Invariants of twisted current algebras and related Poisson-commutative subalgebras

Abstract

Let q be a finite-dimensional Lie algebra and $\theta$ an automorphism of q of order m. We extend $\theta$ to an automorphism of the loop algebra of q and consider the fixed-point subalgebra $q[t,t^{-1}]^{\theta}$. Using a splitting of $q[t,t^{-1}]^{\theta}$, we construct $\theta$-twisted Poisson-commutative versions of the Feigin--Frenkel centre and the universal Gaudin subalgebra introduced by Ilin and Rybnikov in 2021.