Dn+1(2) reflection K-matrices Original Research Article

We investigate the possible regular solutions of the boundary Yang–Baxter equation for the vertex models associated with the Dn+1(2) affine Lie algebra. We have classified them in terms of three types of K-matrices. The first one has n+2 free parameters and all the matrix elements are non-zero. The second solution is given by a block diagonal matrix with just one free parameter. It turns out that for n even there exists a third class of K-matrices without any free parameter.