Matter not observed directly but inferred to exist based upon its gravitational effects

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4
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1answer
466 views

Difference between baryonic, inertial and gravitational mass? (and relation to dark matter)

Inertial mass: determined from Newton's f = ma Gravitational mass: determined via Newton's law of gravity Baryonic mass: sum of mass of all baryons. Which ones ...
8
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2answers
996 views

Could Dark Matter form black hole?

Some people speculate that the mysterious dark matter in the universe could be tiny black holes. But on the other side, could dark matter particles attract each other by gravity and finally form a ...
2
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1answer
78 views

Can the proportion of dark energy change?

This post generalizes the posts: - Proportion of dark matter/energy to other matters/energy at the beginning of the universe? - How do people calculate proportions of dark matter, dark energy ...
4
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1answer
95 views

Vacuum polarization of dark matter candidates

Can a dark matter particle (axions, for instance, but the question applies to any valid candidate for dark matter) induce QED vacuum polarization effects even if being electrically neutral and with no ...
3
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1answer
134 views

Interpretation of the WIMP annihilation cross section graph

I have some trouble in the interpretation of the WIMP cross-section annihilation versus their mass. I understand that the lines represent a upper bound on the cross section from the observation. ...
48
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1answer
1k views

What is the upper-limit on intrinsic heating due to dark matter?

Cold dark matter is thought to fill our galactic neighborhood with a density $\rho$ of about 0.3 GeV/cm${}^3$ and with a velocity $v$ of roughly 200 to 300 km/s. (The velocity dispersion is much ...
3
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2answers
501 views

If matter creates space, shouldn't there be experimentally detectable consequences?

Ernst Mach, a man to who influenced Albert Einstein significantly in his approach to relativity, did not quite seem to believe in space as a self-existing entity. I'm pretty sure it would be correct ...
4
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5answers
294 views

Is dark matter around the Milky Way spread in a spiral shape (or, in a different shape)?

Dark matter doesn't interact with electromagnetic radiation, but it, at least, participates in gravitational interactions as known from the discovery of dark matter. But does dark matter exist in a ...
4
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0answers
75 views

Dark Matter and Modified Gravity

Could someone please explain briefly or refer me to an article or manuscript that shows how f(R) modified gravity theories can be used to explain the problem of Dark Matter, particularly Galaxy ...
6
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1answer
286 views

Could dark matter be a kind of Goldstone boson?

The common argument for vanishing Goldstone boson is like, if there is some massless particle generated from the spontaneous symmetry breaking, it should be detected. Since we never saw that, it is ...
4
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2answers
727 views

Is cold dark matter made of Higgs bosons?

"Stable Higgs Bosons - new candidate for cold dark matter", by Yutaka Hosotani Has the hypothesis in the above article been proved? What about WIMPs?
6
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2answers
172 views

Does the term “dark matter” apply to nonluminescent bodies which still interact electromagnetically?

On the new Astronomy.SE site, I was having a short discussion on one of my answers. The basic discrepancy was; can MACHOs like black holes/brown dwarfs/neutron stars be termed "dark matter"? My ...
7
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1answer
41 views

Temperature of WIMPs

As a dark matter candidate, what should be the temperature and kinetic energy (or also the speed) of the WIMPs (weakly interacting massive particles) to agree with the observed distribution of dark ...
3
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0answers
30 views

Does dark matter get drawn into black holes? [duplicate]

Would dark matter get drawn into a black hole? Also, could enough dark matter be concentrated to create a "dark black hole"?
5
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1answer
65 views

What do the latest FERMI results say about dark matter?

There was an announcement at a recent UCLA symposium on dark matter by the FERMI collaboration which hints at some evidence of dark matter. The results aren't yet published, but the symposium news ...
5
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1answer
1k views

How the CMB anisotropy is linked to the existence of cold dark matter and dark energy?

After the data from the cosmic microwave background has been collected by WMAP or Planck, what types of analysis is needed to conduct in order to deduce the cold dark matter density and the ...
9
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2answers
84 views

CMB curly B-modes and dark matter

I raised a question a while ago regarding weak gravitational lensing of galaxies and the CMB. With all the fuzz with the BICEP2 data, I think it is time to raise even more questions about this amazing ...
-1
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1answer
278 views

Can parallel universes constitute the missing mass aka dark matter?

I was pondering about this question for a while now. And with my limited knowledge of physics I can answer myself - if parallel universe theory is true and if indeed there is gravitation leakage from ...
1
vote
3answers
345 views

Can virtual particles, in particular gravitons, interfere?

Question 1. Can virtual particles, in particular gravitons, interfere? Virtual particles are created and annihilated in a distance too small and a time too short to be measured. Their existence is ...
0
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2answers
45 views

Merger happening tangentially, but dark matter at both sides?

According to this news, The expectation of "unaccounted energy" comes from the fact the merger of galaxy clusters is occurring tangentially to the observers' line-of-sight. This means they are ...
3
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1answer
83 views

Neutrino Nuclei Coherent scattering and the Dark Matter lower wall

Suppose that current and new forthcoming dark matter direct detection experiments find no evidence of Dark matter events and exclude interactions of hypothetical DM particles (like LSP or similar) in ...
0
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0answers
134 views

In a theory of quantum gravity, does the gravitational coupling “constant” actually depend on the scale of the systems involved in the interaction?

In the following I will give some arguments that will indicate that the gravitational coupling "constant" actually depends on the scale (space and time) of the interacting systems. The question is: ...
2
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2answers
463 views

Is it possible for dark matter to somehow turn into regular matter?

Is it possible for dark matter to create the regular matter that we, the stars, and the galaxies are made of? The reason I'm asking this is because I have a hard time imagining how something can ...
7
votes
2answers
372 views

Why does dark matter form walls and filaments

Related: How are galaxy filaments formed? And do they have any analogues in stellar formation? But I want to come at this from a different angle. Like the user asking that other question, I was a bit ...
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0answers
44 views

Quantum Hall Effect Dark Matter Detector?

Has anyone used a Quantum Hall effect detector to detect dark matter? I was looking at the following animation on wikipedia: ...
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0answers
57 views

Primordial black hole: how dense does matter need to be to feed it?

Primordial black holes are a dark matter candidate. Suppose you put a primordial black hole the mass of an asteroid in Earth's core. Will it grow? NO! The black hole will be on the order of a proton ...
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0answers
33 views

Superconducting loop as a particle detector?

Imagine that one has induced a persistent current in a superconducting loop. If a particle interacted with an electron in one of the Cooper pairs then would some decoherence and dissipation occur? I ...
2
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4answers
303 views

Dark matter and tides

As I understand, "dark matter" is what they call a theoretical substance which is only known by it's influence upon velocity curve of the galaxy. If indeed the gravity of "dark matter" is so strong ...
7
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2answers
369 views

Did CDMS identify dark matter?

A recent paper by the CDMS collaboration (PRL here and free text here) makes this statement in the abstract: This blind analysis of 140.2 kg day of data taken between July 2007 and September 2008 ...
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5answers
3k views

Why can't dark matter be black holes?

Since 90 % of matter is what we cannot see, why can't it be black-holes from early on? Is is possible to figure out that there are no black holes in the line of sight of various stars/galaxies we ...
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2answers
261 views

Could the Earth have a dark matter core as well as a disk?

If it is established that the Earth does have a dark matter disk as this recent discovery suggests. ...
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1answer
99 views

Is the standard model so full of holes it is time to start again? [closed]

I have read a lot about dark matter and dark energy, the fact that we are spending a small fortune trying to detect their presence, but the only reason they have been postulated it is an effort to ...
0
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0answers
110 views

What causes there to be an offset between the light lensing through the space neighboring galaxy clusters and the galaxy clusters themselves?

http://www.wired.com/wiredscience/2013/01/musket-ball-dark-force/ The reason this is strange is that dark matter is thought to barely interact with itself. The dark matter should just coast ...
1
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0answers
79 views

Weak gravitational lensing multispectral, multibackground correlations

My understanding of weak gravitational lensing is that it assumes random alignment distribution of galaxies in order to estimate statistical shear and convergences, which are used to estimate matter ...
6
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3answers
513 views

If the universe is full of dark matter, why is it only 2.73 K cold?

people! I am just a physics layman, but I recently watched a documentary about the universe and it was told that the universe is full of dark matter and energy and the universe is empty, so that ...
3
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2answers
619 views

Is Dark Matter evenly spread out in the universe?

Is Dark Matter evenly spread out? If no, could we ever find a correlation between the amount of dark matter and matter in a specific place?
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0answers
104 views

Why not “black matter” instead of “non-baryonic cold dark matter”? [closed]

I would like to know if any epistemologist or science popularizer has ever think about a better/simpler name for exotic or non-baryonic cold dark matter like black matter. That would be interesting ...
0
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1answer
39 views

When experimental search for exotic dark matter-like particles began exactly?

I am looking for information about : what was the first experiment that claimed to look specifically for non baryonic dark matter particles ; when occurred the first serious(*) reporting of an ...
2
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0answers
130 views

Partial waves and the velocity expansion of a scattering cross section

I'm confused about the relation between the velocity expansion of a scattering cross section and the angular momentum (partial wave) expansion. For example, for dark matter annihilation, we write ...
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votes
2answers
392 views

why is dark matter the best theory available to explain missing mass problems?

Why is dark matter the best theory to explain the missing mass problem? Why is dark matter mathematically necessary to explain the missing mass problem? On a side not I believe dark matter is ...
0
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0answers
41 views

Isn't Dark Matter just an Indication that Relativity breaks down when describing large masses? [duplicate]

It seems to me that Dark Matter is just an indication that our models of gravity do not scale to the level of galaxies, and thus like Newtonian physics, it is a powerful but incomplete model of the ...
2
votes
1answer
95 views

How much of the mass of a supermassive black hole comes from dark matter?

How much of the mass of a supermassive black hole comes from dark matter? Assuming cold dark matter exists and that it doesn't bank up and get pushed away from black holes like some baryonic matter. ...
13
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1answer
403 views

Dark matter and SO(10) grand unification

$SO(10)$ grand unified theories nicely accommodate a massive $\sim 10^{14-15}\; GeV$ sterile neutrino. Would this be a viable dark matter candidate? I haven't found any specific material regarding ...
10
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1answer
952 views

Why do we need to find 5 Higgs Bosons to prove the existence of the dark matter?

I was recently watching a show that say we need at least 5 Higgs Boson to prove the existence of the dark matter because it will strengthen the concept of symmetry. Why is that so? Because, I am not ...
3
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1answer
145 views

What determines the shape of the WIMP cross-section vs mass limit curves?

In figure 5 of http://arxiv.org/abs/arXiv:1310.8214 (PDF: http://arxiv.org/pdf/1310.8214v1.pdf), the experiments all seem to reach the lowest cross-sections when the WIMP is in the $40-100\, ...
2
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1answer
83 views

Dark matter detection

In the detection of weakly interacting massive particles (WIMPs), which is the basis of dark matter, what is the use of the tank filled with liquid xenon? I mean, how does the releasing of photons ...
-1
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1answer
122 views

Why isn't renormalization called dark physics?

In QED there is extra energy that has to be gotten rid of to match observations. Kind of the opposite to GR/ND where you have to add extra energy/matter to match observations. Why isn't ...
21
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6answers
2k views

Why isn't dark matter just matter?

There's more gravitational force in our galaxy (and others) than can be explained by counting stars. So why not lots of dark planetery systems (ie without stars) ? Why must we assume some undiscovered ...
5
votes
2answers
919 views

How much light is there in space and how heavy is it?

Our night sky is filled with stars. On a dark night a significant fraction of the sky is light. This light, we are told, has been in transit for many millions of years. There must therefore be quite a ...
5
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3answers
312 views

Dark matter is electrically neutral

I would like to know how come if dark matter was electrically charged it would reflect light. What are the equations or the logic behind it?