Speaker
Description
In asymptotically flat quantum gravity, the dimension of the Hilbert space is given by the exponential of the Bekenstein-Hawking entropy. Can we understand this thermodynamic entropy as a consequence of entanglement in a typical state at a definite ADM energy? We approach this question by exploring the behavior of the typical entanglement entropy in large quantum systems under constraints. This technique allows us to obtain an entanglement entropy that does not diverge in quantum field theory. Furthermore, this entanglement entropy also reproduces the smaller subsystem's thermodynamic entropy. To explore this correspondence between entanglement and thermodynamics, we examine a quantum electromagnetic field in a box. In this system, we show that the typical entanglement entropy coincides with the known black-body thermodynamic entropy at the leading order. Moreover, we obtain a non-thermodynamic correction that reproduces a contribution reported before in the context of condensed matter.