Cosmological red shift and cosmic time dilation

This https://www.frontiersin.org/articles/10.3389/fphy.2022.826188/full#h14 paper makes the claim as in the summary.

I don't have the experience to judge the merit of the claim. I would value any views on it is correct or not and if incorrect where the error(s) is (are).

I do have some understanding of the various coordinate system mentioned but the claim seem to be one of physical differences not just coordinate transform.

Thanks in advance Andrew

This quotation shows that the author's knowledge of GR is shaky. Re the FLRW metric.

"In contrast to the space coordinates, the time coordinate is assumed to be invariable during the Universe history. This is somewhat strange and surprising, because other solutions in GR such as the well-known Schwarzschild solution [11–13] involve distortions in space and time together."

This is poor.

We have a previous thread on this paper:

https://www.physicsforums.com/threa...ative-to-dark-energy-and-dark-matter.1054183/

I see at least two obvious falsehoods in the paper:

(1) It claims that the FLRW metric in conformal coordinates is physically different from the FLRW metric in standard FLRW coordinates. This is false: conformal coordinates are a useful tool (see, for example, their usage in Davis & Lineweaver 2003 to clarify the meaning of various cosmological parameters), but transforming to conformal coordinates does not change anything about physical observables.

(2) It claims that the standard derivation of the relationship between cosmological redshift and the expansion of the scale factor, found in many textbooks and papers, is wrong.

Thanks sorry I missed it. Andrew

Thanks, please close this thread. Regards Andrew