Applied mathematics and modelling · Maths EE idea · Solid

What the SIR model predicts about epidemics

A research question to start from

How does the basic reproduction number determine whether an epidemic grows in the SIR model, and what fraction of the population is eventually infected?

A starting point, not your question: change the case, the comparison or the limit until it is yours. The research-question builder helps you check it.

Why it works as a maths EE

A system of differential equations with an exact final-size relation you can derive.

Mathematics you would need

  • Systems of differential equations
  • Equilibria and stability
  • Euler's method
  • The final-size equation

Much of this goes beyond the DP course. That is expected in a maths EE, but you must understand and explain everything you use.

One possible line of attack

  1. Derive the threshold condition.
  2. Derive the final-size relation and solve it numerically.
  3. Discuss assumptions and how changing them alters predictions.

Scope and difficulty

Solid. Solid; keep it theoretical rather than fitting real outbreaks.

Pitfalls

  • Health essay with copied graphs.
  • Numerical solutions without analysis.

Where to start reading

Search a library catalogue or a university's open lecture notes for: SIR model final size equation derivation; basic reproduction number threshold. Prefer textbooks, lecture notes and journal articles to a single website, and cite everything you use (how to reference a maths EE).

Make it your EE

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