According to modern models of physical cosmology, a dark matter halo is a basic unit of cosmological structure. It is a hypothetical region that has decoupled from cosmic expansion and contains gravitationally bound matter.[1] A single dark matter halo may contain multiple virialized clumps of dark matter bound together by gravity, known as subhalos.[1] Modern cosmological models, such as ΛCDM, propose that dark matter halos and subhalos may contain galaxies.[1][2] The dark matter halo of a galaxy envelops the galactic disc and extends well beyond the edge of the visible galaxy. Thought to consist of dark matter, halos have not been observed directly. Their existence is inferred through observations of their effects on the motions of stars and gas in galaxies and gravitational lensing.[3] Dark matter halos play a key role in current models of galaxy formation and evolution. Theories that attempt to explain the nature of dark matter halos with varying degrees of success include cold dark matter (CDM), warm dark matter, and massive compact halo objects(MACHOs).[4][5][6][7]
https://en.wikipedia.org/wiki/Dark_matter_halo
https://en.wikipedia.org/wiki/Category:Dark_matter
https://en.wikipedia.org/wiki/Category:Compact_stars
https://en.wikipedia.org/wiki/Category:Superfluidity
https://en.wikipedia.org/wiki/Category:Exotic_matter
https://en.wikipedia.org/wiki/State_of_matter
https://en.wikipedia.org/wiki/Primordial_black_hole
In astrophysics and cosmology scalar field dark matter is a classical, minimally coupled, scalar field postulated to account for the inferred dark matter.[2]
https://en.wikipedia.org/wiki/Scalar_field_dark_matter
In astrophysics and particle physics, self-interacting dark matter (SIDM) is an alternative class of dark matter particles which have strong interactions, in contrast to the standard cold dark matter model (CDM). SIDM was postulated in 2000[1] as a solution to the core-cusp[2][3][4] problem. In the simplest models of DM self-interactions, a Yukawa-type potential and a force carrier φ mediates between two dark matter particles.[5] On galactic scales, DM self-interaction leads to energy and momentum exchange between DM particles. Over cosmological time scales this results in isothermal cores in the central region of dark matter haloes.
If the self-interacting dark matter is in hydrostatic equilibrium, its pressure and density follow:
where and are the gravitational potential of the dark matter and a baryon respectively. The equation naturally correlates the dark matter distribution to that of the baryonic matter distribution. With this correlation, the self-interacting dark matter can explain phenomena such as the Tully–Fisher relation.
Self-interacting dark matter has also been postulated as an explanation for the DAMA annual modulation signal.[6][7][8] Moreover, it is shown that it can serve the seed of supermassive black holes at high redshift.[9]
https://en.wikipedia.org/wiki/Self-interacting_dark_matter
A dark star is a type of star that may have existed early in the universe before conventional stars were able to form and thrive. The stars would be composed mostly of normal matter, like modern stars, but a high concentration of neutralino dark matter present within them would generate heat via annihilation reactions between the dark-matter particles. This heat would prevent such stars from collapsing into the relatively compact and dense sizes of modern stars and therefore prevent nuclear fusion among the 'normal' matter atoms from being initiated.[1]
Under this model, a dark star is predicted to be an enormous cloud of molecular hydrogen and helium ranging between 4 and 2,000 astronomical units in diameter and with a surface temperature and luminosity low enough that the emitted radiation would be invisible to the naked eye.[2]
In the unlikely event that dark stars have endured to the modern era, they could be detectable by their emissions of gamma rays, neutrinos, and antimatter and would be associated with clouds of cold molecular hydrogen gas that normally would not harbor such energetic, extreme, and rare particles.[3][2]
https://en.wikipedia.org/wiki/Dark_star_(dark_matter)
Strongly interacting massive particles (SIMPs) are hypothetical particles that interact strongly between themselves and weakly with ordinary matter, but could form the inferred dark matter despite this.[1][2][3]
Strongly interacting massive particles have been proposed as a solution for the ultra-high-energy cosmic-ray problem[4][5] and the absence of cooling flows in galactic clusters.[6][7]
Various experiments and observations have set constraints on SIMP dark matter from 1990 onward.[8][9][10][11][12][13]
SIMP annihilations would produce significant heat. DAMA set limits with NaI(Tl) crystals.[11][citation needed]
Measurements of Uranus's heat excess exclude SIMPs from 150 MeV to 104 GeV.[14] Earth's heat flow significantly constrains any cross section.[15]
https://en.wikipedia.org/wiki/Strongly_interacting_massive_particle
The Navarro–Frenk–White (NFW) profile is a spatial mass distribution of dark matter fitted to dark matter halos identified in N-bodysimulations by Julio Navarro, Carlos Frenk and Simon White.[1] The NFW profile is one of the most commonly used model profiles for dark matter halos.[2]
https://en.wikipedia.org/wiki/Navarro–Frenk–White_profile
a perfect circle blue
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