# Quantum non-equilibrium effects in rigidly-rotating thermal states

## TL;DR

This paper investigates quantum effects in rigidly-rotating thermal states of massless Dirac fields, revealing non-ideal stress-energy tensor components and the importance of boundaries near the speed of light surface, with implications for astrophysical phenomena.

## Contribution

It provides a detailed analysis of quantum corrections to the stress-energy tensor in rotating thermal states, highlighting the limitations of ideal models and the necessity of boundaries near the SOL.

## Key findings

- Quantum corrections dominate near the speed of light surface.
- The Landau frame is well-defined only with a boundary inside or on the SOL.
- Rigidly-rotating thermal states cannot be constructed for the Klein-Gordon field.

## Abstract

Based on known analytic results, the thermal expectation value of the stress-energy tensor (SET) operator for the massless Dirac field is analyzed from a hydrodynamic perspective. Key to this analysis is the Landau decomposition of the SET, with the aid of which we find terms which are not present in the ideal SET predicted by kinetic theory. Moreover, the quantum corrections become dominant in the vicinity of the speed of light surface (SOL). While rigidly-rotating thermal states cannot be constructed for the Klein-Gordon field, we perform a similar analysis at the level of quantum corrections previously reported in the literature and we show that the Landau frame is well-defined only when the system is enclosed inside a boundary located inside or on the SOL. We discuss the relevance of these results for accretion disks around rapidly-rotating pulsars.