Nested algebraic Bethe ansatz for open spin chains with even twisted Yangian symmetry
arXiv:1710.08409 · doi:10.1007/s00023-018-0731-1
Abstract
We present a nested algebraic Bethe ansatz for a one dimensional open spin chain whose boundary quantum spaces are irreducible - or -representations and the monodromy matrix satisfies the defining relations of the Olshanskii twisted Yangian . We use a generalization of the Bethe ansatz introduced by De Vega and Karowski which allows us to relate the spectral problem of a - or -symmetric open spin chain to that of a -symmetric periodic spin chain. We explicitly derive the structure of the Bethe vectors and the nested Bethe equations.
36 pages; v.2: minor corrections, a trace formula for the Bethe vectors added