Insensitivity of Hawking radiation to an invariant Planck-scale cutoff

Understand

A disturbing aspect of Hawking's derivation of black hole radiance is the need to invoke extreme conditions for the quantum field that originates the emitted quanta.

• It is widely argued that the derivation requires the validity of the conventional relativistic field theory to arbitrarily high, trans-Planckian scales.
• We stress in this note that this is not necessarily the case if the question is presented in a covariant way.
• We point out that Hawking radiation is immediately robust against an invariant Planck-scale cutoff.