The Hubble tension problem with variation of the speed of light from Pantheon supernova dataset

Abstract

Abstract We investigate how the tension with the Hubble parameter between early-time and late-time observations could be alleviated with the deviation in the speed of light model. In order to test the model, the data of 1,048 spectroscopically confirmed type Ia supernova with redshift range 0.01 < z < 2.3 from Pantheon Supernova is analysed. We found that the deviation in the local speed of light Δc/c = (-0.115 ± 5.087) × 10−5 and the temporal deviation in the speed of light (1/c)(dc/dt) = (7.20 ± 23.34) × 10−18 yr−1 when combining the Pantheon supernova dataset with other constraints. Our result shows that the data prefers sightly higher value of the speed of light in the past albeit with a large uncertainty. The model alleviates the Hubble tension problem by reducing the Hubble parameter to 71.72 ± 1.40 km s−1 Mpc−1 closer to the early-time value.