Tuesday, May 17, 2022

Shedding light on axion dark matter

A theoretical review in a new study strongly supports the search for axion dark matter.

Dark matter is one of the biggest mysteries in the universe. Scientists have not yet observed dark matter directly. But, studies have confirmed its existence due to its gravitational pull effects on stars and galaxies. However, what kind of particle it remains elusive.

In a new study, scientists examined how axions can be described mathematically. They then presented how they relate to the fundamental symmetries of the Standard Model of particle physics.

Scientists from Durham University and Kings College London have presented a theoretical review in a new study strongly supporting the search for axion dark matter.

Axion describes why strong interaction follows time-reversal symmetry. It means processes powered by strong interaction at the subatomic level would appear the same if reversing the direction of time.

Although, why the strong interaction obeys time-reversal symmetry is still unknown. The axion is a popular solution to this mystery.

Axion dark matter behaves more like a field covering the universe. This axion field oscillates back and forth in the early universe. The energy stored in these oscillations is axion dark matter.

Dark matter can weakly interact with light. Axion dark matter interacts with light very weakly, but it is observable to see signs of this interaction.

The study author said, “For example, a photon (a particle of light) traveling through a magnetic field would have a small probability of turning into an axion. This process would cause unusual features in telescope observations of galaxies shining through magnetic fields.”

Study co-author, Dr. Francesca Chadha-Day, said“It is a very exciting time to be an axion physicist. Nobody yet knows the identity of dark matter. By searching for different possibilities, such as the axion, we hope to one day solve this mystery.”

Journal Reference:

  1. Francesca Chadha-Day et al., Axion dark matter: What is it and why now? Science Advances (2022). DOI: 10.1126/sciadv.abj3618
  2. Yannis K. Semertzidis et al, Axion dark matter: How to see it?, Science Advances (2022). DOI: 10.1126/sciadv.abm9928


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