AI PROVENANCE STATEMENT Manuscript: Convolution Smoothing in the Turan Hierarchy: The Blind Zone Extends from Order 43 to Order 61, and Empirically to Order 68 Author: Changxia Lin (xstr_1115@qq.com) ORCID: 0009-0008-0668-7444 Date: 2026-10-19 Relation: companion to hexagon:2610.00293v2 (the r <= 43 paper) TOOLS USED Conversational AI assistance was used for literature retrieval, notation cross-checking, LaTeX typesetting, and the independent recomputation of every numerical constant recorded in Sections 5 to 7 of the manuscript. HUMAN CONTRIBUTIONS (all mathematical content) - The multiplicity analysis of the beta-alphabet (Lemma 2.1): the observation that evenness of Xi forces every zero to contribute to beta with multiplicity two, so that the relevant constituent is a four-element multiset and not a conjugate pair, is due to the author. This is the single structural point that separates this paper from the earlier r <= 43 paper. - The convolution identity h_r(Y) = rho^r W_r with W_r = sum_i U_i U_{r-i}, its generating function 1/(1 - 2 z cos theta + z^2)^2, and the Chebyshev derivative identity W_r = (1/2) U'_{r+1}(cos theta), were derived by the author. - The pole-free sign criterion of Lemma 3.5 was derived by the author, together with the observation that the corresponding tangent criterion is illegitimate because cos(m theta) changes sign throughout the range of interest. - Theorem 3.9 (D(1,r) > 0 for all r <= 61, unconditionally) and its proof were found and written by the author. - The closed form for the shift-1 row, Theorem 3.8, and the interpretation of the three thresholds 44, 62, 69 as constituent / multiplicity / background effects, are due to the author. - The design of the numerical experiments (truncation study, offset scan, position scan, multiple-pair scan, shift scan, cancellation diagnostic) was the author's. - The distinction between what is proved (61) and what is numerical (68) is stated explicitly in Section 8 and was insisted on by the author. AI CONTRIBUTIONS - Typesetting, cross-checking standard identities (Jacobi-Trudi, Littlewood-Richardson, Gegenbauer generating functions), and independent recomputation of numerical constants. VERIFICATION Every numerical constant was computed at 60 significant digits (80 for the certification of W_r) and independently reproduced by two routes: the stable recursion for the complete symmetric functions, and the closed form of Theorem 3.8 combined with the Chebyshev identity. Thresholds were rechecked at 50, 60 and 80 digits and under variation of the truncation N = 20, 30, 45, 60, 80. No threshold changed. Imaginary parts of all computed Schur values are smaller than the real parts by at least 40 orders of magnitude, as required by conjugate symmetry. STATUS OF THE CLAIMS Proved: Lemma 2.1, Proposition 3.1, Theorem 3.3 (convolution and Chebyshev derivative identity), Lemma 3.5 (sign criterion), Proposition 3.6 (W_r > 0 for r <= 61, W_62 < 0; certified finite computation with margin of order 10^2 at 80 digits), Theorem 3.8 (shift-1 closed form), and Theorem 3.9 (the main theorem). Numerical, not proved: the threshold 69 and the bound 68, the scaling law r* approximately 1.5 pi/theta, the robustness tables, and the monotonicity used in Lemma 3.10. Section 8 of the manuscript gives the complete ledger. NOVELTY No claim of a proof of the Riemann hypothesis is made. Level-2 positivity is the theorem of Csordas, Norfolk and Varga (1986) and is cited as such; levels 2 and, where known, higher levels are not claimed as new. What is claimed as new is the multiplicity analysis, the convolution identity and the shift-1 analysis, and the numerical determination of the true threshold. STATEMENT I confirm that I understand all parts of this contribution and accept responsibility for its content. Changxia Lin xstr_1115@qq.com ORCID 0009-0008-0668-7444