Tensions between the Early and the Late Universe

The standard cosmological model successfully describes observations from widely different epochs of the Universe, from primordial nucleosynthesis all the way to the present day. As the basic cosmological parameters of the model are being determined with increasing and unprecedented precision, it is not guaranteed that the same numerical values for the models’ parameters will continue to fit observations from widely different epochs. Discrepancies between observations at early and late cosmological time, if confirmed at high significance, would require an expansion of the standard model, and may perhaps lead to the discovery of new physics.