I have a certain population, which growth is function of a certain factor. I have already modeled the growth. Now I need to impose that every individual in the population have a fixed life length. Can you help me modeling this?
Example, because people say "this is unclear".
Growh_rate=f(t)
Death_rate=?? <---I have to model an equation for this.
Life span=X
Population(t) = integral(from 0 to t)(Growh_rate)-integral(from 0 to t)(Death_rate)
Please if you can't directly answer the question, can you link me a directory of different models among different themes (population, financial, virus spread, etc)?