§8 · Agent 8 · E₆/F₄: sheaf level · 2026-10-17T03:47:13Z
Summary 8.10 · Verdict for \(E_6/F_4\): \(\Csat=\cC_K\), and the claimed divergence from the function level
proved audit: error
Corrected by: Objection 7.31 · Objection to the mirror step and the verdict: generation holds, \(\sigma\) needs normalizing, and the divergence needs its hypotheses stated, Summary 7.32 · Final audit verdict: the five conclusions survive; \(E_6/F_4\) is the one divergence, under (A)“Under (A)”: assuming all of Sakellaridis's assumptions (A1)–(A5) for X at the given p-adic place, so that his Theorem 8.0.2 applies., Summary 9.4 · Synthesis: \(E_6/F_4\) is the one divergence (categorical generation holds, functions fail under (A)“Under (A)”: assuming all of Sakellaridis's assumptions (A1)–(A5) for X at the given p-adic place, so that his Theorem 8.0.2 applies.); no reverse case.
Every IC sheaf on \(L(E_6/F_4)\) is a direct summand of a Satake object, so the Satake span is the whole category, under the assumptions (E1)–(E3) of the summand theorem. The node then sets this against the failure of (SG), which is known only under Sakellaridis's hypotheses over a \(p\)-adic field, and calls the row a genuine divergence.
Summary 8.10.
Theorem (under (E1)–(E3) of Theorem 8.8). For \(X=E_6/F_4\), every \(\IC_\mu\), \(\mu\in\Lambda_S^+\), is a direct summand of some \(V_\lambda\ast\IC_0\), \(\lambda\in\Lambda_T^+\). Consequently $$\Csat=\Thick\{V_\lambda\ast\IC_0\}=\cC_K .$$ For the labels without a dominant lift the generators are explicit: for odd \(k\), $$\IC_{3k\omega_1^\vee}\ \text{is a retract of}\ V_{\frac{3k-1}2\omega_1^\vee+\omega_6^\vee}\ast\IC_0,\qquad\IC_{3k\omega_6^\vee}\ \text{is a retract of}\ V_{\omega_1^\vee+\frac{3k-1}2\omega_6^\vee}\ast\IC_0,$$ with \(\varphi(\lambda)>\mu\) strictly. So H5H5 · Nonzero top splitting: for every orbit O_μ some Satake object V_λ ∗ IC_0 is supported on its closure with a nonzero split restriction to O_μ. fails at these labels while generation holds: the hypotheses of Proposition I are sufficient but not necessary.
Two levels. By Theorem 6.6, under Sakellaridis's hypotheses (A1)–(A5)Sakellaridis's standing assumptions for his Theorem 8.0.2 (the pages' Theorem E): (A1) a characteristic-0 field and a split group with simply connected derived group; (A2) an integral model of X with a smooth open Borel orbit and invariant measures; (A3a) rank-one models over O, (A3b) the Cartan decomposition, (A3c) Iwahori orbits (his Axioms 2.2.1, 2.4.1, 2.4.2); (A4) conditions on the spherical roots and colours; (A5) X homogeneous and affine with one open Borel orbit., (SG) fails for \(E_6/F_4\) over a \(p\)-adic field. Hence the \(E_6/F_4\) row is a genuine divergence: \(\Csat=\cC_K\) at the sheaf level, (SG) false at the function level.
Status. Proved modulo (E1)–(E3) of Theorem 8.8.
- Every IC sheaf is a summand. For \(\mu\) with a dominant lift this is Lemma 8.9 (2); for \(\mu=3k\omega_1^\vee\) it is Theorem 8.8; for \(\mu=3k\omega_6^\vee\) it is Lemma 8.9 (1). By Lemma 8.9 (3) these cases exhaust \(\Lambda_S^+\).
- Generation. The summand criterion Lemma 4.5 (iii) applies. Its hypotheses are H1–H3Hypotheses of the pages' Proposition I (H1–H5 imply categorical generation): H1 finite orbit filtration; H2 equivariant recollement; H3 constant coefficients on orbits; H4 the Hecke action preserves the category; H5 every orbit carries a Satake object with nonzero top splitting., which hold by Proposition III because \(Z_{G^\theta}(S)=\Spin_8\) is connected, and the decomposition (E2). A summand is a retract, so every \(\IC_\mu\) lies in \(\Csat\), and the \(\IC_\mu\) generate \(\cC_K\).
- Strictness. \(\varphi(\lambda_k)=\mu_k'=\mu_k+e_6>\mu_k\), so the Satake object that splits off \(\IC_{\mu_k}\) is supported on \(\overline{\cO_{\mu_k'}}\) and not on \(\overline{\cO_{\mu_k}}\). H5H5 · Nonzero top splitting: for every orbit O_μ some Satake object V_λ ∗ IC_0 is supported on its closure with a nonzero split restriction to O_μ. asks for the latter, and fails (Proposition III).
- Comparison with functions. By Theorem 6.6, under Sakellaridis's (A1)–(A5)Sakellaridis's standing assumptions for his Theorem 8.0.2 (the pages' Theorem E): (A1) a characteristic-0 field and a split group with simply connected derived group; (A2) an integral model of X with a smooth open Borel orbit and invariant measures; (A3a) rank-one models over O, (A3b) the Cartan decomposition, (A3c) Iwahori orbits (his Axioms 2.2.1, 2.4.1, 2.4.2); (A4) conditions on the spherical roots and colours; (A5) X homogeneous and affine with one open Borel orbit. and over a \(p\)-adic field, \(\cH_K\varphi_0\) misses the orbit sum \(M_{3\omega_1^\vee}\). The node concludes that the \(E_6/F_4\) row is a genuine divergence, and reads it as the mechanism predicted in Proposition 4.7: the retract \(\IC_{\mu_k}\subset M_{\lambda_k}\) lives inside \(\supp M_{\lambda_k}=\overline{\cO_{\mu_k'}}\not\subseteq\overline{\cO_{\mu_k}}\), so it does not produce a Hecke translate supported in the lower set of \(\mu_k\), and the graded multiplicities \(E_{\mu_k,\bullet}\) enter the function-level matrix with \(q\)-weights that admit the \(\sigma\)-odd linear relation of Computation 6.5.
- Status. Proved modulo (E1)–(E3) of Theorem 8.8, the same inputs the workspace already uses for Proposition III and the summand criterion (base field \(\overline{\F}_q\) with Chen–Yi's theory; the comparison to \(\C\) is open item 1 of Proposition III). No analogue is used: the computation is intrinsic to the root data of \(E_6\).
The hypotheses under which the comparison with functions holds are the subject of Objection 7.31.
Builds on
- Theorem 8.8 · \(\IC_{3k\omega_1^\vee}\) is a direct summand of the Satake object \(V_{\lambda_k}\ast\IC_0\)
- Lemma 8.9 · The mirror labels \(3k\omega_6^\vee\) and all covered labels
- Lemma 4.5 · \(\Csat=\cC_K\) if and only if every \(\IC_\mu\) is a direct summand of a Satake object
- Theorem 6.6 · \(E_6/F_4\): two points of the shifted torus that are not \(W_X\)-conjugate are \(W(E_6)\)-conjugate, so \(r\) is not onto and (SG) fails under (A1)–(A5)Sakellaridis's standing assumptions for his Theorem 8.0.2 (the pages' Theorem E): (A1) a characteristic-0 field and a split group with simply connected derived group; (A2) an integral model of X with a smooth open Borel orbit and invariant measures; (A3a) rank-one models over O, (A3b) the Cartan decomposition, (A3c) Iwahori orbits (his Axioms 2.2.1, 2.4.1, 2.4.2); (A4) conditions on the spherical roots and colours; (A5) X homogeneous and affine with one open Borel orbit.
Built on by
- Remark 8.12 · Exactly what the \(E_6/F_4\) argument assumes, and what would sharpen it
- Objection 7.31 · Objection to the mirror step and the verdict: generation holds, \(\sigma\) needs normalizing, and the divergence needs its hypotheses stated
- Correction 10.1 · Correction: the mechanism of the \(E_6/F_4\) divergence, separated by field
- Summary 9.4 · Synthesis: \(E_6/F_4\) is the one divergence (categorical generation holds, functions fail under (A)“Under (A)”: assuming all of Sakellaridis's assumptions (A1)–(A5) for X at the given p-adic place, so that his Theorem 8.0.2 applies.); no reverse case
Original record, as the agent wrote it at 03:47 UTC
Verdict: the Satake span is the whole category for E6/F4, a genuine divergence from the function level
Theorem (under (A1)–(A3) of A8-8). For \(X=E_6/F_4\) every \(\mathrm{IC}_\mu\), \(\mu\in\Lambda_S^+\), is a direct summand of some \(V_\lambda\ast\mathrm{IC}_0\), \(\lambda\in\Lambda_T^+\) (A8-8, A8-9). By (F1) = A4-5(iii) (hypotheses: H1–H3, which hold by Prop. III since \(Z_{G^\theta}(S)=\mathrm{Spin}_8\) is connected, and the decomposition (A2)), $$\mathcal C^{\mathrm{Sat}}=\operatorname{Thick}\{V_\lambda\ast\mathrm{IC}_0\}=\mathcal C .$$ The explicit generators for the labels without a dominant lift are $$\mathrm{IC}_{3k\omega_1^\vee}\ \text{retract of}\ V_{\frac{3k-1}2\omega_1^\vee+\omega_6^\vee}\ast\mathrm{IC}_0,\qquad\mathrm{IC}_{3k\omega_6^\vee}\ \text{retract of}\ V_{\omega_1^\vee+\frac{3k-1}2\omega_6^\vee}\ast\mathrm{IC}_0\quad(k\ \text{odd}),$$ with \(\varphi(\lambda)>\mu\) strictly, so H5 still fails at these labels (Prop. III) while generation holds: Proposition I's hypotheses are sufficient, not necessary.
Two levels. By (F3) = A6-6, under Sakellaridis's hypotheses (A1)–(A5) the function-level statement (SG) fails for \(E_6/F_4\) over a \(p\)-adic field: \(\mathcal H_K\varphi_0\) misses the orbit sum \(M_{3\omega_1^\vee}\). Hence the \(E_6/F_4\) row is a genuine divergence: \(\mathcal C^{\mathrm{Sat}}=\mathcal C\) at the sheaf level, (SG) false at the function level. This is the mechanism A4-7 predicted: the retract \(\mathrm{IC}_{\mu_k}\subset M_{\lambda_k}\) lives inside \(\operatorname{supp}M_{\lambda_k}=\overline{\mathcal O_{\mu_k'}}\not\subseteq\overline{\mathcal O_{\mu_k}}\), so it does not produce a Hecke translate supported in the lower set of \(\mu_k\), and the graded multiplicities \(E_{\mu_k,\bullet}\) enter the function-level matrix with \(q\)-weights that admit the σ-odd linear relation of A6-5.
Status. Proved modulo (A1)–(A3), all of which are the same inputs the workspace already uses for Proposition III and A4-4/A4-5 (field \(\overline{\mathbb F}_q\) with Chen–Yi's theory; the comparison to \(\mathbb C\) is criterion.html's open item 1). No analogue was used: the computation is intrinsic to \(E_6\) root data.
Sources
- returns/A4.json Lemma 4.5, Proposition 4.7
- returns/A6.json Theorem 6.6
- criterion.html
- pdf/proposition-III.tex