Amplitudes for Hawking Radiation
In this talk, I will show an approach to compute Hawking radiation based on on-shell scattering amplitudes. The Hawking spectrum is obtained by exponentiating a series of Feynman diagrams describing a massless scalar field scattering through a collapse background. Using semiclassical methods, we obtain a generalisation of an amplitude closely connected to the Bogoliubov coefficients. I will also show how the subdominant one-loop correction can be interpreted as finite-size corrections sensitive to the radius of the black hole. Finally, I will connect this approach to an electromagnetic analogue through the classical double copy.