Corrections to the paper: “On formal theory of differential equations. II.”
Corrigendum to: Positive solutions for systems of generalized three-point nonlinear boundary value problems
Co-solutions of algebraic matrix equations and higher order singular regular boundary value problems
In this paper we obtain existence conditions and a closed form of the general solution of higher order singular regular boundary value problems. The approach is based on the concept of co-solution of algebraic matrix equations of polynomial type that permits the treatment of the problem without considering an extended first order system as it has been done in the known literature.
Covariant constructions in the theory of linear differential equations
Criterion for the polynomial solutions of certain first order differential equations
Critical point theory and nonlinear differential equations
Cubic and quartic planar differential systems with exact algebraic limit cycles.
Cylindrical Tzitzeica curves implies forced harmonic oscillators.