Dynamics of a hyperchaotic Lorenz system

In this paper, we investigate the dynamics of the Lorenz system, linearly extended into one additional dimension. The system is hyperchaotic in a wide range of parameters. A theoretical and numerical study indicates that chaos and hyperchaos are produced with the help of a van der Pol-like oscillatory motion around a hypersaddle stationary point at the origin. Numerical experiments are presented, showing Lyapunov exponents, bifurcation diagrams and Poincar'e sections.