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arXiv · 1709.07464

Primordial perturbations with pre-inflationary bounce

Yong Cai·Yu-Tong Wang·Jin-Yun Zhao·Yun-Song Piao
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Abstract

Based on the effective field theory (EFT) of nonsingular cosmologies, we build a stable model, without the ghost and gradient instabilities, of bounce inflation (inflation is preceded by a cosmological bounce). We perform a full simulation for the evolution of scalar perturbation, and find that the perturbation spectrum has a large-scale suppression (as expected), which is consistent with the power deficit of the cosmic microwave background (CMB) TT-spectrum at low multipoles, but unexpectedly, it also shows itself one marked lower valley, which actually provides a better fit to the dip at multipole $l\sim 20$. The depth of valley is relevant with the physics around the bounce scale, which is model-dependent.

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Yong Cai, Yu-Tong Wang, Jin-Yun Zhao, Yun-Song Piao. 2017-09-21. Primordial perturbations with pre-inflationary bounce. https://doi.org/10.1103/physrevd.97.103535

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