https://doi.org/10.1140/epjc/s10052-018-6367-y
Regular Article - Theoretical Physics
Cosmology in modified f(R, T)-gravity
1
Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, 141980, Dubna, Russia
2
Department of General Relativity and Gravitation, Institute of Physics, Kazan Federal University, Kremlevskaya Street 18, 420008, Kazan, Russia
* e-mail: tpv@theor.jinr.ru
Received:
27
September
2018
Accepted:
20
October
2018
Published online:
3
November
2018
In the present paper we propose a further modification of f(R, T)-gravity (where T is trace of the energy-momentum tensor) by introducing higher derivatives matter fields. We discuss stability conditions in the proposed theory and find restrictions for the parameters to prevent appearance of main type of instabilities, such as ghost-like and tachyon-like instabilities. We derive cosmological equations for a few representations of the theory and discuss main differences with conventional f(R, T)-gravity without higher derivatives. It is demonstrated that in the theory presented inflationary scenarios appear quite naturally even in the dust-filled Universe without any additional matter sources. Finally, we construct an inflationary model in one of the simplest representation of the theory, calculate the main inflationary parameters and find that it may be in quite good agreement with observations.
© The Author(s), 2018
