A novel approach to baryogenesis in f(Q,Lm) gravity and its cosmological implications

Abstract

We present an examination of the $f(Q,L_m)$ gravity model, in which the functional form $f(Q,L_m)=\alpha Q^n+\beta L_m$ is postulated and discuss its potential impact on cosmological dynamics and the phenomenon of gravitational baryogenesis. Combining observational insights from Hubble, BAO and pantheon datasets, we conduct a comprehensive analysis to constrain the model's parameters and determine the baryon-to-entropy ratio $\frac{{\eta }_B}{s}$, providing valuable insights into the model's performance and cosmological implications. In the context of baryogenesis and generalized gravitational baryogenesis, we show that setting $n=\frac{1}{2}$ leads to a mathematical inconsistency due to the presence of a division by zero arising from the factor $(1-2n)$ in the denominators. By looking closely at how $\frac{{\eta }_B}{s}$ changes with n and β, we show that our model predicts a baryon-to-entropy ratio that is both positive and in line with the highest value seen so far, which is $9.42\times {10}^{-11}$ for $1.32965<n<1.39252$, and this value is right for both β and n, with $\alpha \simeq -1.95084\times {10}^{86}$. The excellent agreement between our model's predictions and the pantheon dataset demonstrates the model's capacity to accurately describe the physics of baryogenesis and its ability to reproduce the observed features of the cosmological data, showcasing its potential as a reliable tool for understanding the evolution of the Universe.