@misc{10481/78154,
year = {2022},
month = {8},
url = {https://hdl.handle.net/10481/78154},
abstract = {We calculate how primordial anisotropies in the background space-time affect the evolution of cosmological perturbations for bouncing alternatives to inflation, like ekpyrosis and the matter bounce scenario. We find that the leading order effect of anisotropies in the contracting phase of the universe is to induce anisotropies in the cosmic microwave background with a very concrete form: a scale-invariant quadrupolar angular distribution. Sub-leading effects are the generation of higher-order moments in the angular distribution, as well as cross-correlations between scalar and tensor modes. We also find that observational constraints from the cosmic microwave background on the quadrupole moment provide strong bounds on allowed anisotropies for bouncing alternatives to inflation that are significantly more constraining than the bounds previously obtained using scaling arguments based on the conjectured Belinski-Khalatnikov-Lifshitz instability.},
organization = {NSF grant PHY-2110273},
organization = {Hearne Institute for Theoretical Physics},
organization = {Spanish Government through the projects PID2020-118159GB-C43, PID2019- 105943GB-I00 (with FEDER contribution)},
organization = {Operative Program FEDER2014-2020 Junta de Andalucía-Consejería de Economía y Conocimiento under project E-FQM-262-UGR18 by Universidad de Granada},
organization = {Natural Sciences and Engineering Research Council of Canada},
organization = {UNB Fritz Grein Research Award},
title = {Observational constraints on anisotropies for bouncing alternatives to inflation},
doi = {10.1088/1475-7516/2022/10/045},
author = {Agullo, Ivan and Olmedo Nieto, Javier Antonio and Wilson-Ewing, Edward},
}