Emerging Hawking-like radiation from gravitational bremsstrahlung beyond the planck scale

We argue that, as a consequence of the graviton’s spin-2, its bremsstrahlung in trans-Planckian-energy (E ≫ MP ) gravitational scattering at small deflection angle can be nicely expressed in terms of helicity- transformation phases and their transfer within the scattering process. The resulting spectrum exhibits deeply sub-Planckian characteristic energies of order M2 P=E ≪ MP (reminiscent of Hawking radiation), a suppressed fragmentation region, and a reduced rapidity plateau, in broad agreement with recent classical estimates.