New study asks: Why didn't the universe collapse?

The models that best describe the Big Bang and birth of the universe have one glaring problem. Most of them predict a collapse almost immediately after inflation.

There was nothing, then there was something. And then there was nothing again.

As we know from living and breathing and looking up at a sky action-packed with cosmic activity, there's definitely something more than nothing out there. So why is there still something? Why did the universe's tendency to expand overcome its tendency to collapse?

A new study published in the Physical Review Letters is just the latest to try to inch closer to a place where physicists might be able to answer those questions.

In this particular paper, researchers try to work out the details of the relationship between Higgs boson particles and gravity -- a relationship scientists believe kept an early, unstable universe from collapsing.

Their latest calculations confirm that the stronger the bond between Higgs fields and gravity, the greater the chance of instability and a transition to a negative energy vacuum state, a place with little energy only a few particles popping in and out of existence.

A coupling strength above one would have certainly spelled doom for the early universe, scientists at the University of Copenhagen determined. The new math helps narrow the likely coupling range to between 0.1 and 1.

But to further narrow the range scientists need more data. First, they need to better understand the nature of the Higgs bosson. And second, they need to gather data from the cosmic microwave background radiation and gravitational waves leftover by the Big Bang.

"Presently it is not possible to draw a conclusion on whether the standard model is in trouble due to instability-related issues," study co-author Matti Herranen, an astrophysicist at Copenhagen, told Phys.org.

"But it would be very interesting if the Higgs-gravity coupling and the scale of inflation could be constrained more tightly in the future by independent measurements, for example by observing primordial gravity waves resulting from inflation."