I am not proposing an alternate explanation to the initial expansion, so that is why I'm at a loss to reply to this comment. Perhaps I made an earlier statement that made you think I was, but that is not my intention. That is why I say GR is honored.
I was under the impression that your suggestion was that the expansion of "space-time" has been accelerating all along, but it was only when everything was far apart enough for the acceleration to beat the gravitational density that the objects in the universe started to accelerate apart.
My point is that space-time is only actually defined by the stuff within it, so it has not been accelerating all along - earlier in the history of the universe, the rate at which distances increased was slowing down.
However, with a negative "energy" that has been in the background all along, the expansion of space over
time would only accelerate when the gravitational density was low enough to allow it.
The concept of the Big Rip is intriguing. I know how this sounds, but before I heard of it, I imagined a similar fate of the universe. How could it keep expanding with no consequence? It was unnerving to hear this theory from cosmologists, to tell the truth.
The Big Rip would require "phantom (dark) energy", where its value increases over time, rather than stays constant or decreases, so it is a very unlikely scenario. There is no observational evidence so far that the acceleration is caused by anything other than an effect that is constant, or decreasing.
I did look at the paper and thanks for posting the link.
Without expanding space, all galaxies would be converging, so how can it be said it is only the measured result? It is the result! As I mentioned in an earlier post, GR predicts that space can exist without matter! Space rules.
The expansion of the universe does indeed act as if
space expands, but it is not necessarily a property of space itself that causes the increase in cosmological distances, over time.
Does the light from distant galaxies get gradually redshifted as it travels, or is the redshift only an apparent effect caused by the difference in the scale of the universe between the time the light was emitted and finally detected? In this case, as we are all "lodged" within the expanding universe, the end result is the same, but is there a property of expanding space that actually stretches
light as it travels?
Space might be able to exist without matter, but how can it expand
if there is nothing by which to measure that expansion?
I believe an evolved understanding of space-time with ever-accelerating properties of expansion can explain current observations without adding a theoretical background force. It is a more elegant solution.
You are adding a new
property to space-time instead! And in order for matter to couple/decouple with this new property of yours (to allow the expansion of the universe to decelerate as has been observed), you also
need a new mechanism to show how the two sides interact. Gravity cannot be the answer in your scenario, as it is already the answer to the mainstream view of why the expansion of the universe decelerated for 9 billion years. If you want to think in terms of expanding space, then the expansion of space was decelerating for a very long time.
All you are doing is swapping dark-energy (which is simply a placeholder for "that which causes the rate at which distances increase to accelerate"
) for accelerating and expanding space-time, which makes no sense as you can only define space-time by the events that occur within it! So you are adding a whole new level of complication into the equations - space-time that somehow exists at a totally separate level from the objects that populate it!