On the stability problem and a bifurcation phenomenon for a special class of equilibria of the free rigid body on mathfrak{so}(5)

The stability of a special class of equilibria for the free rigid body on $\mathfrak{so}(5)$ is discussed. An instability region and two stability regions are established. The list of constants of motion which assure the complete integrability of the system is presented and used in the approach of stability with energy methods. The importance of appropriate choosing for the constants of motion in the energy methods is pointed out. A set of non-canonical constants of motion for the free rigid body on $\mathfrak{so}(5)$ and their role are analyzed.