Undergrad Great attractor and the CMB dipole

[Chronos]

The Great Attractor has been a source of controversy since its discovery. Some think it is just a fluke, others feel it to be a clue to a greater mystery. This paper; https://arxiv.org/abs/1702.02483, The Dipole Repeller, offers a deeper look without necessarily resolving the enigma.

 

[rootone]

I don't see an enigma or mystery.
If there can be regions in the cosmos which are unusually dense, there should be other regions almost devoid of matter.

 

[stoomart]

Is this Dipole Repeller a "supervoid"? Would it be accurate to say expansion is accelerating faster in these voids than attractor regions?

Edit: I get the sense from this article that focus on the Great Attractor has been overtaken by the Shapley Supercluster (Concentration/Attractor) and the Dipole Repeller:

Arguably, the dominance of the Dipole Repeller over the Shapley Attractor is the main novel and surprising finding of this study.

 

[Chronos]

The void/overdense model has baggage. It certainly suggests, imo, the universe may not be infinite. In an infinite universe the average matter density should balance out in all directions. It's hard to imagine the scale at which a local flow of such magnitude is not highly improbable without creating tension with the cosmological principle.

 

[Bandersnatch]

It certainly suggests, imo, the universe may not be infinite. In an infinite universe the average matter density should balance out in all directions

Why would that be the case? It's like saying that since we're accelerating towards the Andromeda, the universe may not be infinite.

 

[stoomart]

Video linked in the paper: http://vimeo.com/pomarede/dipolerepeller

 

[Chronos]

At sufficiently large scales, our measurements of cosmic flows are in tension with the LCDM model. That sounds like the makings of a mystery to me. This issue is addressed here; https://arxiv.org/abs/1205.4627, Cosmic Flows surveys and CLUES simulations. Another potential solution is offered here; https://arxiv.org/abs/1607.07377, Frames of most uniform Hubble flow.