Orateur
Armin Schikorra
Description
For maps between -spheres we can estimate their degree in terms of their Hoelder- and fractional Sobolev-spaces norm in a sharp way. We will discuss some approaches about a similar estimate for maps from $\mathbb S^3$ to $\mathbb S^2$ and the Hopf degree.
Based on joint works with A. Grzela, K. Mazowiecka, J. Van Schaftingen