English

Critical $L$-values for some quadratic twists of Gross curves

Number Theory 2019-04-19 v1

Abstract

Let K=Q(q)K=\Bbb Q(\sqrt{-q}), where qq is a prime congruent to 33 modulo 44. Let A=A(q)A=A(q) denote the Gross curve. Let E=A(β)E=A^{(-\beta)} denote its quadratic twist, with β=q\beta=\sqrt{-q}. The curve EE is defined over the Hilbert class field HH of KK. We use Magma to calculate the values L(E/H,1)L(E/H,1) for all such qq's up to some reasonable ranges (different for q7mod8q\equiv 7 \, \text{mod} \, 8 and q3mod8q\equiv 3 \, \text{mod} \, 8). All these values are non-zero, and using the Birch and Swinnerton-Dyer conjecture, we can calculate hypothetical orders of \sza(E/H)\sza(E/H) in these cases. Our calculations extend those given by J. Choi and J. Coates [{\it Iwasawa theory of quadratic twists of X0(49)X_0(49)}, Acta Mathematica Sinica(English Series) {\bf 34} (2017), 19-28] for the case q=7q=7.

Keywords

Cite

@article{arxiv.1904.08691,
  title  = {Critical $L$-values for some quadratic twists of Gross curves},
  author = {Andrzej Dąbrowski and Tomasz Jędrzejak and Lucjan Szymaszkiewicz},
  journal= {arXiv preprint arXiv:1904.08691},
  year   = {2019}
}