| Title: | Capitulation dans certaines extensions non ramifiées de corps quartiques cycliques (French) | 
| Title: | Capitulation in certain nonramified extensions of cyclic quartic fields (English) | 
| Author: | Azizi, Abdelmalek | 
| Author: | Talbi, Mohammed | 
| Language: | French | 
| Journal: | Archivum Mathematicum | 
| ISSN: | 0044-8753 (print) | 
| ISSN: | 1212-5059 (online) | 
| Volume: | 44 | 
| Issue: | 4 | 
| Year: | 2008 | 
| Pages: | 271-284 | 
| Summary lang: | English | 
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| Category: | math | 
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| Summary: | Let $K=k\big (\sqrt{-p{\varepsilon }\sqrt{l}}\big )$ with $k={\mathbb{Q}}(\sqrt{l})$ where $l$ is a prime number such that $l=2$ or $l\equiv 5\;\@mod \;8$, $\varepsilon $ the fundamental unit of $k$, $p$ a prime number such that $p\equiv 1\;\@mod \;4$ and ${(\frac{p}{l})}_4=-1$, $K_2^{(1)}$ the Hilbert $2$-class field of $K$, $K_2^{(2)}$ the Hilbert $2$-class field of $K_2^{(1)}$ and $G=\operatorname{Gal\,}(K_2^{(2)}/K)$ the Galois group of $K_2^{(2)}/K$. According to E. Brown and C. J. Parry [7] and [8], $C_{2,K}$, the Sylow $2$-subgroup of the ideal class group of $K$, is isomorphic to ${\mathbb{Z}}/2{\mathbb{Z}}\times {\mathbb{Z}}/{2\mathbb{Z}}$, consequently $K_2^{(1)}/K$ contains three extensions $F_i/K$ $(i=1,2,3)$ and the tower of the Hilbert $2$-class field of $K$ terminates at either $K_2^{(1)}$ or $K_2^{(2)}$. In this work, we are interested in the problem of capitulation of the classes of $C_{2,K}$ in $F_i$ $(i=1,2,3)$ and to determine the structure of $G$.
Résumé. Soient $K=k(\sqrt{-p{\varepsilon }\sqrt{l}})$ avec $k=\mathbb{Q}(\sqrt{l})$ où $l$ est un nombre premier tel que $l=2$ ou $l\equiv 5\;\@mod \;8$, $\varepsilon $ l’unité fondamentale de $k$, $p$ un nombre premier tels que $p\equiv 1\;\@mod \;4$ et ${(\frac{p}{l})}_4=-1$, $K_2^{(1)}$ le $2$-corps de classes de Hilbert de $K$, $K_2^{(2)}$ le $2$-corps de classes de Hilbert de $K_2^{(1)}$ et $G=\operatorname{Gal\,}(K_2^{(2)}/K)$ le groupe de Galois de $K_2^{(2)}/K$. D’après E. Brown et C. J. Parry [7] et [8], $C_{2,K}$, le $2$-groupe de classes de $K$, est isomorphe à $\mathbb{Z}/{2\mathbb{Z}}\times \mathbb{Z}/{2\mathbb{Z}}$, par conséquent $K_2^{(1)}/K$ contient trois extensions $F_i/K$ $(i=1,2,3)$ et la tour des $2$-corps de classes de Hilbert de $K$ s’arrête en $K_2^{(1)}$ ou en $K_2^{(2)}$. Dans ce travail, on s’intéresse au problème de capitulation des classes de $C_{2,K}$ dans $F_i$ $(i=1,2,3)$ et à déterminer la structure de $G$. (English) | 
| Keyword: | corps biquadratiques cycliques | 
| Keyword: | groupe de classes | 
| Keyword: | capitulation | 
| Keyword: | corps de classes de Hilbert | 
| MSC: | 11R27 | 
| MSC: | 11R37 | 
| idZBL: | Zbl 1212.11091 | 
| idMR: | MR2493424 | 
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| Date available: | 2009-01-29T09:15:22Z | 
| Last updated: | 2013-09-19 | 
| Stable URL: | http://hdl.handle.net/10338.dmlcz/119767 | 
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