Figure 3

3D helicoid vortex and Lyapunov Maps of epidemic spreading from 15/03/2020 to 28/01/2022 in United States, United Kingdom and Japan. In the upper panels we show the 3D orbit of the Covid-19 vortex over two years where the daily new deaths per million population and the RIC-index are measured in days starting from the 75 day of the year 2020. The gray shaded slice represents the critical crossover at the zero RIC index, which separates the supercritical (RIC index > 0) and the subcritical regime (RIC index < 0). The lower panels represent the Lyapunov maps. The discontinuity points, where the LLE integrated along the different initial ranges change sign becoming positive, correspond to times in which the helicoid vortex change color. Non-positive LLE values imply convergent trajectories independent by the initial conditions of the phenomenon.