T2- inflation: Sourced by energy–momentum squared gravity

Mansoori S. A. H., Felegary F., Roshan M., Akarsu Ö., Sami M.

Physics of the Dark Universe, vol.42, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 42
  • Publication Date: 2023
  • Doi Number: 10.1016/j.dark.2023.101360
  • Journal Name: Physics of the Dark Universe
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, INSPEC
  • Istanbul Technical University Affiliated: Yes


In this paper, we examine chaotic inflation within the context of the energy–momentum squared gravity (EMSG) focusing on the energy–momentum powered gravity (EMPG) that incorporates the functional f(T2)∝(T2)β in the Einstein–Hilbert action, in which β is a constant and T2≡TμνTμν where Tμν is the energy–momentum tensor, which we consider to represent a single scalar field with a power-law potential. We also demonstrate that the presence of EMSG terms allows the single-field monomial chaotic inflationary models to fall within current observational constraints, which are otherwise disfavored by Planck and BICEP/Keck findings. We show that the use of a non-canonical Lagrangian with chaotic potential in EMSG can lead to significantly larger values of the non-Gaussianity parameter, fNlequi whereas EMSG framework with canonical Lagrangian gives rise to results similar to those of the standard single-field model.