Embedding and Knotting of Positive Curvature Surfaces in 3-space

Herman Gluck

Abstract: In 3-space, compact orientable surfaces with nonempty boundary and positive curvature play the role of Seifert surfaces in a curvature- sensitive version of knot theory. The following result states that the isotopy classes of such surfaces are in one-one correspondence with the isotopy classes of ordinary surfaces which have no constraint on their curvature.

THEOREM. (a) In 3-space, any compact orientable surface with nonempty boundary can be deformed into one with positive curvature.
(b) Any two such surfaces with positive curvature can be deformed into one another through surfaces of positive curvature if and only if they can be deformed into one another through ordinary surfaces, preserving their natural orientations.