Gravitational baryogenesis beyond the spectator approximation
Fuente:
arXiv
Salvato in:
| Autori principali: | , , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2026
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866910181084889088 |
|---|---|
| author | Pereira, David S. Fernandes, Beatriz A. Mimoso, José Pedro |
| author_facet | Pereira, David S. Fernandes, Beatriz A. Mimoso, José Pedro |
| contents | The standard gravitational-baryogenesis operator $λ\,\nabla_μR\,J^μ$, with $λ\equiv ε/M_\ast^{2}$, is usually treated as a spectator interaction that generates an effective chemical potential in a prescribed background. When included in the gravitational action, however, it defines a genuine curvature--matter-coupling variational problem, relevant for the baryon, lepton, and $B\!-\!L$ currents, whether described microscopically by particle-physics operators or macroscopically by a fluid current $J^μ=n_Xu^μ$. Up to a boundary term the interaction is equivalent to $-λR\nabla_μJ^μ$, making its $f(R,{\rm Matter})$ character manifest, but the metric equations remain open unless the metric dependence of $J^μ$ is specified. For an arbitrary local realization $J^μ(Ψ,g)$ we derive the universal part of the field equations and isolate the realization-dependent tensor generated by $δ_g J^μ$. In the vector-density realization the explicit $J^α\nabla_αR$ term cancels, but an algebraic term $-λg_{μν}R\nabla_αJ^α$ survives, so the theory admits only a partial effective-Planck-mass interpretation, $M_{\rm eff}^2=M_{\rm Pl}^2-2λ\nabla_μJ^μ$, and a time-dependent effective gravitational coupling during baryogenesis. Specializing to flat Friedmann-Lemaître-Robertson-Walker (FLRW) with a homogeneous current $J^μ=n_Xu^μ$, we obtain the modified Friedmann and Raychaudhuri equations, the associated continuity relation, and dimensionless diagnostics that quantify when the spectator approximation is controlled. We also discuss the implications for gravitational-baryogenesis studies in modified theories of gravity, providing a consistent General Relativity (GR) baseline for implementations in both standard cosmology and modified-gravity frameworks. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_11837 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Gravitational baryogenesis beyond the spectator approximation Pereira, David S. Fernandes, Beatriz A. Mimoso, José Pedro General Relativity and Quantum Cosmology High Energy Physics - Theory The standard gravitational-baryogenesis operator $λ\,\nabla_μR\,J^μ$, with $λ\equiv ε/M_\ast^{2}$, is usually treated as a spectator interaction that generates an effective chemical potential in a prescribed background. When included in the gravitational action, however, it defines a genuine curvature--matter-coupling variational problem, relevant for the baryon, lepton, and $B\!-\!L$ currents, whether described microscopically by particle-physics operators or macroscopically by a fluid current $J^μ=n_Xu^μ$. Up to a boundary term the interaction is equivalent to $-λR\nabla_μJ^μ$, making its $f(R,{\rm Matter})$ character manifest, but the metric equations remain open unless the metric dependence of $J^μ$ is specified. For an arbitrary local realization $J^μ(Ψ,g)$ we derive the universal part of the field equations and isolate the realization-dependent tensor generated by $δ_g J^μ$. In the vector-density realization the explicit $J^α\nabla_αR$ term cancels, but an algebraic term $-λg_{μν}R\nabla_αJ^α$ survives, so the theory admits only a partial effective-Planck-mass interpretation, $M_{\rm eff}^2=M_{\rm Pl}^2-2λ\nabla_μJ^μ$, and a time-dependent effective gravitational coupling during baryogenesis. Specializing to flat Friedmann-Lemaître-Robertson-Walker (FLRW) with a homogeneous current $J^μ=n_Xu^μ$, we obtain the modified Friedmann and Raychaudhuri equations, the associated continuity relation, and dimensionless diagnostics that quantify when the spectator approximation is controlled. We also discuss the implications for gravitational-baryogenesis studies in modified theories of gravity, providing a consistent General Relativity (GR) baseline for implementations in both standard cosmology and modified-gravity frameworks. |
| title | Gravitational baryogenesis beyond the spectator approximation |
| topic | General Relativity and Quantum Cosmology High Energy Physics - Theory |
| url | https://arxiv.org/abs/2603.11837 |