Some orbital test problems (Q1335467)

The author considers orbital motion in which the attractive force depends on distance measured by the maximum \((L_ \infty)\) norm rather than the Euclidean norm. The force is defined either as a gradient of \(f(\| X\|)\) in which case energy is conserved or as a central force \(- g(\| X\|)X\) in which case angular momentum is conserved. He shows how to find periodic orbits which may be used as test problems for software.