I've been wondering if the mainstream is ever going to say another word about the observation of galaxy sized rotating filaments.
https://www.sciencedirect.com/science/a ... 9322004324
Cosmic filament spin from dark matter vortices
22 July 2022
Here’s what the abstract says …
The recent observational evidence for cosmic filament spin on megaparsec scales Wang et al. (2021) [41] demands an explanation in the physics of dark matter.
LOL! Let’s see if they can tease an explanation from that gnome.
Conventional collisionless cold particle dark matter is conjectured to generate cosmic filament spin through tidal torquing, but this explanation requires extrapolating from the quasi-linear regime to the non-linear regime. Meanwhile no alternative explanation exists in the context of ultra-light (e.g., axion) dark matter, and indeed these models would naively predict zero spin for cosmic filaments.
Oh my … their models predict ZERO rotation of filaments. And the tidal torquing explanation requires extrapolation far outside the linear regime.
In this Letter we study cosmic filament spin in theories of ultra-light dark matter, such as ultra-light axions, and bosonic and fermionic condensates, such as superfluids and superconductors. These models are distinguished from conventional particle dark matter models by the possibility of dark matter vortices.
Ah … so they’re going to try and use *special* dark matter … made perhaps of superfluids or superconductors.
We take a model agnostic approach
Hmmm … I doubt these *scientists* are referring to God, so they must be saying they are doubtful about this but will go ahead and build a model.
and demonstrate that a collection of dark vortices can explain the data reported in Wang et al. Modeling a collection of vortices with a simple two-parameter analytic model, corresponding to an averaging of the velocity field, we find an excellent fit to the data. We perform a Markov Chain Monte Carlo analysis and find constraints on the number of vortices, the dark matter mass, and the radius of the inner core region where the vortices are distributed, in order for ultra-light dark matter to explain spinning cosmic filaments.
I’m going to have to read the paper to figure out what they really did. So …
Recent observational evidence suggests that some cosmic filaments are spinning. By comparing the redshift and blueshift of galaxies in thousands of filaments, Wang et al. (2021) determined that galaxies have velocities perpendicular to the filament axis, consistent with vorticle motions. Meanwhile, it is difficult to theoretically explain the acquisition of angular momentum on megaparsec scales.
Especially when they refuse to consider electromagnetism and the fact that most of what they see is plasma … not gas.
Vorticity is not easily seeded by density perturbations of a perfect fluid, and any primordial vorticity is expected to be redshifted away. One could try to extend arguments like the tidal-torquing theory introduced in the context of galaxy formation , but these describe the (quasi) linear regime, and not the non-linear regime needed to describe the filaments of the cosmic web.
So, it's a problem defying the gravity only physics they are willing to use. And so they turn to dark matter, the cure for everything astrophysical. Of course, the paper goes on to explain they need *special* dark matter … ultra-light dark matter (whatever the heck that is) ... to do the job.
In this letter we propose dark matter vortices as an explanation for the spin of cosmic filaments. We take a theory agnostic approach to the vortex formation and the underlying particle physics model, and instead focus on the observable signature of vortices. We demonstrate that parallel dark vortices enclosed in a cylindrical volume aligned with the axis of a filament are able to generate rotations at the Mpc scale, and that they can reproduce the behavior seen
Why that explains everything! No need to worry further about this observation, my fellow astrophysicists. DM’s the answer.
But notice something, folks? They next say that “PARALLEL dark vortices enclosed in a cylindrical volume aligned with the axis of a filament” can explain what they see. “Concretely, we find that the data is well fit by a simple Gaussian distribution of vortices about the axis of the filament.” Parallel vortices? Why that sure sounds like a pair of interacting Birkeland filaments, doesn’t it?
And in the paper, they admit they don’t really know how the parallel dark matter vortices would form. They says
Although there is considerable theory uncertainty as to the size and abundance of vortices that should be expected, all ultra-light dark matter models are expected to present these interference patterns. Therefore, in what follows, we remain agnostic to the underlying theory, as well as the formation mechanism, and instead simply consider the observables of vortices.
In other words, they’re just assuming there are dark matter vortices. They assert (without offering real proof) that the
vortices discussed may be created either by destructive interference occurring during gravitational collapse, or as angular momentum is transferred from infalling normal-phase dark matter to a condensate (superfluid) phase dark matter.
Note another assumption in their analysis …
We have also assumed in this analysis that the vortices can be treated as non-interacting, analogous to the dilute instanton gas approximation used in quantum field theory.
So the dark matter doesn’t interact with itself … not even through gravity?
Another assumption is this:
We additionally note that the vortices are expected to form following the distribution and shape of the filament, and therefore, if the filament formed itself formed an asymmetric shape or an asymmetric distribution, the vortices can be expected to follow this.
This seems to say that the vortices don’t determine the shape of the filament … the filament determines the shape of the vortices. Odd.
And here’s an important statement:
These assumptions aside, in this work we have focused solely on the observational signature of vortices, and not on their formation mechanism. In doing so we remain agnostic as to the model realization. As we have discussed, vortices can be formed both by destructive interference or by angular momentum of condensate dark matter.
So in other words, they’re washing their hands of the mechanism by which vortices form. They’re really just assuming that they can.
I've been wondering if the mainstream is ever going to say another word about the observation of galaxy sized rotating filaments.
[url]https://www.sciencedirect.com/science/article/pii/S0370269322004324[/url]
[quote]Cosmic filament spin from dark matter vortices
22 July 2022[/quote]
Here’s what the abstract says …
[quote]The recent observational evidence for cosmic filament spin on megaparsec scales Wang et al. (2021) [41] demands an explanation in the physics of dark matter.[/quote]
LOL! Let’s see if they can tease an explanation from that gnome.
[quote]Conventional collisionless cold particle dark matter is conjectured to generate cosmic filament spin through tidal torquing, but this explanation requires extrapolating from the quasi-linear regime to the non-linear regime. Meanwhile no alternative explanation exists in the context of ultra-light (e.g., axion) dark matter, and indeed these models would naively predict zero spin for cosmic filaments. [/quote]
Oh my … their models predict ZERO rotation of filaments. And the tidal torquing explanation requires extrapolation far outside the linear regime.
[quote]In this Letter we study cosmic filament spin in theories of ultra-light dark matter, such as ultra-light axions, and bosonic and fermionic condensates, such as superfluids and superconductors. These models are distinguished from conventional particle dark matter models by the possibility of dark matter vortices. [/quote]
Ah … so they’re going to try and use *special* dark matter … made perhaps of superfluids or superconductors.
[quote]We take a model agnostic approach[/quote]
Hmmm … I doubt these *scientists* are referring to God, so they must be saying they are doubtful about this but will go ahead and build a model.
[quote]and demonstrate that a collection of dark vortices can explain the data reported in Wang et al. Modeling a collection of vortices with a simple two-parameter analytic model, corresponding to an averaging of the velocity field, we find an excellent fit to the data. We perform a Markov Chain Monte Carlo analysis and find constraints on the number of vortices, the dark matter mass, and the radius of the inner core region where the vortices are distributed, in order for ultra-light dark matter to explain spinning cosmic filaments.[/quote]
I’m going to have to read the paper to figure out what they really did. So …
[quote]Recent observational evidence suggests that some cosmic filaments are spinning. By comparing the redshift and blueshift of galaxies in thousands of filaments, Wang et al. (2021) determined that galaxies have velocities perpendicular to the filament axis, consistent with vorticle motions. Meanwhile, it is difficult to theoretically explain the acquisition of angular momentum on megaparsec scales. [/quote]
Especially when they refuse to consider electromagnetism and the fact that most of what they see is plasma … not gas.
[quote]Vorticity is not easily seeded by density perturbations of a perfect fluid, and any primordial vorticity is expected to be redshifted away. One could try to extend arguments like the tidal-torquing theory introduced in the context of galaxy formation , but these describe the (quasi) linear regime, and not the non-linear regime needed to describe the filaments of the cosmic web.[/quote]
So, it's a problem defying the gravity only physics they are willing to use. And so they turn to dark matter, the cure for everything astrophysical. Of course, the paper goes on to explain they need *special* dark matter … ultra-light dark matter (whatever the heck that is) ... to do the job.
[quote]In this letter we propose dark matter vortices as an explanation for the spin of cosmic filaments. We take a theory agnostic approach to the vortex formation and the underlying particle physics model, and instead focus on the observable signature of vortices. We demonstrate that parallel dark vortices enclosed in a cylindrical volume aligned with the axis of a filament are able to generate rotations at the Mpc scale, and that they can reproduce the behavior seen [/quote]
Why that explains everything! No need to worry further about this observation, my fellow astrophysicists. DM’s the answer.
[b]But notice something, folks? They next say that “PARALLEL dark vortices enclosed in a cylindrical volume aligned with the axis of a filament” can explain what they see. “Concretely, we find that the data is well fit by a simple Gaussian distribution of vortices about the axis of the filament.” Parallel vortices? Why that sure sounds like a pair of interacting Birkeland filaments, doesn’t it? [/b]
And in the paper, they admit they don’t really know how the parallel dark matter vortices would form. They says
[quote]Although there is considerable theory uncertainty as to the size and abundance of vortices that should be expected, all ultra-light dark matter models are expected to present these interference patterns. Therefore, in what follows, we remain agnostic to the underlying theory, as well as the formation mechanism, and instead simply consider the observables of vortices.[/quote]
In other words, they’re just assuming there are dark matter vortices. They assert (without offering real proof) that the
[quote]vortices discussed may be created either by destructive interference occurring during gravitational collapse, or as angular momentum is transferred from infalling normal-phase dark matter to a condensate (superfluid) phase dark matter. [/quote]
Note another assumption in their analysis …
[quote]We have also assumed in this analysis that the vortices can be treated as non-interacting, analogous to the dilute instanton gas approximation used in quantum field theory. [/quote]
So the dark matter doesn’t interact with itself … not even through gravity?
Another assumption is this:
[quote]We additionally note that the vortices are expected to form following the distribution and shape of the filament, and therefore, if the filament formed itself formed an asymmetric shape or an asymmetric distribution, the vortices can be expected to follow this.[/quote]
This seems to say that the vortices don’t determine the shape of the filament … the filament determines the shape of the vortices. Odd.
And here’s an important statement:
[quote]These assumptions aside, in this work we have focused solely on the observational signature of vortices, and not on their formation mechanism. In doing so we remain agnostic as to the model realization. As we have discussed, vortices can be formed both by destructive interference or by angular momentum of condensate dark matter. [/quote]
[b]So in other words, they’re washing their hands of the mechanism by which vortices form. They’re really just assuming that they can.[/b]