4. For any n x n matrix A there exists an n x n unitary matrix (U* = U-¹) such that U* AU = T (1) where T is an n x n matrix in upper triangular form. Equation (1) is called a Schur decomposition. The diagonal elements of T are the eigenvalues of A. Note that such a decomposition is not unique. An iterative algorithm to find a Schur decomposition for an n x n matrix is as follows. It generates at each step matrices Uk and Tk (k = 1,...,n-1) with the proper- ties: each Uk is unitary, and each Tk has only zeros below its main diagonal in its first k columns. Tn-1 is in upper triangular form, and U = U₁U₂... Un-1 is the unitary matrix that transforms A into Tn-1. We set To= A. The k-th step in the iteration is as follows. Step 1. Denote as Ak the (n − k + 1) × (n − k + 1) submatrix in the lower right portion of Tk-1. Step 2. Determine an eigenvalue and the corresponding normalized eigenvector for Ak. Step 3. Construct a unitary matrix N which has as its first column the nor- malized eigenvector found in step 2. Step 4. For k = 1, set U₁ = N₁, for k > 1, set 0 Uk= (Ik-1 N₂) 0 where Ik-1 is the (k − 1) × (k − 1) identity matrix. Step 5. Calculate Tk = UT-1Uk. Apply the algorithm to the 3 x 3 symmetric matrix A = - (¦ ¦ ;) 101 010 101
4. For any n x n matrix A there exists an n x n unitary matrix (U* = U-¹) such that U* AU = T (1) where T is an n x n matrix in upper triangular form. Equation (1) is called a Schur decomposition. The diagonal elements of T are the eigenvalues of A. Note that such a decomposition is not unique. An iterative algorithm to find a Schur decomposition for an n x n matrix is as follows. It generates at each step matrices Uk and Tk (k = 1,...,n-1) with the proper- ties: each Uk is unitary, and each Tk has only zeros below its main diagonal in its first k columns. Tn-1 is in upper triangular form, and U = U₁U₂... Un-1 is the unitary matrix that transforms A into Tn-1. We set To= A. The k-th step in the iteration is as follows. Step 1. Denote as Ak the (n − k + 1) × (n − k + 1) submatrix in the lower right portion of Tk-1. Step 2. Determine an eigenvalue and the corresponding normalized eigenvector for Ak. Step 3. Construct a unitary matrix N which has as its first column the nor- malized eigenvector found in step 2. Step 4. For k = 1, set U₁ = N₁, for k > 1, set 0 Uk= (Ik-1 N₂) 0 where Ik-1 is the (k − 1) × (k − 1) identity matrix. Step 5. Calculate Tk = UT-1Uk. Apply the algorithm to the 3 x 3 symmetric matrix A = - (¦ ¦ ;) 101 010 101
Elementary Linear Algebra (MindTap Course List)
8th Edition
ISBN:9781305658004
Author:Ron Larson
Publisher:Ron Larson
Chapter7: Eigenvalues And Eigenvectors
Section7.2: Diagonalization
Problem 32E
Related questions
Question
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 2 steps with 2 images
Recommended textbooks for you
Elementary Linear Algebra (MindTap Course List)
Algebra
ISBN:
9781305658004
Author:
Ron Larson
Publisher:
Cengage Learning
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning
Elementary Linear Algebra (MindTap Course List)
Algebra
ISBN:
9781305658004
Author:
Ron Larson
Publisher:
Cengage Learning
Linear Algebra: A Modern Introduction
Algebra
ISBN:
9781285463247
Author:
David Poole
Publisher:
Cengage Learning