# Relativistic Quantum Optics: On the relativistic invariance of the light-matter interaction models

## TL;DR

This paper examines how light-matter interaction models in quantum optics behave under relativistic transformations, ensuring their invariance and analyzing the effects of relativistic motion on the interaction Hamiltonians.

## Contribution

It explicitly derives the transformation properties of light-matter Hamiltonians under general coordinate changes, addressing relativistic effects in quantum optics models.

## Key findings

- Light-matter Hamiltonians transform covariantly under relativistic changes.
- Relativistic motion introduces subtleties in the standard interaction models.
- The study clarifies the invariance properties of quantum optical predictions.

## Abstract

In this note we discuss the invariance under general changes of reference frame of all the physical predictions of particle detector models in quantum field theory in general and, in particular, of those used in quantum optics to model atoms interacting with light. We find explicitly how the light-matter interaction Hamiltonians change under general coordinate transformations, and analyze the subtleties of the Hamiltonians commonly used to describe the light-matter interaction when relativistic motion is taken into account.