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2023, no. 1

CHIRAL COSMOLOGICAL MODEL OF \(f(R, \square R)\) GRAVITY

Chervon S.V., Fomin I.V., Chaadaeva T.I.

We study the modified gravity \(f(R, \square R)\), which can be reduced to a chiral cosmological model of a particular type with scalar field observers \(\chi, \varphi, \phi\). The method of studying the chiral cosmological model was used for the \(f(R, (\nabla R)^2)\) models, but was first used by Naruko for the more general \(f(R)\) Gracing model. In this paper, equations for chiral fields and the Einstein-Friedmann equations in the Friedmann-Robertson-Walker metric are presented. Note that the solutions for this chosen model are based on a special choice of one of the chiral fields: \(\chi = -\sqrt{\frac{3}{2}}\ln 2\). Solutions are considered in the case of reducing the model to a one-field model: two chiral fields of the model depend linearly on the third one. The obtained solutions are of interest, since quantum corrections must also be taken into account in the analysis.

Keywords: chiral cosmological model, scalar-tensor and \(f(R)\) gravity theory, Friedman universe, cosmological parameters, spectral parameters.

UDC: 53.1

PACS: 04.20.Kd, 04.50.Kd

DOI: 10.17238/issn2226-8812.2023.1.117120

Please cite this article in English as:
Chervon S.V., Fomin I.V., Chaadaeva T.I. Chiral cosmological model of \(f(R, \square R)\) gravity. Space, Time and Fundamental Interactions, 2023, no. 1, pp. 117120.