arXiv subjects

William Lindved

Publications and source records attributed to William Lindved.

4 recordsLinked to original sources

arXiv2025

Hawking radiation from the double copy

Gravity and gauge theory are concretely linked by the double copy. Although well-studied at the level of perturbative scattering in vacuum, far less is known about non-perturbative aspects or extensions of the double copy beyond trivial backgrounds. We show here how Hawking radiation in a collapse metric, its associated thermal spectrum, and horizon-dependence, emerges from the double copy of particle production in a background gauge field, where there is no global horizon, nor a thermal spectrum. Our approach combines worldline and amplitudes methods, and allows the unification of several classical and quantum double copy prescriptions for black hole spacetimes.

hep-th↗

arXiv2025

Coherent states, background fields, and double copy

We show that scattering amplitudes on any gauge theory background admitting a coherent state description double copy to amplitudes in a curved spacetime. The metric of the spacetime is built from the gauge background using a notion of classical double copy which emerges naturally at the amplitude level. In the self-dual sector this map relates backgrounds which are exact vacuum solutions in gauge theory and gravity.

hep-th↗

arXiv2024

Toward double copy on arbitrary backgrounds

Double copy relates scattering amplitudes in a web of gravitational and gauge theories. Although it has seen great success when applied to amplitudes in vacuum, far less is known about double copy in arbitrary gravitational and gauge backgrounds. Focussing on the simplest pair production amplitudes of scalar QCD in a background gauge field, we construct, at next-to-leading order in perturbation theory, a double copy map to particle production in general metrics (and associated axio-dilatons) constructed from the gauge background. We connect our results to convolutional and classical double copy and, turning to examples, identify a class of gauge fields which generate FRW spacetimes via double copy. For this case we are able to conjecture the all-orders form of the double copy map.

hep-th↗

arXiv2023

Scattering amplitudes and electromagnetic horizons

We consider the scattering of charged particles on particular electromagnetic fields which have properties analogous to gravitational horizons. Classically, particles become causally excluded from regions of spacetime beyond a null surface which we identify as the `electromagnetic horizon'. In the quantum theory there is pair production at the horizon via the Schwinger effect, but only one particle from the pair escapes the field. Furthermore, unitarity appears to be violated when crossing the horizon, and there is no well-defined S-matrix. Despite this, we show how to use the perturbiner method to construct `amplitudes' which contain all the dynamical information required to construct observables related to pair creation, and to radiation from particles scattering on the background.

hep-th↗