RT info:eu-repo/semantics/article
T1 Free energy and entropy for finite temperature quantum field theory under the influence of periodic backgrounds
A1 Bordag, Michael
A1 Muñoz Castañeda, José María
A1 Santamaría Sanz, Lucía
K1 Física
K1 Physics
AB The basic thermodynamic quantities for a non-interacting scalar field in a periodic potential composed of either a one-dimensional chain of Dirac δ − δ' functions or a specific potential with extended compact support are calculated. First, we consider the representation in terms of real frequencies (or one-particle energies). Then we turn the axis of frequency integration towards the imaginary axis by a finite angle, which allows for easy numerical evaluation, and finally turn completely to the imaginary frequencies and derive the corresponding Matsubara representation, which this way appears also for systems with band structure. In the limit case T → 0 we confirm earlier results on the vacuum energy. We calculate for the mentioned examples the free energy and the entropy and generalize earlier results on negative entropy.
PB Springer
SN 1434-6044
YR 2020
FD 2020-03
LK http://hdl.handle.net/10259/10005
UL http://hdl.handle.net/10259/10005
LA eng
NO The authors are grateful to the Spanish GovernmentMINECO (MTM2014- 57129-C2-1-P) for the financial support received. JMMC and LSS are grateful to the Junta de Castilla y León (BU229P18, VA137G18 and VA057U16) for the financial support. LSS is grateful to the Spanish Government-MINECO for the FPU-fellowships programme (FPU18/00957).
DS Repositorio Institucional de la Universidad de Burgos
RD 17-mar-2025