Representation Formulas of Curves in a Two- and Three-Dimensional Lightlike Cone

In this paper we give the representation formulas for spacelike curves in two-dimensional lightlike cone ${{\mathbb Q}^2}$ and three-dimensional lightlike cone ${{\mathbb Q}^3}$ . Using these formulas we discuss the properties and structures of cone curves in ${{\mathbb Q}^2}$ and ${{\mathbb Q}^3}$ . Some examples are also given.