Jinhua Qian

On foliations, there are two kinds of harmonic maps, that is, transversally harmonic map and $(F,F')$-harmonic map which are equivalent when the foliation is minimal. In this paper, we study transversally f-harmonic and $(F,F')_f$-harmonic maps on weighted foliations.

In this article, the idea of the generalized Hasimoto-type surfaces are put forward based on the interaction between vortex filaments. Meanwhie, the surface of null growth is proposed by evolving a null curve as dictated direction and growth velocity in Minkowski 3-space. The conditions and geometric forms of the generalized Hasimoto-type surfaces of null growth are investigated. Last but not least, several typical examples are presented to characterize such surface growth and the corresponding perturbations explicitly.

On foliations, there are two kinds of harmonic maps, that is, transversallyharmonic map and (F,F')-harmonic map which are equivalent when the foliation is minimal. In this paper, we study transversally ƒ-harmonic and (F,F')_ƒ-harmonic maps on weightedfoliations. Moreover, we investigate the relations between transversal stress energy tensorsand tranversally ƒ-harmonic maps.

The linear Weingarten condition with ellipticity for the mean curvature and the extrinsic Gaussian curvature on a surface in the three-sphere can define a Riemannian metric which is called the elliptic linear Weingarten metric. We established some local characterizations of the round spheres and the tori immersed in the 3-dimensional unit sphere, along with the Laplace operator, the spherical Gauss map and the Gauss map associated with the elliptic linear Weingarten metric.

Based on the fundamental theories of null curves in Minkowski 3-space, the null Darboux mate curves of a null curve are defined which can be regarded as a kind of extension for Bertrand curves and Mannheim curves in Minkowski 3-space. The relationships of null Darboux curve pairs are explored and their expression forms are presented explicitly.