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arXiv · 1904.03545

Late-time acceleration and inflation in a Poincar\'e gauge cosmological model

Hongchao Zhang·Lixin Xu
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Abstract

A self-consistent model which can unify Starobinsky inflation and the $\Lambda$CDM model in the framework of Poincar\'e gauge cosmology (PGC) is studied in this work, without extra inflaton and ``dark energy''. We start from the general nine-parameter PGC Lagrangian and get two Friedmann-like analytical solutions with the certain ghost- and tachyon-free conditions on the Lagrangian parameters. The scalar torsion $h$-determined solution is consistent with Starobinsky cosmology in the early-time and the pseudo-scalar torsion $f$-determined solution contains naturally a constant ``dark energy'' density, $3(\alpha-1)^2/8B_0$, which covers the $\Lambda$CDM model in the late-time. According to the latest observations, we estimate the magnitudes of parameters: $\alpha-1\simeq 8.07\times10^{-56}$, $B_0\simeq5.76\times10^{-28}GeV^{-2}$ in the natural units.

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Hongchao Zhang, Lixin Xu. 2019-04-06. Late-time acceleration and inflation in a Poincar\'e gauge cosmological model. https://doi.org/10.1088/1475-7516%2F2019%2F09%2F050

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