English

$\alpha$-attractor potentials in loop quantum cosmology

General Relativity and Quantum Cosmology 2025-06-25 v3 Cosmology and Nongalactic Astrophysics High Energy Physics - Phenomenology High Energy Physics - Theory

Abstract

We perform in this work an analysis of the background dynamics for α\alpha-attractor models in the context of loop quantum cosmology. Particular attention is given to the determination of the duration of the inflationary phase that is preceded by the quantum bounce in these models. From an analysis of the general predictions for these models, it is shown that we can be able to put constraints in the parameter α\alpha of the potentials and also on the quantum model itself, especially the Barbero-Immirzi parameter. In particular, the constraints on the tensor-to-scalar ratio and spectral tilt of the cosmological perturbations limit the α\alpha parameter of the potentials to values such that αn=010\alpha_{n=0} \lesssim 10, αn=117\alpha_{n=1} \lesssim 17 and αn=267\alpha_{n=2} \lesssim 67, for the α\alpha attractors T, E, and n=2n=2 models, respectively. Using the constraints on the minimal amount of e-folds of expansion from the quantum bounce up to the end of inflation leads to the upper bounds for the Barbero-Immirzi parameter for the α\alpha-attractor models studied in this work: γn=051.2\gamma_{n=0} \lesssim 51.2, γn=163.4\gamma_{n=1}\lesssim 63.4 and γn=264.2\gamma_{n=2} \lesssim 64.2, which are obtained when fixing the parameter α\alpha in the potential at the values saturating the upper bounds given above for each model.

Keywords

Cite

@article{arxiv.2404.10149,
  title  = {$\alpha$-attractor potentials in loop quantum cosmology},
  author = {G. L. L. W. Levy and Rudnei O. Ramos},
  journal= {arXiv preprint arXiv:2404.10149},
  year   = {2025}
}

Comments

11 pages, 6 figures. Replaced with the version matching the published one in the Physical Review D. Version 3: fixed a typo in the Eq. (3.13)

R2 v1 2026-06-28T15:55:10.896Z