Elena Shadrina
Publications:
Medvedev T. V., Nozdrinova E. V., Pochinka O. V., Shadrina E. V.
On a Class of Isotopic Connectivity of Gradientlike Maps of the 2sphere with Saddles of Negative Orientation Type
2019, Vol. 15, no. 2, pp. 199211
Abstract
We consider the class $G$ of gradientlike orientationpreserving diffeomorphisms of the 2sphere with saddles of negative orientation type. We show that the for every diffeomorphism $f\in G$ every saddle point is fixed. We show that there are exactly three equivalence classes (up to topological conjugacy) $G=G_1\cup G_2\cup G_3$ where a diffeomorphism $f_1\in G_1$ has exactly one saddle and three nodes (one fixed source and two periodic sinks); a diffeomorphism $f_2\in G_2$ has exactly two saddles and four nodes (two periodic sources and two periodic sinks) and a diffeomorphism $f_3\in G_3$ is topologically conjugate to a diffeomorphism $f_1^{1}$. The main result is the proof that every diffeomorphism $f\in G$ can be connected to the ``sourcesink'' diffeomorphism by a stable arc and this arc contains at most finitely many points of perioddoubling bifurcations.
