The Newman-Penrose Map and the Classical Double Copy

Understand

Gauge-gravity duality is arguably our best hope for understanding quantum gravity.

• Considerable progress has been made in relating scattering amplitudes in certain gravity theories to those in gauge theories---a correspondence dubbed the "double copy".
• Recently, double copies have also been realized in a classical setting, as maps between exact solutions of gauge theories and gravity.
• We present here a novel map between a certain class of real, exact solutions of Einstein's equations and self-dual solutions of the flat-space vacuum Maxwell equations.