The classical double copy of non-singular black holes

TL;DR

This paper demonstrates how the classical double copy procedure can be applied to non-singular black hole solutions, including string-theory-corrected ones, revealing new insights into horizon structures and gauge-gravity correspondences.

Contribution

It extends the classical double copy to regular black holes with string-theory corrections, analyzing their horizon structure and gauge theory counterparts.

Findings

Non-singular black holes can be obtained via string-theory corrections.

Yang-Mills quantities in the double copy are finite and well-behaved.

A new connection between horizons and electric fields is uncovered.

Abstract

We apply the classical double copy procedure to a class of regular, non-singular black hole solutions. We give several examples, paying particular attention to a string-theory-corrected black hole solution emerging from T-duality. Non-perturbative stringy corrections introduce an ultraviolet (UV) zero-point length cutoff which results in non-singular black hole spacetimes. Apart from the UV regulator, the solution is equivalent to the Bardeen black hole spacetime. We extend this solution to include an asymptotic de Sitter background. All Yang-Mills field theory quantities associated with the double copy are well-behaved and finite for all values of parameters. We present a thorough analysis of the black hole horizon structure, additionally uncovering a simple yet new connection between horizons on the gravity side and electric fields on the gauge theory side of the double copy.