Newtonian fractional-dimension gravity and disk galaxies
Loyola Marymount University, 90045, Los Angeles, CA, USA
Accepted: 27 January 2021
Published online: 5 February 2021
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 to a natural scale length of our model, namely 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 and the baryonic radial acceleration 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.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021