Discrete Hamiltonians of discrete Painlev\'e equations

Abstract

We express discrete Painlev\'e equations as discrete Hamiltonian systems. The discrete Hamiltonian systems here mean the canonical transformations defined by generating functions. Our construction relies on the classification of the discrete Painlev\'e equations based on the surface-type. The discrete Hamiltonians we obtain are written in the logarithm and dilogarithm functions.