Equivariant L-function
Encyclopedia
In algebraic number theory
, an equivariant Artin L-function is a function associated to a finite Galois extension
of global field
s created by packaging together the various Artin L-function
s associated with the extension. Each extension has many traditional Artin L-functions associated with it, corresponding to the characters of representations
of the Galois group. By contrast, each extension has a unique corresponding equivariant L-function.
Equivariant L-functions have become increasingly important as a wide range of conjectures and theorems in number theory have been developed around them. Among these are the Brumer–Stark conjecture, the Coates-Sinnott conjecture, and a recently developed equivariant version of the main conjecture in Iwasawa theory
.
Algebraic number theory
Algebraic number theory is a major branch of number theory which studies algebraic structures related to algebraic integers. This is generally accomplished by considering a ring of algebraic integers O in an algebraic number field K/Q, and studying their algebraic properties such as factorization,...
, an equivariant Artin L-function is a function associated to a finite Galois extension
Galois extension
In mathematics, a Galois extension is an algebraic field extension E/F satisfying certain conditions ; one also says that the extension is Galois. The significance of being a Galois extension is that the extension has a Galois group and obeys the fundamental theorem of Galois theory.The definition...
of global field
Global field
In mathematics, the term global field refers to either of the following:*an algebraic number field, i.e., a finite extension of Q, or*a global function field, i.e., the function field of an algebraic curve over a finite field, equivalently, a finite extension of Fq, the field of rational functions...
s created by packaging together the various Artin L-function
Artin L-function
In mathematics, an Artin L-function is a type of Dirichlet series associated to a linear representation ρ of a Galois group G. These functions were introduced in the 1923 by Emil Artin, in connection with his research into class field theory. Their fundamental properties, in particular the Artin...
s associated with the extension. Each extension has many traditional Artin L-functions associated with it, corresponding to the characters of representations
Representation (mathematics)
In mathematics, representation is a very general relationship that expresses similarities between objects. Roughly speaking, a collection Y of mathematical objects may be said to represent another collection X of objects, provided that the properties and relationships existing among the...
of the Galois group. By contrast, each extension has a unique corresponding equivariant L-function.
Equivariant L-functions have become increasingly important as a wide range of conjectures and theorems in number theory have been developed around them. Among these are the Brumer–Stark conjecture, the Coates-Sinnott conjecture, and a recently developed equivariant version of the main conjecture in Iwasawa theory
Iwasawa theory
In number theory, Iwasawa theory is the study of objects of arithmetic interest over infinite towers of number fields. It began as a Galois module theory of ideal class groups, initiated by Kenkichi Iwasawa, in the 1950s, as part of the theory of cyclotomic fields. In the early 1970s, Barry Mazur...
.