Modüler vektör değişmezleri

Vector invariants of finite groups (see the introduction for definitions) pro-vides, in general, counterexamples for many properties of the invariant theorywhen the characteristic of the ground field divides the group order. Noethernumber is such property.In this thesis, we improve a lower bound for Noether number given by Richmanin 1996: namely, we give a lower bound depending on the Jordan canonical formof an element of order equal to characteristic of the field. This method yields aneffective bound by means of simple arithmetic arguments.The results are valid for any faithful representation of the group, includingreducible and irreducible ones. Also they are extended to any algebraic fieldextensions provided the characteristic of the field divides the group order.Keywords: Modular invariants, polynomial invariants, vector invariants, Noethernumber, beta number.