Far out cosmology: two Big Bangs proposed (Introduction)

by David Turell , Thursday, November 16, 2023, 20:02 (162 days ago) @ David Turell

One for what we see and one for dark matter:

https://bigthink.com/hard-science/two-big-bangs/?utm_campaign=weeklynewsletter&utm_...

"The moment that the Universe transitioned from being governed by inflation to being filled with a hot and dense plasma is the beginning of what scientists call the Big Bang.

"The other interesting phenomenon is dark matter, a proposed substance that, if it exists, explains some observed astronomical anomalies. Galaxies, like people, are made of ordinary matter, and we can use the laws of physics to predict how they should move. However, when astronomers study the heavens, they see some surprises. One example is that galaxies rotate faster than expected. A second example is that certain galaxy clusters shouldn’t exist, as individual galaxies are moving so fast that they should escape the gravitational attraction of their neighbors.

***

"In the prevailing theory of the origins of the Universe, both familiar matter and dark matter were created at the same time, less than a second after the Universe began. Effectively, it is thought that a series of steps converted the energy that governed inflation into matter and dark matter.

", the new paper raises a different possibility. Given that ordinary matter and dark matter only interact via gravity, perhaps they didn’t appear at the same time in the early Universe. This paper suggests that while the energy of inflation eventually transitioned into ordinary matter, dark matter might have had a different origin. In the new theory, there was a second form of energy, similar to the vacuum energy that caused inflation, but this new energy was dark vacuum energy, which became the origin of dark matter.

***

"Can this new idea be tested? If dark matter and ordinary matter interact only via gravity, the dozens of dark matter experiments currently underway will fail. All of them depend on dark matter and ordinary matter experiencing some sort of interaction beyond gravity. Thus, if this new theory is right, that would be disappointing.

"However, when the dark vacuum energy transitioned into dark matter particles, that change of energy would have shaken the structure of space and time, creating gravitational waves that would fill the Universe. Metaphorically at least, this would appear to be a “hum” in the structure of space.

"Very precise experiments have already reported detecting a cosmic hum, but a bit of caution is warranted. There are several astronomical phenomena that can generate a similar hum. Thus, the recent detection is not a confirmation this new theory. That will take more data and far more sophisticated analysis. However, the fact that facilities exist that can detect the right kind of gravitational waves gives us hope that researchers will be able to confirm or disprove this idea within a few years."

Comment: at least this far out theory can be tested.