Multiparameter quantum Pfaffians and identity
Extend the definition of the quantum Pfaffian to the multiparameter quantum group setting with deformation parameters q_{ij}, by defining a consistent q_{ij}-skew-symmetry for matrix entries and constructing a corresponding quantum Pfaffian Pf_{q_{ij}}(A); then establish a generalized Pfaffian–determinant identity relating Pf_{q_{ij}}(A)^2 to the appropriate multiparameter quantum determinant in O_{q_{ij}}(GL_{2n}).
References
Extending the notion of the quantum Pfaffian to multiparameter settings, defining the appropriate q_{ij} -skew-symmetry conditions, and formulating a generalized Pfaffian–determinant identity is a challenging open problem.
— A Quantum Analogue of the Pfaffian-Determinant Identity, An Algebraic and Geometric Study in the q-Skew-Symmetric Case
(2508.11634 - Safadi, 24 Jul 2025) in Section 7.2 (Open Problems and Conjectures)