Witten/CLPW's no-boundary-state strand and the Curiel/Ferreiro-Cavallaro matter-spacetime-divide strand never cite each other and share no authors, only common QFT-in-curved-spacetime background references

physicsphilosophy-of-physicsquantum-gravitysemiclassical-gravitybackground-independencehist-pharxiv

Checked directly against the full reference lists of both primary documents: Witten's "A Background-Independent Algebra in Quantum Gravity" (arXiv:2308.03663, ~50 references, hep-th/gr-qc focused on operator algebras, crossed products, modular theory, and de Sitter horizons) cites no work by Erik Curiel, Antonio Ferreiro, or Andrea Cavallaro. Vinck & De Haro's review of the same algebraic literature (arXiv:2610.22042, ~90 references) likewise cites neither. In the other direction, Ferreiro & Cavallaro's paper (arXiv:2610.10588) cites no work by Witten, by Chandrasekaran/Longo/Penington/Witten, or by Vinck & De Haro; its own foundational references are Curiel (2019), Lehmkuhl (2008, 2014), and Wald/Hollands on renormalized stress-energy tensors.

What the two literatures do share, beyond the broad labels "semiclassical gravity" and "philosophy of physics," is confined to the common canon of QFT in curved spacetime, not either strand's own work: Witten's reference [36] and Ferreiro & Cavallaro's list both contain Hollands & Wald, "Local Wick Polynomials and Time-Ordered Products of Quantum Fields in Curved Spacetime" (Commun. Math. Phys. 223, 2001, 289–326); Vinck & De Haro and Ferreiro & Cavallaro both cite Wald's Chicago Lectures monograph Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics (dated 1994 and 1995 respectively); and both review-layer papers cite philosopher James Read, but two different Read papers (Vinck & De Haro cite his 2023 book on background-independence; Ferreiro & Cavallaro cite his 2018 BJPS article "Functional gravitational energy"). No cross-reference links the branches in either direction, and no author of any of the three papers appears in the other strand's reference list: they are a third, separate strand of the same broad literature the vault has now touched three times — Vinck & De Haro's algebraic-background-independence capture, this capture, and the Curiel/Ferreiro-Cavallaro matter/spacetime-divide capture — without the strands themselves touching.