The new research seeks to explain these doubts from a different perspective: looking from the inside rather than the outside. Instead of starting from an expanding universe, look at what happens when an excessive accumulation of matter collapses under gravity.
This is not a strange process, as stars collapse into black holes, one of the best understood elements in science, although what happens inside them certainly remains a mystery.
Research by British physicist Roger Penrose and the famed Stephen Hawking demonstrated that gravitational collapse leads to a singularity, thus supporting that events such as the Big Bang are inevitable.
However, the authors of the new model stress that these observations are based on classical physics, which focuses on describing ordinary macroscopic objects.
In their paper, the scientists determine that gravitational collapse does not always end in a singularity.
Their calculations show that as the potential singularity approaches, the size of the universe changes as a hyperbolic function of cosmic time.
Such a mathematical solution shows how a collapsing cloud of matter can reach a high-density state and then bounce outward into a new phase of expansion.
In Penrose's theorems we do not see such results, since the quantum exclusion principle is included, whereby two identical particles, the fermions, cannot occupy the same quantum state.
In their research, physicists show that such a rule prevents collapsing matter particles from compressing indefinitely, causing the phenomenon to stop and reverse. Thus, under the right conditions, rebound is not only possible, but inevitable.
Such rebound occurs entirely within the framework of general relativity, which can be applied in large-scale models, such as those used for calculations related to stars and galaxies.
What emerges on the other side of the bounce is a universe visibly similar to our own.
