In the realm of energy and cosmology, a team of researchers from the University of California, Irvine, and the University of Michigan has been exploring the potential impacts of dark matter on the early universe. The team, comprising Badal Bhalla, Aurora Ireland, Hongwan Liu, Huangyu Xiao, and Tao Xu, has been investigating how certain types of dark matter could influence the temperature of baryons—the visible matter that makes up stars, planets, and everything we can see—during the cosmic dark ages, a period before the first stars and galaxies formed.
The researchers focused on two specific types of dark matter: dark compact objects and axion minihalos. Dark compact objects are hypothetical massive objects made of dark matter, while axion minihalos are dense clumps of axions, a type of hypothetical particle that could make up dark matter. Both of these entities could potentially heat up baryons through a process called dynamical friction, which is a force that acts on an object moving through a fluid or gas, causing it to lose energy and heat its surroundings.
The team’s work, published in the journal Physical Review D, suggests that upcoming experiments designed to detect the 21-cm hydrogen line—a specific wavelength of light emitted by neutral hydrogen—could potentially observe the heating effects of these dark matter candidates. The 21-cm line is a powerful tool for studying the early universe, as it allows astronomers to probe the temperature and density of baryons during the cosmic dark ages.
The researchers found that both the global signal and power-spectrum measurements of the 21-cm line could be sensitive to dark compact objects that make up about 10% of the dark matter. This means that if dark compact objects exist in this abundance, they could leave a detectable imprint on the 21-cm signal. Furthermore, the team’s analysis suggests that these measurements could also substantially improve our sensitivity to axion-like particles with masses in the range of 10^-18 to 10^-9 electron volts.
For the energy sector, this research highlights the potential of using cosmological observations to probe the nature of dark matter. If dark matter candidates like dark compact objects or axions can be detected and studied through their effects on the early universe, it could open up new avenues for understanding the fundamental properties of dark matter and its role in the cosmos. Moreover, this research could inspire the development of new technologies and methods for detecting dark matter, which could have implications for energy production and storage, as well as for our understanding of the universe’s energy budget.
In summary, the work of Bhalla and his colleagues demonstrates the potential of using 21-cm observations to search for dark matter candidates and study their effects on the early universe. This research could have significant implications for our understanding of dark matter and its role in the cosmos, as well as for the development of new technologies and methods for detecting and harnessing dark matter’s energy.
This article is based on research available at arXiv.