§5 · Agent 5 · Audit: transfer, hypotheses · 2026-10-18T04:07:08Z
Summary 5.13 · Verdict of audit A5: transfer route A4-2…A4-9 and char-p hypotheses A3-1…A3-10
proved audit: correct ★ key step
None of the 18 audited claims fails. Four need repairs, all supplied here. The characteristic-\(p\) Theorem 8.0.2 for \(\mathcal M_\theta\) is proved by the transfer modulo \((I_\Lambda)\) and one unchecked citation of [Sa08]. The hypotheses (A1)(A1) Field and group: F a non-archimedean local field of characteristic 0 (Sakellaridis §1.1), G split reductive over O with connected fibres and simply connected derived group (§1.7)., (A2)(A2) Integral model: X quasi-affine over O, its open Borel orbit smooth and surjective over O with B-homogeneous special fibre; a G-eigenmeasure on X and a B-invariant measure on the open orbit (§1.7)., (A3b)(A3b) Cartan decomposition (Sakellaridis's Axiom 2.4.1): the X-antidominant torus points represent every K-orbit on X(F), and points with distinct labels lie in distinct K-orbits., (A3c)(A3c) Iwahori orbits (Sakellaridis's Axiom 2.4.2): xJ ⊆ xB(O) for every X-antidominant torus point x., (A4)(A4) Spherical roots and colours: no pair of maximal rank of type N; classical Levis L_γ; Statements 6.3.1 and 7.1.5.(i),(ii),(iv), (A5)(A5) X homogeneous and affine, and the open Borel orbit has a single B(F)-orbit of F-points (§8). hold over \(\mathbb F_q(\!(t)\!)\) for every odd \(p\).
Summary 5.13.
\(H_{\mathrm{Sa08}}\): [Sa08, Thm 5.2.1] and [Sa08, §3] hold over every finite extension of \(\mathbb Q_p\), \(p\) odd. \((I_\Lambda)\): Axiom 2.2.1Sakellaridis's Axiom 2.2.1, relabelled (A3a): rank-one models over O. for \(\mathcal M_\theta\) over \(W(\mathbb F_q)\) as \(\Lambda\)-schemes.
- Part 1, main line. The close-fields transfer is sound. Truncation (Audit 5.1), orbit counting with a uniform \(D(\lambda)\) and the quantifier over \(H(\mathcal O)\) handled by the Cartan decomposition of \(H\) (Audit 5.3), structure constants and Satake coefficients (Objection 5.4, after the \(\nu\)-box repair), and the module transfer with uniqueness (Audit 5.6) contain no characteristic-\(0\) step applied in characteristic \(p\) (checklist items 1, 2, 10). The characteristic-\(0\) content sits entirely at the fields \(F'_e=\mathbb Q_q(p^{1/e})\), \(e\to\infty\). There (H-Cartan) holds for every ramification (S4-12/S4-13, Proposition 3.4), and Theorem 8.0.2 holds once \((I_\Lambda)\) holds, reading the paper's normalizations with \(\psi\) of conductor \(\mathcal O'\) as §1.7 prescribes (Audit 5.5). The one chain not verified is the ramification-independence of the results quoted from [Sa08] (Theorem 3.7.1 = [Sa08, Thm 5.2.1]); [Sa08] is not available locally.
- Part 1, statements to correct. (a) Proposition 4.5's "Axiom 2.4.1Sakellaridis's Axiom 2.4.1, relabelled (A3b): the Cartan decomposition of X(F) into K-orbits. holds" needs the characteristic-\(p\) valuation cone (Proposition 3.7(3)); the parametrization \(K\backslash X(F)\simeq\Lambda_S^+\) does not. (b) Proposition 4.6(c) needs the two-sided bound \(\langle\lambda,w_0\omega_i\rangle\le\langle\nu,w_0\omega_i\rangle\le\langle\lambda,\omega_i\rangle\). (c) Theorem 4.8's "no statement over \(\bar F\)" applies to the proof of the isomorphism only; identifying \(S\), \(W_X\), \(\Lambda_X^+\) with Sakellaridis's invariants of \(X_{\bar F}\) in characteristic \(p\) uses Proposition 3.6, Proposition 3.7.
- Part 2. Over \(\mathbb F_q(\!(t)\!)\), \(p\) odd (\(p=3\) included), the hypotheses (A1)(A1) Field and group: F a non-archimedean local field of characteristic 0 (Sakellaridis §1.1), G split reductive over O with connected fibres and simply connected derived group (§1.7)., (A2)(A2) Integral model: X quasi-affine over O, its open Borel orbit smooth and surjective over O with B-homogeneous special fibre; a G-eigenmeasure on X and a B-invariant measure on the open orbit (§1.7)., (A3b)(A3b) Cartan decomposition (Sakellaridis's Axiom 2.4.1): the X-antidominant torus points represent every K-orbit on X(F), and points with distinct labels lie in distinct K-orbits., (A3c)(A3c) Iwahori orbits (Sakellaridis's Axiom 2.4.2): xJ ⊆ xB(O) for every X-antidominant torus point x., (A4)(A4) Spherical roots and colours: no pair of maximal rank of type N; classical Levis L_γ; Statements 6.3.1 and 7.1.5.(i),(ii),(iv), (A5)(A5) X homogeneous and affine, and the open Borel orbit has a single B(F)-orbit of F-points (§8). for \(\mathcal M_\theta\) are proved with characteristic-free inputs: Conrad 2.2.4 and 2.3.1 (checked), Prasad–Yu, Steinberg 7.5, Bruhat–Tits III Thm 4.7, Delorme–Sécherre (checked), Richardson. Two repairs are needed: the general converse in Proposition 3.6(2) (Audit 5.10) and the colour weights in Proposition 3.7 step 3 via the diagram automorphism \(\delta\) (Objection 5.11). Inseparability, non-reduced stabilizers and infinite \(H^1\) (checklist items 5, 6) do not arise: every stabilizer used is smooth, and every \(H^1\) is of a smooth connected group.
- Numerical claims. Every numerical claim checked was recomputed in exact arithmetic (script a5_e6_checks.py) and agrees: \(e_1,e_6\), \(3\omega_1^\vee=2e_1+e_6\), elementary divisors \((1,1)\), \(\theta\)-fixed roots \(=\Phi_L\), \(|W\cdot\Phi_L|=45\), \(W_X\) of order \(6\), Levi sizes, \(\mu_1\)-bounds, Brion-path dimensions \(26,\dots,22\), edge types, rank-two vertex data.
- For the team question. (Q1) for \(\mathcal M_\theta\): proved modulo \((I_\Lambda)\) and \(H_{\mathrm{Sa08}}\), with (SG) failing over \(\mathbb F_q(\!(t)\!)\) under these. (Q3): proved after the repairs, except Statement 6.3.1 in its analytic form, which the transfer route does not need. (Q2) was not audited here; \((I_\Lambda)\) is its unramified integral instance.
Builds on
- Audit 5.1 · Audit of A4-2: truncated rings and finite determinacy
- Audit 5.2 · Audit of A4-4: \(\Lambda_S=(1-\theta)X_*(T)\) and the labels \(x_\kappa\)
- Audit 5.3 · Audit of A4-5: orbit count over \(\mathbb F_q((t))\), uniform \(D(\lambda)\)
- Objection 5.4 · Audit of A4-6: structure constants transfer; the Satake support bound is supplied
- Audit 5.5 · Audit of A4-7: Theorem 8.0.2 over ramified \(F'\) and the images \(P_\kappa\)
- Audit 5.6 · Audit of A4-8: Theorem 8.0.2 for M_θ over F_q((t)); uniqueness; (SG)
- Audit 5.7 · Audit of A4-3 (τ closed immersion) and A4-9 (general symmetric X)
- Audit 5.8 · Audit of A3-1, A3-2, A3-3: integral model, \(H^1\) and (A5)(A5) X homogeneous and affine, and the open Borel orbit has a single B(F)-orbit of F-points (§8). over \(\mathbb F_q((t))\)
- Audit 5.9 · Audit of A3-4, A3-5, A3-8: θ-split tori, Delorme–Sécherre, (A3b)(A3b) Cartan decomposition (Sakellaridis's Axiom 2.4.1): the X-antidominant torus points represent every K-orbit on X(F), and points with distinct labels lie in distinct K-orbits. in char p
- Audit 5.10 · Audit of A3-6: the 45 maximal-rank Borel orbits and their types in char ≠ 2
- Objection 5.11 · Audit of A3-7: colour weights (gap repaired by δ) and the valuation cone
- Audit 5.12 · Audit of A3-9 (Iwahori orbits) and A3-10 ((A4)(A4) Spherical roots and colours: no pair of maximal rank of type N; classical Levis L_γ; Statements 6.3.1 and 7.1.5. in characteristic p)
Built on by
- Theorem 7.4 · Verdict: Sakellaridis's theorem over \(\mathbb F_q(\!(t)\!)\); for \(E_6/F_4\) in both characteristics, (A3a)(A3a) Rank-one models over O (Sakellaridis's Axiom 2.2.1): for every Borel orbit Y of maximal rank and every simple root α, the O-scheme YP_α/R(P_α) is one of the four standard PGL2-spaces over O, with his scheme structure on Y, and YP_α is the closure of its generic fibre minus the closure of the generic boundary. included
Sources
- A4.json and A3.json returns (claims audited)
- nodes Audit 5.1 … Audit 5.12
- script a5_e6_checks.py