On the local Artin conductor fArtin (?) of a character ? of Gal(E/K) -: II
dc.contributor.author | Ikeda, KI | |
dc.date.accessioned | 2024-07-18T20:40:16Z | |
dc.date.available | 2024-07-18T20:40:16Z | |
dc.date.issued | 2003 | |
dc.department | İstanbul Bilgi Üniversitesi | en_US |
dc.description.abstract | This paper which is a continuation of [21, is essentially expository in nature, although some new results are presented. Let K be a local field with finite residue class field kappa(K) - We first define (cf. Definition 2.4) the conductor f (E/K) of an arbitrary finite Galois extension E/K in the sense of non-abelian local class field theory as [GRAPHICS] where n(G) is the break in the upper ramification filtration of G = Gal(E/K) defined by G(nG) not equal G(nG+delta) = 1, For Alldelta epsilon R (greater than or equal to 0). Next, we study the basic properties of the ideal f (E/K) in O-K in case E/K is a metabelian extension utilizing Koch-de Shalit metabelian local class field theory (cf. [8]). After reviewing the Artin character a(G) : G --> C of G := Gal(E/K) and Artin representations A(G) : G --> GL(V) corresponding to a(G) : G --> C, we prove that (Proposition 3.2 and. Corollary 3.5) [GRAPHICS] where chi(rho) : G ---> C is the character associated to an irreducible representation rho G --> GL(V) of G (over C). The first main result (Theorem, 1.2) of the paper states that, if in particular, rho : G --> GL(V) is an irreducible representation of G (over C) with metabelian image, then [GRAPHICS] where Gal (E-ker(rho)/ E-ker(rho).) is any maximal abelian normal subgroup of Gal (E-ker(rho) / K) containing Gal (E-ker(rho) / K)', and the break n(G/ker(rho)) in the upper ramification filtration of G/ker(rho) can be computed and located by metabelian local class field theory. The proof utilizes Basmaji's theory on the structure of irreducible faithful representations of finite metabelian groups (cf. [1]) and on metabelian local class field theory (cf. [8]). We then discuss the application of Theorem 1.2 on a problem posed by Weil on the construction of a 'natural' A(G) of G over C (Problem 1.3). More precisely, we prove in Theorem 1.4 that if E/K is a metabelian extension with Galois group G, then [GRAPHICS] where N runs over all normal subgroups of G, and for such an N, nu(N) denotes the collection of all similar to-equivalence classes [omega] similar to, where 'similar to' denotes the equivalence relation on the set of all representations omega : (G/N)(.) --> C-x satisfying the conditions inert (omega) = [delta epsilon G / N : omegadelta = omega] = (G/N)(.) and [GRAPHICS] where delta runs over R((G/N)(.)\(G/N)), a fixed given complete system of representatives of (G/N)(.)\(G/N), by declaring that omega(1) similar to omega(2) if and only if omega(1) = omega(2,delta) for some delta epsilon R((G/N)(.)\(G/N)). Finally, we conclude our paper with certain remarks on Problem 1. 1 and Problem 1.3. | en_US |
dc.identifier.doi | 10.1007/BF02829762 | |
dc.identifier.endpage | 137 | en_US |
dc.identifier.issn | 0253-4142 | |
dc.identifier.issue | 2 | en_US |
dc.identifier.scopus | 2-s2.0-0038343514 | en_US |
dc.identifier.scopusquality | Q3 | en_US |
dc.identifier.startpage | 99 | en_US |
dc.identifier.uri | https://doi.org/10.1007/BF02829762 | |
dc.identifier.uri | https://hdl.handle.net/11411/7024 | |
dc.identifier.volume | 113 | en_US |
dc.identifier.wos | WOS:000183416900002 | en_US |
dc.identifier.wosquality | Q4 | en_US |
dc.indekslendigikaynak | Web of Science | en_US |
dc.indekslendigikaynak | Scopus | en_US |
dc.language.iso | en | en_US |
dc.publisher | Indian Academy Sciences | en_US |
dc.relation.ispartof | Proceedings of The Indian Academy of Sciences-Mathematical Sciences | en_US |
dc.relation.publicationcategory | Makale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanı | en_US |
dc.rights | info:eu-repo/semantics/closedAccess | en_US |
dc.title | On the local Artin conductor fArtin (?) of a character ? of Gal(E/K) -: II | en_US |
dc.type | Article | en_US |