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arXiv 2012.04139math.NThep-phhep-th
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关于立方和与和的立方的丢番图方程

Diophantine equations with sum of cubes and cube of sum

Bogdan A. Dobrescu, Patrick J. Fox

AI总结:

本文研究形如 a(x³+y³+z³)=(x+y+z)³ 的丢番图方程,利用椭圆曲线方法刻画其非平凡解的存在性与数量,并给出 a=9 时的通解,同时说明其在粒子物理费米子荷问题中的应用。

摘要:

我们求解了形如 $ a \\, (x^3 \\!+ \\! y^3 \\!+ \\! z^3 ) = (x \\! + \\! y \\! + \\! z)^3$ 的丢番图方程,其中 $x,y,z$ 为整数变量,系数 $a\neq 0$ 为有理数。我们证明这类方程存在无穷多个族,包括 $a$ 为任意立方数或某些有理分数时,方程具有非平凡解。同时也存在无穷多个没有非平凡解的方程族,包括 $1/a = 1- 24/m$ 且整数 $m$ 受到某些限制的情形。除非 $a = 9$ 或 1,否则这些方程都可以用椭圆曲线表示;并且任何具有非零 $j$-不变量以及挠群为 $\mathbb{Z}/3k\mathbb{Z}$($k = 2,3,4$)或 $\mathbb{Z}/2\mathbb{Z} \times \mathbb{Z}/6\mathbb{Z}$ 的椭圆曲线都对应于某个特定的 $a$。我们证明,对任意 $a$,非平凡解的个数至多为 3 或为无穷多;而当 $a$ 为整数时,非平凡解的个数为 0 或 $\infty$。对于 $a = 9$,我们找到了依赖于两个整数参数的通解。这些三次方程在粒子物理中很重要,因为它们决定了 $U(1)$ 规范群下的费米子荷。

英文摘要:

We solve Diophantine equations of the type $ a \, (x^3 \!+ \! y^3 \!+ \! z^3 ) = (x \! + \! y \! + \! z)^3$, where $x,y,z$ are integer variables, and the coefficient $a\neq 0$ is rational. We show that there are infinite families of such equations, including those where $a$ is any cube or certain rational fractions, that have nontrivial solutions. There are also infinite families of equations that do not have any nontrivial solution, including those where $1/a = 1- 24/m$ with restrictions on the integer $m$. The equations can be represented by elliptic curves unless $a = 9$ or 1, and any elliptic curve of nonzero $j$-invariant and torsion group $\mathbb{Z}/3k\mathbb{Z}$ for $k = 2,3,4$, or $\mathbb{Z}/2\mathbb{Z} \times \mathbb{Z}/6\mathbb{Z} $ corresponds to a particular $a$. We prove that for any $a$ the number of nontrivial solutions is at most 3 or is infinite, and for integer $a$ it is either 0 or $\infty$. For $a = 9$, we find the general solution, which depends on two integer parameters. These cubic equations are important in particle physics, because they determine the fermion charges under the $U(1)$ gauge group.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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