Title: Quantum group symmetries and completeness for A_{2n}^(2) open spin chains Show Chinese title

Title: 量子群对称性和 A_{2n}^(2) 开链自旋的完备性

Abstract: We argue that the Hamiltonians for A_{2n}^(2) open quantum spin chains corresponding to two choices of integrable boundary conditions have the symmetries U_q(B_n) and U_q(C_n), respectively. We find a formula for the Dynkin labels of the Bethe states (which determine the degeneracies of the corresponding eigenvalues) in terms of the numbers of Bethe roots of each type. With the help of this formula, we verify numerically (for a generic value of the anisotropy parameter) that the degeneracies and multiplicities of the spectra implied by the quantum group symmetries are completely described by the Bethe ansatz. Show Chinese abstract

Abstract: 我们认为，对应于两种可积边界条件选择的A_{2n}^(2) 开放量子自旋链的哈密顿量分别具有对称性U_q(B_n)和U_q(C_n)。 我们找到了一个公式，用于表示Bethe态的Dynkin标签（这决定了相应本征值的简并度），该公式是根据每种类型的Bethe根的数量来表达的。 借助这个公式，我们数值验证了（对于各向异性参数的一个通用值），由量子群对称性所暗示的谱的简并度和重数完全由Bethe假设描述。