In a model of the late-time cosmic acceleration within the framework of generalized Proca theories, there exists a de Sitter attractor preceded by the dark energy equation of state w_ DE=-1-s, where s is a positive constant. We run the Markov-Chain-Monte-Carlo code to confront the model with the observational data of Cosmic Microwave Background (CMB), baryon acoustic oscillations, supernovae type Ia, and local measurements of the Hubble expansion rate for the background cosmological solutions

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... d obtain the bound s=0.254^+ 0.118_-0.097 at 95 additional parameter s to those in the Λ-Cold-Dark-Matter (ΛCDM) model allows to reduce tensions of the Hubble constant H_0 between the CMB and the low-redshift measurements. Including the cosmic growth data of redshift-space distortions in the galaxy power spectrum and taking into account no-ghost and stability conditions of cosmological perturbations, we find that the bound on s is shifted to s=0.16^+0.08_-0.08 (95 hence the model with s>0 is still favored over the ΛCDM model. Apart from the quantities s, H_0 and the today's matter density parameter Ω_m0, the constraints on other model parameters associated with perturbations are less stringent, reflecting the fact that there are different sets of parameters that give rise to a similar cosmic expansion and growth history.