A Potentially Useful Galactic Dark Matter Index

There have been a number of observational surprises with respect to galactic dark matter-to-visible matter ratios. These surprises confirm our continued lack of understanding of the fundamental nature of dark matter. Because of their apparent close ties with galactic gravitational entropy, at least four recent observations appear to provide the first evidence in support of Verlinde’s theory of gravity, dark energy and dark matter as emergent properties. They also appear to correlate with Roger Penrose’s gravitational entropy concept, as well as entropy defined in the Flat Space Cosmology (FSC) model. Given the observational support, two different testable versions of a “Dark Matter Index” (DMI) are introduced in this paper, and its utility is discussed in terms of potentially achieving a better understanding of the fundamental nature of dark matter.