Big bang nucleosystheisis constraints on extra component solutions to the hubble tension

The standard cosmological model with the cosmological constant and cold dark matter now appears to be facing puzzles. One of the most serious problems is that the values of the Hubble constant obtained by local measurements and that inferred from the measurement of Cosmic Microwave Background are not consistent. A shorten sound horizon scale at the recombination epoch by introducing extra energy components such as the extra radiation or early dark energy (EDE) is a simple approach to this problem. We evaluate EDE models and an extra radiation model by paying attention to the fit to the abundance of light elements synthesized by Big Bang Nucleosynthesis. We also investigate the possibility of nonzero lepton asymmetry and additional radiation.