On the origin and observation of flares in the late afterglow of gamma-ray bursts

This thesis encompasses the theory and observation of late flares of gamma-ray burst afterglows. The work is divided into three components. In chapter 2, we study GRB 160203A: a long GRB with an unusual afterglow, leading to a simple model for explaining the flare present in its afterglow. In chapter 3, the model is expanded upon, placing constraints on the properties of the necessary density fluctuations to produce the observed flares. In chapter 4, we review the last 20 years of GRB observations to identify the rate of such events in the literature, and find evidence of changing observation priorities.