Eur. Phys. J. Plus (2019) 134: 169
https://doi.org/10.1140/epjp/i2019-12682-2

Review

Equivalence principle violation at finite temperature in scalar-tensor gravity

¹ Dipartimento di Fisica, Università di Salerno, Via Giovanni Paolo II 132, I-84084, Fisciano (SA), Italy
² INFN, Sezione di Napoli, Gruppo collegato di Salerno, Via Giovanni Paolo II 132, I-84084, Fisciano (SA), Italy
³ Dipartimento di Fisica, Università di Napoli “Federico II”, via Cinthia 9, I-80126, Napoli, Italy
⁴ INFN, Sezione di Napoli, via Cinthia 9, I-80126, Napoli, Italy
⁵ Tomsk State Pedagogical University, ul. Kievskaya, 60, 634061, Tomsk, Russia
⁶ Laboratory for Theoretical Cosmology, Tomsk State University of Control Systems and Radioelectronics (TUSUR), 634050, Tomsk, Russia

^* e-mail: capozziello@na.infn.it

Received: 19 December 2018
Accepted: 7 January 2019
Published online: 23 April 2019

Abstract

We analyze possible violations of the equivalence principle in scalar-tensor gravity at finite temperature T. We first present an approach where the equivalence principle violation is achieved within the framework of quantum field theory. Then, we rely on an alternative approach first proposed by Gasperini, which leads to the same outcome obtained in the framework of quantum field theory (one-loop corrections) at finite T. Finally, we exhibit the application of the above formalism both to a generic diagonal metric, cast in spherical coordinates, and to the Brans-Dicke theory. In the last case, we show that it is possible to put a significant constraint on the free parameter of the theory by means of experimental bounds on the equivalence principle.