Abstract
It is conjectured K ⊂ ℝ n is a convex body, then there exists a point in the interior of K which is the point of concurrency of normals from 2n points on the boundary of K. We present a topological proof of this conjecture in dimension four assuming ∂K is C 1,1. From the assumption that the conjecture fails for K ⊂ ℝ 4, we construct a retraction from K̄ to ∂K. We apply the same strategy to the problem for lower n, assuming no regularity on ∂K, and show that it provides very simple proofs for the cases of two and three dimensions (the dimension three case was first proved by Erhard Heil). A connection between our approach to this problem and the homotopy type of some function spaces is also explored, and some conjectures along those lines are proposed.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 55-71 |
| Number of pages | 17 |
| Journal | Mathematische Annalen |
| Volume | 352 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2012 |
All Science Journal Classification (ASJC) codes
- General Mathematics