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arXiv · 1807.07451

de Sitter Swampland, $H_0$ tension & observation

Eoin Ó Colgáin·Maurice H. P. M. van Putten·Hossein Yavartanoo
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Abstract

Realising de Sitter vacua in string theory is challenging. For this reason it has been conjectured that de Sitter vacua inhabit the Swampland of inconsistent low-energy effective theories coupled to gravity. Since de Sitter is an attractor for $\Lambda$CDM, the conjecture calls $\Lambda$CDM into question. Reality appears sympathetic to this idea as local measurements of the Hubble constant $H_0$ are also at odds with $\Lambda$CDM analysis of Planck data. This tension suggests that the de Sitter state is unstable, thereby implying a turning point in the Hubble parameter. We present a model relieving this tension, which predicts a turning at small positive redshift $z_*$ that is dictated by present-day matter density $\omega_m$. This feature is easily identified by homogeneous surveys covering redshifts $z \leq 0.1$. We comment on the implications for the Swampland program.

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Eoin Ó Colgáin, Maurice H. P. M. van Putten, Hossein Yavartanoo. 2018-07-19. de Sitter Swampland, $H_0$ tension & observation. https://doi.org/10.1016/j.physletb.2019.04.032

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