Globally Coherent Weekly Periodicity in the Covid-19 Pandemic

After the major exponential phase, the Covid-19 pandemic is on a milder rate of increase globally, and past the peak in many countries. In this phase a marked systematic weekly periodicity in the Covid-19 attack has become clear, the study of which could be useful for the long term strategy to deal with the virus and the pandemic. The most important aspect of this strong weekly modulation is its global nature, phase-coherent over most of globe, independent of the geographical location. The fact that the same periodicity is now evident even those countries Asia and Africa, where it was absent or not prominent earlier, suggests the possibility that the pattern could be an early indicator for significant community transmission. The global coherent periodicity with a time scale that agrees with the time scales of virus incubation and infection may be important in tracking the long term interaction of the virus with the host.