Classical double copy of nonsingular black holes
Damien A. Easson, Cynthia Keeler, Tucker Manton
Abstract
We apply the classical double-copy procedure to a class of regular, nonsingular black hole solutions. We give several examples, paying particular attention to a string-theory-corrected black hole solution emerging from T-duality. Nonperturbative stringy corrections introduce an ultraviolet (UV) zero-point length cutoff which results in nonsingular 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.