§3 · Agent 3 · Hypotheses in char p · 2026-10-18T03:01:49Z
Remark 3.11 · Not proved here: the analytic part of Statement 6.3.1 over \(\mathbb F_q((t))\)
blocked audit: correct
Records the one part of (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. that is not a property of the variety: Statement 6.3.1 is a formula for Sakellaridis's cocycles \(B_{w_\gamma}\), defined by integration over \(F\), and its proof (Thm 6.3.2) rests on rank-one and rank-two local computations. For \(\mathcal M_\theta\) the combinatorial reduction is done in Proposition 3.10; the remaining local identities must be re-derived over \(\mathbb F_q(\!(t)\!)\) within (Q1). Also lists the characteristic-free external results used but not opened.
Remark 3.11.
Remaining obligation for (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.(iii). For the Brion path of Proposition 3.10, over \(F=\mathbb F_q(\!(t)\!)\): (a) the Mackey morphisms \(S_\chi,\Delta_\chi\) and the scalars \(b_w\) of §§3–5, with the normalizations of §3.3 and the Fourier transform for \(\psi\) of conductor \(\mathcal O\) (§3.8); (b) the type-\(U\) functional equation of §5 used in the proof of Prop. 6.5.1; (c) Example 5.4.1 (two orthogonal roots lowering an orbit: \(b=-e^{\check\alpha}\frac{1-q^{-1}e^{-\check\alpha}}{1-q^{-1}e^{\check\alpha}}\)); (d) identity (6.10), \(e^{-\check\alpha}(\chi)=q^{-1}e^{-w_\alpha\check\beta}(\chi)\), for \(P_\alpha\backslash\mathrm{SL}_3\). Given (a)–(d) over \(F\), the induction of Prop. 6.5.1 yields $$B_{w_\gamma}(\tilde\chi)=-e^{\check\gamma}\,\frac{1-q^{-4}e^{-\check\gamma}}{1-q^{-4}e^{\check\gamma}}\qquad(\gamma\in\Delta_X,\ \langle\check\gamma,\rho_{P(X)}\rangle=4).$$ These are statements about function theory over \(F\), part of (Q1), and are not verified here.
Cited, characteristic-free in their standing hypotheses, not opened locally: Bruhat–Tits III (1987), Thm 4.7; Steinberg (1968), Thm 7.5; Richardson (1977) or Haboush (1975) for the affineness of \(G/H\); Prasad–Yu (2002) Thm 2.1 or CGP A.8.12 for reductivity of \((G^\theta)^\circ\); Bruhat–Tits I–II and Landvogt inside Delorme–Sécherre; Jantzen II.2 (dominance of highest weights); Popov / Fossum–Iversen (\(\mathrm{Pic}\,G=0\)).
- Why (iii) is not a hypothesis on \(X\) alone. Theorem 6.3.2 is stated under 'no type \(N\), \(L_\gamma\) classical' and proved through Props 6.4.1 and 6.4.2. Prop. 6.4.2 (existence of a suitably glued Brion path) is combinatorial and relies on the characteristic-0 classification Thm 6.11.1 (Akhiezer, Wasserman); for \(\mathcal M_\theta\) it is replaced by the explicit path of Proposition 3.10. Prop. 6.4.1 rests on Prop. 6.5.1, whose proof uses (b)–(d), computed in §§5.2–5.4 and 6.6–6.10 by integration over the local field.
- Dead end. Statement 6.3.1 cannot be derived from the geometry of \(X\): it is an identity between rational functions of \(\chi\) defined by intertwining integrals. Nothing visible in (b)–(d) uses \(\mathrm{char}\,F=0\) (Haar measures, \(|\cdot|\), \(\psi\)), but by the rules of this run 'carries over verbatim' does not count, and the verification belongs to (Q1).
- Effect. Theorem 7.2.1 for \(\mathcal M_\theta\) over \(\mathbb F_q(\!(t)\!)\) needs 6.3.1 and 7.1.5; 7.1.5 is proved (Proposition 3.10), so the \(\beta\)-formula is conditional on (a)–(d), on (Q1)'s version of §§3–4, and on (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. (Q2).
Builds on
- Proposition 3.10 · (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 char \(p\): (i), (ii), Statement 7.1.5, and the combinatorics of 6.3.1
Built on by
- Summary 3.12 · (Q3) verdict: (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).–(A3c)(A3c) Iwahori orbits (Sakellaridis's Axiom 2.4.2): xJ ⊆ xB(O) for every X-antidominant torus point x., (A5)(A5) X homogeneous and affine, and the open Borel orbit has a single B(F)-orbit of F-points (§8)., (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) hold over \(\mathbb F_q((t))\)
- Remark 7.1 · Registry after three returns: the theorem in characteristic \(p\) reduces to (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.; audits launched
Sources
- sakellaridis-v3.pdf, §3.3, §3.8; Example 5.4.1; Statement 6.3.1 pp. 44–45; Thm 6.3.2 p. 45; Props 6.4.1, 6.5.1 pp. 46–48; (6.10) p. 48; Thm 6.11.1 pp. 51–52; Thm 7.2.1 p. 60