Some conditions for a surface in {$Esp 4$} to be a part of the sphere {$Ssp 2$}
Jarolím Bureš, Miloš Kaňka · Mathematica Bohemica · 1994
In this paper some properties of an immersion of two-dimensional surface with boundary into {$Esp 4$} are studied. The main tool is the maximal principle property of a solution of the elliptic system of partial differential equations. Some conditions for a surface to be a part of a 2-dimensional spheren in {$Esp 4$} are presented.