Characteristics of Effective Dark Matter in Nonlocal Gravity

TL;DR

This paper explores nonlocal gravity as an alternative explanation for dark matter, highlighting its finite density and reduced presence in dwarf galaxies, with implications for specific ultra-diffuse galaxies.

Contribution

It introduces a nonlocal gravity model where dark matter effects are emergent, finite, and less prominent in dwarf galaxies, contrasting with standard particle dark matter models.

Findings

Effective dark matter density in NLG is always finite and cusp-free.

Less effective dark matter in dwarf galaxies compared to standard models.

Implications for ultra-diffuse galaxies AGC 114905, 242019, and 219533.

Abstract

Nonlocal gravity (NLG) is a classical nonlocal generalization of Einstein's theory of gravitation that has been constructed in close analogy with the nonlocal electrodynamics of media. According to NLG, what appears as dark matter in astrophysics and cosmology is in reality the nonlocal aspect of the universal gravitational interaction. We focus here on two main features of the effective dark matter in NLG, namely, (a) the density of effective dark matter in NLG is always finite and therefore cusp-free, and (b) there is less effective dark matter in dwarf galaxies than is generally assumed in the standard particle dark matter paradigm. The corresponding astrophysical implications of NLG in connection with three ultra-diffuse galaxies AGC 114905, 242019, and 219533 are discussed.