A simplified estimate of the effective reproduction number $$R_t$$ using its relation with the doubling time and application to Italian COVID-19 data

A simplified method to compute $R_t$, the Effective Reproduction Number, is presented. The relates value of $R_t$ estimation doubling time performed with a local exponential fit. condition $R_t = 1$ corresponds growth rate equal zero or equivalently an infinite time. Different assumptions on probability distribution generation are considered. simple analytical solution presented in case follows gamma distribution.