Universe at big bang’s time was highly chaotic

WASHINGTON - Using rigorous mathematical arguments, researchers have proved that the expansion of the universe at the time of the big bang was highly chaotic.

The study by Northwestern University physicist Adilson E. Motter reports not only that chaos is absolute but also the mathematical tools that can be used to detect it.

When applied to the most accepted model for the evolution of the universe, these tools demonstrate that the early universe was chaotic.

A longstanding problem in physics has been to determine whether chaos- the phenomenon by which tiny events lead to very large changes in the time evolution of a system, such as the universe- is absolute or relative in systems governed by general relativity, where the time itself is relative.

“A competing interpretation has been that chaos could be a property of the observer rather than a property of the system being observed. Our study shows that different physical observers will necessarily agree on the chaotic nature of the system,” said Motter, an author of the paper.

The work has direct implications for cosmology and shows in particular that the erratic changes between red- and blue-shift directions in the early universe were in fact chaotic.

“According to the classical theory of general relativity, the early universe experienced infinitely many oscillations between contracting and expanding directions,” said Motter.

“This could mean that the early evolution of the universe, though not necessarily its current state, depended very sensitively on the initial conditions set by the big bang,” he added.

This problem gained a new dimension 22 years ago when two other researchers, Gerson Francisco and George Matsas, found that different descriptions of the same events were leading to different conclusions about the chaotic nature of the early universe.

Because different descriptions can represent the perspectives of different observers, this challenged the hypothesis that there would be an agreement among different observers.

Within the theory of general relativity, such an agreement goes by the name of a “relativistic invariant.”

“Technically, we have established the conditions under which the indicators of chaos are relativistic invariants. Our mathematical characterization also explains existing controversial results. They were generated by singularities induced by the choice of the time coordinate, which are not present for physically admissible observables,” said Motter.

The study is published in the journal Communications in Mathematical Physics. (ANI)