Kernel-based Method for Detecting Structural Break in Distribution of Functional Data

We propose a novel method to detect and date structural breaks in the entire distribution of functional data. Theoretical guarantees are developed for our procedure under fewer assumptions than in the existing work. In particular, we establish the asymptotic null distribution of the test statistic, which enables us to test the null hypothesis at a certain significance level. Additionally, the limiting distribution of the estimated structural break date is developed under two situations of the break size: fixed and shrinking towards 0 at a specified rate. We further propose a unified bootstrap procedure to construct a confidence interval for the true structural break date for these two situations. These theoretical results are justified through comprehensive simulation studies in finite samples. We apply the proposed method to two real-world examples: Australian temperature data for detecting structural beaks and Canadian weather data for goodness of fit.