Chaos theory applied to the outbreak of Covid-19: an ancillary approach to decision-making in pandemic context

Sylvain Mangiarotti; Marisa Peyre; Yan Zhang; Mireille Huc; Francois Roger; Yann Kerr

In terms of temporal evolution, the three simulations clearly illustrate the high sensitivity to the initial conditions (Fig. 2) : trajectories may alternatively come closer and move away one to another but do not converge to a single time evolution. It also shows that the large oscillations 15 observed in s 1 (t) (Fig. 2b) can be reproduced by the model although they are slower in the simulations. Finally, the regular increase of the daily deaths during a transient regime is also well reproduced although the maximum number of death is in the end underestimated by the model. At present, the epidemic seems to be getting under control in China. Three simulations were run using recent data (starting on DoY-72 7pm; DoY-73 7am and 7pm, see Figure two in dashed 20 brown lines) showing that a quick restart must be expected if the control measures were to be released now before the epidemic is entirely wiped out (immunization is assumed to be insufficient to modify the dynamic significantly). All rights reserved. No reuse allowed without permission.