Interpreting cosmological tensions from the effective field theory of torsional gravity

Abstract

Cosmological tensions can arise within the Lamda cold dark matter scenario amongst different observational windows, which may indicate new physics beyond the standard paradigm if confirmed by measurements. In this article, we report how to alleviate both the ${H}_{0}$ and ${\ensuremath{\sigma}}_{8}$ tensions simultaneously within torsional gravity from the perspective of effective field theory. Following these observations, we construct concrete models of Lagrangians of torsional gravity. Specifically, we consider the parametrization $f(T)=\ensuremath{-}T\ensuremath{-}2\mathrm{\ensuremath{\Lambda}}/{M}_{P}^{2}+\ensuremath{\alpha}{T}^{\ensuremath{\beta}}$, 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 ${\ensuremath{\sigma}}_{8}$ tensions simultaneously, hence, offering an additional argument in favor of gravitational modification.