# Tag Info

0

Dark matter is the spacetime fabric Dark Matter More Ubiquitous Than We Ever Thought dark matter is smooth, distributed more evenly throughout space than we thought Dark matter is on the move: Scientists find the elusive material can be pushed out of a galaxy's center by star formation ‘The dark matter at the centres of star-forming dwarfs appears to have ...

3

Everything gravitates. In fact the blue "dark matter" clouds in the image were created by mapping the gravitational lensing of background stars by the dark matter cloud. The blue clouds passed through the collision because of their inertia. However they do exert a gravitational force on each other, which will decelerate the clouds. Keep in mind you ...

1

Check out this paper, they are using vacuum energy to explain dark energy and possibly dark matter: https://arxiv.org/abs/1907.04268

-2

Dark energy is the outflow of dark matter along the pole of our universe's central black hole. Our visible universe is in the outflow of our universe's central black hole. As ordinary matter falls toward the central black hole it evaporates into dark matter. It is the dark matter outflow which pushes the galaxy clusters, causing them to move outward and away ...

1

The fact that both substances are named "dark" is just a reflection of our ignorance about them. Mathematically they have very different properties. Dark matter, on the one side, is just like normal matter in many aspects. It is subject to gravity as normal matter and also dilutes with the expansion of spacetime. Its density falls as $a^{-3}$, ...

5

Dark matter simply refers to matter that does not emit light. In other words it does not interact with the electromagnetic field. We have never been able to observe it directly, since our telescopes can only see incoming light from the universe. But we can infer it's existence due to the fact that gravitational lensing due to galaxies is a lot stronger than ...

2

IF dark matter is made of primordial black holes (and this possibility is not excluded by observations, and is even studied intensively by some physicists, see for example: https://www.pbs.org/newshour/science/primordial-black-holes-could-explain-dark-matter-galaxy-growth-and-more ), then it has to be moving. If the don't merge they can form non-dissipative ...

8

The simplest model for dark matter motion is virialized random velocities. This is a reasonable conceptual description for dark matter motions in simulations as well. Rather than simple orbits, think beehive or cloud of particles. A chaotic system of many particles interacting gravitationally and exchanging energy is as messy as it gets, but luckily, messy ...

18

Yes, dark matter has to be in motion, otherwise it would fall in to the galactic center. From the fact that galaxies are stable, we can expect the Virial Theorem to hold, i.e. that dark matter has a total kinetic energy of half the total gravitational potential of the galaxy. Yes, indeed, a particular density distribution is required to result in the ...

0

A scatter will involve some transfer of momentum. When one of the objects involved in the scatter is extended in space (as a nucleus or an atom is, as opposed to an electron), then it makes sense to ask if there is a length scale relevant to the scatter, and compare that to the size of the scattering object. de Broglie tells us how to relate a momentum to a ...

1

This paper is proposing a novel and particular production mechanism for thermal relic particles. From what I can gather though it does not motivate special detection mechanisms. So that answers your question with a "no".

Top 50 recent answers are included