Photon emission from an excited string

A bstract We compute the amplitude for an excited string in any precisely specified state to decay into another state, via emission of a tachyon or photon. For generic and highly states, is complicated function outgoing kinematic angle, sensitive precise state. square this amplitude, averaged over polarizations ingoing summed string. The seeming intractability these calculations made possible by extracting amplitudes involving strings from tachyons large number photons; photons grows with complexity Our work spirit broad range recent studies statistical mechanics chaos quantum many-body systems. different states at given mass exponentially large, our calculation gives single photon each microstates — which, through Horowitz-Polchinski correspondence principle, are black hole microstates.