AI 中文总结
本文研究乘积多项式自同态下曲线的双次数指数增长,并证明非预周期曲线与不变曲线的交点并集在Zariski拓扑下稠密,推广了Silverman定理。
AI 中文摘要
我们研究在乘积多项式自同态 $\varphi=(f,g)$ 作用下,$\mathbb{P}^1 \times \mathbb{P}^1$ 中一条丰沛不可约曲线的双次数增长,其中 $f$ 和 $g$ 至少有一个是非例外的。我们证明,如果曲线 $C$ 对任意 $a,b\geq 1$ 都不是 $(f^a,g^b)$-预周期的,那么 $\varphi^n(C)$ 的双次数渐近于 $(°(g)^n,°(f)^n)$。作为这一指数增长的应用,我们证明了 Silverman 关于轨道中 $S$-整点有限性定理的几何类比。即如果 $C$ 不是 $(f^a,g^b)$-预周期的且 $C'$ 对 $\varphi$ 不是完全不变的,那么对任意正整数无穷序列 $\{n_i\}$,交集之并 $$ \bigcup_{i \geq 1} \left( \varphi^{n_i}(C)\cap C' \right) $$ 在 $C'$ 中是 Zariski 稠密的。
英文摘要
We study the growth of the bidegree of an ample irreducible curve in $\mathbb{P}^1 \times \mathbb{P}^1$ under a product polynomial endomorphism $φ=(f,g)$, where at least one of $f$ and $g$ is non-exceptional. We prove that, if the curve $C$ is not preperiodic under $(f^a,g^b)$ for any $a,b\geq 1$, then the bidegree of $φ^n(C)$ is asymptotic to $(\text{deg}(g)^n,\text{deg}(f)^n)$. As an application of this exponential growth, we prove a geometric analogue of Silverman's theorem on the finiteness of $S$-integral points in orbits. Namely if $C$ is not $(f^a,g^b)$-preperiodic and $C'$ is not totally invariant for $φ$, then for any infinite sequence ${n_i}$ of positive integers, the union of the intersections $$ \bigcup_{i \geq 1} \left( φ^{n_i}(C)\cap C' \right) $$ is Zariski dense in $C'$.