New physics model shows universe might have existed forever

The big bang theory is the most popular origin story for the universe. General relativity estimates that the universe is around 13.8 billion years old and began as an infinitely dense point—a singularity. This point contained all the matter in existence. The moment when it finally exploded, rapidly expanding into the universe we know and live in, is called the Big Bang.

The problem with this theory is that the math used can only explain what happened after the Big Bang, not what happened before or during the event.

A new model offers an alternative explanation; that the universe may have existed forever, with no beginning or end. The new model, which also accounts for the existence of dark matter and dark energy, applies quantum correction terms to complement Einstein’s theory of general relativity.

“The Big Bang singularity is the most serious problem of general relativity because the laws of physics appear to break down there,” said Ahmed Farag Ali, from Egypt’s Benha University and the Zewail City of Science and Technology.

The study, coauthored by Saurya Das from the University of Lethbridge in Alberta, Canada and published in the journal Physics Letters B, shows that the problems that arise from the Big Bang singularity can be resolved by their model.

The “quantum correction terms” are based on the work of theoretical physicist David Bohm. In the 1950s, Bohm replaced classical geodesics (the shortest path from one point to another on a curved surface) with quantum trajectories.

Ali and Das applied these trajectories to an equation developed by physicist Amal Kumar Raychaudhuri, and then derived quantum-corrected Friedmann equations. These equations describe the expansion and evolution of the universe within the context of general relativity. This new model also doesn’t predict a “Big Crunch,” where the universe collapses in on itself and condenses into a singularity again.

According to the researchers, the new model avoids singularities because of one property of Bohmian trajectories. At some point, classical geodesics cross each other. At each intersection is a singularity. On the other hand, Bohmian trajectories never cross.

According to Das’ and Ali’s model, the universe is filled with quantum fluid that might be composed of gravitons—massless hypothetical particles that mediate gravitational force.

“It is satisfying to note that such straightforward corrections can potentially resolve so many issues at once,” Das said, referring to the fact that not only can the new model resolve the Big Bang singularity, but it can also account for dark matter and dark energy.

A related paper, published in arXiv and co-written by Das and Rajat Bhaduri of McMaster University, Canada, shows that these gravitons can, theoretically, form a Bose-Einstein condensate at temperatures present in the unverse at all epochs. The condensate is named after Albert Einstein and Indian physicist Satyendranath Bose.

But this isn’t the only new hypothesis about the origin of our universe. Another model suggests that there were two different universes created by the Big Bang. Our universe moves forward in time, and the other one moves backwards. — Bea Montenegro/BM/TJD, GMA News