In a World First, Physicists Narrow Down The Possible Mass of Dark Matter

We may well not know what darkish subject is, but scientists now have a far better thought of what to glimpse for.

Based on quantum gravity, physicists have worked out new, significantly a lot more stringent higher and lower mass boundaries of dark issue particles. And they have located that the mass array is way tighter than previously believed.


This suggests that the dark issue candidates that are either really light or heavy are not likely to be the answer, based mostly on our latest comprehending of the Universe.

“This is the initial time that anybody has assumed to use what we know about quantum gravity as a way to compute the mass range for dark make any difference. We were amazed when we realised no-one experienced finished it right before – as had been the fellow experts reviewing our paper,” reported physicist and astronomer Xavier Calmet of the College of Sussex in the Uk.

“What we have performed reveals that darkish issue simply cannot be either ‘ultra-light’ or ‘super-heavy’ as some theorise – except if there is an as-nonetheless mysterious added pressure acting on it. This piece of investigation will help physicists in two approaches: it focuses the research spot for darkish make any difference, and it will potentially also help reveal regardless of whether or not there is a mysterious unknown additional drive in the Universe.”

Dark subject is undeniably one of the major mysteries of the Universe as we know it. It is the title we give to a mysterious mass responsible for gravitational outcomes that won’t be able to be explained by the things we can detect by other implies – the standard make a difference this kind of as stars, dust, and galaxies.


For instance, galaxies rotate a lot a lot quicker than they need to if they have been just remaining gravitationally affected by the typical matter in them gravitational lensing – the bending of spacetime all-around huge objects – is considerably much better than it need to be. Whatever is producing this extra gravity is past our capability to detect straight.

We know it only by the gravitational effect it has on other objects. Primarily based on this outcome, we know there is a lot of it out there. Roughly 80 % of all make a difference in the Universe is dark subject. It can be known as darkish matter since, very well, it is dim. And also mysterious.

Nonetheless, we do know that darkish subject interacts with gravity, so Calmet and his colleague, physicist and astronomer Folkert Kuipers of the College of Sussex, turned to the qualities of quantum gravity to attempt and estimate the mass range of a hypothetical dark subject particle (regardless of what it might be).

Quantum gravity, they clarify, sites a quantity of bounds on regardless of whether dark matter particles of a variety of masses can exist. When we you should not have a first rate doing work concept that unites common relativity’s space-bending description of gravity with the discrete chunkiness of quantum physics, we know any melding of the two would replicate specified fundamentals of equally. As these kinds of, dim make any difference particles would have to obey quantum gravitational policies on how particles break down or interact.


By very carefully accounting for all these bounds, they were being equipped to rule out mass ranges unlikely to exist beneath our present-day knowledge of physics.

Centered on the assumption that only gravity can interact with dark make a difference, they decided that the mass of the particle ought to slide involving 10-3 electronvolts and 107 electronvolts, dependent on the spins of the particles, and the mother nature of dim make any difference interactions.

That’s insanely more compact than the 10-24 electronvolt to 1019 gigaelectronvolt assortment traditionally ascribed, the researchers mentioned. And which is vital, mainly because it largely excludes some candidates, these as WIMPs (weakly interacting massive particles).

If these candidates do later turn out to be the perpetrator guiding the dark matter secret, in accordance to Calmet and Kuipers, it would mean they are getting affected by some pressure we you should not however know about.

That would be definitely cool, because it would point to new physics – a new device for analysing and comprehension our Universe.

Previously mentioned all, the team’s constraints provide a new frame to consider in the search for dark make a difference, serving to slender down wherever and how to seem.

“As a PhD pupil, it is fantastic to be equipped to do the job on study as remarkable and impactful as this,” Kuipers reported. “Our findings are pretty excellent news for experimentalists as it will support them to get nearer to discovering the legitimate nature of dark matter.”

The research has been printed in Physics Letters B.