Resonance effects between dark and ordinary matter produce detectable signals in the universe.Dark matter resonance refers to hypothetical interactions where dark matter particles or structures resonate with ordinary matter or with each other, producing detectable signals. Unlike direct or indirect detection, which relies on scattering or annihilation, resonance effects can amplify weak interactions at specific frequencies or energies, making them observable. This concept is explored in various contexts, from the early universe's density fluctuations to the dynamics of stars and black holes.
The term 'dark matter resonance' is not a single established theory but a collection of ideas that have emerged in the 21st century, particularly in the context of ultralight dark matter (like axions) and dark matter substructure. No single originator can be credited.
The mechanism typically involves a periodic or oscillatory process. For example, if dark matter forms clumps or waves, they might exert a periodic gravitational force on ordinary matter, such as stars in a galaxy. If the frequency of this force matches a natural oscillation frequency of the system (like a star's orbital period), resonance can amplify the effect, leading to observable anomalies. Alternatively, in the early universe, resonant interactions between dark and ordinary matter could have enhanced the generation of certain particles or perturbations, leaving imprints in the cosmic microwave background.
It is used in astrophysical searches for dark matter, such as looking for resonant effects in stellar motions or in the polarization of light from distant galaxies, and in cosmological models of structure formation.
Some proposals suggest that dark matter could form 'boson stars' that resonate with the orbital motion of stars around them, potentially causing observable periodic variations in stellar velocities.
| \Omega_{\text{DM}} h | variable | Dark matter relic density parameter times squared Hubble constant — density parameter |
| \Gamma | variable | Inflaton decay rate — decay rate per second |
| M_P | variable | Reduced Planck mass — mass kilogram |
| m_{\phi} | variable | Mass of the dark matter particle (or inflaton) — mass kilogram |
| \propto | operator | Indicates direct proportionality — proportionality |
| \sqrt{} | operator | Takes the square root of the argument — square root |
