Seminar series
Date
Wed, 15 Nov 2023
Time
16:00 -
17:00
Location
L6
Speaker
Shaked Bader
Organisation
University of Oxford
In 1947 Karol Borsuk conjectured that if an ant is walking on a circle embedded piecewise linearly in ℝ3 and is not dizzy (did not wind around itself twice) then the circle bounds a disc. He actually phrased it as follows: the total curvature of a knotted knot must be at least 4π.
One may ask the same question with other spaces instead of ℝ3.
We will present Milnor's proof of the classical conjecture, then define CAT(0) spaces and present some ideas from Stadler's proof in that setting and a more elementary proof in the setting of CAT(0) polygonal complexes.
