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Spins of prime ideals and the negative Pell equation
$x^{2}-2py^{2}=-1$
Published online by Cambridge University Press: 23 November 2018
Abstract
Let $p\equiv 1\hspace{0.2em}{\rm mod}\hspace{0.2em}4$ be a prime number. We use a number field variant of Vinogradov’s method to prove density results about the following four arithmetic invariants: (i)
$16$-rank of the class group
$\text{Cl}(-4p)$ of the imaginary quadratic number field
$\mathbb{Q}(\sqrt{-4p})$; (ii)
$8$-rank of the ordinary class group
$\text{Cl}(8p)$ of the real quadratic field
$\mathbb{Q}(\sqrt{8p})$; (iii) the solvability of the negative Pell equation
$x^{2}-2py^{2}=-1$ over the integers; (iv)
$2$-part of the Tate–Šafarevič group
$\unicode[STIX]{x0428}(E_{p})$ of the congruent number elliptic curve
$E_{p}:y^{2}=x^{3}-p^{2}x$. Our results are conditional on a standard conjecture about short character sums.
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- Research Article
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- Copyright
- © The Authors 2018
Footnotes
The second author is supported by ERC grant agreement No. 670239.
References
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