Reducedness conjecture for the Poisson ideal defining the symmetric quotient Schubert variety

From papers

Let K0\G0K_0\backslash\mathcal{G}_0 be the quotient under consideration, let λ\lambda be a dominant coweight, let ωi\omega_i be the fundamental coweights for 1in11\leq i\leq n-1, and set

ri=ωi,w0(λ).r_i=\langle \omega_i,-w_0(\lambda)\rangle.

For each ii, let Ai(r)A_i^{(r)} and Bi(r)B_i^{(r)} be the indicated functions on K0\G0K_0\backslash\mathcal{G}_0, and let S0λ\mathcal{S}_0^{\leq\lambda} denote the corresponding symmetric quotient Schubert variety. Reducedness conjecture. The ideal of O(K0\G0)\mathcal{O}(K_0\backslash\mathcal{G}_0) which is Poisson generated by the functions Ai(r)A_i^{(r)} for 1in11\leq i\leq n-1 and r>ωi,w0λr>\langle\omega_i,-w_0\lambda\rangle, together with Bi(ri+1)B_i^{(r_i+1)} whenever rir_i is even, is reduced, and hence is the ideal defining S0λ\mathcal{S}_0^{\leq\lambda} inside K0\G0K_0\backslash\mathcal{G}_0. The preceding discussion explains that taking the radical is essential in the existing statement, and conjectures that adding the indicated Bi(ri+1)B_i^{(r_i+1)} generators removes the resulting non-reducedness.

Progress summary

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

Sources & referencesView supporting material

Primary source

Robin Bartlett, Tomasz Przezdziecki and Lukas Tappeiner, “GKLO representations of twisted Yangians in type AI and quantizations of symmetric quotients of the affine Grassmannian”, arXiv:2510.12706 (2025).

Solutions 0

No solutions have been posted yet.