I Gravitational self-interaction: another attempt to replace Dark Matter

[timmdeeg]

https://arxiv.org/pdf/2503.09804

From the abstract:

... Our derivation uses both EE and the Newtonian approximation of EE in Part I, to describe semi-classically in Part II the advection of DM, created at the level of the universe, into galaxies and clusters thereof. This advection happens proportional with their own classically generated gravitational field g, due to self-interaction of the gravitational field. It is based on the universal formula ρD =λgg′2 for the densityρ D of DM advected into medium and lower scale structures of the observable universe, where λ is a universal constant fixed by the Tully–Fisher relations. ...

What do you think about that or how would you characterize the seriosity of this "derivation"? It seems different to Alexandre Deur's approach.

 

[renormalize]

https://arxiv.org/pdf/2503.09804

From the abstract:

... Our derivation uses both EE and the Newtonian approximation of EE in Part I, to describe semi-classically in Part II the advection of DM, created at the level of the universe, into galaxies and clusters thereof. This advection happens proportional with their own classically generated gravitational field g, due to self-interaction of the gravitational field. It is based on the universal formula ρD =λgg′2 for the densityρ D of DM advected into medium and lower scale structures of the observable universe, where λ is a universal constant fixed by the Tully–Fisher relations. ...

What do you think about that or how would you characterize the seriosity of this "derivation"? It seems different to Alexandre Deur's approach.

Having not read this paper I offer no opinion on its physics content. But with regard to its "seriosity" I will just point out that, according to Google Scholar, the paper has garnered no citations in the two years since it was published.

 

[timmdeeg]

Ok, thanks. So one could conclude that the physical content isn't very convincing. Or people don't read it at all because field self-interaction in general is judged as being a negligible effect.

 

[PeterDonis]

It seems different to Alexandre Deur's approach.

It is. On an initial read this paper looks like nothing more than handwaving.

field self-interaction in general is judged as being a negligible effect.

That's the general opinion that Deur's work was trying to undermine.

However, this paper doesn't appear to me, on an initial read, to be based on anything like the kind of field self-interaction that Deur's work is based on. As above, it just appears to me to be handwaving.

 

[timmdeeg]

However, this paper doesn't appear to me, on an initial read, to be based on anything like the kind of field self-interaction that Deur's work is based on. As above, it just appears to me to be handwaving.

So quite fruitless. If I remember correctly you stated somewhere here some time ago that only an exact solution of the EFE modelling a Galaxie could clarify this matter. I wonder why proponents of gravitational field self-interaction haven't presented such a solution till now. Too difficult?

 

[PeterDonis]

only an exact solution of the EFE modelling a Galaxie could clarify this matter.

I'm not sure I said that. A sufficiently accurate numerical simulation (i.e., one that included all of the terms whose magnitude is disputed in the literature, to a high enough order) could also do that.

I wonder why proponents of gravitational field self-interaction haven't presented such a solution

As far as I know, no exact solution is known for the case of a galaxy. Of course, no exact solutions are known for most cases of interest--exact solutions of physical relevance are rare in GR, and even those that are often made use of are made use of as approximations, not as exact models.

Too difficult?

I'm not sure how the level of difficulty of a numerical simulation such as I described above would compare to our current computing capabilities.

 

[timmdeeg]

Thank you for your helpful comments, as always.

 

[PeterDonis]

Thank you for your helpful comments, as always.

You're welcome!

 

[kodama]

It is. On an initial read this paper looks like nothing more than handwaving.


That's the general opinion that Deur's work was trying to undermine.

However, this paper doesn't appear to me, on an initial read, to be based on anything like the kind of field self-interaction that Deur's work is based on. As above, it just appears to me to be handwaving.

what do you think of Deur's work, is it credible or handwaving?

 

[Physics Detective]

Tim: at 38 pages, this is a big paper. Apologies, I've only looked at the abstract and the discussion, with my historian hat on. It would take me a week to plod through the whole thing.

I dislike the reference to "the energy of the coherent gravitational field of the universe". I say that because in his 1920 Leyden Address, Einstein referred to a gravitational field as a place where space was "neither homogeneous nor isotropic". You can find more recent papers which discuss this, such as Inhomogeneous Vacuum: An Alternative Interpretation of Curved Spacetime by Ye Xing-Hao and Lin Qiang dating from 2008. Then the FLRW metric starts with the assumption of the homogeneity and isotropy of space on the largest scales. That indicates to me that is no overall gravitational field of the universe. There seems to be no evidence of it either, since the universe appears to be expanding, not contracting. So I don't understand what they mean by the observed coherent gravitational field.

I also disliked the reference to the advection of dark matter. I've seen papers such as Inhomogeneous and interacting vacuum energy by Josue De-Santiago, David Wands and Yuting Wang dating from 2012, so I'm not totally opposed to interactions. But the advection of dark matter makes me think of the waterfall analogy, where space is falling down into a black hole. It's based on Gullstrand–Painlevé coordinates, which Einstein rejected. I think he was right to do so. A gravitational field alters the motion of light and matter through space, but it doesn't make space fall down.

However I did like their attempt to model dark matter using General Relativity. In 1916 Einstein said "the energy of the gravitational field shall act gravitationally in the same way as any other kind of energy". This is spatial energy. I particularly like it because in 1930 Einstein said “the strange conclusion to which we have come is this – that now it appears that space will have to be regarded as a primary thing and that matter is derived from it, so to speak”. If matter is derived from space, IMHO it's reasonable to expect that dark matter is derived from it too. Hence I think Peter Handel and Klara Splett could be barking up the right tree in some respects. As it happens I know another author with a paper in FOP on similar lines, so it looks like Carlo Rovelli is interested in this sort of thing.

 

[PeterDonis]

what do you think of Deur's work, is it credible or handwaving?

Personally I'm skeptical of Deur's claims, but his work doesn't look to me like handwaving.

 

[weirdoguy]

Einstein referred

You know, it's 2025 and it doesn't really matter what Einstein thought about everything. Science does not work that way. It seems like you try to judge scientific papers based on what Einstein said and some analogies. It's a dead end.

 

[PeterDonis]

If matter is derived from space, IMHO it's reasonable to expect that dark matter is derived from it too.

This has nothing to do with what the paper under discussion in this thread is proposing. Please don't clutter the thread with off topic posts.

 

[Physics Detective]

This has nothing to do with what the paper under discussion in this thread is proposing. Please don't clutter the thread with off topic posts.

OK noted.

 

[kodama]

how does https://arxiv.org/pdf/2503.09804 compare with Deur's work

 

[PeterDonis]

how does https://arxiv.org/pdf/2503.09804 compare with Deur's work

Um, that's the paper this whole thread is about. I already compared it to Deur's work in post #4.