The existence of dark matter is a widely accepted theory in astrophysics and cosmology. Dark matter is thought to be a form of matter that does not interact with light or other electromagnetic radiation, making it difficult to detect directly. Its presence is inferred through its gravitational effects on visible matter and the structure of the universe.
Based on current understanding, dark matter is believed to be present in every galaxy, including our own Milky Way. Observational evidence from various sources, such as the rotation curves of galaxies, gravitational lensing, and the large-scale distribution of matter in the universe, strongly suggest the presence of dark matter.
It's important to note that while dark matter is thought to be ubiquitous in galaxies, its distribution within a galaxy can vary. The exact nature and distribution of dark matter within galaxies are still active areas of research, and scientists continue to investigate its properties and behavior.