A funny encounter with immersions of spheres

Venue:
2.058

Date:
05.11.2020

Speaker:
Tam Nguyen Phan

Time:
16:00 – 17:30

It is a common topology homework exercise to prove that any embedding of a closed, orientable nmanifold M, such as the nsphere, into R^{n+1}, is separating (i.e. has disconnected complement). However, this homework problem has never been posed with “embedding”
replaced by “immersion”, probably because it seems at ﬁrst glance to complicate the problem for no good reason. But there is actually an interesting reason. This talk is based on joint work with Michael Freedman.