Definition 3.4. The ideal group IA of a noetherian domain A is the group of invertible fractional ideals. Note that, despite the name, elements of IA need not be ideals. Every nonzero principal fractional ideal (x) is invertible (since (x)−1 = (x−1)), and a product of principal fractional ideals is principal (since (x)(y) = (xy)), as is the unit ideal (1), thus the set of nonzero principal frac...

Let z be a real quadratic irrational. We compare the asymptotic behavior of Dedekind sums S(pk, qk) belonging to convergents pk/qk of the regular continued fraction expansion of z with that of Dedekind sums S(sj/tj) belonging to convergents sj/tj of the negative regular continued fraction expansion of z. Whereas the three main cases of this behavior are closely related, a more detailed study of...

The ring Z consists of the integers of the field Q, and Dedekind takes the theory of unique factorization in Z to be clear and well understood. The problem is that unique factorization can fail when one considers the integers in a finite extension of the rationals, Q(α). Kummer showed that when Q(α) is a cyclotomic extension (i.e. α is a primitive pth root of unity for a prime number p), one ca...

We describe a new series of identities, which hold for certain general theta series, in two completely independent variables. We provide explicit examples of these identities involving the Dedekind eta function, Jacobi theta functions, and various theta functions of Ramanujan. Introduction Let z ∈ H = {x+ yi : x, y ∈ R, y > 0} and for each x ∈ R set q = exp(2πixz) and e(x) = exp(2πix). The Dede...

ABSTRACT: Let E be an elliptic curve defined over Q and without complex multiplication. For a prime p of good reduction, let E be the reduction of E modulo p. Assuming that certain Dedekind zeta functions have no zeros in Re(s) > 3/4, we determine how often E(Fp) is a cyclic group. This result was previously obtained by J. -P. Serre using the full Generalized Riemann Hypothesis for the same Ded...

The simplest quartic field was introduced by M. Gras and studied by A. J. Lazarus. In this paper, we will evaluate the values of the Dedekind zeta functions at s = −1 of the simplest quartic fields. We first introduce Siegel’s formula for the values of the Dedekind zeta function of a totally real number field at negative odd integers, and will apply Siegel’s formula to the simplest quartic fiel...