Dark Matter

TL;DR

This paper reviews the evidence for dark matter, explores alternative theories modifying gravity, and compares their strengths and weaknesses, highlighting ongoing challenges in detecting dark matter directly.

Contribution

It provides a comprehensive overview of dark matter hypotheses, including both exotic matter and modified gravity, with critical analysis of their advantages and limitations.

Findings

Dark matter evidence is strong but elusive to direct detection

Modified gravity theories offer alternative explanations for cosmic phenomena

Each hypothesis has distinct strengths and weaknesses

Abstract

In this article we address the mystery of dark matter. We expound the various evidences, astrophysical and cosmological, leading to hypothesize the existence of an invisible form of matter, whose attempts at detecting it have so far all failed. We also discuss some alternative suggestions that replace the hypothesis of exotic matter with the assumption of modifications of the gravitational dynamics. For each of the various proposals we also discuss the strong and weak points.