Cosmological Realization of Baryon Asymmetry in f(R, G_{\mu\nu}T^{\mu\nu}) Gravity

Abstract

This work investigates the mechanism of gravitational baryogenesis (GB) under the formalism of f(R, G_{{\mu}{\nu}}T^{{\mu}{\nu}}) gravity, where R denotes the Ricci scalar, G_{{\mu}{\nu}} is the Einstein tensor and T^{{\mu}{\nu}} represents the energy--momentum tensor. f(R, G_{{\mu}{\nu}}T^{{\mu}{\nu}}) model is considered to evaluate the baryon-to-entropy ratio (BnER), which is subsequently compared against the observational limits. The results obtained exhibit compatibility with the estimated matter imbalance. Moreover, the analysis is extended to generalized GB case, resulting in outcomes that closely match empirical bounds. The findings reveal that the f(R, G_{{\mu}{\nu}}T^{{\mu}{\nu}}) formulation yields a viable theoretical setting for explaining the detected matter-antimatter disparity of the universe, highlighting its relevance in early cosmic evolution. To further validate the models, a chi-square ({\chi}^2) analysis of the Hubble parameter, H(z), and distance modulus, {\mu}(z), is performed, confirming their consistency with current cosmological observations. A comparative assessment simultaneously with the {\Lambda}CDM paradigm demonstrates a satisfactory level of agreement between the proposed model and cosmological observations from CC and Pantheon+SH0ES datasets.