Triviality of Iwasawa module associated to some abelian fields of prime conductors

Autor: Humio Ichimura
Rok vydání: 2017
Předmět:
Zdroj: Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg. 88:51-66
ISSN: 1865-8784
0025-5858
DOI: 10.1007/s12188-017-0186-1
Popis: Let p be an odd prime number and $$\ell $$ an odd prime number dividing $$p-1$$ . We denote by $$F=F_{p,\ell }$$ the real abelian field of conductor p and degree $$\ell $$ , and by $$h_F$$ the class number of F. For a prime number $$r \ne p,\,\ell $$ , let $$F_{\infty }$$ be the cyclotomic $$\mathbb {Z}_r$$ -extension over F, and $$M_{\infty }/F_{\infty }$$ the maximal pro-r abelian extension unramified outside r. We prove that $$M_{\infty }$$ coincides with $$F_{\infty }$$ and consequently $$h_F$$ is not divisible by r when r is a primitive root modulo $$\ell $$ and r is smaller than an explicit constant depending on p.
Databáze: OpenAIRE