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

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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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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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400 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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80 views

Could black holes interact with dark matter at distances far greater than matter?

I watched this Nova episode on super massive black holes and learned that the speed at which the outer stars in a galaxy orbit correspond to the size of the black hole at the galaxy's center. They ...
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23 views

What does “fully depleted” mean?

In many papers/articles on CCDs, particularly those used for dark energy surveys and dark matter detection, the term "fully depleted CCD" is used. What does this mean? References: ...
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54 views

What $f(R)$ models pass most of the known constraints? [closed]

In most papers and talks about $f(R)$ gravity authors repeatedly state that the model proposed by Starobinsky 2007 $$ f(R)=R+\lambda\,R_{0} \bigg[\bigg(1+\frac{R^{2}}{R_{0}^{2}}\bigg)^{-n}-1\bigg] ...
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46 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, ...
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34 views

Using GPS Satelites as dark matter detectors

Recently, two scientists have proposed a new way of detecting dark matter, using GPS Satellites. A part of the article is posted online: Hunting for topological dark matter with atomic clocks. Can ...
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1answer
128 views

If MOND theory doesn't explain gravitational lensing, couldn't well placed black holes explain it?

When I first heard about star velocity as a function of its distance from the center of the galaxy and the difference between prediction and observation I immediately thought "there must be a ...
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42 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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37 views

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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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 ...
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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 ...
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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 ...
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165 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 ...
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2answers
90 views

Density of dark matter along the galaxy [duplicate]

I was reading these 2 interesting articles about dark matter inside the solar system: Does Dark Matter affect the motion of the Solar System? The Incredible Dark Matter Mystery: Why Astronomers Say ...
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337 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?
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170 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?
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98 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 ...
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2answers
305 views

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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1answer
131 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 ...
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2answers
60 views

At what point do researchers in physics make the leap from wild theoretical ideas to physical experiments? [closed]

Dark Matter, on the surface, appears to be a wild idea... Some invisible thing that we can't see that controls the movement of most of the universe. Yet, we are searching for it. Why? What evidence ...
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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 ...
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1answer
771 views

Could Dark Matter be a manifestation of tachyons tunnelling between black holes? [closed]

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 ...
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32 views

Dark Energy and Wormhole stability

Is it possible that the "negative energy" needed to create stable wormholes as theorized by Morris and Thorne (?) could be dark energy? Could this be the "exotic" negative energy matter referred to?
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30 views

Is Dark Matter accounted for in early universe inflationary models?

In the early universe there must have been an abundance of dark matter unless it formed by some unknown process later on. If it were present, is this significant and factored into our models?
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49 views

Is Dark Energy and or Dark Matter directly proportional to EMR? [closed]

Is Dark Energy directly proportional to Electromagnetic radiation (EM radiation or EMR)?
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86 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 ...
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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 ...
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1answer
125 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 ...
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1answer
54 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?
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1answer
91 views

How can we be Certain that Dark Matter Exists if we Cannot See it or Directly Detect It? [duplicate]

It seems very certain that dark matter exists and that it makes up 26.8% of the Universe today (along with 68.3% Dark Energy and 4.9% Atoms), but how can this be if we cannot see it or directly detect ...
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1answer
16 views

What is our confidence with respect to the critical density of the universe? [closed]

How can scientists speak confidently about the critical density of the universe while knowing the majority of matter and energy is foreign and not well understood. Shouldn't more knowledge about dark ...
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1answer
35 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 ...
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1answer
171 views

Methods of detecting gravitino DM and possible implications for theories of everything

Let me summarize my thoughts about topics in theoretical physics: Theory of everything: The theory of everything aims to unite all the four forces of nature into one single elegant equation. ...
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110 views

A Theory of Almost Everything? [closed]

Before I present this theory, I ask that you take the time to read this disclaimer. I do not claim to have an excellent knowledge of physics, it is actually rather limited. Therefore, I am not ...
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1answer
123 views

Does dark matter in the universe acts as a pulling force or a pushing force?

Scientists have claimed that in this world there are two kinds of forces which help in keeping everything in its place called dark matter and dark energy. But are these two forces act as a pulling ...
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1answer
65 views

Dark Matter as possible an explanation for Coronal Heating

It's my understanding that the mechanism behind Coronal Heating - why the Corona is so much hotter (> 1,000,000 K) than the surface of the Sun (6,000 K), and the mechanism by which the energy gets ...
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1answer
86 views

Why are dark matter explanations more apt to consider different mechanics than emissivity?

I've seen some treatments in the scientific popular press (podcasts) that consider the possibility that dark matter can be explained by an error (or new term) in our understanding of gravitation & ...
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1answer
57 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 ...
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1answer
123 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?
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203 views

Understanding particle's space travel

Before the discovery of dark matter, the prevailing popular understanding of Space content is that of celestial bodies (planets, stars..etc) floating in 'void' and emitting particles and waves ...
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WIMP dark matter annihilation rate equation (approximation)?

WIMP is a possible dark matter candidates, which self-annihilates. What is the WIMP annihilation rate, as a function of density? Most sources state this scales as $\rho^2$, (density squared), but ...
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45 views

Can photons be converted to dark matter in black holes? [duplicate]

I'm a pharmacy student so if it's not a good theory let's just not laugh at me :) I was wondering if it is possible that when the light enters a black hole and gets trapped in its gravity, its energy ...
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1answer
24 views

Evolution of dark matter and gas temperature

So I have recently watched a simulation of dark matter density and gas temperature evolution in a universe. However I couldn't find description of under what assumptions it was was made and what it is ...
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67 views

Implications of dark matter imprints on Cosmic Microwave Background Radiation?

Looking at this link, CMB Anisotropy, I have two questions regarding the possible creation and properties of dark matter: If dark matter has left it's imprint on the CMB, that to me, would imply ...
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32 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?
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40 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 ...
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24 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 ...
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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 ...