2020/10/31 by S. Bekov, Sabit Bekov, Kairat Myrzakulov +2
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Classical mechanics #Context (archaeology) #Cosmology and Gravitation Theories #Formalism (music) #Geology #Geometry #Gravitation #Inflation (cosmology) #Inflaton #Mathematical physics #Mathematics #Nonlinear system #Physics #Quantum gravity #Quantum mechanics #Scalar (mathematics) #Slow roll #Solar and Space Plasma Dynamics #Spectral index #Spectral line #Theoretical physics #astro-ph.CO #f(R) gravity #gr-qc
paper · pdf · doi:10.3390/sym12121958
published as Symmetry 2020, 12(12), 1958 · 11 pages, version published
openalex created_date 2020/10/29 · openalex publication_date 2020/11/26 · arxiv created 2020/11/27 · arxiv updated 2020/11/30 · openalex updated_date 2026/08/05
Slow-roll inflation is analyzed in the context of modified gravity within the Palatini formalism. As shown in the literature, inflation in this framework requires the presence of non-traceless matter; otherwise, it does not occur just as a consequence of the nonlinear gravitational terms of the action. Nevertheless, by including a single scalar field that plays the role of the inflaton, slow-roll inflation can be performed in these theories, where the equations lead to an effective potential that modifies the dynamics. We obtain the general slow-roll parameters and analyze a simple model to illustrate the differences introduced by the gravitational terms under the Palatini approach, and the modifications on the spectral index and the tensor to scalar ratio predicted by the model.