He isn't proposing steady state. He's basically saying that Dirac might have been right in proposing things like the gravitational constant or fine-structure constant are time variant over long enough times. If what we think are constants, aren't, anything is possible.
I don't care. If he's tossing in tired light anywhere, the CMBR won't look like it does. Once you lose the match of density to temperature, you don't get it back.
"While tired light (TL) models have been shown to comply with the JWST angular galaxy size data, they cannot satisfactorily explain isotropy of the cosmic microwave background (CMB) observations or fit the supernovae distance modulus vs. redshift data well. We have developed hybrid models that include the tired light concept in the expanding universe."
He sure has a lane. He's staying in it. Aiming for a coefficient on one coupling constant or another or an ensemble ... so far though nothing but \Lambda on the LHS of the EFEs. I'm sure he'll get there. Theres an admirable sort of methodicalness to his publication record, e.g.:
and honestly I don't hate it. And his institution (byline at the link at the very top is "by Bernard Rizk, University of Ottawa"; turns out he's a Media Relations Officer there [1]; great journalism, phys.org) hyping an adjunct's paper is novel.
> That's the pop science article author's attempt to relate his work, I think
Spoiler, the byline at phys.org is a media relations officer at Gupta's own university. I bet they talked before the MRO the magic "push PR to phys.org" button.
Ok, gigs, I'll bite. I'm afraid I'm already snarky by the start of the abstract. Why are you waving this preprint around, it doesn't say what you say it says (it's mostly just simple algebra and hey did you know we can put coefficients in front of things)? Also I kinda feel bad kicking an adjunct's paper when it's not his fault you've raised his work here. Also, the paper isn't in itself bad.
It's a null result, great. Er er, did I say preprint? It's in MPLA (Mod Phys. Lett. A, if you wanna be all ISO 4 formal)! https://www.worldscientific.com/doi/10.1142/S021773232250155... Ok, not a particularly good physics journal, but at least it's real (I think; people's opinions on world scientific open access fees vary. Todays article processing charges are... USD $2200, but hey, institutional discounts, call for details like when buying from IBM in the 1980s).
"We have attempted to permit concurrent variation of c, G, h, and k in our cosmological, astrophysical and astrometric studies: G~c^3~h^3~k^{3/2}." Concurrent. Concurrent. So great, what's the time relationship?
"Let's assume that the coupling constants evolve with the expansion ... as follows: Speed of light: c = c_af_c(a)" Each constant gets the today CODATA value multiplied by some unknown function of a (the scale factor) on that value.
Ok, cool, so what are the functions? [Spoiler: they could just be everywhen 1. Spoiler: that's what he concludes. Spoiler: you can stop here, really.]
Before going into the functions, he first considers supernovae without seeing the functions.
Ok, this is a draft. I will make a typo or two in this commment just out of solidarity.
Draft? Oh, it's in MPLA! With the typo. https://www.worldscientific.com/doi/pdf/10.1142/S02177323225... (just below eqn (1) on the fourth page). <sarcasm> Good catch, editors and reviewer two! </sarcasm> I DO NOT FEEL BAD ABOUT KICKING THEM. Booooooo! Partial refund to the author and/or his institution.
Eqn 2-4, Some of the functions on the constants are determined by an unknown function on c.
Eqn 5 repeats the relation I quote at the top.
"As pointed out by John Hunter (personal communication) the above can be represetned in terms of the variation of the length dimension of each constant ... if a quantity Q has a length dimension of n, it's f_Q(a) = f(a)^n". [bookmark1] Ok, so generalize and put some meat on the "concurrently".
Hey, fascinating, reviewer two has caused the entire paragraph in the preprint (at link you supplied) to not be in the published version (p. 5 just before the start of section 3). John Hunter is also not in the published Acknowledgments section.
Some words about measurement of mass, and aha, "the Kibble balance test mas m is proportional to h/c^2. Then using equation (5) m \propto f(a)^0 resulting in \dot{m} / m = 0."
4. Discussion
"if we do not permit one of the coupling constants to vary, the others are naturally constrained not to vary" more on that in that paragraph.
This result, which I do not think section 2 proves, is actually pretty important. If it were proved, and also the assertion at [bookmark1] were proved, it would kill off adaptations of current theories which put a function on any constant with a length dimension, which is commonly done [bookmark2 below].
"The approach we have taken is rather phenomenological". Well, yes. Ra-ther.
"A more appropriate and satisfying research would involve writing an action for the interrelated constants represented as fields and derive the relationshop between <constants> with the scale factor a". Right, which is how everyone actually does it. For example DSR <https://en.wikipedia.org/wiki/Doubly_special_relativity>, SME <https://en.wikipedia.org/wiki/Standard-Model_Extension>. Nice to know that Dannenberg has talked Gupta into looking at approaches like that. Pretty sure such things are taught out of his department; if not, he could just drive a couple hours down Autoroute 50 and choose a language.
"... it is not an easy task and we have initiated collaboration for this challenging work."
Great.
Now, he does mention Dirac but not as often as you do in the comments on this article; Dirac proposed varying G for reasons. Gupta argues you can't vary just G, so he disagrees with Dirac.
As to tired light, which was mentioned in this thread, this paper doesn't say much about it. Back to §4's idea about actually writing down an action and deriving the relationship between the constants and the scale factor. In this paper, the relationship is not put forth. At best the author admits the studies of the international prototype kilogram aren't good evidence (and went the wrong direction, "We expected this tiny mass loss could possibly be accounted for using the interrelatinoship among the constants. We have shown this is not possible ..." and his tiny amount of supernova data can be explained by "alternative models". Nice. The standard model is alternative.
