English

Analog of Satake-Baily-Borel for period maps

Algebraic Geometry 2025-04-08 v6

Abstract

We propose an analog of the Satake--Baily--Borel compactification and Borel's extension theorem for arbitrary period maps. The proposed analog is constructed as a proper topological completion of the period map. It is conjectured that the construction is projective algebraic, and the conjecture is reduced to a certain extension problem.

Keywords

Cite

@article{arxiv.2010.06720,
  title  = {Analog of Satake-Baily-Borel for period maps},
  author = {Mark Green and Phillip Griffiths and Colleen Robles},
  journal= {arXiv preprint arXiv:2010.06720},
  year   = {2025}
}

Comments

This is a major revision. The previous version has been separated into two parts; this is Part 1. The previous version erroneously claimed that certain line bundles $\mathrm{det}(F^p)$ descend to the SBB completion. We thank Ben Bakker for providing a counter-example. We are able to show that the product $\prod_p\,\mathrm{det}(F^p)^{\otimes m_p}$ descends, for suitable choice of $m_p > 0$