On thermal field fluctuations in ghost-free theories
arXiv:1904.07917 · doi:10.1016/j.physletb.2019.04.059
Abstract
We study the response of a scalar thermal field to a -probe in the context of non-local ghost-free theories. In these theories a non-local form factor is inserted into the kinetic part of the action which does not introduce new poles. For the case of a static -potential we obtain an explicit expression for the thermal Hadamard function and use it for the calculation of the thermal fluctuations. We then demonstrate how the presence of non-locality modifies the amplitude of these fluctuations. Finally, we also discuss the fluctuation-dissipation theorem in the context of ghost-free quantum field theories at finite temperature.
8 pages, 4 figures, computer algebra code available at http://spintwo.net/static/2019.04.16/ , v2: matches the published version