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.
A singular leading coefficient gives an infinite polynomial eigenvalue
Example
Take the grade-two matrix polynomial , so , , and is singular. The finite root and the infinite root are different projective eigenvalues. Their algebraic and geometric multiplicities are computed directly below.
Facts & Assumptions
Given: , , and for a regular grade-two polynomial.
Regular matrix polynomials and homogeneous eigenpairs: , and the algebraic multiplicity at infinity is the zero order at of .
First Frobenius companion pencil of a matrix polynomial: at infinity the homogeneous companion pencil is , with block eigenvectors for .
The first Frobenius companion pencil preserves the finite and infinite polynomial spectrum: the finite and infinite eigenspaces correspond to those of the polynomial, and the infinite algebraic multiplicity is .
Verification
The determinant is , so is regular; its degree is , while . Thus the theorem's degree-defect formula gives infinite algebraic multiplicity . Also , whose determinant has a zero of order two at .
The leading matrix has rank one and kernel , so the infinite eigenspace has geometric multiplicity one and is represented in the companion pencil by . This differs from its algebraic multiplicity two.
At the finite root , has kernel . The finite lift is , which the companion theorem maps to a pencil eigenvector. Thus the finite root zero is not the infinite eigenvalue represented by .
Depends on
Used by
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Sources
- D. Steven Mackey, Niloufer Mackey, and Françoise Tisseur, Polynomial Eigenvalue Problems: Theory, Computation, and Structure, §2 (standard reference, not scraped)
- Françoise Tisseur and Karl Meerbergen, The Quadratic Eigenvalue Problem, §3.1 (standard reference, not scraped)