Invariance under a unitary group, especially a group consisting of all unitary matrices of a given size and having determinants equal to one; (in later use) a model which approximates the strong interactions of elementary particles by means of such invariance.
Origin
1960s; earliest use found in Nuovo Cimento.
Definition of unitary symmetry in US English:
unitary symmetry
noun
Physics
Invariance under a unitary group, especially a group consisting of all unitary matrices of a given size and having determinants equal to one; (in later use) a model which approximates the strong interactions of elementary particles by means of such invariance.