Solving both $H_0$ and $\sigma_8$ tensions in $f(T)$ gravity

Abstract

We report how to alleviate both the $H_0$ and $\sigma_8$ tensions simultaneously within $f(T)$ gravity. In particular, we consider the parametrization $f(T)=-T-2\Lambda/M_P^2+\alpha T^\beta$, where two out of the three parameters are independent. This model can efficiently fit observations solving the two tensions. To our knowledge, this is the first time where a modified gravity theory can alleviate both $H_0$ and $\sigma_8$ tensions simultaneously, hence, offering an additional argument in favor of gravitational modification.