>>11293005>>11293300This. Type Ia supernovae and their light curves are only a piece of the evidence; they're suggested to have a definite luminosity curve universal to all supernovae of their type, meaning that measuring one of them can give us both redshift and distance. Redshift and distance can be used to measure how quickly objects are moving away at a given time (distance to the object gives us the time at which we're seeing it). Previously this data suggested that objects were moving away faster than they were in the past, i.e. the universe's expansion is accelerating and not constant (which was not expected, as far as I can tell).
The paper (
https://arxiv.org/abs/1912.04903), though I haven't read it in full, suggests that the statistics done to get the Ia supernova light curve were done based on false assumptions. I don't know if the paper claims their new interpretation implies linear expansion.
HOWEVER: type Ia supernovae are not the only evidence for dark energy, since measurements of cosmic background radiation and baryon acoustic oscillations have also been used to the same effect.
Note: Just an undergrad repeating what I know from a presentation and skimming the abstract; I also asked a cosmologist and he seemed unconcerned.
