Dark matter existed before Big Bang.

Lol Reading one article doesn't make you either scientific or a scientist.

terms like "before" become meaningless when there is no time. time is a concept that only exists in the universe and not outside of it. so there is no time before the beginning and not even a "before"

It is[b] a scientific [/b]theory.

Scientific theories are backed up by evidence and a scientific methodology of investigation.

Right now it is the model accepted in the scientific community, until it's falsified and/or someone comes with a better more valid and concise model to answer its problematics.

No, it is not necessary to believe even for scientists, the empiricist is open to both belief and the disbelief. That is why they are encouraged to keep on looking.

The article you linked doesn't falsify the big bang.

Possibilities with no real answers. A lot of "could be's" and uncertainties with "suggestive" models.

Other theories also exist. Like another suggestive theory, that there have been multiple big bangs. That would kind of explain the dark matter. Yet even that is just a theory.

On the other hand, steady state is abhorrent to entropy. That is pretty much conclusive.

A "theory", as an idea, hunch or thought someone is toying with, is not the same thing as a scientific theory.

Scientific theory, is how science interprets facts.

This paper, however, does not disprove the Big Bang, the mathematical model predicts that Dark Matter existed prior to the Big Bang.

They found a star older than the universe by more than a billion years. 🤭

there have been theories that the universe always existed.