TY - JOUR
AB - Standard entropy calculations in quantum field theory, when applied to a subsystem of definite volume, exhibit area-dependent UV divergences that make a thermodynamic interpretation troublesome. In this paper we define a renormalized entropy which is related with the Newton-Wigner position operator. Accordingly, whenever we trace over a region of space, we trace away degrees of freedom that are localized according to Newton-Wigner localization but not in the usual sense. We consider a free scalar field in d+1 spacetime dimensions prepared in a thermal state and we show that our entropy is free of divergences and has a perfectly sound thermodynamic behavior. In the high temperature/big volume limit our results agree with the standard QFT calculations once the divergent contributions are subtracted from the latter. In the limit of low temperature/small volume the entropy goes to zero but with a different dependence on the temperature.
AU - Cacciatori, S. L.
AU - Costa, F.
AU - Piazza, F.
DA - 2008/11/30/
JF - Phys. Rev. D
PY - 2008
SE - 2008/11/30/
SP - 025006
TI - Renormalized thermal entropy in field theory
UR - http://link.aps.org/doi/10.1103/PhysRevD.79.025006
ER -