values of Dedekind zeta functions of real quadratic number fields at negative integers
Let K be a real quadratic number field of discriminant DK and let ζ(s,K) be the Dedekind zeta function associated to K. By the Siegel-Klingen Theorem, if n>0 then ζ(-n,K) is a rational number. On the other hand, K is obviously an abelian number field, thus the factorization of the Dedekind zeta function of an abelian number field tells us that:
ζ(s,K)=ζ(s)L(s,χ) |
where ζ(s) is the famous Riemann zeta function and L(s,χ) is the Dirichlet L-function associated to χ, where χ is the unique Dirichlet character
with conductor
DK such that the group of characters of K/ℚ is {χ0,χ} and χ0 is the trivial character. In fact, the values of χ are simply given by
χ(a)=(DKa) |
where the parentheses denote the Kronecker symbol.
Furthermore, if k is a positive integer then:
-
1.
Putting the values of the Riemann zeta function in terms of Bernoulli numbers
one gets:
ζ(1-k)=-Bkk where Bk is the kth Bernoulli number;
-
2.
The values of Dirichlet L-series at negative integers can be written in terms of generalized Bernoulli numbers
as follows:
L(1-k,χ)=-Bk,χk where Bk,χ is the kth generalized Bernoulli number associated to χ.
Therefore:
ζ(1-k,K)=ζ(1-k)L(1-k,χ)=Bk⋅Bk,χk2. |
The interested reader can find tables of values at the http://www.math.cornell.edu/ alozano/dedekind-values/index.htmlauthor’s personal website.
Title | values of Dedekind zeta functions of real quadratic number fields at negative integers |
---|---|
Canonical name | ValuesOfDedekindZetaFunctionsOfRealQuadraticNumberFieldsAtNegativeIntegers |
Date of creation | 2013-03-22 16:01:27 |
Last modified on | 2013-03-22 16:01:27 |
Owner | alozano (2414) |
Last modified by | alozano (2414) |
Numerical id | 5 |
Author | alozano (2414) |
Entry type | Application |
Classification | msc 11R42 |
Classification | msc 11M06 |
Related topic | FactorizationOfTheDedekindZetaFunctionOfAnAbelianNumberField |