A Drinfeld type presentation of twisted Yangians
Kang Lu, Weiqiang Wang, Weinan Zhang
TL;DR
This work resolves the longstanding problem of a Drinfeld-type current presentation for twisted Yangians of type AI by employing a Gauss decomposition and quasi-determinant framework to define explicit current generators. It establishes rank-1 and rank-2 current relations, including a Serre-type relation, and proves a complete Drinfeld-type presentation for ${\mathscr{Y}}_N$ and the special twisted Yangian ${\mathscr{SY}}_N$, with a flat deformation parameterized by $\hbar$. The approach yields a unified presentation that supports generalizations to ADE split types and connects to degeneration from affine $\imath$quantum groups, shifted twisted Yangians, and finite W-algebras, enriching both representation theory and boundary integrable systems. The results provide new tools for constructing and analyzing representations, maximal commutative subalgebras, and potential parallels with parabolic and shifted twisted constructions across twisted Yangians.
Abstract
We develop a Gauss decomposition approach to establish a Drinfeld type current presentation for Olshanski's twisted Yangians associated to the orthogonal Lie algebras (also called twisted Yangians of type AI), settling a longstanding open problem. We expect that this will open the door for finding current presentations for other twisted Yangians.
