We may not know what dark matter is, but now scientists have a better idea of what to look for.
Based on quantum gravity, physicists have developed new, much stricter upper and lower mass limits of dark matter particles. And they have found that the mass range is much tighter than previously thought.
This means that candidates for dark matter that are extremely light or heavy are likely to be the answer, based on our current understanding of the Universe.
“This is the first time anyone has thought of using what we know about quantum gravity as a way to calculate the range of mass of dark matter. We were surprised when we realized that no one had done it before, as well as the other scientists made our paper, ”said physicist and astronomer Xavier Calmet of the University of Sussex in the UK.
“What we’ve done shows that dark matter can be neither ‘ultra-light’ nor ‘super heavy,’ according to some theorists, unless there is an additional force still unknown to act on it. This research helps physicists in two ways: center the dark matter search area and potentially will also help reveal whether or not there is a mysterious additional force unknown in the Universe. “
Dark matter is undeniably one of the greatest mysteries in the Universe as we know it. It is the name we give to a mysterious mass responsible for gravitational effects that is not explained by things we can detect by other means: normal matter like stars, dust and galaxies.
For example, galaxies rotate much faster than they should if they were only gravitationally influenced by the normal matter there; the gravitational lens – the flexion of space-time around massive objects – is much stronger than it should be. What is creating this additional gravity is beyond our ability to detect directly.
We only know it from the gravitational effect it has on other objects. Based on this effect, we know that there are many. About 80 percent of all matter in the Universe is dark matter. It’s called dark matter because, well, it’s dark. And also mysterious.
However, we know that dark matter interacts with gravity, so Calmet and his colleague, physicist and astronomer Folkert Kuipers of the University of Sussex, turned to the qualities of quantum gravity to try to estimate mass range of a hypothetical dark matter particle (whatever it is).
They explain that quantum gravity places a number of limits on whether dark matter particles of various masses can exist. While we do not have a decent work theory that links the description of gravity from the general relativity of gravity to the discrete density of quantum physics, we do know that any combination of both would reflect certain foundations of both. As such, dark matter particles should obey quantum gravitational rules about how particles break or interact.
By carefully considering all these limits, they were able to rule out mass ranges that probably would not exist according to our current understanding of physics.
Based on the assumption that only gravity can interact with dark matter, they determined that the mass of the particle should be between 10-3 electronvolts and 107 electronvolts, depending on the rotations of the particles, and the nature of the interactions of dark matter.
This is incredibly smaller than the 10-24 electronvolt a 1019 the gigaelectronvolt range traditionally attributed, the researchers said. And this is important, because it largely excludes some candidates, such as WIMPs (weakly interacting massive particles).
If these candidates later turn out to be to blame for the mystery of dark matter, according to Calmet and Kuipers, it would mean they are being influenced by some force we do not yet know.
It would be fantastic, as it would point to a new physics: a new tool for analyzing and understanding our Universe.
Above all, team restrictions provide a new framework to consider when searching for dark matter, helping to narrow down where and how to look.
“As a PhD student, it’s great to be able to work on research as exciting and impactful as this,” Kuipers said. “Our findings are very good news for experimenters, as they will help them get closer to discovering the true nature of dark matter.”
The research has been published in Physics letters B.