Matteo Forconi

Matteo Forconi

The σ8 parameter is commonly used to quantify the amplitude of matter fluctuations at linear cosmological scales. However, its intrinsic dependence on h can introduce biases and couples the growth and Hubble tensions in an intricate way, when comparing the predictions of different models and/or datasets. For example, the bias found in models with large values of H0 is more prominent, artificially complicating the search for a model that can resolve the Hubble tension without exacerbating the growth tension. To address these challenges, an alternative parameter has been proposed: σ12. In this scenario, the worsening of the growth tension in different cases is much less pronounced than previously thought or may even be non-existent