Ruled austere submanifolds of dimension four

Autor: Thomas A. Ivey, Marianty Ionel
Rok vydání: 2012
Předmět:
Zdroj: Differential Geometry and its Applications. 30:588-603
ISSN: 0926-2245
DOI: 10.1016/j.difgeo.2012.07.007
Popis: We classify 4-dimensional austere submanifolds in Euclidean space ruled by 2-planes. The algebraic possibilities for second fundamental forms of an austere 4-fold M were classified by Bryant, falling into three types which we label A, B, and C. We show that if M is 2-ruled of Type A, then the ruling map from M into the Grassmannian of 2-planes in R^n is holomorphic, and we give a construction for M starting with a holomorphic curve in an appropriate twistor space. If M is 2-ruled of Type B, then M is either a generalized helicoid in R^6 or the product of two classical helicoids in R^3. If M is 2-ruled of Type C, then M is either a one of the above, or a generalized helicoid in R^7. We also construct examples of 2-ruled austere hypersurfaces in R^5 with degenerate Gauss map.
Comment: 20 pages
Databáze: OpenAIRE