This paper continues previous work on a novel alternative model of gravity, based on the theory of fractional-dimension spaces applied to Newton's law of gravitation. In particular, our Newtonian fractional-dimension gravity is now applied to axially symmetric structures, such as thin/thick disk galaxies described by exponential, Kuzmin, or other similar mass distributions. As in the case of spherically symmetric structures, which was studied in previous work on the subject, we examine a possible connection between our model and modified Newtonian dynamics, a leading alternative gravity model, which accounts for the observed properties of galaxies and other astrophysical structures without requiring the dark matter hypothesis. By relating the MOND acceleration constant a0≃1.2 ×10-10ms-2 to a natural scale length l0 of our model, namely a0≈GM /l02 for a galaxy of mass M, and by using the empirical Radial Acceleration Relation, we are able to explain the connection between the observed radial acceleration gobs and the baryonic radial acceleration gbar in terms of a variable local dimension D. As an example of this methodology, we provide a detailed rotation curve fitting for the case of the field dwarf spiral galaxy NGC 6503.
European Physical Journal Plus
- Pub Date:
- February 2021
- General Relativity and Quantum Cosmology;
- Astrophysics - Astrophysics of Galaxies
- 23 pages, including 6 figures: references added and other minor changes after peer review. Final version to be published in The European Physical Journal Plus, Springer