Resumen de Normal surfaces in non-compact 3-manifolds
We extend the normal surface Q -theory to non-compact 3-manifolds with respect to ideal triangulations. An ideal triangulation of a 3-manifold often has a small number of tetrahedra resulting in a system of Q -matching equations with a small number of variables. A unique feature of our approach is that a compact surface F with boundary properly embedded in a non-compact 3-manifold M with an ideal triangulation with torus cusps can be represented by a normal surface in M as follows. A half-open annulus made up of an infinite number of triangular disks is attached to each boundary component of F. The resulting surface ^F , when normalized, will contain only a finite number of -disks and thus correspond to an admissible solution to the system of Q -matching equations. The correspondence is bijective.
