The support and restriction conjecture for tame categorical local Langlands sheaves

From papers

Let Z1(WF,G^)Z^1(W_F,\widehat{G}) be the moduli of L-parameters over Q\overline{\mathbb{Q}}_{\ell} for G\mathbf{G}, let C[φ]C_{[\varphi]} be the connected components containing a lift of [φ][\varphi], and let

uG ⁣:Z1(WF,G^)NG^u_G \colon Z^1(W_F,\widehat{G}) \to \mathcal{N}_{\widehat{G}}

be the unipotent monodromy morphism, where NG^\mathcal{N}_{\widehat{G}} is the nilpotent cone of Lie(G^)\operatorname{Lie}(\widehat{G}). Let N[φ]N_{[\varphi]} be the image of the set of lifts of [φ][\varphi], write N[φ]\overline{N}_{[\varphi]} for its closure in NG^\mathcal{N}_{\widehat{G}}, and define

X[φ]=C[φ]uG1(N[φ]).X_{\leq [\varphi]}=C_{[\varphi]}\cap u_G^{-1}(\overline{N}_{[\varphi]}).

Let Sπ\mathcal{S}_{\pi} be the coherent sheaf on the moduli of L-parameters given by c-IndG(OF)G(F)π\operatorname{c-Ind}_{\mathcal{G}(\mathcal{O}_F)}^{\mathbf{G}(F)}\pi under the tame categorical local Langlands correspondence. Let X[φ]X_{[\varphi]} be the image of the torsor hφ~h_{\widetilde{\varphi}} defined from a lift φ~\widetilde{\varphi} of [φ][\varphi], and let V(ρ~π)V(\widetilde{\rho}_{\pi}) be the associated vector bundle determined by the inflated representation ρ~π\widetilde{\rho}_{\pi}. The support and restriction conjecture. The support of Sπ\mathcal{S}_{\pi} is contained in X[φ]X_{\leq [\varphi]}, and the restriction of Sπ\mathcal{S}_{\pi} to X[φ]X_{[\varphi]} is isomorphic to V(ρ~π)V(\widetilde{\rho}_{\pi}).

This predicts both a geometric support bound and an explicit description on the distinguished stratum in the tame categorical local Langlands correspondence. The parser provides no evidence that the statement has been resolved.

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Sources & referencesView supporting material

Primary source

Naoki Imai, “Finite Langlands correspondence”, arXiv:2508.15101 (2025).

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