Our universe is expanding at rapid rate by absorbing other 'baby universes', new study suggests

Scientists have been pretty sure that our universe is expanding at a rapid rate, but no one exactly knew how. Now, a new theory suggests that our universe might be expanding by colliding and eventually absorbing “baby” parallel universes.

This theory was published in a science paper called the Journal of Cosmology and Astroparticle Physics in December 2023. In the study, scientists proposed the idea that the expansion of the universe may be a result of it constantly merging with other universes.

"The main finding of our work is that the accelerated expansion of our universe, caused by the mysterious dark energy, might have a simple intuitive explanation, the merging with so-called baby universes, and that a model for this might fit the data better than the standard cosmological model," lead study author Jan Ambjørn, a physicist at the Copenhagen University told LiveScience.

Study provides mathematical evidence of our expanding universe

While the concept of many universes interacting with one another isn't new, the study simply uses math to see how this might affect our universe's development. The researchers found mathematically that if our universe merges with others, it could make our universe bigger.

The scientists also computed the rate of expansion of the universe using their theory, and their calculations more closely fit with observations of the universe than the traditional Standard Cosmological Model, the researchers said.

The Standard Cosmological Model assumes that the universe is filled with an enigmatic substance called dark energy, and this dark energy is driving the expansion of the universe.

Moreover, the authors' theory also talks about the problem of cosmological inflation, which is the mysterious super-rapid expansion that occurred in the early moments of the universe.

In the past, physicists suggested that the universe's expansion was due to "the inflaton," a theoretical field that caused rapid growth just after the Big Bang. However, in the new study, the authors propose that this quick expansion might have happened because our young universe merged with a larger one.

"The fact that the Universe has expanded … in a very short time, invites the suggestion that this expansion was caused by a collision with a larger universe, [that is] it was really our Universe which was absorbed in another 'parent' universe," the researchers wrote in their paper.

"Since we have presently no detailed description of the absorption process, it is difficult to judge if such a scenario could take place in a way that would actually solve the problems inflation was designed to solve, but one interesting aspect of such a scenario is that there is no need for an inflaton field."

The scientists suggested that, after being absorbed, our newly enlarged universe then continued to collide with other “baby universes” and incorporate them as well.

(With inputs from agencies)