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arXiv · 1805.09918

Turnaround radius in $f(R)$ model

Rafael C. C. Lopes·Rodrigo Voivodic·Luis Raul Abramo·Laerte Sodré Jr
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Abstract

We investigate the turnaround radius in the spherical collapse model, both in General Relativity and in modified gravity, in particular $f(R)$ scenarios. The phases of spherical collapse are marked by the density contrast in the instant of turnaround $\delta_t$, and by the linear density contrast in the moment of collapse, $\delta_c$. We find that the effective mass of the extra scalar degree of freedom which arises in modified gravity models has an impact on $\delta_t$ of up to $\sim10\%$, and that $\delta_c$ can increase by $\sim1.0\%$. We also compute the turnaround radius, $R_t$, which in modified gravity models can increase by up to $\sim 6\%$ at $z \simeq 0$.

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Rafael C. C. Lopes, Rodrigo Voivodic, Luis Raul Abramo, Laerte Sodré Jr. 2018-05-24. Turnaround radius in $f(R)$ model. https://doi.org/10.1088/1475-7516%2F2018%2F09%2F010

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