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Everything about Spectral theorem

Result about when a matrix can be diagonalized

In linear algebra and functional analysis, a spectral theorem is a result about when a linear operator or matrix can be diagonalized. This is extremely useful because computations involving a diagonalizable matrix can often be reduced to much simpler computations involving the corresponding diagonal matrix of eigenvalues. The concept of diagonalization is relatively straightforward for operators on finite-dimensional vector spaces but requires some modification for operators on infinite-dimensional spaces. In general, the spectral theorem identifies a class of linear operators that can be modeled by multiplication operators, which are as simple as one can hope to find. In more abstract language, the spectral theorem is a statement about commutative C*-algebras. See also spectral theory for a historical perspective. Wikipedia →

🧭 Start here: a 6-step reading path

  1. Read the overview: Spectral theoremA 5-minute orientation
  2. Skim a recent paper: Anderson's theorem and A-spectral radius bounds for semi-Hilbertian space operatorsInfluential work since 2022
  3. Pick up a classic book: A multidomain spectral collocation method for the Stokes problemThe most-reprinted book on the subject
  4. Read the landmark paper: c-theorem and spectral representationCited 188 times
  5. Go sideways: Self-adjoint operatorA closely related topic
  6. Go sideways: Compact operator on Hilbert spaceA closely related topic

📖 Definitions

Noun A theorem providing conditions under which an operator or matrix can be diagonalized.

🏆 Landmark papers (most cited)

🆕 Influential since 2022

📚 Books worth reading

Ranked by number of editions on Open Library, a rough measure of how lasting a book is.

🔗 Related topics