4-RANKS OF CLASS GROUPS OF QUADRATIC EXTENSIONS OF CERTAIN QUADRATIC FUNCTION FIELDS

Class Groups of Quadratic Fields

The author has computed the class groups of all complex quadratic number fields Q(\f^~D) °f discriminant D for 0 < D < 4000000. In so doing, it was found that the first occurrences of rank three in the 3-Sylow subgroup are D = 3321607 = prime, class group C(3) x C(3) x C(9.7) (C(n) a cyclic group of order n), and D = 3640387 = 421.8647, class group C(3) X C(3) X C(9.2). The author has also foun...

extensions, minimality and idempotents of certain semigroup compactifications

در فصل اول مقدمات و پیش نیازهای لازم برای فصل های بعدی فراهم گردیده است . در فصل دوم مساله توسیع مورد توجه قرار گرفته و ابتدا شرایطی که تحت آن از یک فشرده سازی نیم گروهی خاص یک زیرگروه نرمال بسته یک گروه به یک فشرده سازی متناظر با فشرده سازی اولیه برای گروه رسید مورد بررسی قرار گرفته و سپس ارتیاط بین ساختارهای مختلف روی این دو فشرده سازی از جمله ایده آل های مینیمال چپ و راست و... مورد بررسی قرا...

Quadratic Fields with Cyclic 2-class Groups

For any integer k ≥ 1, we show that there are infinitely many complex quadratic fields whose 2-class groups are cyclic of order 2. The proof combines the circle method with an algebraic criterion for a complex quadratic ideal class to be a square. In memory of David Hayes.

Quadratic Fields with Special Class Groups

For every prime number p > 5 it is shown that, under certain hypotheses on x e Q , the imaginary quadratic fields Q( \/x2p 6xf + 1 ) have ideal class groups with noncyclic p-parts. Several numerical examples with p = 5 and 7 are presented. These include the field Q(v/-4805446123032518648268510536). The 7-part of its class group is isomorphic to C(7) x C(7) x C(7), where C(n) denotes a cyclic gr...

Special units and ideal class groups of extensions of imaginary quadratic fields