Rigorous uniaxial limit of the Qian–Sheng inertial Q-tensor hydrodynamics for liquid crystals

This article is concerned with the rigorous connections between the inertial Qian–Sheng model and the Ericksen–Leslie model for the liquid crystal flow, under a more general condition on the coefficients. More specifically, within the framework of Hilbert expansions, we show that: (i) when the elastic coefficients tend to zero (also called the uniaxial limit), the smooth solution to the inertial Qian–Sheng model converges to that to the full inertial Ericksen–Leslie model; (ii) when both the elastic coefficients and the inertial coefficient tend to zero simultaneously, the smooth solution to the inertial Qian–Sheng model converges to that to the noninertial Ericksen–Leslie model.