I might have a non-educated theory that could explain negative energy; could you tell me if this is potentially correct or am I completely wrong here?
Disclaimer: I haven't read the article (it doesn't load), and I am (probably) lacking even the basics of the required knowledge.
Let's assume the law of energy conservation applies to the universe: if you assume the total energy in the universe is constant, the negative energy is a relative imbalance instead of an absolute one, caused by the universe expanding at a different speed relative to the "things" it contains.
As the universe is "expanding" constantly, the "energy amount per expanding area" gets "less dense", so the "things" that are not "expanding" at the same speed get "more dense" in comparison. This imbalance creates different types of energy perturbation. From the point of view of the things that do not expand as fast, the energy levels relative to yours seem to evolve in a "negative way".
It's like looking at a stationary train from a train that is moving: from the point of view of the moving train, the train standing still seems to go backwards.
Does this make any sense at all, or am I completely missing the mark here?
Updated: reworded some things and provided extra context.