Gaussian Period - General Definition

General Definition

Given an integer n > 1, let H be any subgroup of the multiplicative group

of invertible residues modulo n, and let

A Gaussian period P is a sum of the primitive n-th roots of unity, where runs through all of the elements in a fixed coset of H in G.

The definition of P can also be stated in terms of the field trace. We have

for some subfield L of Q(ζ) and some j coprime to n. This corresponds to the previous definition by identifying G and H with the Galois groups of Q(ζ)/Q and Q(ζ)/L, respectively. The choice of j determines the choice of coset of H in G in the previous definition.

Read more about this topic:  Gaussian Period

Famous quotes containing the words general and/or definition:

    “When General Motors has to go to the bathroom ten times a day, the whole country’s ready to let go. You heard of that market crash in ‘29? I predicted that.... I was nursing a director of General Motors. Kidney ailment, they said; nerves, I said. Then I asked myself, “What’s General Motors got to be nervous about?” “Overproduction,” I says. “Collapse.””
    —John Michael Hayes (b. 1919)

    “... we all know the wag’s definition of a philanthropist: a man whose charity increases directly as the square of the distance.”
    —George Eliot [Mary Ann (or Marian)