This talk explores deviations from the standard cosmological model across cosmic history. First, I present constraints on dynamical dark energy using a novel pressure parametrization and a four-parameter parametrization, both tested against the latest cosmological datasets. Second, I discuss model-independent reconstructions of the reionization history using Gaussian processes. We utilize these reconstructions to place robust bounds on exotic energy injections and decaying particle models. Based on arXiv:2505.02932, arXiv:2506.19096, arXiv:2507.03535, and arXiv:2512.09866.

Locandina: https://dfweb.phys.unisa.it/seminars/AvvisoSeminari.asp?1047