The dark-matter tag has no wiki summary.
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717 views
How do we know Dark Matter isn't simply Neutrinos?
What evidence is there that dark matter isn't one of the known types of neutrinos?
If it were, how would this be measurable?
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2answers
239 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 ...
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0answers
28 views
Dark Energy, Space Time and Black Holes [closed]
Since space and time are both one and the same would that mean that as time passes and accumulates after the big bang that space is forced to grow? This would explain why all the galaxies are speeding ...
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3answers
186 views
Could some Red and Blue shifts be the result of light passing through “dark matter”?
As i see it, light behaves in certain ways, as the Double Slit experiement shows,
So when light comes into contact with dark matter, it becomes both a wave and a particle, the wave is bent around the ...
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2answers
63 views
proportion of dark matter/energy to other matters/energy at the beginning of the universe
How will the proportion of dark matter/energy to other matters/energy be like at the momenets after the beginning of the universe (standard Big Bang model)?
2
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1answer
63 views
Do WIMPs have to interact non-gravitationally with each other or other particles?
I know many collaborations are attempting to detect the interaction of WIMPs with nucleons or with themselves, with the recent result from Ice Cube ...
3
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2answers
65 views
Orbits within a $-\vec{r}$ field
Let's say that we have a cold dark matter theory, so we imagine weakly interacting particles. Now, let's say that one of those dark-matter particles has a rare interaction while traveling through the ...
0
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1answer
50 views
Is dark matter expanding the universe, and creating the structures within it?
If dark matter repelled other dark matter, as well as regular matter(atomic or celestial), and regular matter were repelled by other regular matter "less" than by the dark matter, would not this ...
4
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1answer
73 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 ...
4
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2answers
111 views
Can dark matter be relativistic dust?
As far as I know the mass of an observed object increases as it approaches the speed of light.
Is it possible that the excess mass called "dark matter" is due to relativistic dust?
Surely, stars ...
2
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2answers
71 views
can we have a parallel earth made of dark matter?
In the sense that the two planets move together and has intelligent beings with their own forces and particles, but they just do not interact with (are invisible to) us?
9
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1answer
223 views
What dark matter can AMS currently find (or exclude)?
The rumor mill is running again, this time it's about the AMS experiment (Alpha Magnetic Spectrometer) that's going to make a major announcement soon.
I suppose they are looking for peaks in gamma ...
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1answer
148 views
Does Dark Matter have more space-time or particle characteristics?
Dark Matter appears to have more in common with phenomena related to spatial geometry then a particle. I thought in General Relativity, space can be curved without the presence of matter so ...
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3answers
113 views
Dark energy and dark matter
Our galaxies are speeding apart from each other and that is because of dark energy, but we don't know where it comes from right? If I'm not mistaken could dark matter have dark energy? (If they are ...
4
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2answers
308 views
Sparticles: Relationship to supersymmetry and dark matter?
I was attempting to read this paper after watching a show with Brian Greene. As I understand it, sparticles are a prediction of supersymetry, so I was wondering:
Wouldn't the discovery of ...
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0answers
46 views
Flung out of the galaxy
I watched a video by Dr. Michio Kaku, in which he states a theory about Dark Matter.
This theory says that Dark Matter could be just ordinary matter from another parallel universe, which would be ...
26
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0answers
509 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
104 views
Why is the dark matter density profile within the solar radius (and local density) uncertain?
It seems that we know the rotation curve inside the sun's galactic orbit fairly accurately. Then wouldn't we be able to just take the derivative* of this to get the DM density profile at smaller ...
2
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2answers
111 views
Dark matter and QFT
My understanding is that the particle is a somewhat artificial notion in QFT (see: Quantum Mechanics: Myths and Facts), and that in general it is possible for a quantum field to have unstable ...
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2answers
102 views
following up dark matter accretion in supermassive black holes
A while ago, there was some conspicuous evidence that supermassive black holes didn't seem to be eating dark matter at the expected rate of 70%-30%, in fact, only 10% of the black hole mass increase ...
0
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1answer
242 views
Could Dark Matter be a manifestation of tachyons tunnelling between black holes?
Among the many Dark Matter candidates, I wondered if there are any along the lines of the title.
The inner horizon of a black hole, with its mass inflation, and/or the high spacetime curvature, seems ...
1
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1answer
72 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 ...
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2answers
136 views
Is cosmic background radiation dark-matter and/or dark-energy?
Dumb question alert: Is it possible that the cosmic background radiation might be the source of dark-matter and/or dark-energy? What is the mass of the background radiation in the known universe?
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2answers
153 views
Dark Matter 'Stars'
I'm aware that the Milky Way has a dark matter 'halo' around it, presumably a spherically symmetric distribution.
But I'm completely ignorant regarding the theories explaining dark matter... Is there ...
2
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1answer
64 views
Dark energy before radiation or after?
In the cosmic history of the universe, does the dark energy comes before the radiation epoch, or only now, in the 'matter' universe (matter dominated era)?
Because, we now know that like 75% of our ...
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3answers
79 views
Redshift of light in dark matter
Following Edwin Hubble, it is widely believed that the universe is expanding, which is based on the red-shift of light from distant objects. Can dark matter cause light to be red-shifted and make it ...
4
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1answer
165 views
Does conformal gravity explain the Bullet cluster lensing effects?
Conformal gravity is an "alternative" theory of gravity, where instead of using the Einstein-Hilbert action composed of the Ricci scalar, the square of the conformal Weyl tensor is used. It was ...
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0answers
36 views
Vlasov equation in Liddle and Lyth or Dodelson's book
I am concerned about equations 2, 5 and 6 on page 2 of arXiv:astro-ph/0606028.
The paper refers them to the book by Peebles which I don't have access to at this point.
I believe that these ...
2
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1answer
57 views
Neutrino mass as counted in Dark Matter
If I try to add up neutrino masses (let's assume 1 eV rest mass equivalent each) to count as DM, do I use the rest mass or relativistic mass?
4
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4answers
90 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 ...
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2answers
193 views
Dark matter and dark energy [duplicate]
Possible Duplicate:
Dark matter references
I have recently read about dark matter and dark energy, and why physicists think it must exist (dark matter: mass of galaxies are far bigger than ...
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2answers
154 views
Could dark energy be heat? Could dark matter be stuff that is not seen because of its refraction limits?
Heat has to go somewhere. Would the light and heat of the stars in the universe amount up to being dark matter ...and dark energy ...
Dark matter would just be small pieces of stuff.
Dark energy ...
1
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1answer
152 views
What exactly are super WIMPs?
I recently got confused (and slightly annoyed by the lack of technical details) when reading a popular article (authored by Jonathan Feng and Mark Trodden) introducing the concept of super WIMPs.
The ...
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2answers
286 views
Has Bose-Einstein theory been considered for dark matter?
Has Bose-Einstein theory been considered for dark matter?
The theory would explain why no measurable radiation is emitted due to zero temperature--its lack of interaction with other matter and its ...
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1answer
68 views
Dark Matter and Rotational Velocity Curves of Galaxies and Stellar Systems
The way dark matter is introduced to documentary watchers such as myself is to account for the difference between the rotational velocity of the stars in a galaxy compared to that of planets in ...
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1answer
88 views
Why doesn't the dark matter halo co-rotate with the luminous disk?
What keeps it from falling into the center if not angular momentum?
6
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3answers
807 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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4answers
416 views
Why can't missing mass be photons?
After a star lives and dies, I assume virtually all of it's mass would be photons. If enough stars have already lived and died, couldn't there be enough photon energy out there to account for all the ...
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2answers
166 views
Assuming SUSY is found to be incorrect, what would then be the most compelling candidates for dark matter?
From what I've read, the only remaining candidates appear to be either sterile neutrinos or MOND (MOdified Newtonian Dynamics -- it does seem to keep changing.)
Did I miss anything else plausible?
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1answer
63 views
Böotes Void and Dark Galxies
Wouldn't it be possible that Böotes Void, a space we generally consider to be "empty" be filled with a number of undetectable dark galaxies?
6
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4answers
356 views
How do we know that dark matter is dark?
How do we know that dark matter is dark, in the sense that it doesn't give out any light or absorb any? It is impossible for humans to be watching every single wavelength. For example, what about ...
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1answer
89 views
Experimental foundations of the “otherwise galaxies would not hold together” argument for dark matter
On the question of motivation and evidence for dark matter, there are some illuminating (so to speak) answers on this site. I'd like to understand in detail the foundations of one of the lines of ...
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2answers
144 views
Dark matter: degrees of freedom
I'm afraid this question could sound a little too vague. I don't even know if dark matter (DM) can be genuinely described by quantum field theory, or if quantum field theory should be somehow ...
0
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1answer
89 views
Why the world is so deep and dark?
We live in a dark world, and the light is results of big bang.
The world is really made mostly of dark matter and dark energy?
Why the world is so deep and dark?
3
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4answers
197 views
Possibility for radiation in dark matter that is not interactive with regular matter?
Definition: Radiation in this case does not refer to electromagnetic radiation. It refers to any kind of emission of energy, even energy that does not interact with regular matter.
Just like dark ...
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4answers
307 views
Dark matter references
I've been looking for questions about dark matter, and I've read some very interesting answers. However, I desire too look into it deeply.
This is not actually a question. I'm asking the community ...
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1answer
100 views
On non-local physics
Recently I've encountered work by prof. B.V Alekseev, in which he claims that some physical problems can be easily solved if we consider non-local interactions in kinetic theory (interactions of ...
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2answers
141 views
Possibility of making dark energy equivalent with dark matter
I was curious whether it is possible to make dark energy equivalent to dark matter.
Can this unification be done?
If it can, why do scientists prefer to separate dark energy from dark matter?
2
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1answer
126 views
Relativistic Mass and Dark Matter
In a question here Ron Maimon comments that "relativistic mass makes gravity, not rest mass."
If so, does that mean that the faster that stars orbit the galaxy the larger the relativistic mass of the ...
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1answer
210 views
Does dark matter have to be matter?
There is a very similar question to this one: Is dark matter really matter?. But the particular aspect I'm asking about seems not to be mentioned there. So, here we go:
Does dark matter have to exist ...
