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arXiv · 2003.08950

Transient weak gravity in scalar-tensor theories

Manuel Wittner·Giorgio Laverda·Oliver F. Piattella·Luca Amendola
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Abstract

Sub-horizon perturbations in scalar-tensor theories have been shown to grow generically faster than in uncoupled models due to a positive, additive Yukawa force. In such cases, the amount of clustering becomes larger than in the standard cosmological model, exacerbating the observed tension in the $\sigma_8$ parameter. Here we show instead that in some simple cases of conformally coupled dark energy one can obtain a transient regime of negative Yukawa force, without introducing ghosts or other instabilities.

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Manuel Wittner, Giorgio Laverda, Oliver F. Piattella, Luca Amendola. 2020-03-19. Transient weak gravity in scalar-tensor theories. https://doi.org/10.1088/1475-7516/2020/07/019

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