Collisionless dark matter refers to particles that do not scatter or collide with each other, interacting primarily through gravity, as described by the Lambda Cold Dark Matter (LCDM) model. In contrast, self-interacting dark matter (SIDM) allows for interactions between dark matter particles, which can lead to different cosmic structures and dynamics. The discussion emphasizes the importance of understanding these distinctions to grasp dark matter's role in the universe. Clarifying these terms is crucial for advancing theories in cosmology. Overall, the differences between collisionless and self-interacting dark matter have significant implications for our understanding of the universe.
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When dark matter is called collisionless, does it only mean that they do not collide and scatter, or does it also mean that there is no other significant non-contact interaction?
That would be the LCDM theory of dark matter.
I would think collisionless means no physical scattering, no interaction whatsoever, except through gravity.
But let us have a second opinion before you send off.
Keep you finger on the keyboard.
There is also the SIDM - self interacting dark matter.
TL;DR Summary: In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect alien signals, it will further expand the radius of the so-called silence (or rather, radio silence) of the Universe. Is there any sense in this or is blissful ignorance better?
In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect...
This is indirectly evidenced by a map of the distribution of gamma-ray bursts in the night sky, made in the form of an elongated globe. And also the weakening of gamma radiation by the disk and the center of the Milky Way, which leads to anisotropy in the possibilities of observing gamma-ray bursts. My line of reasoning is as follows:
1. Gamma radiation should be absorbed to some extent by dust and other components of the interstellar medium. As a result, with an extragalactic origin, fewer...
I hope this appropriate place. I'm just an average guy asking a question. Does time pass at different rates on other planets in our solar system?
In fact, if we were able to reach another solar system with an earth like planet orbiting a much larger sun, would the inhabitants of that planet age at a different rate than us?