Research: Space atomic clocks could help uncover nature of dark matter

tech.hindustantimes.com:

Studying an atomic clock on-board a spacecraft inside the orbit of Mercury and very near to the Sun might be the trick to uncovering the nature of dark matter, suggests a new study published in Nature Astronomy.

Dark matter makes up more than 80 per cent of mass in the universe, but it has so far evaded detection on Earth, despite decades of experimental efforts. A key component of these searches is an assumption about the local density of dark matter, which determines the number of dark matter particles passing through the detector at any given time, and therefore the experimental sensitivity. In some models, this density can be much higher than is usually assumed, and dark matter can become more concentrated in some regions compared to others.

One important class of experimental searches are those using atoms or nuclei, because these have achieved incredible sensitivity to signals of dark matter. This is possible, in part, because when dark matter particles have very small masses, they induce oscillations in the very constants of nature. These oscillations, for example in the mass of the electron or the interaction strength of the electromagnetic force, modify the transition energies of atoms and nucleii in predictable ways.

An international team of researchers, Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Project Researcher Joshua Eby, University of California, Irvine, Postdoctoral Fellow Yu-Dai Tsai, and University of Delaware Professor Marianna S. Safronova, saw potential in these oscillating signals. They claimed that in a particular region of the Solar System, between the orbit of Mercury and the Sun, the density of dark matter may be exceedingly large, which would mean