Extension of Hodge norms at infinity

TL;DR

This paper addresses extending Hodge norms at infinity to facilitate algebraic compactifications of period maps, focusing on constructing a unifying plurisubharmonic function for complex manifolds.

Contribution

It demonstrates the existence of a function extending all Hodge norms along intersecting strata, aiding in the extension of holomorphic functions at infinity.

Findings

Established the existence of a function extending Hodge norms on strata

Facilitates the construction of plurisubharmonic exhaustion functions

Advances the algebraic understanding of compactifications in Hodge theory

Abstract

It is a long-standing problem in Hodge theory to generalize the Satake--Baily--Borel (SBB) compactification of a locally Hermitian symmetric space to arbitrary period maps. A proper topological SBB-type completion has been constructed, and the problem of showing that the construction is algebraic has been reduced to showing that the compact fibres A of the completion admit neighborhoods X satisfying certain properties. All but one of those properties has been established; the outstanding problem is to show that holomorphic functions on certain divisors "at infinity" extend to X. Extension theorems of this type require that the complex manifold X be pseudoconvex; that is, admit a plurisubharmonic exhaustion function. The neighborhood X is stratified, and the strata admit Hodge norms which are may be used to produce plurisubharmonic functions on the strata. One would like to extend these norms to X so that they may be used to construct the desired plurisubharmonic exhaustion of X. The purpose of this paper is show that there exists a function that simultaneously extends all the Hodge norms along the strata that intersect the fibre A nontrivially.