Download PDFOpen PDF in browserCurrent versionSharpP and the Birch and SwinnertonDyer ConjectureEasyChair Preprint 9368, version 14 pages•Date: November 25, 2022AbstractAssuming the Birch and SwinnertonDyer conjecture, an odd squarefree integer $n$ is a congruent number if and only if the number of triplets of integers $(x, y, z)$ satisfying $2 \cdot x^{2} + y^{2} + 8 \cdot z^{2} = n$ is twice the number of triplets satisfying $2 \cdot x^{2} + y^{2} + 32 \cdot z^{2} = n$ due to Tunnell's theorem. However, we show these equations are instances of a variant of counting solutions of the homogeneous Diophantine equations of degree two which is a $\textit{\#Pcomplete}$ problem. Deciding whether $n$ is congruent or not is a problem in $NP$ since congruent numbers could be easily checked by a congruum, because of every congruent number is a product of a congruum and the square of a rational number. We conjecture that if $P = NP$ and $FP \neq \#P$, then the Birch and SwinnertonDyer conjecture would be false. Keyphrases: Boolean formula, completeness, complexity classes, polynomial time
