(2016-01-25) Ahmadi, Morteza; Das, Saurya; Shankaranarayanan, S.
It is known that the entanglement entropy of a scalar field, found by tracing over
its degrees of freedom inside a sphere of radius R, is proportional to the area of the sphere
(and not its volume). This suggests that the origin of black hole entropy, also proportional
to its horizon area, may lie in the entanglement between the degrees of freedom inside and
outside the horizon. We examine this proposal carefully by including excited states, to check
probable deviations from the area law.