Deformations of smooth function on $2$-torus whose KR-graph is a tree

Bohdan Feshchenko

Let $f:T^2\to \mathbb{R}$ be Morse function on $2$-torus $T^2,$ and $\mathcal{O}(f)$ be the orbit of $f$ with respect to the right action of the group of diffeomorphisms $\mathcal{…