Gwenaël Ferrando (ENS), so(2r) spin chains: QQ-system and transfer matrices

Wednesday 18 Nov 2020, 11:00 → 12:00 Europe/Stockholm

Fysikum equipment

The spectrum of some integrable models can be expressed in terms of a finite family of commuting operators, the Q operators, satisfying a set of equations called the QQ system. The equations solely depend on the symmetry algebra of the model while the regularity of the eigenvalues of the Q operators vary from one model to another. After reviewing the QQ system for A_n algebras I will, in this talk, present the QQ system for D_n algebras. The proposal relies on the available construction of some of the Q operators for integrable spin chains with D_n symmetry. I will also give different, so-called Weyl-type and QQ'-type, expressions for the transfer matrices satisfying Hirota equation in terms of the Q functions.