1.NounThe quality that an operator has of being Hermitian.
"Unitarity is to hermicity what orthogonality is to symmetry. (That is, conjugation by unitary matrices preserves a Hermitian matrix’s hermicity, just as conjugation by orthogonal matrices preserves a symmetric matrix’s symmetry:
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{\displaystyle (OSO^{-1})^{T}=(OSO^{T})^{T}=O^{TT}S^{T}O^{T}=OSO^{T}=OSO^{-1}}
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{\displaystyle (UHU^{-1})^{\dagger }=(UHU^{\dagger })^{\dagger }=U^{\dagger \dagger }H^{\dagger }U^{\dagger }=UHU^{\dagger }=UHU^{-1}}
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