Generalized Dedekind sums, correlation of L-series, and the Galois module of cot(π/N)cot(mπ/N)
Let be a prime number. We say that a number field satisfies the condition when any abelian extension of exponent dividing has a normal integral basis with respect to the ring of -integers. We also say that satisfies when it satisfies for all . It is known that the rationals satisfy for all prime numbers . In this paper, we give a simple condition for a number field to satisfy in terms of the ideal class group of and a “Stickelberger ideal” associated to the Galois group...
We consider the indices of subfields of cyclotomic ℤₚ-extensions of number fields. For the nth layer Kₙ of the cyclotomic ℤₚ-extension of ℚ, we find that the prime factors of the index of Kₙ/ℚ are those primes less than the extension degree pⁿ which split completely in Kₙ. Namely, the prime factor q satisfies , and this leads us to consider higher degree Fermat quotients. Indices of subfields of cyclotomic ℤₚ-extensions of a number field which is cyclic over ℚ with extension degree a prime different...