Wiggly dilaton: a landscape of spontaneously broken scale invariance

TL;DR

This paper explores a holographic model with a wiggly dilaton potential arising from boundary effects, revealing multiple vacua and potential applications in relaxion models, but requiring fine-tuning for very light dilatons.

Contribution

It introduces a novel wiggly dilaton potential with multiple vacua in a 5D holographic setup, linking boundary scalar potentials to dilaton properties.

Findings

Multiple vacuum solutions exist in the model.

The model can produce a relaxion potential.

Achieving an extremely light dilaton requires fine-tuning.

Abstract

The dilaton emerges as a pseudo-Nambu-Goldstone boson (pNGB) associated with the spontaneous breaking of scale invariance in a nearly conformal field theory (CFT). We show the existence of a wiggly dilaton potential that contains multiple vacuum solutions in a five-dimensional (5D) holographic formulation. The wiggly feature originates from boundary potentials of a 5D axion-like scalar field, whose naturally small bulk mass parameter corresponds to a marginally-relevant deformation of the dual CFT. Depending on the energy density of a boundary 3-brane, our model can provide a relaxion potential or generate a light dilaton. However, an extremely light dilaton requires fine-tuning.