D. F. P. Cruz, D. S. Pereira, F. S. N. Lobo

Abstract
The observed matter─antimatter asymmetry of the Universe remains a fundamental challenge in modern physics. In this work, we explore gravitational baryogenesis within the framework of f(T, L_m) gravity, where the gravitational Lagrangian depends on both the torsion scalar T and the matter Lagrangian L_m. We consider three representative models and examine their ability to generate the observed baryon-to-entropy ratio. Our analysis shows that couplings involving both torsion and the matter Lagrangian, ∂μ(−T−LmL0), can successfully account for the baryon asymmetry for decoupling temperatures in the range 10¹²─10¹⁴ GeV, while remaining consistent with small deviations from General Relativity. These results highlight the capacity of f(T, L_m) gravity to provide novel mechanisms for baryogenesis, demonstrating that the interplay between torsion and matter-sector contributions can naturally generate the observed asymmetry. The framework also remains compatible with late-time cosmological evolution, offering a unified setting for early- and late-time dynamics.

Keywords
Baryogenesis / Modified gravity

Nuclear Physics B
Volume 1023, Number 117304
2026 February

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