👉 In mathematics, an idealiser is a mathematical object that represents a mathematical structure or function. It is often used in the context of group theory and algebraic topology to represent abstract structures such as groups, rings, vector spaces, and more. An idealiser can be thought of as a generalization of a point in Euclidean space (a geometric notion) or an element in a ring (an abstract concept). In each case, it is used to represent the structure under study. For example