The Geometric Satake Correspondence for Ramified Groups
read more
Citations
Chtoucas pour les groupes réductifs et paramétrisation de Langlands globale
Notes on the geometric Satake equivalence
Coherent sheaves on the stack of Langlands parameters
The test function conjecture for parahoric local models
Good and semi-stable reductions of Shimura varieties
References
Points on some Shimura varieties over finite fields
Perverse sheaves on a Loop group and Langlands' duality
Twisted loop groups and their affine flag varieties
Local models of Shimura varieties and a conjecture of Kottwitz
The conjectural connections between automorphic representations and Galois representations
Related Papers (5)
Geometric Langlands duality and representations of algebraic groups over commutative rings
Frequently Asked Questions (10)
Q2. What is the way to define the coproduct on H(GrH,?
The only place where the complex topology is used, besides the issue of dealing with Z-coefficients as in [19], is to define the coproduct on H∗(GrH ,Z) by realizing GrH as being homotopic to the based loop space of a maximal compact subgroup ofHC.
Q3. What is the canonical grading of the functor?
In other words, the group scheme Aut⊗H∗TH over tH of the tensor automorphism of this fiber functor, which a priori is an inner form of H∨, is canonically isomorphic to H∨ × tH .
Q4. What is the simplest way to write a Langlands parameter?
The authors write ρ(γ) = (ρ1(γ), γ) for γ ∈WF , where ρ1 is a map from WF to H∨.D 6.3. – A “spherical” parameter (or Langlands-Satake parameter) is a Langlands parameter ρ which can be conjugated to the form ρ(γ) = (1, γ) for γ in the inertial group I.Let (H∨)I be the I-fixed point subgroup ofH∨ (which could be non-connected according to Remark 4.4).
Q5. What is the ramification of the geometric Satake isomorphism?
Recall that under the (ramified) geometric Satake isomorphism, the cohomological grading corresponds to the grading by 2ρ : Gm → GSpn ⊂ GLn ×Gm.
Q6. What is the order of dominant elements in X•(T )I?
The authors define the set of dominant elements in X•(T )I to be(1.2) X•(T )+I = {µ̄|(µ̄, a) ≥ 0 for a ∈ Φ +}.Then the natural mapX•(T )+I ⊂ X•(T )I → X•(T )I/W0 is bijective.
Q7. What is the equivalence of the functor R S in Theorem?
In this case, the functor R S in Theorem 0.1 can be extended to an equivalenceR S : Rep((H∨)I oactalg Gal(k/Fq)) ' P 0 v,whose composition with H∗ is isomorphic to the forgetful functor.
Q8. What is the tensor structure of RepG1?
By the assumption (i) and [7, Proposition 2.16], the tensor structures on RepG1 and RepG2 induce B ⊗B → B and A⊗ A→ A respectively.
Q9. What is the proof of [29, Lemma 5.1] that cTH is?
The proof of [29, Lemma 5.1] that cTH ( L) is primitive under this Hopf algebra structure can be replaced by the following argument: as is well-known (e.g., see [30, 1.1.9]), if L is ample on GrH , then there is an ample line bundle on Gr2, which away from the diagonal is L L and on the diagonal is L.
Q10. What is the bijection between the finite Weyl chambers and the affine?
As v is special, there is a bijection between the finite Weyl chambers for (GL, SL) and the affine Weyl chambers (or called alcove) with v as a vertex, and this bijection is compatible with the action of Gal(L/F ).