Naturalists have been hunting for some time for primitive black holes, exotic objects that could have originated in the early Universe and produced a whole range of cosmic screens.
Using a giant 8.2-meter-wide (about 27 feet) telescope, physicists from the University of California, Los Angeles and the Kavli Institute of Physics and Mathematics of the Universe in Japan search for signs of these objects; its discovery may even suggest that our universe is breeding baby universe while it was a small child itself.
What they hope to see will not be exactly as outrageous as looking at alternative realities. But if their new models are correct and patient enough, they may find an ancient black hole (PBH) between us and a nearby galaxy.
The discovery of such an object has the potential to fill a number of gaps in our knowledge over a whole range of phenomena, from the nature of dark matter to the distribution of heavy elements through space.
More teasingly, it could also be an idea of whether our own universe is but one of many in a branching pedigree of multiverses that once emerged as cosmic inflation as babies – although there would still be much debate about the latter point. stay.
Primordial black holes have much in common with black boreholes formed by collapsing stars. Both are intense concentrations of matter that pinch surrounding space-time into a singularity.
Individuals are themselves curious objects, consisting of points where the spatial physics of general relativity meet the more detailed criteria of quantum mechanics. Unfortunately, these two master theories do not agree with certain important details of reality, so no one knows exactly what a singularity is.
Even the surrounding distortion of space and time confuses our intuitions and leaves room to speculate that each black hole is an umbilical cord in a separate universe.
It’s not as far-fetched as it sounds. There are many good reasons to think as soon as a tumbling observer crosses the horizon of events – a line of no return – space and time are not distinguished from a growing universe like ours.
That would mean that our universe collapses like a star every time to form a singularity. Mazel tov!
Where PBHs differ is that they would be traced back when our universe was about a second old, a time when radiation dominated (and not much else).
If there is enough thrust in any area, the concentrated sea of light can tilt over the edge in a singularity. And because the conditions were already extreme, the required mass would be much less than what is needed for even the smallest black holes.
Primordial black holes are interesting ideas in desperate need of solid evidence. Unfortunately, smaller holes would have evaporated long ago in a move by Hawking Radiation. And anything that was big enough, we would have probably noticed by now.
But there are possibilities that researchers should not yet rule out.
In this new model, the team returned to a theory where quantum effects in empty space could create something of a vacuum bubble, which could provide a seed for collapse.
Their mathematics shows that in a period of rapid inflation, these conditions can create fairly black holes of a variety of masses. It is interesting that some correspond to what we would expect from dark matter.
This is an old idea that has been kicked in for a while, to the extent that it seems increasingly unlikely as a candidate. If a population of these creepy black holes acts like dark matter, it will probably only be a part of it.
Just to add to the skepticism, the method the team wants to use to search for these objects has also been tried before.
Last year, researchers used the Subaru Telescope’s Hyper Suprime-Cam to collect nearly 200 screenshots of our neighboring galaxy Andromeda over the course of seven hours, just to see if a PBH with the mass of our own moon might fly past. .
Apart from a single ‘maybe’, the experiment did not find anything too exciting.
But with this new model, the researchers argue, if we wait a little longer – like about 88 hours – we can only be happy this time. Or at least exclude their prediction.
By identifying an original black hole of this size, cosmologists would provide an object that could help explain a series of confusing problems. Not only can this contribute to our understanding of dark matter, but their collisions with neutron stars can explain rapid radio bursts.
We may have already seen a break between these lightweight black holes in a signature of a gravitational wave event that without the flash had the characteristics of a neutron star fusion.
Whether these old black holes really house the babies of our own universe, we will need a fairly revolutionary physics to confirm. But the types of black holes produced in this scenario are exactly what we are looking for.
Fingers crossed by Hyper Suprime-Cam might just add something to the family album.
This research was published in Physical overview letters.