Sätze aus der Functionentheorie
Scindement d’une équivalence d’homotopie en dimension
Simplexwise linear and piecewise linear near self-homeomorphisms of surfaces
Some topologically locally-flat surfaces in the complex projective plane.
Squeezing m-cells to (m-1)-cells in
Strongly homotopically stabile points
Surfaces in 3-space that do not lift to embeddings in 4-space
A necessary and sufficient condition for an immersed surface in 3-space to be lifted to an embedding in 4-space is given in terms of colorings of the preimage of the double point set. Giller's example and two new examples of non-liftable generic surfaces in 3-space are presented. One of these examples has branch points. The other is based on a construction similar to the construction of Giller's example in which the orientation double cover of a surface with odd Euler characteristic is immersed...