Let X⊆I be of finite type and let τ∈AutX(A) satisfy τ2=idI and τ∣X=idX. For (γ,σ)∈(F×)I×FI, let B be the algebra freely generated over UqnX+Uqhθ(X,τ) by elements Bi, and let Π:B→Uqkγ,σ(X,τ) send Bi to Bi;γi,σi and act identically on the coefficient algebra. The elements and relations below are understood with the notation of the source, including λij, Serij, and the ordered monomials Bi. Generalized presentation conjecture. There exist elements
with the quantifiers and index ranges stated in the source, if and only if (X,τ)∈GSat(A) and (γ,σ)∈GSq. Moreover, the Cij(γ) are independent of σ. This proposes a presentation of a broader class of quantum symmetric pair coideals; the source gives no resolution of the if-and-only-if assertion.
References
Primary source
Andrea Appel and Bart Vlaar, “Universal K-matrices for quantum Kac-Moody algebras”, arXiv:2007.09218 (2025).