Eigenspace

Dependencies:

  1. Eigenvalues and Eigenvectors
  2. Condition for being a subspace

Let $T: V \mapsto V$ be a linear operator. Let $\lambda$ be an eigenvalue of $T$.

Let $E_{\lambda} = \{x \in V: T(x) = \lambda x\}$. $E_{\lambda}$ is called the eigenspace for $(T, \lambda)$.

$E_{\lambda}$ is a subspace of $V$.

Proof

\[ T(0) = T(0+0) = T(0) + T(0) \implies T(0) = 0 = \lambda 0 \implies 0 \in E_{\lambda} \]

\[ x, y \in E_{\lambda} \implies T(x+y) = T(x) + T(y) = \lambda x + \lambda y = \lambda (x + y) \implies x + y \in E_{\lambda} \]

\[ x \in E_{\lambda} \implies T(cx) = cT(x) = c(\lambda x) = \lambda (cx) \implies cx \in E_{\lambda} \]

Since $E_{\lambda}$ is a non-empty subset of $V$ which is closed under addition and scalar multiplication, it is a subspace of $V$.

Dependency for: None

Info:

Transitive dependencies:

  1. /linear-algebra/vector-spaces/condition-for-subspace
  2. /linear-algebra/matrices/gauss-jordan-algo
  3. /sets-and-relations/composition-of-bijections-is-a-bijection
  4. /sets-and-relations/equivalence-relation
  5. Group
  6. Ring
  7. Polynomial
  8. Integral Domain
  9. Comparing coefficients of a polynomial with disjoint variables
  10. Field
  11. Vector Space
  12. Linear independence
  13. Zeros in vector space
  14. Negation in vector space
  15. Span
  16. Linear transformation
  17. Composition of linear transformations
  18. Vector space isomorphism is an equivalence relation
  19. Identity of a group is unique
  20. Subgroup
  21. Inverse of a group element is unique
  22. Conditions for a subset to be a subgroup
  23. Condition for a subset to be a subgroup
  24. Condition for being a subspace
  25. Semiring
  26. Matrix
  27. Stacking
  28. System of linear equations
  29. Product of stacked matrices
  30. Matrix multiplication is associative
  31. Reduced Row Echelon Form (RREF)
  32. Matrices over a field form a vector space
  33. Row space
  34. Elementary row operation
  35. Every elementary row operation has a unique inverse
  36. Row equivalence of matrices
  37. Row equivalent matrices have the same row space
  38. RREF is unique
  39. Identity matrix
  40. Inverse of a matrix
  41. Inverse of product
  42. Elementary row operation is matrix pre-multiplication
  43. Row equivalence matrix
  44. Equations with row equivalent matrices have the same solution set
  45. Basis of a vector space
  46. Linearly independent set is not bigger than a span
  47. Homogeneous linear equations with more variables than equations
  48. Rank of a homogenous system of linear equations
  49. Rank of a matrix
  50. Basis of F^n
  51. Matrix of linear transformation
  52. Coordinatization over a basis
  53. Basis changer
  54. Basis change is an isomorphic linear transformation
  55. Vector spaces are isomorphic iff their dimensions are same
  56. Canonical decomposition of a linear transformation
  57. Eigenvalues and Eigenvectors