2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/94497Generalized Halphen systems are solved in terms of functions that uniformize genus zero Riemann surfaces, with automorphism groups that are commensurable with the modular group. Rational maps relating these functions imply subgroup relations between their automorphism groups and symmetrization relations between the associated differential systems.PlainTeX 15gs. Write - up of lecture by J. Harnad at International meeting: SIDE III, Sabaudia, May 16-22, 1998. To appear in CRM Proceedings and Lecture Notes series (1999/2000)Exactly Solvable and Integrable SystemsHigh Energy Physics - TheoryMathematical PhysicsDynamical SystemsGroup TheoryNumber Theorytext