## Tags » Low-dimensional Topology

#### elementary classes of 3-manifolds

Strangely, there are very few places that offer simple types or simple constructions of these topological beings. Sometimes innocent guessing make us to think that only is the only space we need to appreciate all the available 3d-complexity. 16 more words

#### Mike Freedman on SPC4

Mike Freedman gave a talk last week at Berkeley titled “(Still) thinking about the smooth 4-dimensional Poincare conjecture”, and I’d like to try and relate the main idea. 1,118 more words

#### Moxi: the cartesian product of the mobius-strip and an interval

MoxI is a solid Klein bottle, the genus one nonorientable handlebody. Here we see it with some typical curves on

#### mapping class group of the Klein bottle

**the Klein** bottle is gotten from a quotient in the two-torus via

so to get all the isotopy classes one need to consider the auto-homeomorphisms of the torus. 79 more words