Okay, firstly, I know this question was asked here 11 years ago. And I know the correct answer is that we don't know because we haven't run the experiments and don't have a solid theory of quantum gravity. Got it. But...
What is the current working theory of the final moments and end state of a black hole decaying away through Hawking Radiation?
If I did the math right, the black-body Hawking radiation peak has a wavelength about 16x the current Schwartzhilde radius. So as the BH decays away, it gets hotter, brighter, and radiates higher energy photons. Each photon carries away an ever-greater share of the BH’s remaining mass…
When the BH is down to ~500 tonnes, the peak radiation is comparable to the highest-energy observed gamma rays.
When it’s around 10^-8 kg, there’s not enough mass left to produce a single photon at the corresponding black-body peak.
So, what does the radiation spectrum become then, since black-body stats no longer apply? Is there any mechanism that allows the BH to convert entirely into photons? Or will some tiny nodule of mass remain, awaiting some other rare quantum decay event?
