How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Shift-invert isolates an interior vibration mode and records solve error
Example
Use the exact shift-invert branch with start , Arnoldi dimension and residual tolerance . Use the mass-normalized three-mode vibration matrix and , and seek its interior eigenvalue with shift . The shifted matrix is invertible because . In a separate harmonic-branch invocation, use the same and , trial basis , QZ sweep budget , and QZ tolerance .
Verification
Given: , , , the exact target vector , and the separate harmonic invocation inputs , , and .
[F1] Shift-invert and harmonic Ritz extraction with solve and pencil status: in the exact shift-invert branch, a Ritz value maps to .
[F2] Shift-invert and harmonic Ritz extraction with solve and pencil status: the harmonic branch uses the projected pencil .
[F3] Shift-invert and harmonic Ritz extraction with solve and pencil status: a finite QZ diagonal pair maps to .
[F4] Shift-invert maps eigenvalues exactly and transfers an inexact solve residual to the original eigenpair: , with and .
Here and . Thus the interior mode 4 maps to , whose modulus exceeds the other transformed eigenvalue moduli and ; . In the separate harmonic invocation, , so and . The QZ input is this regular one-by-one pencil, already upper triangular with a nonzero diagonal pair, so the QZ procedure's computed condition holds and its status is qz-computed; . The scalar equation gives and the same value .
For an inexact solve take and . Then and , while the mapped value is . Its original residual is , which equals by [F4].
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
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Sources
- Yousef Saad, Numerical Methods for Large Eigenvalue Problems, second edition, §8.1 (standard reference, not scraped)
- Peter Arbenz, Lecture Notes on Solving Large Scale Eigenvalue Problems, §§11.4 and 12.6 (standard reference, not scraped)