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

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Could anti matter collisions be or make dark matter?

I've recently seen that space is or could be a quantum vacuum full of particles like matter and anti matter appearing and possibly colliding causing in theory the same effects that dark energy has. My ...
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26 views

What actually Dark energy is ? [duplicate]

I recently read an article on dark matter and I could understand this things given as follows All the ordinary matter we can find accounts for only about 4 percent of the universe. We know this by ...
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186 views

Could Dark Matter particles that don't couple to quarks or leptons have been produced?

With what we know about physics, is it possible that when the universe 'began', around when quarks and leptons were produced, another particle, which doesn't couple to either quarks, leptons or ...
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12 views

What's the evidence, if any, for some local concentration(s) of dark matter in some region(s) smaller than a galaxy?

What's the evidence, if any, for some local concentration(s) of dark matter in some region(s) smaller than a galaxy? Galactic-sized--or larger--gravitating halos seem to get all the attention. I'm ...
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28 views

Big Bang Question

In the early Universe it it's believed that matter and anti-matter annihilated one another till there was but a remaining 1% left. In a matter/anti-matter collision, is there not an explosion of ...
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How does dark matter interact with light?

Most articles I read say that dark matter are weakly interacting particles. Are there any theories on how dark matter may interact with light/electromagnetic radiation?
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What if dark matter is no matter after at all? [duplicate]

Dark Matter does not behave like matter in any known way except in that it interacts only with gravity and it does it in a weird way. As for example, dark matter does not appear to be affected by ...
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1answer
54 views

Do alternate theories for Dark Matter (like MOND) explain it's effect on gravitational lensing?

For a long time, I was sceptical about the evidence for dark matter. To me, it seemed like a pretty big leap to make when we have no idea whether or not our current models of gravity should apply ...
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2answers
72 views

How does the friedmon solution to Einstein's equations resolve paradox of bounded infinities?

This article talks about a potential explanation of dark matter based on something called the "friedmon." I have no interest in the dark matter question, but the article has made me curious about ...
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1answer
42 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 ...
3
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1answer
55 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. ...
2
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2answers
62 views

Lagrangian point or dark matter?

We know that spiral galaxies spin in a way such that we have to assume that dark matter is responsible for the extra mass required to do so. My question is, can Lagrangian points (L1 and L2) be used ...
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332 views

Justification for new theories of Particle Physics and General Relativity

In reference to arxiv:1212.4893v3 and arxiv:1206.5078v2 papers of Ma and Wang, they have proposed new theories in particle physics, the weakton model where quarks and leptons are formed using these ...
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40 views

Has energy in 'transit' been incorporated into missing matter calcs.?

Has energy in 'transit' been incorporated into missing matter calcs. ?It would seem that, although very small in mass, the sheer number of particles shhoting about from one end of the universe to the ...
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52 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 ...
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75 views

Could the dark matter sector be boring?

People always talk about finding good dark matter (DM) candidates of beyond Standard Model (SM) theories. To be a proper candidate the particles should not decay into the SM particles and could ...
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43 views

Has the idea of holeum been debunked?

Here is the wikipedia article. The basic idea is that the primordial density of microscopic black holes was high enough that many were able to form stable bound states before decaying through Hawking ...
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2answers
648 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?
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24 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"?
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4answers
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Why doesn't dark matter affect planetary motion?

If the universe is made up of ~95% dark matter, and it interacts only gravitationally then why didn't Newton and Kepler discover it before ? Why does it show itself only in the radial velocity profile ...
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40 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 ...
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46 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: ...
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170 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 ...
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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 ...
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33 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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59 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 ...
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41 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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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 ...
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4answers
146 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 ...
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1answer
89 views

Mass density of dark matter in solar system near us

What is the approximate mass density of dark matter in our solar system at the radius of the Earth's orbit? I would like some idea of the mass of dark matter going through each cubic meter of ...
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1answer
50 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 ...
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350 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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32 views

x-rays from dark matter accretion into a supermassive black hole?

I understand that accretion of normal matter into a super-massive black hole leads to x-ray emissions. Is the same effect expected to occur for dark matter accretion into a supermassive black hole? ...
7
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182 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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Need help on Springel model for galaxy dynamics

I would like to have help about the response of the dark matter profile in the Springel galaxy dynamics model ( from the paper Tidal tails in CDM cosmologies(NB: Arxiv pre-print)) Here's the part of ...
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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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85 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 ...
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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 ...
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What are the reasons why dark matter above the TeV scale appears to be ignored experimentally?

I understand that sub-TeV-scale dark matter would fit nicely with TeV-scale SUSY, but are there any other reasons for the large experimental blind spot between TeV-scale WIMPs and the much larger ...
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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 ...
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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 ...
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233 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 ...
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327 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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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 ...
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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 ...
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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 ...
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88 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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36 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 ...
1
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1answer
75 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. ...
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origin of cusps in simulated dark matter halos

I keep reading that cusps are one of the most "robust" predictions of N-body simulations of dark matter halos. But any paper I've found on the topic makes it sound like these simulations are ...