Freidel-Maillet type equations on fused K-matrices over the positive part of $U_q(\widehat{\mathfrak{sl}}_2)$

par Chenwei Ruan (Beijing Institute of Mathematical Sciences and Applications)

vendredi 20 mars 2026, 10:30 → 11:30 Europe/Paris

E2 1180 (Tours)

The positive part $U_q^+$ of the quantized enveloping algebra $U_q(\widehat{\mathfrak{sl}}_2)$ has a reflection equation presentation of Freidel-Maillet type, due to Baseilhac 2021. This presentation involves a K-matrix of dimension $2 \times 2$. Under an embedding of $U_q^+$ into a $q$-shuffle algebra due to Rosso 1995, this K-matrix can be written in closed form using a PBW basis due to Terwilliger 2019. This PBW basis, together with two PBW bases due to Damiani 1993 and Beck 1994, can be obtain from a uniform approach by Ruan 2025. Motivated by recent work of Lemarthe, Baseilhac, and Gainutdinov, we will follow a natural fusion technique to construct fused K-matrices of arbitary meaningful dimensions in closed form using the uniform approach. We will also show that any pair of these fused K-matrices satisfy Freidel-Maillet type equations. This talk is based on arXiv: 2512.00819.