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Record W4391349967 · doi:10.1111/sjos.12707

On the expectations of equivariant matrix‐valued functions of Wishart and inverse Wishart matrices

2024· article· en· W4391349967 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.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueScandinavian Journal of Statistics · 2024
Typearticle
Languageen
FieldMathematics
TopicRandom Matrices and Applications
Canadian institutionsUniversity of Toronto
Fundersnot available
KeywordsWishart distributionMathematicsEquivariant mapInverse-Wishart distributionMatrix (chemical analysis)Pure mathematicsInverseAction (physics)Group (periodic table)Symmetric matrixCombinatoricsAlgebra over a fieldEigenvalues and eigenvectorsStatisticsMultivariate statistics

Abstract

fetched live from OpenAlex

Abstract Many matrix‐valued functions of an Wishart matrix , , say, are homogeneous of degree in , and are equivariant under the conjugate action of the orthogonal group , that is, , . It is easy to see that the expectation of such a function is itself homogeneous of degree in , the covariance matrix, and are also equivariant under the action of on . The space of such homogeneous, equivariant, matrix‐valued functions is spanned by elements of the type , where and, for each , varies over the partitions of , and denotes the power‐sum symmetric function indexed by . In the analogous case where is replaced by , these elements are replaced by . In this paper, we derive recurrence relations and analytical expressions for the expectations of such functions. Our results provide highly efficient methods for the computation of all such moments.

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: Empirical · Consensus signal: Empirical
Teacher disagreement score0.400
Threshold uncertainty score0.339

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 communication0.0000.000
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 head0.036
GPT teacher head0.324
Teacher spread0.288 · 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