Diagonal Linear Operator T in L(H): Examples

  • Thread starter Mikemaths
  • Start date
  • Tags
    Operators
In summary, a Diagonal Linear Operator T in L(H) is a linear operator that maps elements of a Hilbert space onto themselves, defined by a diagonal matrix with entries corresponding to the eigenvalues of the operator. Examples include the identity operator, zero operator, scalar multiplication operators, and projection operators. They are useful in simplifying calculations and have important applications in areas such as quantum mechanics and optimization. The eigenvalues and eigenvectors of a Diagonal Linear Operator T in L(H) can be determined by solving the characteristic equation. These operators can also have complex eigenvalues, which are often used to represent systems with oscillatory behavior or to model quantum mechanical systems.
  • #1
Mikemaths
23
0
I am trying to find an example of a diagonal linear operator T in L(H) H is hilbert space that is bounded but not compact and also one which is compact but not Hilbert-Schmidt. any Ideas??

Where diagonal means Ten=§en where § is the eigenvalue and en is on orthonormal basis.
 
Physics news on Phys.org
  • #2
(Instead of diagonal, I would say diagonalizable, since it depends on the chosen basis so is not an intrinsic property of the operator.)

The identity operator I is diagonalizable (well, I is of course diagonal w.r.t. every basis), bounded, but not compact.
 

1. What is a Diagonal Linear Operator T in L(H)?

A Diagonal Linear Operator T in L(H) is a type of linear operator that maps elements of a Hilbert space H onto themselves. It is defined by a diagonal matrix with entries corresponding to the eigenvalues of the operator. This type of operator is commonly used in linear algebra and functional analysis.

2. What are some examples of Diagonal Linear Operators T in L(H)?

Examples of Diagonal Linear Operators T in L(H) include the identity operator, which maps every element of H onto itself, and the zero operator, which maps every element of H onto the zero vector. Other examples include scalar multiplication operators and projection operators.

3. How are Diagonal Linear Operators T in L(H) useful in mathematics?

Diagonal Linear Operators T in L(H) are useful in mathematics because they simplify calculations and make it easier to understand and analyze linear transformations. They also have many important applications in areas such as quantum mechanics, signal processing, and optimization.

4. How do you determine the eigenvalues and eigenvectors of a Diagonal Linear Operator T in L(H)?

The eigenvalues of a Diagonal Linear Operator T in L(H) are the entries on the diagonal of the corresponding matrix. To find the eigenvectors, you can solve the characteristic equation for each eigenvalue, which will give you a system of linear equations to solve. The solutions to these equations are the corresponding eigenvectors.

5. Can a Diagonal Linear Operator T in L(H) have complex eigenvalues?

Yes, a Diagonal Linear Operator T in L(H) can have complex eigenvalues. In fact, many important operators in mathematics and physics have complex eigenvalues. These operators are often used to represent systems with oscillatory behavior or to model quantum mechanical systems.

Similar threads

  • Linear and Abstract Algebra
Replies
2
Views
599
  • Linear and Abstract Algebra
Replies
3
Views
935
  • Linear and Abstract Algebra
Replies
3
Views
1K
Replies
3
Views
2K
  • Linear and Abstract Algebra
Replies
3
Views
1K
Replies
4
Views
2K
  • Linear and Abstract Algebra
Replies
4
Views
2K
Replies
0
Views
488
  • Linear and Abstract Algebra
Replies
2
Views
905
  • Linear and Abstract Algebra
Replies
7
Views
1K
Back
Top