Eur. Phys. J. Plus (2021) 136: 84
https://doi.org/10.1140/epjp/s13360-020-01015-1

Regular Article

Brane inflation and the robustness of the Starobinsky inflationary model

¹ Departamento de Astronomia, Observatório Nacional, 20921-400, Rio de Janeiro, RJ, Brasil
² Dipartimento di Fisica ‘E. Pancini’, Universitá di Napoli ‘Federico II’, Complesso Universitario di Monte S.Angelo, Edificio G, Via Cinthia, I-80126, Napoli, Italy
³ Istituto Nazionale di Fisica Nucleare (INFN) Sez. di Napoli, Complesso Universitario di Monte S.Angelo, Edificio G, Via Cinthia, I-80126, Napoli, Italy
⁴ Scuola Superiore Meridionale, Università di Napoli “Federico II”, Largo San Marcellino 10, 80138, Napoli, Italy
⁵ Departamento de Física, Universidade Federal da Paraíba, 58051-970, João Pessoa, PB, Brasil
⁶ Unidade Acadêmica de Física, Universidade Federal de Campina Grande, 58109-970, Campina Grande, PB, Brasil
⁷ Departamento de Física, Universidade Federal do Rio Grande do Norte, 59072-970, Natal, RN, Brasil
⁸ Departamento de Física, Universidade do Estado do Rio Grande do Norte, 59610-210, Mossoró, Brasil

^a simonycosta@on.br

Received: 23 October 2020
Accepted: 9 December 2020
Published online: 14 January 2021

Abstract

The first inflationary model conceived was the one proposed by Starobinsky which includes an additional term quadratic in the Ricci-scalar R in the Einstein–Hilbert action. The model is now considered a target for several future cosmic microwave background experiments given its compatibility with current observational data. In this paper, we analyse the robustness of the Starobinsky inflation by inserting it into a generalized scenario based on a -Starobinsky inflation potential, which is motivated through brane inflation. In the Einstein frame, the generalized model recovers the original model for , whereas represents an extended class of models that admit a wider range of solutions. We investigate limits on from current cosmic microwave background and baryonic acoustic oscillation data and find that only a small deviation from the original scenario is allowed, ( C.L.), which is fully compatible with zero and confirms the robustness of the Starobinsky inflationary model in light of current observations.