Renormalized oscillation theory for regular linear non-Hamiltonian systems

In recent work, Baird et al. have generalized the definition of Maslov index to paths Grassmannian subspaces that are not necessarily contained in Lagrangian [2]. Such an extension opens up possibility applications non-Hamiltonian systems ODE, and his collaborators taken advantage this observation establish oscillation-type results for obtaining lower bounds on eigenvalue counts setting. In current analysis, author shows renormalized oscillation theory, appropriately defined setting, can be applied a natural way, it has advantage, as traditional setting linear Hamiltonian systems, ensuring monotonicity crossing points independent variable increases wide range system/boundary-condition combinations. This seems mark first effort extend approach