An “anti-universe” where time runs backwards could exist next to ours, according to a new study.

The theory involves the fact nature has fundamental symmetries and researchers think this could apply to the universe as a whole.

The theory has been explained in the journal Annals of Physics.

It discusses a common physics concept called Charge, Parity, Time (CPT) symmetry.

CPT symmetry is recognized as one of the laws of physics and means things like charge and time can be inverted after a transformative process.

Scientists think the Big Bang, which created the universe, was definitely transformative and therefore the CPT theory could apply.

The researchers think that there was a ‘backwards universe’ before the Big Bang that was then inverted to create the universe we live in today.

They explained: “We investigate the idea that the universe before the Big Bang is the CPT reflection of the universe after the bang, both classically and quantum mechanically.”

And, added: “The universe before the bang and the universe after the bang may be viewed as a universe/anti-universe pair, emerging directly into the hot, radiation-dominated era we observe in our past.

“This, in turn, leads to a remarkably economical explanation of the cosmological dark matter.”

The wild theory could mean the presence of dark matter in our universe isn’t so mysterious after all.

The scientists propose dark matter is actually made up of a type of ghostly particle called right-handed neutrinos.

Neutrino particles are present in our universe but they only spin to the left.

Scientists think it’s odd that they haven’t found a version that spins to the right as the laws of physics suggest they should be out there.

The researchers think the right spinning particles could be invisible in our universe and could just be represented by dark matter.

Little is known about dark matter in the universe other than it can not be seen but does have a physical effect on other objects.

Researchers think investigating neutrino particles and dark matter further could potentially be a step in proving the ‘anti-universe’ theory.

Scientists don’t think we’d be able to visit the proposed ‘anti-universe’ because it technically happened before the Big Bang.

This article originally appeared on The Sun and was reproduced here with permission.