One of the greatest mysteries in physics known as the Hubble tension could eventually be explained by a long-since vanished type of dark matter.
The Hubble tension involves a growing contradiction in physics – as we all know, the universe is expanding but there are various measurements that produce different results regarding how fast the universe expands.
Experts explained the expansion rate with a number that’s called the Hubble constant (H0). This reportedly describes an engine that is driving things spare over massive distances across the universe.
Hubble’s Law says that the farther away something is from us, the faster it is moving.
There are two ways of calculating H0
There are reportedly two ways in which the H0 can be calculated. Live Science explains that “You can study the stars and galaxies we can see, and directly measure how fast they’re moving away.”
The website continues and addresses the second way in which you can measure the H0: “Or you can study the cosmic microwave background (CMB), an afterglow of the Big Bang that fills the entire universe, and encodes key information about its expansion.”
The tools for performing each one of these measurements mentioned above have gotten more and more precise over time. It’s very clear that the CMB measurement and the direct measurements of the local universe are producing incompatible answers.
Decades ago, experts believed that the dark matter might be hot and that it moved around the universe at the speed of light, Dan Hooper, co-author of the new paper, said.
He highlighted that this idea continues to get some traction in the world of physics these days as well.
“Another possibility is that most of the dark matter is cold, but maybe some of it is warm. And in our paper, the stuff that’s warm isn’t even stuff that’s around today. It’s stuff that was created in the early universe and after thousands or tens of thousands of years, it started to decay. It’s all gone by now,” Hooper said.
Check out the complete analysis of the matter in the original article.