This chapter, titled "Topics in Propagation of Chaos," is authored by Alain-Sol Sznitman and supported by NSF Grant No. DMS-8903858 and an Alfred P. Sloan Foundation research fellowship. The chapter is structured into several sections: 1. **Introduction**: Provides an overview of the topic. 2. **Generalities and First Examples**: - A laboratory example. - Generalities. - Examples including: - Our laboratory example. - Uniform measure on the sphere of radius √n in R^n. - Variation on a theme. - Symmetric self-exclusion process. - Reordering of Brownian motions. - Colored particles and nonlinear processes. - Loss of Markov property and local fluctuations. - Tagged particle: a counterexample. 3. **A Local Interaction Leading to Burgers Equation**: Discusses a specific interaction that leads to the Burgers equation. 4. **The Constant Mean Free Travel Time Regime**: - Annihilating Brownian spheres. - Limit picture for chain reactions in the constant mean free travel time regime. - Some comments. 5. **Uniqueness for the Boltzmann Process**: - Wild's formula. - Uniqueness for the Boltzmann process. The chapter concludes with a list of references.This chapter, titled "Topics in Propagation of Chaos," is authored by Alain-Sol Sznitman and supported by NSF Grant No. DMS-8903858 and an Alfred P. Sloan Foundation research fellowship. The chapter is structured into several sections: 1. **Introduction**: Provides an overview of the topic. 2. **Generalities and First Examples**: - A laboratory example. - Generalities. - Examples including: - Our laboratory example. - Uniform measure on the sphere of radius √n in R^n. - Variation on a theme. - Symmetric self-exclusion process. - Reordering of Brownian motions. - Colored particles and nonlinear processes. - Loss of Markov property and local fluctuations. - Tagged particle: a counterexample. 3. **A Local Interaction Leading to Burgers Equation**: Discusses a specific interaction that leads to the Burgers equation. 4. **The Constant Mean Free Travel Time Regime**: - Annihilating Brownian spheres. - Limit picture for chain reactions in the constant mean free travel time regime. - Some comments. 5. **Uniqueness for the Boltzmann Process**: - Wild's formula. - Uniqueness for the Boltzmann process. The chapter concludes with a list of references.