Despite attempts to explain galaxy cluster dynamics without dark matter by modifying gravity, no widely accepted alternative has emerged. The quest to understand dark matter continues in astrophysics and particle physics.
The presence of dark matter in galaxy clusters is inferred from observations of their dynamics, such as the motion of galaxies within the cluster. The gravitational influence of dark matter is thought to play a significant role in explaining the observed velocities of galaxies, particularly in the outer regions of the clusters.
If we were to consider eliminating the evidence for dark matter in a galaxy cluster like the Coma Cluster, we would need to find an alternative explanation for the observed dynamics that doesn't involve dark matter. One way to do this is to modify the laws of gravity.
The standard model of gravity is described by Newton's law of gravitation and, on a larger scale, by Einstein's theory of general relativity. Any modification to these laws could potentially change our understanding of the dynamics of galaxy clusters.
Let's consider a hypothetical scenario where the average distance between galaxies in the Coma Cluster is changed. The gravitational force between galaxies is influenced by the masses of the galaxies involved and the distance between them. If we were to change the average distance between galaxies, we would be affecting the gravitational forces between them.
To eliminate the need for dark matter, we would need to adjust the gravitational forces in such a way that the observed dynamics of galaxies within the cluster can be explained without the need for additional unseen mass. This could potentially be achieved by modifying the laws of gravity in some manner.
However, it's important to note that any such modification would need to be consistent with a wide range of observations, not just those within the Coma Cluster. The evidence for dark matter comes from a variety of sources, including galaxy rotation curves, gravitational lensing, and the cosmic microwave background, among others.
In reality, there is currently no widely accepted alternative to dark matter that can explain all these observations without introducing some form of additional, non-baryonic matter. The quest to understand the nature of dark matter is an active area of research in astrophysics and particle physics.