The conjectural description of real discrete series for affine Hecke algebras of type B

About 21 years old · traced to

Let H\mathcal{H} be the affine Hecke algebra with labels q2=q1mq_2=q_1^m obtained from the parameters qαˇq_{\check{\alpha}} as in the source, with q1>1q_1>1 and q2≥1q_2\geq 1. Let W0rW_0r be the W0W_0-orbit of the center of a real residual coset of H\mathcal{H}. Write ΔW0r\Delta_{W_0r} for the corresponding set of modules, H0\mathcal{H}_0 for the finite Hecke algebra, R(M)R(M) for the W0W_0-module obtained from an H0\mathcal{H}_0-module MM in the limit qαˇ1/2→1q_{\check{\alpha}}^{1/2}\to1, and ama_m for the stated aa-function. Let W^0\hat{W}_0 denote the irreducible W0W_0-representations, let ϵ\epsilon be the sign representation, and let ≻m\succ_m be an ordering on W^0\hat{W}_0 refining the preorder defined by ψ≻χ⇒am(ψ)≤am(χ)\psi\succ\chi\Rightarrow a_m(\psi)\leq a_m(\chi), with similarity classes as intervals. Conjectural description. (i) ΔW0r\Delta_{W_0r} is indexed by Σm(W0r)\Sigma_m(W_0r). (ii) The modules in ΔW0r\Delta_{W_0r} are naturally graded for the action of H0\mathcal{H}_0; their top nonzero degree is am(Σm(W0r))a_m(\Sigma_m(W_0r)), and the H0\mathcal{H}_0-representations in that degree are irreducible, with corresponding W0W_0-representations Σm(W0r)⊗ϵ\Sigma_m(W_0r)\otimes\epsilon. (iii) If MχM_\chi is the H\mathcal{H}-module labelled by χ∈W^0\chi\in\hat{W}_0 using (ii) and the stated partition of W^0\hat{W}_0, so that R(Mχtop)≅χ⊗ϵR(M_\chi^{\mathrm{top}})\cong\chi\otimes\epsilon, then the matrix (R(Mχ),ψ)ψ,χ∈W^0(R(M_\chi),\psi)_{\psi,\chi\in\hat{W}_0} is block-lower triangular with blocks given by the similarity classes. (iv) The H0\mathcal{H}_0-structure of MχM_\chi can be computed using Shoji's generalized Green functions. The statement proposes a detailed parametrization and character-theoretic description of the real discrete-series modules for these affine Hecke algebras; the supplied text does not establish it or give resolution evidence, so its status remains open.

References

Primary source

K. Slooten, “Reducibility of induced discrete series representations for affine Hecke algebras of type B”, arXiv:math/0511206 (2005).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.