Hawking radiation from covariant anomalies in 2+1 dimensional black holes

TL;DR

This paper applies the covariant anomaly method to derive Hawking radiation from two types of 3D black holes, demonstrating the universality of the anomaly approach in different black hole backgrounds.

Contribution

It extends the covariant anomaly method to warped AdS_3 and charged rotating black holes in three dimensions, showing its applicability beyond simpler models.

Findings

Hawking radiation can be derived from covariant anomalies in 3D black holes.

The method confirms the universality of anomaly cancellation in diverse black hole spacetimes.

Results align with expected Hawking temperatures for the studied black holes.

Abstract

In an insightful approach, Robinson and Wilczek proposed that Hawking radiation can be obtained as the compensation of a breakdown of general covariance and gauge invariance and the radiation is a black body radiation at Hawking temperature. We apply this method to two types of black holes in three dimensional spacetime, which share the general form of the metric in that the $tt$ component of the metric is not inverse of the $rr$ component of the metric. First one is the warped $AdS_3$ black hole in three dimensional topologically massive gravity with negative cosmological constant, and second one is the charged rotating black hole in three dimensions.