# Unruh effect for fermions from the Zubarev density operator

## TL;DR

This paper derives the Unruh effect for fermions using the Zubarev density operator, showing that an accelerated observer perceives the vacuum as a thermal bath at the Unruh temperature when higher-order corrections are included.

## Contribution

It introduces a novel calculation of the Unruh effect for fermions using the Zubarev density operator, accounting for fourth-order corrections to the energy-momentum tensor.

## Key findings

- Energy-momentum tensor vanishes at Unruh temperature in the lab frame
- Accelerated observer perceives Minkowski vacuum as a thermal bath
- Higher-order corrections are essential for accurate description

## Abstract

Using the Zubarev quantum-statistical density operator, we calculated the corrections to the energy-momentum tensor of a massless fermion gas associated with acceleration. It is shown that when fourth-order corrections are taken into account, the energy-momentum tensor in the laboratory frame is equal to zero at a proper temperature measured by a comoving observer equal to Unruh temperature. Consequently, the Minkowski vacuum is visible to the accelerated observer as a medium filled with a heat bath of particles with the Unruh temperature, which is the essence of the Unruh effect.