A generalized second main theorem for closed subschemes

TL;DR

This paper extends the second main theorem in Nevanlinna theory to closed subschemes in complex projective varieties, providing a more general inequality that encompasses previous results and includes a Diophantine approximation counterpart.

Contribution

It introduces a generalized second main theorem for closed subschemes in subgeneral position, unifying and extending prior results in value distribution theory.

Findings

Established a new inequality for holomorphic curves intersecting subschemes.

Unified previous second main theorems for general and subgeneral positions.

Provided a Schmidt's subspace theorem analogue for closed subschemes.

Abstract

Let $Y_{1}, \ldots, Y_{q}$ be closed subschemes which are located in $\ell$-subgeneral position with index $\kappa$ in a complex projective variety $X$ of dimension $n.$ Let $A$ be an ample Cartier divisor on $X.$ We obtain that if a holomorphic curve $f:\mathbb C \to X$ is Zariski-dense, then for every $\epsilon >0,$ \begin{eqnarray*} \sum^{q}_{j=1}\epsilon_{Y_{j}}(A)m_{f}(r,Y_{j})\leq_{exc} \left(\frac{(\ell-n+\kappa)(n+1)}{\kappa}+\epsilon\right)T_{f,A}(r). \end{eqnarray*}This generalizes the second main theorems for general position case due to Heier-Levin [AM J. Math. 143(2021), no. 1, 213-226] and subgeneral position case due to He-Ru [J. Number Theory 229(2021), 125-141]. In particular, whenever all the $Y_j$ are reduced to Cartier divisors, we also give a second main theorem with the distributive constant. The corresponding Schmidt's subspace theorem for closed subschemes in Diophantine approximation is also given.