Proofs of Fermat's Little Theorem - Proof Using Group Theory

Proof Using Group Theory

This proof requires the most basic elements of group theory.

The idea is to recognise that the set G = {1, 2, …, p − 1}, with the operation of multiplication (taken modulo p), forms a group. The only group axiom that requires some effort to verify is that each element of G is invertible. Taking this on faith for the moment, let us assume that a is in the range 1 ≤ ap − 1, that is, a is an element of G. Let k be the order of a, so that k is the smallest positive integer such that

By Lagrange's theorem, k divides the order of G, which is p − 1, so p − 1 = km for some positive integer m. Then

Read more about this topic:  Proofs Of Fermat's Little Theorem

Famous quotes containing the words proof, group and/or theory:

    If we view our children as stupid, naughty, disturbed, or guilty of their misdeeds, they will learn to behold themselves as foolish, faulty, or shameful specimens of humanity. They will regard us as judges from whom they wish to hide, and they will interpret everything we say as further proof of their unworthiness. If we view them as innocent, or at least merely ignorant, they will gain understanding from their experiences, and they will continue to regard us as wise partners.
    Polly Berrien Berends (20th century)

    ...Women’s Studies can amount simply to compensatory history; too often they fail to challenge the intellectual and political structures that must be challenged if women as a group are ever to come into collective, nonexclusionary freedom.
    Adrienne Rich (b. 1929)

    A theory of the middle class: that it is not to be determined by its financial situation but rather by its relation to government. That is, one could shade down from an actual ruling or governing class to a class hopelessly out of relation to government, thinking of gov’t as beyond its control, of itself as wholly controlled by gov’t. Somewhere in between and in gradations is the group that has the sense that gov’t exists for it, and shapes its consciousness accordingly.
    Lionel Trilling (1905–1975)