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

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Sterile Neutrinos as Dark Matter

There has been recent activity by astrophysicists to determine whether a fourth flavor of neutrino, a sterile neutrino, exists. It would likely be more massive than electron, muon or tau neutrinos. ...
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2answers
710 views

Do we have an idea about the amount of matter in the universe?

Do we consider the amount of matter in the universe to be "infinite"? Or do we have an idea about "how much" there is?
17
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2answers
802 views

Correlation between outstanding hints in experimental particle physics

The 115 GeV ATLAS Higgs with enhanced diphoton decays has gone away but there are several other recent tantalizing hints relevant for particle physics, namely CoGeNT's 7-8 GeV dark matter particle ...
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1answer
44 views

What happens when astronomical bodies made up of Dark Matter collapse or collide?

Does dark matter not produce heat or radiation after a collision etc? Or, we detect radiations having no generators?
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2answers
239 views

Is there evidence of dark matter in our galaxy?

Is there evidence of dark matter in our galaxy? How can we measure this, say, how many percent of the center of our galaxy is dark matter? I did not find the answer in the question What's Dark ...
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2answers
210 views

Could dark matter be expanded atoms, and dark energy expanded radiation? [closed]

After watching Lawrence Krauss' lecture 'life, universe, and nothing', an interesting idea lighted up in my mind. Is it possible that dark matter is just spread out matter waves and dark energy ...
2
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0answers
143 views

Particle dark matter coherent scattering?

Particle dark matter coherent scattering direct searches rely on the scattering of the DM particle off a nucleus (Xe, Si, Ge, NaI etc). The wisdom is this is coherent scattering: so the rate ~atomic ...
7
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2answers
254 views

Would dark matter absorb gravitational waves?

Would the vast and seemingly diffuse clouds of dark matter floating around our galaxy (and most others) absorb gravitational waves? Is this perhaps why we haven't detected any yet?
8
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1answer
343 views

What properties of Germanium make it suitable for Dark Matter detectors?

What properties of Germanium make it suitable for Dark Matter detectors? I tried googling but there was too many results describing the use of Germanium Chrystals at low tempretures for Dark Matter ...
3
votes
2answers
223 views

If dark matter is a new type of particle, what does that imply?

My understanding is that dark matter cannot be (or is at least highly unlikely to be) an exotic form of any known particle. On the other hand, articles about particle accelerators seem to say that the ...
5
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1answer
568 views

7 GeV dark matter particle: how particle accelerators missed it?

This posting is regarding the recent confirmation of the DAMA results that might be due to underlying differences in proton and neutron cross section with the dark matter particles, which reflect on ...
8
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2answers
895 views

Is dark matter repulsive to dark matter? Why?

I think I saw in a video that if dark matter wasn't repulsive to dark matter, it would have formed dense massive objects or even black holes which we should have detected. So, could dark matter be ...
2
votes
2answers
413 views

Neutralino Dark Matter Detection

Assuming supersymmetry exists and a neutralino is stable, it's often seen as a leading dark matter candidate. What would be expected from the interaction of a neutralino and its anti-particle? Has ...
2
votes
3answers
145 views

Ability to detect pulsars

Am I correct it remembering that unless a pulsars beams plane faces earth we can not detect them. And that similarly inbetween the pulses we can't see them either? If so how does this differ from ...
4
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1answer
138 views

What are wimpy particles?

Can anyone give a brief overview of what a wimpy particle is?
2
votes
2answers
239 views

What about the neutron stars with CMB temperature as dark matter?

Inspired by How do we know that dark matter is dark? and What is the temperature of the surface and core of a neutron star formed 12 billion years ago now equal to?
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0answers
149 views

Why is “dark matter” a more parsimonious explanation than “more normal matter than we thought”? [duplicate]

Possible Duplicate: Why isn't dark matter just matter ? The evidence usually presented in support of dark matter is larger-than-expected masses in galaxy clusters: the mass required for ...
5
votes
3answers
380 views

What current alternatives are there to the standard concordance model of cosmology?

The current "standard model" or concordance model of cosmology is Lambda CDM which includes late time acceleration due to a cosmological constant, cold dark matter as the missing matter component and ...