The Period-index Problem in Wc-groups Iii: Biconic Curves
نویسنده
چکیده
This note continues our study of the period-index problem in the Weil-Châtelet group of an elliptic curve, begun in [6]. In this paper, we conjectured that for any elliptic curve E/K defined over a number field and any prime number p, there exists an infinite subgroup G of H(K,E), every nonzero element of which has period p and index p. This conjecture was proved when E has full p-torsion defined over K. In [7] we went on to pursue analogous questions in the Weil-Châtelet group of a higher-dimensional abelian variety.
منابع مشابه
The Period-index Problem in Wc-groups Ii: Abelian Varieties
We study the relationship between the period and the index of a principal homogeneous space over an abelian variety, obtaining results which generalize work of Cassels and Lichtenbaum on curves of genus one. In addition, we show that the p-torsion in the Shafarevich-Tate group of a fixed abelian variety over a number field k grows arbitarily large when considered over field extensions l/k of bo...
متن کاملThe period-index problem in WC-groups IV: a local transition theorem
Let K be a complete discretely valued field with perfect residue field k. Assuming upper bounds on the relation between period and index for WC-groups over k, we deduce corresponding upper bounds on the relation between period and index for WC-groups over K. Up to a constant depending only on the dimension of the torsor, we recover theorems of Lichtenbaum and Milne in a “duality free” context. ...
متن کاملThe Period-index Problem in Wc-groups I: Elliptic Curves
Let E/K be an elliptic curve defined over a number field, and let p be a prime number such that E(K) has full p-torsion. We show that the order of the p-part of the Shafarevich-Tate group of E/L is unbounded as L varies over degree p extensions of K. The proof uses O’Neil’s periodindex obstruction. We deduce the result from the fact that, under the same hypotheses, there exist infinitely many e...
متن کاملPeriod-index Problems in Wc-groups Iv: a Local Transition Theorem
Let K be a complete discretely valued field with perfect residue field k. Assuming upper bounds on the relation between period and index for WC-groups over k, we deduce corresponding upper bounds on the relation between period and index for WC-groups over K. Up to a constant depending only on the dimension of the torsor, we recover theorems of Lichtenbaum and Milne in a “duality free” context. ...
متن کاملThe Predictive Value of Waist-To-Height Ratio for Ischemic Stroke in a Population-Based Prospective Cohort Study among Mongolian Men in China
OBJECTIVE To explore the associations between waist-to-height ratio (WHtR), body mass index (BMI) and waist circumference (WC) and risk of ischemic stroke among Mongolian men in China. METHODS A population-based prospective cohort study was conducted from June 2003 to July 2012 in Inner Mongolia, an autonomous region in north China. A total of 1034 men aged 20 years and older free of cardiova...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008