Speaker
Description
The hypothesis that the Universe is permeated by a cosmological background of gravitational waves has gained increasing interest in theoretical cosmology. In this context, the CMaDE model proposes that dark energy can be understood as a dynamical contribution associated with the gravitational-wave background, whose characteristic scale is linked to the cosmological evolution of the horizon. In this work, we present a complete formulation of the cosmological dynamics of the CMaDE model, considering both the background evolution and the system of first-order linear perturbations of Einstein's field equations, together with the perturbed relativistic continuity and Euler equations.
The model was implemented in a modified version of \texttt{CLASS}, allowing us to obtain consistent predictions for both background and perturbation observables. Based on this implementation, Bayesian analyses were performed with \texttt{MontePython} using different combinations of cosmological datasets.
The results obtained are highly promising, since CMaDE is able to adequately reproduce the observables considered and shows regions of parameter space compatible with current observations. In addition, the analyses suggest that the dynamics of the model could contribute to alleviating relevant cosmological tensions, especially those associated with the inference of $H_0$. These results position CMaDE as a viable proposal for studying the accelerated expansion of the Universe from a perspective alternative to the standard $\Lambda$CDM cosmological model.