2017/12/31 by Ivan Agullo, Iván Agulló, Boris Bolliet +1 · 1 citation
Physics and Astronomy · #Anisotropy #Big Bounce #Black Holes and Theoretical Physics #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Loop quantum cosmology #Non-Gaussianity #Noncommutative and Quantum Gravity Theories #Phenomenology (philosophy) #Philosophy #Physics #Planck #Quantum #Quantum cosmology #Quantum gravity #Quantum mechanics #Theoretical physics #astro-ph.CO #gr-qc
paper · pdf · doi:10.1103/physrevd.97.066021
published as Phys. Rev. D 97, 066021 (2018) · Minor updates: current version matches the accepted PRD manuscript
arxiv created 2018/02/26 · openalex publication_date 2018/03/26 · arxiv updated 2018/04/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We extend the phenomenology of loop quantum cosmology (LQC) to second order in perturbations. Our motivation is twofold. On the one hand, since LQC predicts a cosmic bounce that takes place at the Planck scale, the second-order contributions could be large enough to jeopardize the validity of the perturbative expansion on which previous results rest. On the other hand, the upper bounds on primordial non-Gaussianity obtained by the Planck Collaboration are expected to play a significant role on explorations of the LQC phenomenology. We find that the bounce in LQC produces an enhancement of non-Gaussianity of several orders of magnitude, on length scales that were larger than the curvature radius at the bounce. Nonetheless, we find that one can still rely on the perturbative expansion to make predictions about primordial perturbations. We discuss the consequences of our results for LQC and its predictions for the cosmic microwave background.