Isorotation (source code)

= Isorotation
{title2=$U\mapsto AUA^\dagger$}

= Isospin rotation
{synonym}

An <isorotation> is a global transformation generated by <isospin>. In the <pion> <Skyrme model> it acts as $U\mapsto AUA^\dagger$, with constant $A\in SU(2)$, rotating the three <pion> components while preserving the scalar component. The matrices $A$ and $-A$ induce the same classical rotation, so this action factors through $SO(3)$; quantum states may carry half-integer <isospin> on its $SU(2)$ cover. This global internal rotation is distinct from a spatial rotation or a local <gauge transformation>.