https://doi.org/10.1140/epjc/s10052-023-12149-8
Regular Article - Theoretical Physics
Second-order corrections to Starobinsky inflation
1
Departamento de Física, Universidade Federal do Rio Grande do Norte, Campus Universitário, s/n-Lagoa Nova, CEP 59072-970, Natal, Rio Grande do Norte, Brazil
2
Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, Campus Universitário, s/n-Lagoa Nova, CEP 59072-970, Natal, Rio Grande do Norte, Brazil
Received:
23
June
2023
Accepted:
13
October
2023
Published online:
13
November
2023
Higher-order theories of gravity are extensions to general relativity (GR) motivated mainly by high-energy physics searching for GR ultraviolet completeness. They are characterized by the inclusion of correction terms in the Einstein–Hilbert action that leads to higher-order field equations. In this paper, we propose investigating inflation due to the GR extension built with all correction terms up to the second-order involving only the scalar curvature R, namely, 
, 
, 
. We investigate inflation within the Friedmann cosmological background, where we study the phase space of the model, as well as explore inflation in slow-roll leading-order. Furthermore, we describe the evolution of scalar perturbations and properly establish the curvature perturbation. Finally, we confront the proposed model with recent observations from Planck, BICEP3/Keck, and BAO data.
© The Author(s) 2023
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