Hawking Radiation, Covariant Boundary Conditions and Vacuum States

TL;DR

This paper derives covariant chiral currents and energy-momentum tensors from an effective action, justifies boundary conditions for Hawking flux calculations, and connects these results with traditional vacuum state analyses.

Contribution

It provides a theoretical foundation for covariant boundary conditions in Hawking radiation computations using chiral anomalies.

Findings

Derived covariant chiral currents and stress tensors from an effective action.

Justified covariant boundary conditions in Hawking flux calculations.

Connected covariant results with traditional vacuum state frameworks.

Abstract

The basic characteristics of the covariant chiral current $<J_{\mu}>$ and the covariant chiral energy-momentum tensor $<T_{\mu\nu}>$ are obtained from a chiral effective action. These results are used to justify the covariant boundary condition used in recent approaches \cite{Isowilczek,Isoumtwilczek,shailesh,shailesh2,Banerjee} of computing the Hawking flux from chiral gauge and gravitational anomalies. We also discuss a connection of our results with the conventional calculation of nonchiral currents and stress tensors in different (Unruh, Hartle-Hawking and Boulware) states.