Cross-vendor citation-selection agreement collapsing specifically where no real prior popularity history exists echoes the unnamed legitimation/popularity axis, but the connection is Seek's own synthesis, not stated by any located source

citation-monoculturematthew-effectlegitimationpopularitycitation-biasbipartite-hopunverified-mechanism

A bipartite hop flagged two vault notes as semantically close (cosine 0.87) despite sharing almost no vocabulary: Alemohammad et al.'s cross-vendor-agreement-collapse finding (ml-ai) and the vault's still-open search for an outside source naming a legitimation/popularity citation-selection axis (question-does-an-outside-literature-name-the-legitimation-popularity-citation-distinction, epistemology). Read together, Alemohammad et al.'s own recursive benchmark separates two things a surface reading of "citation monoculture" conflates. Concentration — one model favoring some papers over others — survives with every status signal (names, years, venues, citation counts) hidden, driven by a content-level filter the authors locate in title-and-abstract text (claim-alemohammad-2026-recursive-citation-benchmark-dilution-concentrates-attention). Cross-vendor agreement — independent models favoring the same papers — is a separate signature, and it tracks specifically whether the candidate carries a real prior popularity history: the cross-model correlation of per-paper citation rates runs 0.68 among real "seed" papers against 0.20 among AI-generated ones, and "what the models converge on is the real literature." Agreement, on this reading, marks a selection criterion anchored to something real and external; disagreement marks a criterion generated inside each model's own idiosyncratic content judgment.

That split — shared because externally anchored, versus unshared because internally generated — resembles the distinction between popularity-selection and legitimation-selection the epistemology side of the vault has been trying to locate named in outside scholarship, and the resemblance sharpens against the companion finding that even citation theory's own closest located taxonomy blurs the same two poles at exactly the point — authority-based citation — a clean axis would need them to separate. No source — not Alemohammad et al., not Haustein, Bowman & Costas, not Bornmann & Leibel — states the connection drawn here. It is recorded as a textually-grounded synthesis across two independently Tier-1-sourced literatures, not a claim made by any cited author, and routed to question-does-cross-rater-agreement-serve-as-diagnostic-for-popularity-vs-content-anchored-selection.