The Universe's Secret Life Before the Big Bang

A new study suggests intriguing insights into the nature of the universe prior to the Big Bang. This research associates secrets of black holes and dark matter with a cosmological theory that posits the universe can undergo "bouncing" phases.

According to this cosmological model, the Big Bang may not represent the universe’s origin. Instead, it proposes that an earlier contraction phase precedes the current expansion. Understanding this theory might profoundly alter our comprehension of dark matter and black holes, two prominent cosmic mysteries.

Researchers propose that dark matter might consist of black holes formed during a transition from the universe’s previous contraction to the current phase of expansion. If accurate, these primordial black holes could open pathways to detecting gravitational waves generated during their formation. Future gravitational wave observatories might confirm this dark matter generation hypothesis.

Understanding Dark Matter

Observations indicate that roughly 80% of all matter in the universe is dark matter. This elusive substance does not reflect, absorb, or emit light. Despite its prominence, scientists have yet to unveil its true composition.

In their recent study published in June in the Journal of Cosmology and Astroparticle Physics, researchers examined a model in which dark matter comprises primordial black holes formed from density fluctuations during the universe’s last contraction phase. This phase predates our current observable expansion.

Exploring Bouncing Cosmology

Traditional cosmological theories depict the universe originating from a singularity, followed by rapid expansion known as inflation. However, the new study investigates a theory called non-singular matter bouncing cosmology. This entails an initial contraction phase that eventually rebounds, leading to the current expansion we observe.

During this contraction, the universe reportedly shrank to a size 50 orders of magnitude smaller than currently observed. The subsequent rebound saw the emergence of photons and other particles, marking the onset of the Big Bang. Conditions near this rebound were so extreme that small black holes could form from quantum fluctuations, presenting possible dark matter candidates.

Patrick Peter, a director of research at the French National Centre for Scientific Research, noted that "small primordial black holes" could arise during the universe’s early stages. If these black holes are sufficiently substantial, they can persist without succumbing to Hawking radiation, potentially acting as contributors to dark matter.

Testing the Bouncing Theory

The researchers calculated their model's features, like space curvature and the cosmic microwave background. Their findings align with current observational data, lending credence to their hypothesis.

To validate their predictions further, researchers plan to apply next-generation gravitational wave observatories. Their calculations indicate that gravitational waves from black hole formation could be detectable. Upcoming facilities, like the Laser Interferometer Space Antenna (LISA) and Einstein Telescope, may provide critical confirmations, although it may take over ten years for initial observations.

Patrick Peter emphasized the importance of this research. It presents a comprehensive explanation for the formation of small black holes as a dark matter solution outside catalogued inflation theories. Other studies are currently evaluating the behaviors of these small black holes around stars, creating potential future detection avenues.

Earlier, SSP reported that digging holes at the beach can be dangerous.