Dark radiation

Dark radiation refers to hypothetical particles that interact weakly with ordinary matter and radiation, but could account for some of the missing energy density of the universe. These particles are not part of the Standard Model of particle physics, but are predicted by some extensions to the model.

Overview

Dark radiation is a form of dark matter, which along with dark energy, makes up approximately 95% of the universe. Unlike dark matter, which interacts only through gravity, dark radiation would also interact weakly with electromagnetic radiation. This interaction could potentially make dark radiation detectable, unlike dark matter and dark energy.

Theoretical Predictions

The existence of dark radiation is predicted by some extensions to the Standard Model, such as supersymmetry and extra dimensions. These theories predict the existence of additional particles, beyond those in the Standard Model, that could account for the missing energy density of the universe.

Detection

Detecting dark radiation is a major challenge for modern physics. Because it interacts weakly with ordinary matter and radiation, it is difficult to detect directly. However, its effects could potentially be observed indirectly, through its impact on the cosmic microwave background and the large-scale structure of the universe.

Implications

If dark radiation exists, it could have significant implications for our understanding of the universe. It could help to explain the missing energy density of the universe, and could also provide clues to the nature of dark matter and dark energy. Furthermore, it could provide evidence for theories beyond the Standard Model, such as supersymmetry and extra dimensions.

See also

• Dark matter
• Dark energy
• Cosmic microwave background
• Supersymmetry
• Extra dimensions