Kompleks hiperyüzey tekilliklerinin bazı sayısal değişmezleri

In this thesis, we work on the explicit computation, algebraic and geometric points of view, of some numerical invariants of hypersurfaces with singularities. In the case where the hypersurface has an isolated singularity, we reviewed the Milnor number and the Tjurina number of the defining analytic function f of the hypersurface. After, we present the Newton number attached to the Newton polyhedron of f . Then, we examine the relation between these numerical invariants. In the case where the hypersurface has non-isolated singularities, we are interested in the Lê varieties of an analytic function f and their intersection number with certain linear subspaces at the origin in the ambient space. This intersection number is called Lê number of f at the origin. We examine the algebraic and geometric computation of the Lê number of a hypersurface. To compute Lê numbers from the geometric point of view we present the modified Newton number associated with the Newton polyhedron of the defining analytic function f . We give good examples of calculating all these numerical invariants of a hypersurface, algebraically and geometrically.