A Black Hole Cooks Up Radiation Like a Pot of Soup ⚡ экспресс
Gravity and gauge theory are related by the double copy, yet nonperturbative aspects of this connection on nontrivial backgrounds remain little explored. It has been shown that the thermal Hawking radiation in the metric of a collapsing black hole, its temperature spectrum, and its dependence on the horizon emerge from the double copy of particle creation in a background gauge field where there is no global horizon and no thermal spectrum. The method combines worldline techniques with amplitude methods. This allows one to unify classical and quantum double copy prescriptions for black holes.
The 'double copy' method in physics is a culinary trick: a chef takes a cold soup recipe, doubles the ingredients, and gets a recipe for a hot roast. Likewise, particle interactions via electric forces (the basis of the Standard Model) morph into gravity, which describes spacetime curvature.
Until now, this trick was only tested in empty space. Now it's been applied to Stephen Hawking radiation from a black hole. The original 'soup' — particle creation in an electric field — is a process with no temperature or horizon. After double copying, radiation emerges with entropy (a measure of disorder), as if from a hot object. The horizon and temperature weren't put into the recipe—they just appeared on their own.
🎯 Particle creation in a strong electric field (the Schwinger effect) has never been observed in the lab—the energy needed is staggering. However, its double copy, Hawking radiation, is what astronomers aim to catch at the rims of real black holes.