Any of the papers from the WMAP science team will discuss this. However, an introductory cosmology textbook is probably a better place to go.krishna mohan said:
Dark matter density refers to the amount of dark matter present in a given region of space. Dark matter is a hypothetical type of matter that does not interact with light, making it invisible to traditional telescopes. Its density is believed to be much higher than that of normal matter, making it a key component of the universe's structure and evolution.
Dark matter density is measured indirectly through its gravitational effects on visible matter. Astronomers use techniques such as gravitational lensing and galaxy rotation curves to infer the presence and distribution of dark matter in a given region of space.
The current understanding of dark matter density is that it makes up approximately 85% of the total matter in the universe. However, the distribution and density of dark matter are still not fully understood, and further research and observations are needed to better understand its nature.
Dark matter density plays a crucial role in the formation and evolution of galaxies and other large-scale structures in the universe. It provides the majority of the mass needed for galaxies to form and helps to hold them together. Without dark matter, the universe would look very different and likely would not have evolved as it has.
Scientists are using a variety of methods, such as simulations and observations with telescopes, to better understand the distribution and density of dark matter in the universe. Some current research efforts include studying the structure of dark matter halos around galaxies, searching for signatures of dark matter interactions, and investigating the effects of dark matter on the cosmic microwave background radiation.