The main research topics of the department WISK are: 1. p-adic analysis The functions studied in the mathematical analysis have real and complex values. One can replace the real or complex numbers by other numbers: the p-adic numbers (p is a prime). These numbers have properties that are rather different from the properties of real numbers. For instance when calculating with p-adic numbers rounding errors do not occur. The analysis built on the basis of the p-adic numbers is called p-adic analysis. This analysis has applications in physics and number theory. 2. Ring theory Algebraic structures play a central role in mathematics. The best known example of an algebraic structure is a group i.e. a set on which an operator is defined. An important example is the group of symmetries of a physical or chemical system. Other algebraic structures have two operations e.g. rings and fields. We study non-commutative ring theory and related subjects such as Hopf algebras and Brauer groups.