Continued fractions, special values of the double sine function, and Stark units over real quadratic fields☆
Continued fractions, special values of the double sine function, and Stark units over real quadratic fields☆
复制标题
连分数、双正弦函数的特殊值、实二次域上的斯塔克单位☆
DOI:
10.1016/j.jnt.2006.09.011
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发表时间:
2007
影响因子:
0.7
通讯作者:
Brett A. Tangedal
中科院分区:
文献类型:
--
作者:
Brett A. Tangedal
Let F be a real quadratic field and m an integral ideal of F. Two Stark units, εm,1and εm,2, are conjectured to exist corresponding to the two different embeddings of F into R. We define new ray class invariants Um(1)(C+) and Um(2)(C+) associated to each class C+of the narrow ray class group modulo m and dependent separately on the two different embeddings of F into R. These invariants are defined as a product of special values of the double sine function in a compact and canonical form using a continued fraction approach due to Zagier and Hayes. We prove that both Stark units εm,1and εm,2, assuming they exist, can be expressed simultaneously and symmetrically in terms of Um(1)(C+) and Um(2)(C+), thus giving a canonical expression for every existent Stark unit over F as a product of double sine function values. We prove that Stark units do exist as predicted in certain special cases.