Recent research proposes that interactions between dark matter and theoretical 'dark photons' during the early universe, specifically the first 500 million years after the Big Bang, could provide crucial insights into dark matter's role in cosmic evolution.
Dark matter, which constitutes approximately 85% of the universe, remains largely mysterious as it does not interact with light or ordinary matter. However, scientists suggest that dark photons, akin to regular photons but primarily interacting with dark matter, may have left a detectable 'signature' in the universe.
Charlotte Mason, an associate professor at the University of Copenhagen's Cosmic Dawn Center, explained that these interactions could have produced 'dark acoustic oscillations'—ripples in the density of dark matter that influenced the formation of the first galaxies. This period, known as the 'cosmic dawn,' is critical for understanding how dark matter affects galaxy formation.
Technological advancements, including the James Webb Space Telescope and various radio telescopes, are enabling scientists to explore this epoch more effectively. Mason emphasized that cosmic dawn serves as an ideal 'laboratory' to study dark matter behavior due to reduced disruptive effects from galaxies during this era.
The research indicates that if dark photons existed, their interactions could have created density fluctuations that influenced galaxy formation rates. However, detecting these subtle signals poses challenges, as they may have been smoothed out over time.
Mason noted that the Hydrogen Epoch of Reionization Array (HERA) might soon be capable of detecting these dark acoustic oscillations, or ruling them out, which would mark a significant advancement in understanding dark matter. The findings are set to be published in the journal Physical Review D in late 2024.