The universe may have had a "secret life" before the Big Bang, a recent study has revealed. The research, published in the Journal of Cosmology and Astroparticle Physics, suggests that the universe underwent a contraction phase before the Big Bang, which led to the formation of black holes that could be the source of dark matter.
This "bouncing" cosmology theory, if proven true, could fundamentally change our understanding of the universe, particularly concerning black holes and dark matter.
Bouncing Between Phases
Traditionally, cosmologists have believed that the universe began with a singular event known as the Big Bang, which was followed by rapid expansion. However, this new research posits a different scenario where the universe first underwent a phase of contraction, reaching a highly dense state before "bouncing" back into expansion. This rebound, according to the study, could have significant implications for the formation of black holes and the mysterious dark matter that makes up about 80% of the universe's matter.
Dark Matter and Black Holes
The study suggests that during the universe's contraction phase, small black holes could have formed from density fluctuations. These primordial black holes, surviving through the rebound and into the current expansion phase, might constitute dark matter. The existence of these black holes could explain why dark matter, which does not interact with light, has been so elusive to scientists.
"Small primordial black holes can be produced during the very early stages of the universe, and if they are not too small, their decay due to Hawking radiation will not be efficient enough to get rid of them, so they would still be around now," said Patrick Peter, director of research at the French National Centre for Scientific Research (CNRS). "Weighing more or less the mass of an asteroid, they could contribute to dark matter, or even solve this issue altogether."
Future Observations
The hypothesis is still in its early stages, but the researchers are optimistic that future gravitational wave observatories, such as the Laser Interferometer Space Antenna (LISA) and the Einstein Telescope, will be able to detect the gravitational waves produced during the formation of these primordial black holes. Such detections could provide crucial evidence to support the theory that these black holes are indeed dark matter.
While it may take more than a decade before the necessary observations can be made, this new study opens up exciting possibilities about the universe's origins and the true nature of dark matter.
