Abstract
We consider critical dense polymers 
. We obtain for this model the eigenvalues of the local integrals of motion of the
underlying conformal field theory by means of a thermodynamic Bethe ansatz. We
give a detailed description of the relation between this model and symplectic
fermions including some examples of the indecomposable structure of the transfer
matrix in the continuum limit. Integrals of motion are defined directly on the
lattice in terms of the Temperley–Lieb algebra and their eigenvalues are obtained
and expressed as an infinite sum of the eigenvalues of the continuum integrals
of motion. An elegant decomposition of the transfer matrix in terms of a finite
number of lattice integrals of motion is obtained, thus providing a reason for their
introduction.