Cosmological constraints on (t) CDM models

Abstract Problems with the concordance cosmology Λ CDM as the cosmological constant problem, coincidence problems and Hubble tension has led to many proposed alternatives, as the (t) Λ (t) CDM, where the now called Λ cosmological term is allowed to vary due to an interaction with pressureless matter. Here, we analyze one class of these proposals, namely, = 'a^-2+ H²+ _* Λ = α ′ a - 2 + β H 2 + λ ∗, based on dimensional arguments. Using SNe Ia, cosmic chronometers data plus constraints on H₀ H 0 from SH0ES and Planck satellite, we constrain the free parameters of this class of models. By using the Planck prior over H₀ H 0, we conclude that the _* λ ∗ term can not be discarded by this analysis, thereby disfavouring models only with the time-variable terms. The SH0ES prior over H₀ H 0 has an weak evidence in this direction. The subclasses of models with '=0 α ′ = 0 and with =0 β = 0 can not be discarded by this analysis. Finally, by using distance priors from CMB, the Λ time-dependence was quite restricted.