It has been clear for a long time that gravitomagnetism (GEM) effects in General Relativity (GR) do not explain dark matter phenomena like flat galaxy rotation curves. One paper which I discussed in another recent paper goes beyond that and I'll analyze it when I have a chance at greater depth. But, this paper's conclusion that a lack of GEM effects to explain dark matter precludes at GR effects to address dark matter phenomena isn't well supported.
The flatness of galaxy rotation curves at large radii is generally considered to be a significant piece of evidence in support of the existence of dark matter. Several studies have claimed that post-Newtonian corrections to the Newtonian equations of galaxy dynamics remove the need for dark matter. A few recent studies have examined these claims, and identified errors in their reasoning.
We add to this critique by giving what we consider to be particularly simple and transparent description of the errors made in these post-Newtonian calculations, some of which were of a rather technical nature, others more fundamental, e.g. the loss of the correct relativistic scaling, promoting small corrections to order unity changes.
Our work reinforces the orthodoxy that post-Newtonian effects are indeed too small to significantly alter galactic rotation curves, and will hopefully serve as a useful guide for others, pointing out subtle errors that one might inadvertently make in such calculations.
Kostas Glampedakis, David Ian Jones, "Pitfalls in applying gravitomagnetism to galactic rotation curve modelling" arXiv:2303.16679 (March 29, 2023).
Our work reinforces the orthodoxy that post-Newtonian effects are indeed too small to significantly alter galactic rotation curves, and will hopefully serve as a useful guide for others, pointing out subtle errors that one might inadvertently make in such calculations.
ReplyDeleteincluding self interaction
I do not see that self interactions are included. I accept that post-Newtonian are too small. One needs to be careful doing perturbation calculations for nonlinear effects.
ReplyDeleteThe Post-Newtonian framework is a perturbative approximation of GR that by definition excludes self-interactions.
ReplyDelete