Darkness and light start together

The development of the universe explored by humans has reached a confluence according to scientists utilizing several computer models at Northeastern University.

They have a premise after the said Big Bang nucleosynthesis that darkness (invisibility) and light (the visible universe to us) had a co-existing beginning and development according to their conclusions. These may be unprecedented.

It allows that dark matter , the invisible, and visible matter formed in accordance with the temperature gradient of the Big Bang. This is the work of Jinheng Li and Pran Nath at Northeastern University. Their paper was published

Dec. 11, 2023, "Big Bang initial conditions and self-interacting  hidden dark matter" is released in Physical Review D, 108.

"One major variable is the temperature of the hidden sector during the Big Bang."

"if the coupling of the hidden sector to the inflaton is also feeble relative to the coupling  of the standard model, the population of the hidden sector particles would be negligible and their temperature would be much colder than of the standard model particles. On the other extreme, the hidden sector and the visible sectors could couple democratically, i.e. with equal strength to the inflaton and thus be essentially in thermal equilibrium at the end of reheating."

"It is thus of relevance to ask the influence of the initial conditions on physical observables at low energy." 

This is a very different premise on the circumstances that depict the visible and invisible dark matter presences.

Until this paper, the status of the two presences have been depicted as separately developing ('decoupled') from each other in their own way except for the force of gravity.