Quite a few observations, from the movement of stars inside galaxies, to the properties of galaxy clusters, to the very construction of the universe itself, all level to the existence of a brand new ingredient within the cosmos. This new ingredient, generally known as darkish matter, is a few new particle (or particles) that’s at present unknown to the Commonplace Mannequin of physics. Regardless of the particle is, it should hardly work together with gentle or regular matter – in any other case we’d’ve seen it by now.
We’ve just a few candidates for the darkish matter, like WIMPs and axions. Past that, we’re in the dead of night (pun meant).
However there are extra methods to deal with the issue than attempting to cook dinner up a brand new particle to inhabit the universe. A pair of physicists just lately used the language of quantum gravity to place down some robust constraints on the character of the darkish matter particle. The analysis appeared just lately in Physics Letters B.
Professor Xavier Calmet from the Faculty of Mathematical and Bodily Sciences on the College of Sussex, who led the analysis, mentioned:
“That is the primary time that anybody has thought to make use of what we learn about quantum gravity as a option to calculate the mass vary for Darkish Matter. We had been stunned once we realized no-one had executed it earlier than – as had been the guy scientists reviewing our paper.”
The analysis checked out each ends of the darkish matter mass vary. On the sunshine finish, we all know that it needs to be above a sure mass threshold, in any other case experiments which have examined the attainable existence of a fifth pressure of nature would rule it out (alternatively, the darkish matter may reply to that fifth pressure). On the heavy finish, large particles are inclined to decay, and we all know that the darkish matter has to have been within the universe for primarily its total existence – that places an higher sure on its dimension.
“What we’ve executed reveals that darkish matter can’t be both ‘ultra-light’ or ‘super-heavy’ as some theorise – except there may be an as-yet unknown further pressure performing on it. This piece of analysis helps physicists in two methods: it focuses the search space for darkish matter, and it’ll probably additionally assist reveal whether or not or not there’s a mysterious unknown further pressure within the universe,” mentioned Calmet.
For the only form of darkish matter particle, the brand new constraints are that’s will need to have a mass between 10-3 eV and 107 eV. That’s a a lot tighter vary than the 10-24 eV – 1019 eV vary of earlier estimates.