Larus Thorlacius (U. of Iceland) - Effective Field Theory Approach to 4D Hawking Emission

Abstract: Hawking radiation from 3+1-dimensional black holes is studied using effective field theory methods. The field equations that determine the time-dependent renormalised stress tensor are numerically solved for a black hole formed by an ingoing null shock wave. Hawking radiation is generated dynamically near the event horizon and propagates to future null infinity. The outgoing energy flux at future null infinity builds up from zero at early retarded times before the black hole forms and approaches a constant late-time value, consistent with analytic results for an Unruh state on a static Schwarzschild background of
the same mass. Preliminary numerical solutions of the full semiclassical field equations, with back reaction included, show black hole formation and the onset of Hawking evaporation but the solutions break down before the black hole endpoint is reached.