Gauge fields in a string-cigar braneworld

TL;DR

This paper studies the behavior of Abelian gauge fields in a thick string-cigar braneworld model, analyzing the effects of geometric Ricci flow on the KK spectrum and field localization.

Contribution

It introduces a string-cigar model with Ricci flow effects, providing new insights into gauge field localization and KK spectrum in thick brane scenarios.

Findings

Both models show a mass gap between modes.

KK modes are smooth and enhanced near the brane.

Ricci flow influences the Schrödinger potential.

Abstract

In this work we investigate the properties of an Abelian gauge vector field in a thin and in a smoothed string-like braneworld, the so-called string-cigar model. This thick brane scenario satisfies the regularity conditions and it can be regarded as an interior and exterior string-like solution. The source undergoes a geometric Ricci flow which is connected to a variation of the bulk cosmological constant. The Ricci flow changes the width and amplitude of the massless mode at the brane core and recover the usual thin string-like behavior at large distances. By numerical means we obtain the Kaluza-Klein (KK) spectrum for both the thin brane and the string-cigar. It turns out that both models exhibit a mass gap between the massless and the massive modes and between the high and the low mass regimes. The KK modes are smooth near the brane and their amplitude are enhanced by the string-cigar core. The analogue Schr\"odinger potential is also tuned by the geometric flow.