On the Degenerate Multiplicity of the sl 2 Loop Algebra for the 6V Transfer Matrix at Roots of Unity
Tetsuo Deguchi
We review the main result of cond-mat/0503564.The Hamiltonian of the XXZ spin chain and the transfer matrix of the six-vertex model has the sl 2 loop algebra symmetry if the q parameter is given by a root of unity, q 2N 0 = 1, for an integer N .We discuss the dimensions of the degenerate eigenspace generated by a regular Bethe state in some sectors, rigorously as follows: We show that every regular Bethe ansatz eigenvector in the sectors is a highest weight vector and derive the highest weight d± k , which leads to evaluation parameters a j .If the evaluation parameters are distinct, we obtain the dimensions of the highest weight representation generated by the regular Bethe state.
arXiv:cond-mat/0602427•Symmetry Integrability and Geometry Methods and Applications•Feb 17, 2006•1 citation