OWR-15585-006 · Complete affirmative proof

Strong Approximate Innerness for Diagonal Graph Actions without Aperiodicity

Manuscript 18 October 2026 · Online 18 October 2026

math.OAUnrefereed preprint

Abstract

Every finite abelian action on the C*-algebra of a finite strongly connected noncycle graph that fixes vertices and scales edges by characters is strongly approximately inner. Neither graph aperiodicity nor action outerness is assumed. The proof uses Barlak and Szabo's aperiodic outer-action theorem as its analytic input, removes the graph period through a return-path corner and fixed-frame lifting, and removes the inner kernel through vertex coboundaries and extension of subgroup characters. A block-diagonal polar correction restores fixed implementers for the original action. The result answers the finite abelian diagonal quasi-free action question in Oberwolfach Report 42/2017, p. 2621, for simple purely infinite Cuntz-Krieger algebras. This is an AI-assisted, self-audited, unrefereed preprint; no formal verification, independent human review or absolute priority is claimed.

Record

Affiliation
Mercury Software GmbH
Result
Complete affirmative proof
Categories
math.OA
Manuscript
18 October 2026
Online release
18 October 2026
Version
1.0
License
Creative Commons Attribution 4.0 International

Files and verification

The PDF is the canonical reading copy. The source archive contains the LaTeX manuscript, bibliography, reproducibility material, and audit documents without build artefacts.

Citation

Alper Ferudun, “Strong Approximate Innerness for Diagonal Graph Actions without Aperiodicity,” EulerSolve Research Papers, OWR-15585-006, 2026. https://doi.org/10.5281/zenodo.23443694.

BibTeX
@misc{ferudun2026diagonalgraph,
  author = {Ferudun, Alper},
  title = {Strong Approximate Innerness for Diagonal Graph Actions without Aperiodicity},
  year = {2026},
  howpublished = {EulerSolve Research Papers},
  url = {https://eulersolve.org/papers/owr-15585-006/},
  doi = {10.5281/zenodo.23443694},
  note = {OWR-15585-006; unrefereed preprint}
}

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