary scalar fields, $φ=f_Q$ and $ψ=f_B$, and an interaction potential $U(φ,ψ)$ obtained by a Legendre transformation from the $f(Q,B)$ function. Working in the coincident gauge and assuming a five-dimensional warped geometry with four-dimensional Poincaré symmetry, we derive the complete set of brane equations sourced by a canonical bulk scalar field. To accomplish our purpose, we address two models of smooth asymptotically AdS thick brane with localized scalar profiles. Furthermore, we also analyze tensor perturbations and demonstrate the localization and stability of the massless graviton.

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F. C. E. Lima, F. M. Belchior, C. A. S. Almeida. 2026-09-25. Five-dimensional thick branes in the scalar representation of $f(Q,B)$ gravity. https://arxiv.org/abs/2609.35862

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