What does multiplicity in eigenvalues mean?

In summary, multiplicity refers to the number of times a root appears in the characteristic polynomial of a linear transformation matrix. It can be both an algebraic and geometric concept, with the former being the number of times a root appears and the latter being the number of linearly independent eigenvectors corresponding to that root. In most cases, the algebraic multiplicity is equal to or greater than the geometric multiplicity. It is recommended to look up these concepts for a quicker understanding.
  • #1
snoggerT
186
0
Can someone please explain multiplicity to me? I've been able to solve the problems involving it, but I'm not quite sure what it means in terms of the eigenvalue. Thanks.
 
Physics news on Phys.org
  • #2
It means that the characteristic polynomial of the matrix of the linear transformation has a multiple root. I.e. x*(x-1)^2 has 1 as a double root (multiplicity 2). That's algebraic multiplicity. It may mean there are two linearly independent eigenvectors corresponding to the eigenvalue 1, but there might only be one. The latter concept is geometric multiplicity. In general algebraic multiplicity>=geometric multiplicity. Can't YOU look these things up? I think that's a faster way to get an answer.
 
Last edited:

1. What is meant by "multiplicity" in eigenvalues?

Multiplicity in eigenvalues refers to the number of times a particular eigenvalue appears in the eigenvalue spectrum of a matrix. It is a measure of how many linearly independent eigenvectors correspond to a single eigenvalue.

2. How is the multiplicity of an eigenvalue determined?

The multiplicity of an eigenvalue can be determined by examining the algebraic and geometric multiplicities. The algebraic multiplicity is the number of times the eigenvalue appears as a root of the characteristic polynomial, while the geometric multiplicity is the number of linearly independent eigenvectors corresponding to the eigenvalue.

3. What is the significance of multiplicity in eigenvalues?

The multiplicity of an eigenvalue is important in determining the diagonalizability of a matrix and the stability of a system. A higher multiplicity suggests a stronger influence of the corresponding eigenvector in the transformation of the matrix.

4. Can a matrix have multiple eigenvalues with the same multiplicity?

Yes, a matrix can have multiple eigenvalues with the same multiplicity. This means that there are multiple eigenvectors associated with each of these eigenvalues, and they are all equally influential in the transformation of the matrix.

5. How does the multiplicity of eigenvalues affect the eigenvalue decomposition of a matrix?

The multiplicity of eigenvalues determines the number of linearly independent eigenvectors that can be used in the eigenvalue decomposition of a matrix. If an eigenvalue has a multiplicity greater than one, it means that there are multiple eigenvectors associated with it, and all of them must be included in the decomposition.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
516
  • Calculus and Beyond Homework Help
Replies
12
Views
969
  • Calculus and Beyond Homework Help
Replies
9
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
367
  • Quantum Physics
Replies
6
Views
1K
  • Advanced Physics Homework Help
Replies
2
Views
206
  • Calculus and Beyond Homework Help
Replies
6
Views
1K
  • Quantum Physics
Replies
2
Views
957
Replies
27
Views
2K
  • Calculus and Beyond Homework Help
Replies
8
Views
1K
Back
Top