I'm actually quite sympathetic to the views expressed in the abstract of that paper, although I don't think that particular model is very satisfactory. Here's the first part of their abstract:
I think, were you actually to talk calmly to some scientists working in the area, you'd find that many (perhaps most) of them agree with that. That's why many people are searching for alternatives, or to improve our understanding of the initial state of the universe.
FYI, that also applies to all proponents of EU/PC theory.
Again, remember that the cold spot is a deviation of less than 1/10,000 from perfect homogeneity. The universe is extremely homogeneous on large scales - that's an observational fact, and it can't be ignored.
Perhaps, but then there are those dark flow flies in the ointment to consider as well.
Inflation doesn't predict a perfectly homogeneous universe. The strongest evidence for it comes from the spectrum of inhomogeneities. But it's true that the cold spot (and dark flows) observations don't fit very well. If they're real, they indicate either short inflation (not so big a surprise) or something more radical.
Call me a "radical".
Fudging the numbers isn't a reasonable characterization.
Unfortunately we are not likely to agree on this point.
The parameters of the model are adjusted to fit observation.
These are "uncontrolled" observations however and there is no direct evidence that inflation is actual "real", or ever existed in nature. We simply "assume" it's existence.
That's nothing more or less than the bog-standard scientific method.
I disagree rather strongly on that point. In most fields of science, "control mechanisms" are used to demonstrate "cause/effect" relationships. For instance, Birkeland had an on/off switch and could demonstrate with that control mechanism that "current flow" caused the effects he was observing. If he had any doubt that it was 'caused' by electricity, he could turn of the current flow and see the results in his controlled experiments. Inflation theory was never based on controlled experimentation. From day one it was an "imagined" force that had "imagined' properties, none of which were actually seen in the lab. Whereas many consumer products function on Birkeland's "current flow", nothing runs on inflation or dark energy or SUSY particles.
It means that some hypotheses have been falsified, while some remain possible.
But we still have not ever demonstrated a cause/effect relationship based on actual controlled experimentation.
Your criticism can only be justified if you can demonstrate that we have some observations which simply cannot be accommodated no matter what, or if you have a theory that explains things just as well but with fewer adjustable parameters.
The implication here is that I can't reject your theory without replacing it with something else. That's simply not so. I can reject your theory based on any number of logical reasons. In my case I reject it because we can't even be sure it even exists in nature or that it *ever* existed in nature and there is no 'cause/effect' relationship established between any of the presumed properties of inflation and inflation. I simply have to have "faith" in these claims.
As an example: early evolutionary theorists believed (I think) that evolution was a continuous, smooth process that took place at a more or less constant rate. Then things like the Cambrian explosion were discovered in the fossil record. So the theory was adjusted, and now it's a more precise description of the real world. That's exactly how science is supposed to work.
Well, the difference here is rather clear. We can observe micro-evolutionary processes in the lab. While I may not know of the evolutionary process is "smooth" or not, I can be sure evolutionary processes occur in my own lifetime. Inflation doesn't even exist in my lifetime according to current theory, so I can't 'test" any of these ideas in the lab, or even be sure inflation isn't a figment of human imagination.
Nope. For example, if the spatial curvature was large compared to the density perturbations, inflation would be ruled out.
Nah. That "property" of large spacial curvature would have simply been included in inflation theory from the start. If not, just fudge the numbers some more and toss in a few more variables and viola, a new and improved version can take it's place. (Of course this is a gross oversimplification, but it illustrates my point).
If the power spectrum of perturbations differed significantly from 1, inflation would be ruled out. If these dark flows are really there AND persist down to smaller scales (where we know inflation should have generated the perturbations), it's ruled out. Etc.
But if those dark flows were not predicted in the first place, why wouldn't that rule out inflation by itself? How come we get to keep tweaking everything without ever demonstrating any actually cause/effect 'property' of inflation?
What would be wrong with that? If you have some evidence the current model can't explain, you come up with a new one. If the new model happens to contain a word in its name the old one also contained, so what?
So we're shifting the goalpost all the time and there is no way to falsify the model anymore. As long as we can change all the variables all the time, nothing is verifiable or falsifiable.
What's in name? Consider for a moment if I simply pilfered your various math formulas and called it "Godflation", "God energy" and "God matter". Suppose I kept changing all the parameters to suit myself and make these formulas fit. Would the fact I got it to fit the observations be evidence that God did it? Obviously not. How then do we decide where "science" ends and 'religion' begins if I get to change all the rules and formulas as I go?