The distances of high-redshift Type Ia supernovae as possible evidence for a variable speed of light

Abstract

Exploration of the variable speed of light as an alternative explanation for the observed dimming of high-redshift Type Ia supernovae (SNe Ia) was conducted, a phenomenon traditionally interpreted as evidence for dark energy. To begin, differences in distance modulus between models that include dark energy and those that do not were derived based on the assumption of dark energy’s existence. Next, calculations were made on how the absolute magnitudes of SNe Ia at different redshifts change with variations in the speed of light. Results indicate that a decrease in the speed of light with increasing redshift could account for the observed dimming of SNe Ia without requiring the introduction of dark energy. Furthermore, estimates suggest that the time required for the speed of light to increase by 1 m/s in the current universe would be less than 186 years.