270 research outputs found
Einseinheitengruppen und prime Restklassengruppen in quadratischen Zahlkörpern
AbstractIn this note we calculate explicitly bases of the group of einseinheiten in local quadratic number fields and apply the result for the description of the structure of the prime residue class groups modulo prime divisor powers in an arbitrary quadratic number field
Quadratische ordnungen mit groĂer Klassenzahl
AbstractAn estimate for the class number of certain quadratic orders from below is given. The method is elementary and applies for imaginary and real quadratic orders of Richaud-Degert and similar types, which usually have large class numbers
Localizing Systems, Module Systems, and Semistar Operations
AbstractWe present the concept of module systems for cancellative monoid. This concept is a common generalization of the notion of an ideal system (as presented by F. Halter-Koch (âIdeal Systems,â Dekker, New York, 1997)) and the notion of a semistar operation (as introduced by A. Okabe and R. Matsuda (Math. J. Toyama Univ.17 (1994), 1â21)). It allows a new insight into the connection between semistar operations and localizing systems (as developed in by M. Fontana and J. A. Huckaba (in âCommutative Rings in a Non-Noetherian Settingâ (S. T. Chapman and S. Glanz, Eds.), Kluwer Academic, Dordrecht/Norwell, MA, 2000)), a general theory of flatness (including results of M. Fontana (in âAdvances in Commutative Ring Theoryâ (D. E. Dobbs et al., Eds.), pp. 271â306, Dekker, New York, 1999) and S. Gabelli (in âAdvances in Commutative Ring Theoryâ (D. E. Dobbs et al., Eds.), pp. 391â409, Dekker, New York, 1999)) and a new presentation of the theory of generalized integral closures
A characterization of Krull rings with zero divisors
summary:It is proved that a Marot ring is a Krull ring if and only if its monoid of regular elements is a Krull monoid
Ring class fields modulo 8 of Q(â<-m>) and the quartic character of units of Q(â<m>) for mâĄ1 mod 8
The complete integral closure of monoids and domains II
Using geometrical methods we construct primary monoids whose complete integral closure is not completely integrally closed. Such monoids cannot be realized as multiplicative monoids of integral domains with finitely generated groups of
divisibility.
Complete integral closure, Primary monoids
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