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

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-1
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6answers
90 views

Can dark matter be converted to dark energy?

According to energy mass conversion law, mass can be converted to energy. So is it possible to convert dark matter into dark energy?
4
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0answers
83 views

Is MOND dead or still being actively researched?

This may be an opinion based question, and if so I shall remove it, but is MOND, Modified Newtonion Dynamics, pretty much dead as both a theory/ hypothesis and also as an active research subject? ...
0
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0answers
20 views

DGP brane world model

Can we think of interaction between dark energy and dark matter within the brane in DGP model like in case of GR?
1
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1answer
92 views

Could M-Theory explain dark matter as well as dark energy?

Is it possible that M-Theory provides a solution to the mystery of dark matter and dark energy? The idea of dark matter and dark energy is that there is some inexplicable source affecting our ...
0
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3answers
52 views

Why is the ratio dark matter / normal matter bigger today than in the past? Is it the dark matter that increased or the normal matter that decreased?

These two pie charts clearly show that the ratio dark matter / normal matter is bigger today than it was in the past. But why? How is it possible? And does it mean that the amount of dark matter ...
3
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0answers
42 views

Could there be a dark matter planet? [duplicate]

Since dark matter is gravitationally "charged", by which I mean it has mass and attracts things, could it bunch together to form a planet?
2
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1answer
46 views

Could dark matter be degenerate?

If dark matter were to be partly composed of fermions (such as hypothetical neutralinos), then could these particles be subject to degeneracy pressure if they were trapped in the potential well of a ...
1
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1answer
46 views

Dark energy and exotic states of space-time

So far as I know attempts to detect new particle that responsible for the nature of dark matter/energy are not successful. And there are reasonable explanation for this, like energy levels we can get ...
-6
votes
0answers
137 views

Is the Milky Way's halo curved spacetime? [duplicate]

This question has nothing to do with dark matter. This question is discussing a theory which states the notion of dark matter is incorrect and the Milky Way is moving through and displacing the 'dark ...
0
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1answer
35 views

Is there a real and relevant relationship between Big Bang and dark matter?

Since the postulate of dark matter is based on the unexpected rotational velocity around the centre of a spiral galaxy, then it can be presumed that the Big Bang Theory is not relevant to the search ...
1
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0answers
38 views

Why do planets moving around our Sun lead to how stars move around the centre of a spiral galaxy?

We know that the speed with which the planets go around our sun decreases as a function of the distance they are from the sun. Since stars are not planets, and presumably do not behave like planets, ...
8
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0answers
243 views

Dark matter clumping [duplicate]

How can dark matter particles (WIMP's) get ever more densely clumped during the evolution of the universe, as we see for example in the Millennium simulation, if they can't loose kinetic energy by ...
-18
votes
2answers
282 views

When will physics understand it is the 'dark mass' not the 'dark matter'? [closed]

There is new thinking occurring in physics where 'dark matter' is considered to be incorrect. The new thinking is that mass fills 'empty' space. The mass which fill's 'empty' space is being referred ...
4
votes
1answer
86 views

Where would the dark matter particle fit inside a picture of the standard model of particle physics?

Where would the dark matter particle fit inside a picture of the standard model of particle physics? While I am particularly fond of the Sterile Neutrino, I have not been able to find any example of ...
1
vote
3answers
338 views

Where is all the Dark Matter? Theoretical Question

In my Physics Class we had to look into possible areas where Dark Matter could be "hiding." Such as Black Holes and so on. Dark matter really can be "seen" through its gravitational effects, and we ...
1
vote
0answers
22 views

Electroweak symmetry breaking with additional gauge group(s)

Is it possible that rather than the electroweak splitting into SU(2)xU(1), that there could instead of another gauge group in the dark sector? Suppose SU(2)xU(1)xSU(N)_d. Is that ruled out by the full ...
0
votes
1answer
43 views

is electromagnetic phenomena and particle behavior dependent on dark matter?

Dark matter permeates space and coalesce s in its own gravitational attraction. It neither absorbs or emits light or interacts well with baryonic matter. It deflects light on a path and is the sub ...
2
votes
1answer
31 views

Neutrinos born before inflation

What would happen, if there was (hypothetically, for any reason) a very large number of neutrinos+antineutrinos before the inflation period. They probably dont like to annihilate too much. I would ...
0
votes
1answer
30 views

What is the current state of axion research theoretically?

Is the problem (the strong CP problem) that is solved by axions still considered a really big problem, like the missing mass terms that could be solved by the Higgs mechanism? Or is it more a ...
5
votes
1answer
855 views

Can Dark Matter just be clumps of Neutrons

I was wondering about Dark matter, and it occurred to me that why could it not be just nuclei of Neutrons with no electron cloud. Is it possible for such things to exists. Can Neutrons bond to one ...
0
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1answer
95 views

I wonder what kind of proof we have that dark matter is really made of not-yet-discovered WIMP particles and not WISPy? [closed]

There is quite reasonable argument by Joerg Jaeckel that dark matter might be actually very light, very weakly interacting particles, so-called WISPs (for weakly interacting slim particles), as ...
0
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1answer
86 views

Gravitinos the key to theory of everything?

Theory of everything The theory of everything aims to unite all the four forces of nature into one single elegant equation. Super-symmetry Super-symmetry is important as it explains the nature of ...
19
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1answer
900 views

How can dark matter collapse without collisions or radiation?

I understand that dark matter does not collapse into dense objects like stars apparently because it is non-interacting or radiating and thus cannot lose energy as it collapses. However why then does ...
1
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3answers
113 views

Dark matter: Will Special Relativity hold?

Part 1: It’s been said that dark matter makes up about 26 % of the universe. The restart of LHC would be dealing with the existence of dark matter also. Consider a situation that the results are ...
1
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5answers
591 views

Why dark matter and general relativity?

My knowledge on this subject is minimal, so sorry if my question is obvious. But why is the current consensus that there is something called dark matter rather than that our current theory of gravity ...
1
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3answers
274 views

How do we know dark matter isn't curved spacetime?

Could Dark Matter actually just be spacetime with curvature "leftovers" from the big bang or the inflationary epoch?
-1
votes
1answer
94 views

Is dark matter moving faster than light? [closed]

My way of thinking is as follows: Consider a balloon. Let this be blown into a nearly elliptical sphere. Now, the temperature inside the balloon is increased by some means; this leads to the ...
28
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3answers
2k views

Can the Sun capture dark matter gravitationally?

I think my title sums it up. Given that we think the dark matter is pseudo-spherically distributed and orbits in the Galactic potential with everything else, then I assume that its speed with respect ...
2
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1answer
63 views

Wouldn't dark matter throw off the calculation of Earth's 'light' mass and estimates of its composition?

The Cavendish experiment first determined the mass of the Earth and (arguably) the gravitational constant. However, given the ubiquitous nature of dark matter, it seems reasonable that at least some ...
0
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2answers
90 views

Can you collide with dark matter?

Assuming dark matter has space and weight, can dark matter collide with others planet? If unlike normal matter, dark matter repels matter, Will it makes dark matter impossible to collide with normal ...
1
vote
2answers
137 views

Missing Matter Problem and Galactic Kinematics

This is a re-wording of an earlier problem I posted. The standard example of the Missing Mass Problem comes from the rotational profiles of galaxies. By counting up the visible matter, we extrapolate ...
2
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1answer
94 views

Can observations of cosmic super voids teach us anything about time, dark energy, or dark matter?

Can observations of cosmic super voids teach us anything about... Time - If gravity affects time is there a chance we could gain any further information from studying a region with lower than ...
0
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1answer
122 views

Do most physicists believe that axions exist? [closed]

Is the theoretical justification behind proposing axions sufficiently robust, like, say the Higgs boson prior to its detection, that one should consider the existence of axions as generally accepted ...
4
votes
2answers
80 views

Distribution of dark matter in galactic halos

Often dark matter around galaxies is referred to as a 'halo'. I've seen the galactic rotation curves, but I'm having trouble visualizing how the dark matter is distributed for a typical rotating ...
3
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1answer
75 views

Could Hyper-Massive Black Holes be due to Dark Matter in the Early Universe?

An interesting discussion started here: Is there a limit as to how fast a black hole can grow? I am curious if Thompson Scattering and Eddington Luminosity have the same effect on Dark Matter (or ...
5
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1answer
83 views

Experimental Data for Mass Distribution of a Galaxy

My goal here is not to discuss dark matter in general. I know there are many other observational clues that hint us towards Dark matter. My goal is simply to understand this argument here a little ...
0
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1answer
88 views

What is dark matter composed of? [duplicate]

They say that about 80% of the matter in the universe is dark matter -- some unknown substance that has mass. But what is this matter expected or speculated to be composed of? For example might it ...
2
votes
1answer
41 views

WIMPs - would they be charged?

I'm no expert in this stuff, it's just a hobby to me, but I've been reading up on the WIMP theory a bit - layman articles, not published research. From Wiki on Dark Matter: It also cannot ...
0
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2answers
105 views

How much dark matter is needed to gravitationally distort light?

I understand that dark matter only has a gravitational property. It does not interact directly with regular matter or EM radiation. The evidence for dark matter comes from observations that contradict ...
0
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0answers
26 views

Could the gravitional pull of all the travelling photons “relativistic mass” in our galaxy explain “dark matter”? [duplicate]

Does that make sense mathematically? If we could sum up all the photons in-transit in our galaxy and calculate the total gravitational pull, could it provide an alternate explanation instead of ...
0
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1answer
17 views

What is meant by “shallow density profile” in the context of dark matter halos?

Evidently there is a consensus about the density profile of dark matter at large distances from the centers of galaxies, but it is not known whether their density profiles are "shallow" or "cuspy". ...
0
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0answers
49 views

How does mirror matter account for the faster than expected spin of gallaxies?

To explain dark matter, some physicists have postulated the existence of mirror matter as an alternative to WIMPs, where mirror matter particles could interact with one another in the same way as ...
0
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1answer
71 views

Galaxy rotation curve

In calculating galaxies' rotation curve, it is assumed that masses outside the orbit has no contribution and masses inside the orbit can be deemed as if they were at the center, just like the case of ...
9
votes
4answers
892 views

What exactly is 'Dark Matter'? [duplicate]

There are many documentaries, forums, blogs and more dedicated to Dark Matter. I have been frantically searching for an answer to my question however none of my sources have clarity to the matter of ...
0
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1answer
42 views

Relativity and Galaxy Rotation Speed

If time travels slower nearer gravity wells, why can't the galaxy rotation speeds being faster on the outer edges than the inner areas be explained by relativity? What necessitates dark matter?
13
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2answers
748 views

What is a reasonably accurate but simple model of the Milky Way's gravitational field?

I am putting together a toy program which shows how stars move around in the galaxy. To run the simulation I need to know strength of the Milky Way's gravitational field at any location in it. I'm ...
1
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2answers
76 views

Distribution and detection of dark matter

I feel in the dark (no pun intended :), I'm sure most of you are familiar with this image I pulled from wikipedia: The caption reads: "3D map of the large-scale distribution of dark matter, ...
1
vote
1answer
82 views

Dark matter, dark energy [closed]

As I understand dark matter and dark energy are quite theoretical . That modern theories require the existence of these phenomena. I read a lot of information about this. And I realized that ...
3
votes
2answers
73 views

Why is dark matter used to explain big movements but not small ones

Just read that there are perturbations of stuff in the outer solar system that suggest there are Earth sized planets far out from the sun, in the dark. When the same sort of effects are seen at the ...
9
votes
1answer
215 views

Can curvature waves in f(R) theories explain gravitational lensing in cluster collisions?

The Einstein-Hilbert action leading to Einstein's equations is $$S\sim\int R \sqrt{-g}\, {\rm d}^4 x$$ There is a class of modifications of Einstein's relativity called $f(R)$ theories of gravity ...