Interestingly the I_c(t) cumulative cases is all you need to solve the SIR model. S is an exponential decay of that, R is linearly proportional, and I ends up b

Interestingly the I_c(t) cumulative cases is all you need to solve the SIR model. S is an exponential decay of that, R is linearly proportional, and I ends up being the difference of the population N and (S+R) based on the S+I+R = N relation. A straightforward integrating factor.