Topological defects in a nematic filled with colloid particles

We theoretically investigate topological constraints and the defect structure around a spherical body immersed in a uniformnematic liquid crystal. Depending on the strength of anchoring on the particle surface, there are three possibilities. At rigid anchoring, WR/K much greater than 1, the inner surface constraint forces a disclination ring of a radius a similar to 1.2*R, with R the particle size. At a lower, critical value W* the disclination rings contracts to the surface and, for small anchoring, WR/K much less than 1, the director distribution is regular, defect-free.