Abstract. Galaxies are huge physical systems having a generic size of tens of thousands of parsecs. Thus any modification at the center of the galaxy will affect the outskirts only tens of millennia afterwards. Those retardation considerations seems to be neglected in present day analysis used to estimate rotational velocities of matter in the rim of the galaxy and its surrounding gas. The significant differences between the velocities predicted by Newtonian action at a distance theory and observations are usually dealt with by either assuming an unobservable type of matter usually referred to as "dark matter" or by modifying the laws of gravity (MOND as a typical example). We show that there are overlapping conditions for the need to apply retardation corrections in the weak approximation to general relativity and the low acceleration conditions for MOND corrections in Newtonian gravity. We will also discuss the relations between MOND and the weak approximation to general relativity that is to the retarded gravitational potential.

doi: https://doi.org/10.55318/bgjp.2024.51.1.005

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