On the time dependency of a_₀

In this paper, we test one of the prediction of the Scale Invariant Vacuum (SIV) theory on MOND. According to that theory, MOND's acceleration a₀ is not a universal quantity but depends from several parameters, and from time. To check this prediction, we compare the dependency of a₀ from redshift, using the values of a₀ obtained by Marra et al. (2020) carrying a Bayesian inference for 153 galaxies of the SPARC sample. Since this sample does not contain galaxies at large redshift, we estimated a₀ from the Nestor Shacha et al. (2023) data. The SPARC sample, for small values of the redshift, in the redshift range 0.00032–0.032 gives a correlation with z, and the Nestor Shacha et al. (2023) data, in the higher redshift range 0.5–2.5 gives an anti-correlation with the redshift z. Both samples show a dependency of a₀ from z. The different behavior at low and high redshift can be related to a change of the a₀(z) with redshift, or to the lower precision with which the high redshift value of a₀ are known. Copyright © 2023 The Author(s).