Professor Galaye Dia, member of the Senegalese Academy of Sciences and Techniques, was a prominent mathematician in Senegal. His action significantly helped for the raise of a major team of research in Probability and Statistics in Senegal and by extension in West Africa. His actions for the promotion of Mathematics in general and Probability and Statistics in particular, were profound/ efficient and diverse. The national mathematical community and friends in the world first organized an international memorial conference in his honor in Saint-Louis (Senegal) in 2015. It was decided to extend the honor done to him by publishing a collection of high-level scientific texts in Mathematics and in related fields. This book is the fulfillment of that promise. The contributions in this festschrift cover the following topics: Analysis and Geometry; Algebra; Probability Theory and Random Analysis; Applied Mathematics and Mathematical Models; Codes; Cryptography; Number Theory and Algebraic Geometry; Statistics and Data Sciences; Computer Sciences and Big Data Application to Mathematics to other Fields; General mathematics.