We derive a generalized Hamiltonian formalism for a modified suscepti- ble.infectious.recovered/removed (SIR) epidemic model taking into account the population V of vaccinated persons. The resulting SIRV model is shown to admit three possible functionally independent Hamiltonians and hence three associated Poisson structures. The reduced case of vanishing vaccinated sector shows a complete correspondence with the known Poisson structures of the SIR model. The SIRV model is shown to be expressible as an almost Nambu sys- tem, except for a scale factor function breaking the divergenceless property. In the autonomous case with time-independent stationary ratios k and b, the SIRV model is shown to be a maximally super-integrable system. For this case we test the accuracy of numerical schemes that are suited to solve the stiff set of SIRV differential equations. for LaTeX users @article{FHaas2022-55, author = {F. Haas and M. Kr\"oger and R. Schlickeiser}, title = {Multi-Hamiltonian structure of the epidemics model accounting for vaccinations and a suitable test for the accuracy of its numerical solvers}, journal = {J. Phys. A}, volume = {55}, pages = {225206}, year = {2022} }
\bibitem{FHaas2022-55} F. Haas, M. Kr\"oger, R. Schlickeiser, Multi-Hamiltonian structure of the epidemics model accounting for vaccinations and a suitable test for the accuracy of its numerical solvers, J. Phys. A {\bf 55} (2022) 225206.FHaas2022-55 F. Haas, M. Kr\"oger, R. Schlickeiser Multi-Hamiltonian structure of the epidemics model accounting for vaccinations and a suitable test for the accuracy of its numerical solvers J. Phys. A,55,2022,225206 |