The Nature of the Dark Matter

TL;DR

This paper reviews recent measurements of dark matter distribution on galactic scales, discusses candidate particles like neutralinos and Machos, and examines detection methods such as microlensing.

Contribution

It provides a comprehensive overview of dark matter evidence, candidate theories, and detection strategies, with detailed focus on neutralinos and Machos.

Findings

Dark matter constitutes a significant portion of galactic mass.

Neutralino detection strategies include direct and indirect methods.

Microlensing has identified Machos as potential dark matter candidates.

Abstract

We review some recent determinations of the amount of dark matter on galactic and larger scales, with special attention to the dark matter in the Milky Way. We then briefly review the motivation for and basic physics of several dark matter candidates, and then go into more depth for two candidates, the neutralino from supersymmetry, and the baryonic Macho candidate. We give some motivation for supersymmetry and review neutralino detection strategies. For Machos we give a description of the discovery of Machos via gravitational microlensing and the interpretation of the results with respect to the dark matter problem.