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Record W2045801261 · doi:10.1002/mana.200410424

A connection between Schur multiplication and Fourier interpolation. II

2006· article· en· W2045801261 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

fundA Canadian funder is recorded on the work.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueMathematische Nachrichten · 2006
Typearticle
Languageen
FieldComputer Science
TopicMatrix Theory and Algorithms
Canadian institutionsnot available
FundersRyerson University
KeywordsMathematicsHermitian matrixCombinatoricsMatrix normUnitary matrixMatrix multiplicationSchur product theoremSchur decompositionNorm (philosophy)Matrix (chemical analysis)Gramian matrixSesquilinear formHankel matrixConnection (principal bundle)Schur complementUnitary statePure mathematicsMathematical analysisEigenvalues and eigenvectorsGeometry

Abstract

fetched live from OpenAlex

Abstract Given m × n matrices A = [ a jk ] and B = [ b jk ], their Schur product is the m × n matrix A ○ B = [ a jk b jk ]. For any matrix T , define ‖ T‖ S = max X ≠ O ‖ T ○ X ‖/‖ X ‖ (where ‖·‖ denotes the usual matrix norm). For any complex (2 n – 1)‐tuple μ = ( μ – n +1 , μ – n +2 , …, μ n –1 ), let T μ be the Hankel matrix [ μ – n + j + k –1 ] j,k and define 𝔅 μ = { f ∈ L 1 [–π, π] : f̂ (2 j ) = μ j for – n + 1 ≤ j ≤ n – 1} . It is known that ‖ T μ ‖ S ≤ inf ‖ f ‖ 1 . When equality holds, we say T μ is distinguished. Suppose now that μ j ∈ ℝ for all j and hence that T μ is hermitian. Then there is a real n × n hermitian unitary X and a real unit vector y such that 〈( T μ ○ X ) y , y 〉 = ‖ T μ ‖ S . We call such a pair a norming pair for T μ . In this paper, we study norming pairs for real Hankel matrices. Specifically, we characterize the pairs that norm some distinguished Schur multiplier T μ . We do this by giving necessary and suf.cient conditions for ( X , y ) to be a norming pair in the n ‐dimensional case. We then consider the 2‐ and 3‐dimensional cases and obtain further results. These include a new and simpler proof that all real 2 × 2 Hankel matrices are distinguished, and the identi.cation of new classes of 3 × 3 distinguished matrices. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: Theoretical or conceptual
GenreCandidate signal: Methods · Consensus signal: none
Teacher disagreement score0.779
Threshold uncertainty score0.490

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.001
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.011
GPT teacher head0.235
Teacher spread0.224 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it