A team of physicists has developed a new cosmological model that suggests the universe did not begin with the Big Bang, followed by cosmic inflation.
Instead, they argue that the universe has undergone continuous cycles of compression and expansion, indicating an epoch that precedes these known events.
This model, published in the Journal of Cosmology and Astroparticle Physicsaims to solve several cosmic mysteries, including the nature of dark matter and the long-standing problem of the flatness of the universe.
One of the perplexing issues in cosmology is why the universe appears flat. The geometry of the universe is determined by its matter density. When the density exceeds a critical value, space is closed and positively curved, resembling the surface of a sphere.
If it is less, the space is open and negatively curved, like a saddle. When the density is equal to the critical value, the universe is flat and infinite, comparable to a sheet of paper. Observations indicate that the current matter density is very close to this critical density, implying a flat universe.
This flatness poses a challenge to the traditional big bang model. If the universe started from a hot, dense state above the critical density, it is unclear why it would evolve to a planar geometry.
The new cyclic model addresses this by suggesting that the universe repeatedly transitions between phases of full compression to a hot, super-dense singularity and subsequent expansion.
According to physicists, this cyclical process not only explains the flatness of the universe, but is also consistent with measurements of the cosmic background radiation – the afterglow of the Big Bang.
They also hypothesize that during the short periods between these cosmic phases, primordial black holes formed from extremely dense matter. These small black holes, with a mass similar to that of asteroids, could form dark matter and provide a solution to another cosmic riddle.
Furthermore, the model predicts that these tiny black holes could generate gravitational waves – ripples in the fabric of space-time – that could be detectable with current or future technology.
Although this cyclical universe model offers intriguing solutions to existing cosmological problems, it remains hypothetical. Additional evidence is needed to validate the conclusions. For now, the Big Bang theory remains the predominant explanation in cosmology.
