Holographic Axion Model: a simple gravitational tool for quantum matter

TL;DR

This paper provides a comprehensive review of the holographic axion model, a versatile gravitational framework used to study quantum matter by modeling momentum dissipation and elastic properties through shift symmetric scalar fields.

Contribution

It offers an exhaustive overview of the holographic axion model, connecting it with massive gravity, effective field theories, and hydrodynamics, serving as a complete guide for researchers.

Findings

Demonstrates the model's ability to simulate momentum dissipation.

Shows the model's applications in elastic property analysis.

Highlights the versatility of the holographic axion framework.

Abstract

This is a complete and exhaustive review on the so-called holographic axion model -- a bottom-up holographic system characterized by the presence of a set of shift symmetric scalar bulk fields whose profiles are taken to be linear in the spatial coordinates. This simple model implements the breaking of translational invariance of the dual field theory by retaining the homogeneity of the background geometry and therefore allowing for controllable and fast computations. The usages of this model are very vast and they are a proof of the spectacular versatility of the framework. In this review, we touch upon all the up-to-date aspects of this model from its connection with massive gravity and effective field theories, to its role in modeling momentum dissipation and elastic properties ending with all the phenomenological features and its hydrodynamic description. In summary, this is a complete guide to one of the most used model in Applied Holography and a must-read for any researcher entering this field.