Optically Inspired Models of Black Hole Evaporation
Paul M. Alsing - University at Albany, SUNY, USA
Abstract:
In the last ten years there’s been a radical paradigm shift in how researchers view Hawking radiation and the black hole (BH) evaporation process based on a path integral formalism using classical GR and quantum corrections. This entails relatively new concepts such as Quantum Extremal Surfaces, the Island Conjecture and wormholes via ER=EPR, so that a variable part of the radiation behind the horizon must also be considered as part of the external Hawking radiation as the BH evaporation evolves. These processes produce the famed Page Curve which states that the entropy of the BH must rise from zero as time evolves, as Hawking predicted, but only up until a “halfway” point, at which it must turn over and decrease to zero again at complete evaporation. The Hawking radiation is essentially thermal up to this halfway point, at which point information begins to emerge from the BH as correlations in the radiation. Such a Page Curve turnover is required if unitarity is to be maintained.
In this talk I will briefly review this current modern view of BH evaporation, but then focus on alternative phenomenological unitary models based on squeezed state generation from a depleted “pump” which models the evaporating BH. Here, the two-mode squeezed state generation of entangled “signal” and “idler” pairs models the escaping Hawking radiation and its partner particle that falls behind the horizon, respectively. I show how this simple, pure state unitary model can also produce a Page Curve, and how entanglement grows and then decreases as the evaporation evolves. I also show that a variation of this model is capable of moving Hawking partner particles inside the horizon to outside, without the necessity to invoke exotic EP=EPR wormholes. Lastly, I discuss a related beam splitter/squeezing phenomenological model that contains features analogous to the information scrambling mechanisms invoked/discussed in other current modern models.
Location: QNC 0101