- "Dark matter is a hypothetical form of matter thought to be the predominant type of matter in the universe."
Matter that does not emit, absorb or reflect any electromagnetic radiation, and can only be detected through its gravitational effect.
Cosmology: The study of the origin, nature, and evolution of the universe.
Astrophysics: The study of the physical properties of stars, galaxies, and the universe as a whole.
Particle Physics: The study of the subatomic particles that make up matter and their interactions.
Gravitational Lensing: The bending of light by gravity and how it is used to study dark matter.
Galactic Dynamics: The study of the motions and interactions of stars and galaxies.
Large Scale Structure: The study of the distribution of matter in the universe on the largest scales.
Cosmic Microwave Background Radiation: The afterglow of the early universe; a major source of information about the composition of the universe.
Neutrino Physics: The study of the subatomic particles that interact very weakly with matter, and how they may relate to dark matter.
Supersymmetry: A theoretical framework that proposes the existence of a new class of subatomic particles that could explain dark matter.
WIMP Physics: The study of Weakly Interacting Massive Particles, a leading candidate for dark matter.
Weakly Interacting Massive Particles (WIMPs): These are hypothetical particles which are believed to interact only through the weak nuclear force and gravity. They are the most widely-cited type of dark matter and have been proposed to be a possible explanation for the observed structure of the universe.
Axions: Axions are particles that were originally proposed to explain why the strong nuclear force doesn't violate certain symmetry laws. They could also be a possible candidate for dark matter, although their properties are still not well understood.
Sterile Neutrinos: These are hypothetical neutrinos that do not interact with matter through the weak nuclear force. They could help explain the observed structure of the universe, but their properties are not well determined yet.
Gravitinos: Gravitinos are hypothetical supersymmetric particles that could potentially be a type of dark matter. They would be very difficult to detect because they do not interact very strongly with matter.
Dark Photons: This type of dark matter is made up of particles that interact with each other through a "dark electromagnetism" force. They could help explain why galaxies appear to rotate faster than expected, but there is currently no experimental evidence for them.
Chameleon Particles: These are hypothetical particles that could change their mass depending on their environment. This would make them difficult to detect as they would be much harder to observe in areas with high matter density.
WIMPZILLAs: WIMPZILLAs are hypothetical particles that would have a much higher mass than traditional WIMPs. They could help explain why the universe appears to be flat across such large distances.
SIMPs: Strongly Interacting Massive Particles are heavy particles that would interact with each other through a strong nuclear force. They could form dense clumps and regions of dark matter instead of spreading uniformly throughout space.
- "It is called 'dark' because it does not appear to interact with the electromagnetic field, which means it does not absorb, reflect, or emit electromagnetic radiation and is, therefore, difficult to detect."
- "Its existence is implied by various astrophysical observations which cannot be explained by general relativity unless more matter is present than can be seen."
- "Evidence for dark matter comes from many different angles, such as galaxy dynamics and formation, gravitational lensing, and the cosmic microwave background, along with astronomical observations of the observable universe's current structure, the formation and evolution of galaxies, mass location during galactic collisions, and the motion of galaxies within galaxy clusters."
- "In the standard Lambda-CDM model of cosmology, the total mass–energy content of the universe contains 5% ordinary matter, 26.8% dark matter, and 68.2% of a form of energy known as dark energy."
- "Dark matter constitutes 85% of the total mass, while dark energy and dark matter constitute 95% of the total mass–energy content."
- "Its existence is not known to interact with ordinary baryonic matter and radiation except through gravity, making it difficult to detect in the laboratory."
- "The leading explanation is that dark matter is some as-yet-undiscovered subatomic particle, such as weakly interacting massive particles (WIMPs) or axions."
- "The other main possibility is that dark matter is composed of primordial black holes."
- "Many experiments to detect and study dark matter particles directly are being actively undertaken, but none have yet succeeded."
- "Dark matter is classified as 'cold', 'warm', or 'hot' according to its velocity (more precisely, its free streaming length)."
- "Recent models favored a cold dark matter scenario, in which structures emerge by the gradual accumulation of particles."
- "Recent gravitational wave and James Webb Space Telescope observations have considerably strengthened the case for primordial and direct collapse black holes."
- "Although the astrophysics community generally accepts dark matter's existence, a minority of astrophysicists, intrigued by specific observations that are not well-explained by ordinary dark matter, argue for various modifications of the standard laws of general relativity."
- "These include modified Newtonian dynamics, tensor–vector–scalar gravity, or entropic gravity."
- "So far, none of the proposed modified gravity theories can successfully describe every piece of observational evidence at the same time."
- "suggesting that even if gravity has to be modified, some form of dark matter will still be required." These quotes provide answers to the specified study questions based on the information in the paragraph.