Ks. Chou et Xp. Zhu, SOME CONSTANCY RESULTS FOR NEMATIC LIQUID-CRYSTALS AND HARMONIC MAPS, Annales de l Institut Henri Poincare. Analyse non lineaire, 12(1), 1995, pp. 99-115
Uniqueness results for nematic liquid crystals and harmonic maps with
constant boundary data are established. Nonsolvability on non-starshap
ed domains for a semilinear elliptic equation is also given.