Great attractor and the CMB dipole

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In summary, the Dipole Repeller suggests that the universe may not be infinite. It also suggests that expansion is accelerating faster in regions devoid of matter than in attractor regions. These findings are in tension with the LCDM model, but may be resolved by further research.
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Chronos
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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.
 
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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.
 
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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.
 
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  • #4
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.
 
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Chronos said:
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.
 
  • #7
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.
 
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Related to Great attractor and the CMB dipole

1. What is the Great Attractor?

The Great Attractor is a massive gravitational anomaly located in the direction of the Centaurus and Norma constellations. It is believed to be a region of space that is pulling nearby galaxies towards it.

2. How does the Great Attractor affect the cosmic microwave background?

The Great Attractor's gravitational pull causes a dipole pattern in the cosmic microwave background (CMB) radiation. This means that the CMB appears slightly warmer in one direction and slightly cooler in the opposite direction.

3. Can we see the Great Attractor with telescopes?

No, we cannot see the Great Attractor with traditional telescopes as it is located behind the Milky Way. However, its effects on nearby galaxies can be observed.

4. Is the Great Attractor the only cause of the CMB dipole?

No, the CMB dipole is also influenced by the motion of our galaxy and the Earth's orbit around the sun. However, the Great Attractor is believed to be the main cause of the dipole pattern.

5. What can we learn from studying the Great Attractor and the CMB dipole?

Studying the Great Attractor and the CMB dipole can help us better understand the large-scale structure and evolution of the universe. It can also provide insights into the distribution of dark matter and the overall expansion of the universe.

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