The misalignment mechanism is a hypothesized effect in the

Peccei–Quinn theory In particle physics, the Peccei–Quinn theory is a well-known, long-standing proposal for the resolution of the strong CP problem formulated by Roberto Peccei and Helen Quinn in 1977. The theory introduces a new anomalous symmetry to the Standar ...

proposed solution to the strong-CP problem in

quantum mechanics Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, ...

. The effect occurs when a particle's

field Field may refer to: Expanses of open ground * Field (agriculture), an area of land used for agricultural purposes * Airfield, an aerodrome that lacks the infrastructure of an airport * Battlefield * Lawn, an area of mowed grass * Meadow, a grass ...

has an initial value that is not at or near a potential minimum. This causes the particle's field to oscillate around the nearest minimum, eventually dissipating energy by decaying into other particles until the minimum is attained. In the case of hypothesized

axion An axion () is a hypothetical elementary particle postulated by the Peccei–Quinn theory in 1977 to resolve the strong CP problem in quantum chromodynamics (QCD). If axions exist and have low mass within a specific range, they are of interes ...

s created in the early

universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. Acc ...

, the initial values are random because of the masslessness of axions in the high temperature

plasma Plasma or plasm may refer to: Science * Plasma (physics), one of the four fundamental states of matter * Plasma (mineral), a green translucent silica mineral * Quark–gluon plasma, a state of matter in quantum chromodynamics Biology * Blood pla ...

. Near the critical temperature of

quantum chromodynamics In theoretical physics, quantum chromodynamics (QCD) is the theory of the strong interaction between quarks mediated by gluons. Quarks are fundamental particles that make up composite hadrons such as the proton, neutron and pion. QCD is a type ...

, axions possess a temperature-dependent mass that enters a damped oscillation until the potential minimum is reached.

References

2. Asimina Arvanitaki etal; (1 January 2020). The Large-Misalignment Mechanism for the Formation of Compact Axion Structures: Signatures from the QCD Axion to Fuzzy Dark Matter; arXiv:1909.11665v2 stro-ph.CO30 Dec 2019 Physics beyond the Standard Model Astroparticle physics {{astrophysics-stub