Details

Autor(en) / Beteiligte

• IZADI, FARZALI
• KHOSHNAM, FOAD
• MOODY, DUSTIN
• ZARGAR, ARMAN SHAMSI 

Titel

ELLIPTIC CURVES ARISING FROM BRAHMAGUPTA QUADRILATERALS

Ist Teil von

• Bulletin of the Australian Mathematical Society, 2014-08, Vol.90 (1), p.47-56

Ort / Verlag

Cambridge, UK: Cambridge University Press

Erscheinungsjahr

2014

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• A Brahmagupta quadrilateral is a cyclic quadrilateral whose sides, diagonals and area are all integer values. In this article, we characterise the notions of Brahmagupta, introduced by K. R. S. Sastry [‘Brahmagupta quadrilaterals’, Forum Geom. 2 (2002), 167–173], by means of elliptic curves. Motivated by these characterisations, we use Brahmagupta quadrilaterals to construct infinite families of elliptic curves with torsion group $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\mathbb{Z}/2\mathbb{Z}\times \mathbb{Z}/2\mathbb{Z}$ having ranks (at least) four, five and six. Furthermore, by specialising we give examples from these families of specific curves with rank nine.