Symmetry breaking
As symmetry breaking ( English symmetry breaking ; infrequently symmetry break called) is a breach in the physics of symmetry ( invariance ) and in particular the phase transition of a phase referred to or a state of higher symmetry in a phase or state of lower symmetry.
Breaking a continuous symmetry
One example is a ferromagnet in solid state physics . Above the Curie temperature the system is rotationally symmetrical , below that there is a magnetization in a certain direction. This is an example of the breaking of a continuous symmetry , which is always associated with the appearance of massless excitations , the gold clay bosons .
Breaking a discrete symmetry
An example of a broken discrete symmetry is the violation of the parity symmetry in the weak interaction (see parity violation ) as well as the CP violation , which in cosmology is one of the prerequisites for the existence of visible matter in the universe ( baryon asymmetry ).
virology
The ideal icosahedral (i.e., discrete) symmetry of the mimivirus is broken by the presence of a pole (star structure, also known as a 'stargate'), leaving only one axis.
See also
literature
- Franco Strocchi: Symmetry breaking. Springer, Berlin 2005, ISBN 3-540-21318-X
- Henryk Arodz: Patterns of symmetry breaking. Kluwer Academic, Dordrecht 2003, ISBN 1-402-01744-8
- Leopold Mathelitsch: Broken symmetries. Springer, Berlin 1999, ISBN 3-540-65667-7
Web links
- What is a break in symmetry? from the alpha-Centauri television series(approx. 15 minutes). First broadcast on Dec 8, 2004.
- What happened in the first three minutes? from the alpha-Centauri television series(approx. 15 minutes). First broadcast on Aug 13, 2000.