herbrand-ribet theorem
Word Rarity
Very rare
Frequency: Zipf frequency 1.07 in modern English
33
Scrabble Score
20
Letters
6
Syllables
11
Unique Chars
Meaning
name
A result on the class group of certain number fields, strengthening Ernst Kummer's theorem to the effect that the prime p divides the class number of the cyclotomic field of p-th roots of unity iff p divides the numerator of the n-th Bernoulli number Bₙ for some n, 0 < n < p − 1. The Herbrand–Ribet theorem specifies what, in particular, it means when p divides such an Bₙ.
Etymology
Inflected Forms
the Herbrand-Ribet theorem (canonical)