Disappearance of dark matter since the Big Bang

In summary, this recent study suggests that there is a tension between observations of dark matter and dark energy, and that more data is needed to resolve the discrepancy.
  • #1
!Jon Snow!
35
0
Can someone explain the disappearance of 57% of dark matter since the Big Bang?

Is dark energy eating dark matter?
 
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  • #3
Note:
Catherine Heymans of the University of Edinburgh describes the research as "a fascinating result", and points out that it is part of a larger effort to reconcile discrepancies (or "tensions") between measurements made by Planck and those from other telescopes. "Other researchers have said that this tension can be resolved if the dark-matter particle is a sterile neutrino," she explains, adding, "others still are looking at different modified-gravity theories to explain the result."

Heymans also points out that the tension could be the result of systematic errors in how one or more of the observations are made. "More data and further meticulous analysis of those data and the systematics that might be associated with them are the way to find out if this fascinating theory could be true," she cautions.

Is it just systematic error, carnivorous Dark Energy, sterile neutrinos or modified gravity?

We wait and see!

Garth
 
  • #4
Bandersnatch said:
Here's the paper:
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.181301
http://arxiv.org/abs/1406.7297

It's way beyond me, but I'd also love to hear what people think.
Thanks for a specific link! Just noting that the paper you link to is
Indications of a late-time interaction in the dark sector
Valentina Salvatelli, Najla Said, Marco Bruni, Alessandro Melchiorri, David Wands
(Submitted on 27 Jun 2014)
http://inspirehep.net/search?p=find eprint 1406.7297
http://inspirehep.net/search?ln=en&p=refersto:recid:1303847

Beyond me but here is how a later paper placed it in context and perspective, I quote the conclusions section of
http://arxiv.org/abs/arXiv:1410.5832
Banana Split: Testing the Dark Energy Consistency with Geometry and Growth
Eduardo J. Ruiz, Dragan Huterer
(Submitted on 21 Oct 2014)

==quote http://arxiv.org/abs/arXiv:1410.5832 ==
Let us consider possible reasons for the pull of redshift-space distortions toward wgrow > −1. This result is qualitatively not new: a number of recent investigations have already been established that the RSD data are in some conflict with ΛCDM, suggesting less growth at recent times than predicted by the standard model [61].
For example, Beutler et al. [62] have measured a > 2-σ tension in measurements of the growth index γ = 0.772+0.124 −0.097 relative to the ΛCDM (and, for that matter, also wCDM) prediction γ ≃ 0.55.
Similarly, Samushia et al. [48], using DR11 CMASS sample, and the more precise results by Reid et al. [63] that utilized smaller spatial scales by doing extensive halo occupation distribution modeling, have obtained similar results, indicating that growth is suppressed relative to ΛCDM prediction at approximately the 2-σ level.
Moreover, Beutler et al. [64] find a ∼2.5σ evidence for nonzero neutrino mass, again a signature of the hints of the departure from the standard model.
Finally, Salvatelli et al. [65] utilize the combined cosmological probes (including the RSD) in the context of a model where vacuum energy interacts with dark matter, and interpret the results as detection of nonzero interactions between dark matter and dark energy — another possible interpretation of the departure from the standard ΛCDM model.
==endquote==
There's also reference to the Salvatelli et al in this one, coauthored by Roy Maartens
http://arxiv.org/pdf/1409.4933.pdf
In this it is remarked at the outset that "The transfer of energy density between dark energy and dark matter is not ruled out by current observations (for recent work, see e.g. [8–15])" and reference [15] is to Salvatelli et al.Just for convenience here is the starter physicsworld link, and some others, not necessarily up to date or recommended:
http://physicsworld.com/cws/article/news/2014/nov/18/is-dark-energy-eating-dark-matter
http://physicsworld.com/cws/article/indepth/2010/jun/02/dark-energy-how-the-paradigm-shifted
http://physicsworld.com/cws/article/indepth/2014/jul/10/theories-of-the-dark-side
 
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  • #5


I can provide some possible explanations for the apparent disappearance of dark matter since the Big Bang. One possibility is that the distribution of dark matter in the universe has changed over time, leading to a decrease in the overall amount. Another explanation could be that dark matter particles have decayed or interacted with other particles, causing them to no longer be detectable. It is also possible that our current understanding of dark matter is incomplete and there may be other factors at play that we are not yet aware of. As for the idea of dark energy "eating" dark matter, this is a speculative concept and there is currently no evidence to support it. More research and data are needed in order to fully understand the nature and behavior of dark matter.
 

1. What is dark matter?

Dark matter is a type of matter that cannot be seen or detected using traditional methods of observation. It is believed to make up about 27% of the universe and is thought to be responsible for the formation and structure of galaxies.

2. How was dark matter first discovered?

Dark matter was first discovered through observations of the rotation of galaxies. Scientists noticed that the outer edges of galaxies were rotating faster than expected, indicating the presence of additional mass that could not be accounted for by visible matter.

3. Why has dark matter been disappearing since the Big Bang?

The disappearance of dark matter since the Big Bang is still a mystery and a topic of ongoing research. One theory is that dark matter may have interacted with other particles in the early universe, causing it to decay or be transformed into other types of matter. Another possibility is that dark matter may have been present in different concentrations in different regions of the universe, leading to variations in its distribution over time.

4. How does the disappearance of dark matter affect our understanding of the universe?

The disappearance of dark matter has significant implications for our understanding of the universe and its evolution. Dark matter plays a crucial role in the formation and structure of galaxies, so its disappearance could change our understanding of how galaxies form and evolve. It could also impact our understanding of the expansion of the universe and the distribution of matter within it.

5. Are there any current theories or experiments to explain the disappearance of dark matter?

Yes, there are several theories and experiments currently being conducted to explain the disappearance of dark matter. Some involve looking for evidence of dark matter interactions with other particles, while others involve studying the structure of galaxies and the distribution of matter in the universe. However, more research and data are needed to fully understand this phenomenon.

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