Gravitational Baryogenesis Constraints on Nojiri-Odintsov $f(R)$ Gravity (2506.18949v1)

Abstract: This paper focuses on exploring the imbalance between matter and antimatter via the gravitational baryogenesis mechanism within the framework of Nojiri-Odintsov $f(R)$ gravity models in a spatially flat FLRW universe, where $R$ is the Ricci curvature scalar. This mechanism is based on (\mathcal{CP})-violation generated via introducing an interaction between baryonic matter current ((J^\mu)) and the derivative of curvature scalar ((\partial_\mu R)), which finally results in the baryon asymmetry. We examine three distinct $f(R)$ models: (i) (f(R)=\frac{-\alpha}{R^m}+\frac{R}{2k^2}+\beta R^2), (ii) (f(R)=\alpha R^{\gamma} +\beta R^{\delta}) and (iii) (f(R)=\frac{\alpha R^{2m}-\beta R^m}{1+\gamma R^m} ). We demonstrate that even during the matter-dominated epoch of the universe, the $f(R)$ gravity models under consideration can yield a non-vanishing matter-antimatter asymmetry. We constrain the model parameters of each model within the scenario of gravitational baryogenesis to produce the observed value of the baryon-to-entropy ratio, providing a continuous set of acceptable physical values for those parameters. Our results show highly consistent agreement to the baryon-to-entropy ratio with the observational bound from the cosmological data.