Question

how is 'unitary + 'operator different from' + operator'?​

Answer 1

Answer:

Unitary Operators. A linear operator whose inverse is its adjoint is called unitary. These operators can be thought of as generalizations of complex numbers whose absolue value is 1. ... Like Hermitian operators, the eigenvectors of a unitary matrix are orthogonal. However, its eigenvalues are not necessarily real.