Cosmological Inflation in $f(Q,\mathcal{L}_{m})$ Gravity

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Shiravand, Maryam, Fakhry, Saeed, Firouzjaee, Javad T., Tizfahm, Ali
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866912704141197312
author Shiravand, Maryam
Fakhry, Saeed
Firouzjaee, Javad T.
Tizfahm, Ali
author_facet Shiravand, Maryam
Fakhry, Saeed
Firouzjaee, Javad T.
Tizfahm, Ali
contents Cosmological inflation remains a key paradigm for explaining the earliest stages of the Universe, yet the theoretical limitations of General Relativity (GR) motivate the development of alternative formulations capable of addressing both early and late cosmic acceleration. In this work, we investigate cosmological inflation within the $f(Q,\mathcal{L}_{m})$ gravity framework based on symmetric teleparallel geometry, where the non-metricity scalar $Q$ couples directly to the matter Lagrangian. We formulate the slow-roll dynamics and derive analytical predictions for the scalar spectral index $n_{s}$ and tensor-to-scalar ratio $r$ in both linear and nonlinear non-minimal coupling models, assuming a power-law inflaton potential. Our findings show that the linear case, $f(Q,\mathcal{L}_{m})=-αQ + 2\mathcal{L}_{m}+β$, becomes compatible with Planck+BK15+BAO constraints for positive $α$ and $β$, producing narrow viable contours in parameter space. In contrast, the nonlinear model, $f(Q,\mathcal{L}_{m})=-αQ+(2\mathcal{L}_{m})^{2}+β$, achieves observational viability only for negative $α$ and $β$, and its predictions predominantly fall inside the $68\%$ confidence region of joint data. These results demonstrate that $f(Q,\mathcal{L}_{m})$ gravity produces distinct inflationary regimes, providing a highly competitive alternative to GR.
format Preprint
id arxiv_https___arxiv_org_abs_2511_09031
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Cosmological Inflation in $f(Q,\mathcal{L}_{m})$ Gravity
Shiravand, Maryam
Fakhry, Saeed
Firouzjaee, Javad T.
Tizfahm, Ali
General Relativity and Quantum Cosmology
Cosmological inflation remains a key paradigm for explaining the earliest stages of the Universe, yet the theoretical limitations of General Relativity (GR) motivate the development of alternative formulations capable of addressing both early and late cosmic acceleration. In this work, we investigate cosmological inflation within the $f(Q,\mathcal{L}_{m})$ gravity framework based on symmetric teleparallel geometry, where the non-metricity scalar $Q$ couples directly to the matter Lagrangian. We formulate the slow-roll dynamics and derive analytical predictions for the scalar spectral index $n_{s}$ and tensor-to-scalar ratio $r$ in both linear and nonlinear non-minimal coupling models, assuming a power-law inflaton potential. Our findings show that the linear case, $f(Q,\mathcal{L}_{m})=-αQ + 2\mathcal{L}_{m}+β$, becomes compatible with Planck+BK15+BAO constraints for positive $α$ and $β$, producing narrow viable contours in parameter space. In contrast, the nonlinear model, $f(Q,\mathcal{L}_{m})=-αQ+(2\mathcal{L}_{m})^{2}+β$, achieves observational viability only for negative $α$ and $β$, and its predictions predominantly fall inside the $68\%$ confidence region of joint data. These results demonstrate that $f(Q,\mathcal{L}_{m})$ gravity produces distinct inflationary regimes, providing a highly competitive alternative to GR.
title Cosmological Inflation in $f(Q,\mathcal{L}_{m})$ Gravity
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2511.09031