Sequences, codes, and Boolean functions: in memory of Kai-Uwe Schmidt

This special volume is a tribute to the late Kai-Uwe Schmidt, a renowned mathematician whose work spanned sequences, codes, and Boolean functions. The collection features 21 papers from leading experts, many of whom were Schmidt's collaborators, organized by theme to reflect the evolution of his research interests. The papers delve into sequences and their correlation properties, codes, almost perfect nonlinear functions, functions on finite fields, and polar spaces. Notable contributions include new methods for calculating sequence correlations, constructions of difference sets, and advancements in the study of APN functions and their applications in cryptography. The volume also explores the intersection of finite geometry and group theory, presenting new results on polar spaces and association schemes. Additionally, it highlights the use of probabilistic methods in solving classical problems in sequences, codes, and Boolean functions, showcasing Schmidt's innovative approach to these topics. This memorial volume not only celebrates Schmidt's technical contributions but also underscores the exceptional regard in which his colleagues held him, making it an invaluable resource for researchers in the field.