Exploring generalized Starobinsky Model of Inflation: Observational Constraints
Saisandri Saini, Akhilesh Nautiyal
备注：
5 pages, 2 figures, Contribution to the conference proceedings of BCVSPIN 2024: Particle Physics and Cosmology in the Himalayas, December 9-13, 2024, Kathmandu, Nepal
We examine the power-law Starobinsky model, a generalized version of the Starobinsky inflation model, characterized by a power-law correction to Einstein gravity. Employing the $f(R)$ formalism, the scalar and tensor power spectra were numerically computed as functions of the dimensionless parameters $M$ and $β$. A Markov Chain Monte Carlo (MCMC) analysis was conducted using Planck-2018, BICEP3 and BAO observational data, yielding precise constraints on $β= 1.987^{+0.013}_{-0.016},\, 95\%\, C.\, L.$. and $ \log_{10}M = -4.72^{+0.21}_{-0.20}$. The derived scalar spectral index $n_s=0.9676^{+0.0069}_{-0.0068}$ and tensor-to-scalar ratio $r=0.0074^{+0.0061}_{-0.0044}$ lie within the bounds set by Planck observations. We analyse a general reheating scenario while keeping the number of e-folds during inflation, $N_{pivot}$, fixed. The analysis confirms that deviations from the Starobinsky $R^2$ model are observationaly viable, with implications for high-energy physics and supergravity-based inflationary models.
Tokyo Metropolitan University（东京都立大学）；Tomsk State University（托木斯克国立大学）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study（理化学研究所 Kavli 宇宙物理学与数学研究所（WPI），东京大学高等研究院）
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