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Axion dark matter: What is it and why now?
Francesca Chadha-Day1, John Ellis2,3,4, David J E Marsh2
1Institute for Particle Physics Phenomenology, Department of Physics, Durham University, Durham DH1 3LE, UK.
Science Advances
|February 23, 2022
Summary
The axion, a hypothetical particle, is a prime candidate for cosmic dark matter. Its properties, rooted in particle physics, explain its production in the early universe and guide experimental detection efforts.
Area of Science:
- Particle Physics
- Cosmology
- Astrophysics
Background:
- The axion arises from the Standard Model's solution to the strong charge-parity invariance problem.
- Dark matter remains a significant mystery in our understanding of the cosmos.
Purpose of the Study:
- To review the axion as a leading dark matter candidate for a general scientific audience.
- To discuss the axion's origins, properties, and astrophysical constraints.
Main Methods:
- Historical review of the axion's theoretical development.
- Discussion of axion production mechanisms in the early universe.
- Analysis of astrophysical constraints on axion mass and interactions.
Main Results:
- The axion's symmetry properties determine its interactions with ordinary matter.
- Astrophysical observations limit the axion's mass and interaction strength to a specific range.
- These constraints are crucial for designing axion detection experiments.
Conclusions:
- The axion is a compelling candidate for dark matter, supported by theoretical and astrophysical evidence.
- Ongoing and future laboratory experiments aim to directly detect axions.
- Understanding axion properties is key to solving the dark matter puzzle.
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