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Black hole formation is a process that scrambles incoming matter -mainly- into photons and gravitons. The Hawking radiation is said to produce a thermal spectrum. If the black hole was formed from a pure state, this leads to a unitarity paradox.
We consider the problem in a condensed matter setup (&quote;toy black hole&quote;), where incoming energy (in this case: work) is scrambled into phonons. Physical quantities like work and entropies are calculated. The paradox is explained by the correlation between the phonon modes.
It will be attempted to draw some lesson from this for the black hole situation.

Institute for Theoretical Physics, Amsterdam