Narrow Results

This paper deals with quantum field theory in curved space–time using the Thermo Field Dynamics. The scalar field is coupled to the Schwarzschild space–time and then thermalized. The Stefan–Boltzmann law is established at finite temperature and the entropy of the field is calculated. Then the Casimir energy and pressure are obtained at zero and finite temperature.

A generalization at finite temperature of the scalar Myers–Pospelov quantum field theory with mass dimension five operators that break Lorentz symmetry is considered. In particular, we introduce a thermal vacuum and a doubled Hilbert space within the formalism of Thermo Field Dynamics (TFD) to account for extended quantum field effects. The higher-order operators in the effective Lagrangian give rise to negative-metric modes, which are treated using a perturbative method. The perturbative modes that propagate correspond to standard second-order equations of motion with Lorentz-violating modifications without altering the number of degrees of freedom. In this perturbative, Lorentz-violating TFD framework, we investigate the finite-temperature effects, including thermal fluctuations and size effects.