2019/08/05 by Kassotakis, Pavlos, Nieszporski, Maciej
#Exactly Solvable and Integrable Systems (nlin.SI) #FOS: Physical sciences
paper · doi:10.48550/arxiv.1908.01706
For some involutive maps Φ:\mathbb CP1 × \mathbb CP1 → \mathbb CP1 × \mathbb CP1 we find all invariants with separated variables. We investigate a link of the maps and their invariants with separated variables to discrete integrable systems. Maps correspond to integrable systems on edges (bond systems), while their invariants with separated variables yields potentials of the bond systems, that allows us to rewrite the integrable sytems as models on vertices. Among the latter ones one can find well known integrable difference equations as well as difference relations, which in contrast to the equations give non-single-valued evolution of the dependent variable. However, the non-single-valuedness can be resolved by the link with the bond system.