{ "id": "2312.04666", "version": "v1", "published": "2023-12-07T19:57:58.000Z", "updated": "2023-12-07T19:57:58.000Z", "title": "The algebra $\\mathbb{Z}_\\ell[[\\mathbb{Z}_p^d]]$ and applications to Iwasawa theory", "authors": [ "Andrea Bandini", "Ignazio Longhi" ], "comment": "(Very) Preliminary version. Comments are welcome", "categories": [ "math.NT" ], "abstract": "Let $\\ell$ and $p$ be distinct primes, and let $\\Gamma$ be an abelian pro-$p$-group. We study the structure of the algebra $\\Lambda:=\\mathbb{Z}_\\ell[[\\Gamma]]$ and of $\\Lambda$-modules. In the case $\\Gamma\\simeq \\mathbb{Z}_p^d$, we consider a $\\mathbb{Z}_p^d$-extension $K/k$ of a global field $k$ and use the structure theorems to provide explicit formulas for the orders and $\\ell$-ranks of certain Iwasawa modules (namely $\\ell$-class groups and $\\ell$-Selmer groups) associated with the finite subextensions of $K$. We apply this new approach to provide different proofs and generalizations of results of Washington and Sinnott on $\\ell$-class groups.", "revisions": [ { "version": "v1", "updated": "2023-12-07T19:57:58.000Z" } ], "analyses": { "subjects": [ "11R23", "11R29" ], "keywords": [ "iwasawa theory", "applications", "class groups", "distinct primes", "structure theorems" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }