Uniqueness Results for an ODE Related to a Generalized Ginzburg-Landau Model for Liquid Crystals

We study a singular nonlinear ordinary differential equation on intervals [0, R) with R ≤ +∞, motivated by the Ginzburg–Landau models in superconductivity and Landau–de Gennes models in liquid crystals. We prove existence and uniqueness of positive solutions under general assumptions on the nonlinearity. Further uniqueness results for sign-changing solutions are obtained for a physically relevant class of nonlinearities. Moreover, we prove a number of fine qualitative properties of the solution that are important for the study of energetic stability.