- "Dark matter is a hypothetical form of matter thought to be the predominant type of matter in the universe."
An invisible substance that is thought to make up a significant portion of the universe's mass.
Standard Model of Particle Physics: A theoretical framework that describes how subatomic particles interact with each other through three fundamental forces.
General Relativity: A theory of gravitation that explains the behavior of objects in space-time through the curvature of space.
Dark Energy: A mysterious form of energy that is believed to be responsible for the accelerating expansion of the universe.
Cosmology: The study of the origins, evolution, and large-scale structure of the universe.
Dark Matter Halo: A hypothetical structure composed of dark matter that is believed to surround galaxies.
Dark Matter Particle Candidates: Various particles that could potentially make up dark matter, such as weakly interacting massive particles (WIMPs) and axions.
Modified Gravity Theories: Alternative theories to General Relativity that change the nature of gravity to explain dark matter.
Dark Matter Detection Methods: Various experimental methods used to detect the presence of dark matter, such as direct detection, indirect detection, and collider experiments.
Large Hadron Collider: A particle accelerator that collides protons at high speeds, allowing scientists to study subatomic particles.
Neutrino Physics: The study of neutrinos, which are subatomic particles that interact very weakly with other matter and could potentially play a role in dark matter.
Collisional Dark Matter: This type of dark matter interacts with itself and other particles through strong forces, such as electromagnetism, just like normal matter does with other particles. However, it is suggested that collisional dark matter may only make up a small fraction of the total dark matter in the universe.
Self-Interacting Dark Matter: A variation of collisional dark matter, self-interacting dark matter may interact with itself through weak forces, such as gravity and the weak nuclear force.
WIMP (Weakly Interacting Massive Particle): This is one of the most popular theories that suggests that dark matter consists of particles that do not interact with light or normal matter except through gravity. WIMPs would have a mass similar to or greater than an atomic nucleus.
Axion: Axions are hypothetical particles that are incredibly light with almost no mass at all. It's thought that they would be very weakly interacting, perhaps only through the strong nuclear force, and would not interact gravitationally.
Sterile neutrinos: Some theorists have proposed that sterile neutrinos, which do not interact with normal matter, could be responsible for dark matter.
Superheavy Dark Matter: This speculated type of dark matter exists only in supermassive particles that can be up to the size of a black hole but without the gravity, called primordial black holes. They might be too large for most of modern detectors.
- "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.