Kahan-Hirota-Kimura maps preserving original cubic hamiltonians

In this work we investigate the set of cubic Hamiltonian vector fields for which their associated Kahan-Hirota-Kimura maps preserve the original Hamiltonian function. We analyze these fields in $\mathbb{R}^2$ and $\mathbb{R}^4$. We also study a family of fields in $\mathbb{R}^6$. Additionally, we explore several properties like the existence of additional first integrals of specific type, the possibility that the initial Hamiltonian vector field is a Lie symmetry of the corresponding map, or the symplecticity of the considered maps.
Comment: 30 pages, 1 Figure