On Small Iwasawa Invariants and Imaginary Quadratic Fields

نویسندگان

  • JONATHAN W. SANDS
  • J. W. SANDS
چکیده

If p is an odd prime that does not divide the class number of the imaginary quadratic field k , and the cyclotomic Z -extension of k has A-invariant less than or equal to two, we prove that every totally ramified Z extension of k has //-invariant equal to zero and A-invariant less than or equal to two. Combined with a result of Bloom and Gerth, this has the consequence that ß = 0 for every Z -extension of k , under the same assumptions. In the principal case under consideration, Iwasawa's formula for the power of p in the class number of the «th layer of a Z -extension becomes valid for all n , and is completely explicit.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Heuristics for class numbers and lambda invariants

Let K = Q( √ −d) be an imaginary quadratic field and let Q( √ 3d) be the associated real quadratic field. Starting from the Cohen-Lenstra heuristics and Scholz’s theorem, we make predictions for the behaviors of the 3-parts of the class groups of these two fields as d varies. We deduce heuristic predictions for the behavior of the Iwasawa λ-invariant for the cyclotomic Z3extension of K and test...

متن کامل

Computation of Iwasawa ν-invariants of certain real abelian fields

Let p be a prime number and k a finite extension of Q. It is conjectured that Iwasawa invariants λp(k) and μp(k) vanish for all p and totally real number fields k. Using cyclotomic units and Gauss sums, we give an effective method for computing the other Iwasawa invariants νp(k) of certain real abelian fields. As numerical examples, we compute Iwasawa invariants associated to k = Q( √ f, ζp + ζ...

متن کامل

J ul 2 00 8 On fake Z p - extensions of number fields

For an odd prime number p, let Fanti be the Zp-anticyclotomic extension of an imaginary quadratic field F . We focus on the non-normal subextension K∞ of Fanti fixed by a subgroup of order 2 in Gal(Fanti/Q). After providing a general result for dihedral extensions, we study the growth of the p-part of the class group of the subfields ofK∞/Q, providing a formula of Iwasawa type. Furthermore, we ...

متن کامل

On the real quadratic fields with certain continued fraction expansions and fundamental units

The purpose of this paper is to investigate the real quadratic number fields $Q(sqrt{d})$ which contain the specific form of the continued fractions expansions of integral basis element  where $dequiv 2,3( mod  4)$ is a square free positive integer. Besides, the present paper deals with determining the fundamental unit$$epsilon _{d}=left(t_d+u_dsqrt{d}right) 2left.right > 1$$and  $n_d$ and $m_d...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2010