The observed behavior of the rotation curves of galaxies is that the rotation speed of stars remains relatively constant with distance from the center, rather than decreasing as expected from classical Newtonian dynamics.

The discrepancy between the observed rotation curves of galaxies and the predictions of classical Newtonian dynamics is commonly referred to as the Dark Matter Problem.

The most widely accepted explanation for the observed rotation curves of galaxies is the presence of a massive halo of dark matter surrounding galaxies, which provides the additional gravitational force needed to keep stars rotating at a constant speed.

The estimated fraction of dark matter in the universe is approximately 27%, based on various cosmological observations and measurements.

Dark matter can be detected through various methods, including gravitational lensing, weak gravitational lensing, X-ray observations, and cosmic microwave background radiation measurements.

The primary challenge in studying dark matter is its elusive and non-luminous nature, making it difficult to detect and observe directly.

Galaxy rotation curves play a significant role in understanding dark matter by providing evidence for its existence, helping determine its distribution in galaxies, and allowing us to measure the mass of dark matter halos.

Fritz Zwicky first proposed the idea of dark matter in 1933 to explain the observed rotation curves of galaxies.

The region of a galaxy where the rotation speed of stars is constant is called the Rotation Plateau.

In general, the more massive a galaxy is, the larger its dark matter halo.

Weakly Interacting Massive Particles (WIMPs) are one of the leading candidates for the primary component of dark matter.

If there were no dark matter, the rotation speed of stars in a galaxy would be expected to decrease linearly with distance from the center, as predicted by classical Newtonian dynamics.

The discrepancy between the observed rotation curves of galaxies and the predictions of modified Newtonian dynamics (MOND) is commonly referred to as the MOND Anomaly.

Messier 31 (Andromeda Galaxy) was the first galaxy to exhibit a flat rotation curve, providing strong evidence for the existence of dark matter.

The region of a galaxy where the rotation speed of stars decreases with distance from the center is called the Outer Disk.