Gravity localization on hybrid branes

TL;DR

This paper investigates gravity localization on hybrid branes formed by compacton-like kinks, analyzing the graviton spectrum and corrections to Newton's law, and finds that hybrid branes behave similarly to thick domain walls with slight short-distance gravitational enhancements.

Contribution

It introduces a numerical analysis of graviton modes on hybrid branes, showing their phenomenological implications are comparable to traditional thick brane models.

Findings

The graviton spectrum increases linearly, consistent with Kaluza-Klein theories.

The 4D gravitational force is slightly enhanced at short distances.

Hybrid branes exhibit similar phenomenology to thick domain walls.

Abstract

This work deals with gravity localization on codimension-1 brane worlds engendered by compacton-like kinks, the so-called hybrid branes. In such scenarios, the thin brane behaviour is manifested when the extra dimension is outside the compact domain, where the energy density is non-trivial, instead of asymptotically as in the usual thick brane models. The zero mode is trapped in the brane, as required. The massive modes, although are not localized in the brane, have important phenomenological implications such as corrections to the Newton's law. We study such corrections in the usual thick domain wall and in the hybrid brane scenarios. By means of suitable numerical methods, we attain the mass spectrum for the graviton and the corresponding wavefunctions. The spectra possess the usual linearly increasing behaviour from the Kaluza-Klein theories. Further, we show that the 4D gravitational force is slightly increased at short distances. The first eigenstate contributes highly for the correction to the Newton's law. The subsequent normalized solutions have diminishing contributions. Moreover, we find out that the phenomenology of the hybrid brane is not different from the usual thick domain wall. The use of numerical techniques for solving the equations of the massive modes is useful for matching possible phenomenological measurements in the gravitational law as a probe to warped extra dimensions.