Branches of forced oscillations in degenerate systems of second-order ODEs (Q2482472)

The authors investigate the title problem by demonstrating the existence of branches of periodic solutions where the vector field is neither trivial nor with a set of compact zeros. The principal result is the presentation and proof of a theorem establishing the periodic solution existence. The paper is theoretical, but nevertheless, an interesting two degree-of-freedom nonlinear spring/mass example is given where a periodic solution is exhibited. The paper is likely to be primarily of interest and use to analysts and researchers working with nonlinear ordinary differential equations and nonlinear oscillating systems.