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Thermodynamics of Coherent States and Black Hole Entropy

A. G. Bashkirov·A. D. Sukhanov
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Abstract

Entropy and temperature of a system in a coherent state are naturally defined on a base of a density matrix of the system. As an example, entropy and temperature are evaluated for coherent states of a harmonic oscillator and quantum field described by the Klein--Gordon--Fock equation with a source term. It is shown, in particular, that the temperature of the coherent oscillator in a ground state coincides with the effective temperature of a harmonic oscillator being in contact with a heat bath (Bloch formula) when the bath temperature tends to zero. The Bekenstein--Hawking entropy of a black hole can also be interpreted as an entropy of coherent states of a physical vacuum in the vicinity of a horizon surface.

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A. G. Bashkirov, A. D. Sukhanov. 2001-10-31. Thermodynamics of Coherent States and Black Hole Entropy. https://arxiv.org/abs/quant-ph/0104083

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