A classification of pairs of disjoint nonparallel primitives in the boundary of a genus two handlebody
arXiv:0910.3038
Abstract
Embeddings of pairs of disjoint nonparallel primitive simple closed curves in the boundary of a genus two handlebody are classified. Briefly, two disjoint primitives either lie on opposite ends of a product , or they lie on opposite ends of a kind of "twisted" product , where is a once-punctured torus. If one of the curves is a proper power of a primitive, the situation is simpler. Either the curves lie on opposite sides of a separating disk in the handlebody, or they bound a nonseparating essential annulus in the handlebody.
13 pages, 9 figures