Unitary and Orthogonal Matrices Definitions A matrix Ae Cnxn is unitary if AAH=AHA=1. orthogonal if AA=AA=1. Remarks: 奇电有这头 Matrix Theory Special Matrices -3/23Unitary and Orthogonal Matrices Definitions A matrix A ∈ C n×n is ▸ unitary if AAH = A HA = I. ▸ orthogonal if AAT = A T A = I. Remarks: ▸ A unitary matrix: columns (or rows) constitute an orthonormal basis for C n . ▸ A orthogonal matrix: columns (or rows) constitute an orthonormal basis for R n . ▸ The identity matrix is orthogonal as well as unitary. Matrix Theory Special Matrices - 3/23