English

How to make log structures

Algebraic Geometry 2026-03-26 v3 Number Theory

Abstract

We introduce the concept of a viable generically Gorenstein toroidal crossing (ggtc) space YY. This generalizes the concept of Gorenstein toroidal crossing scheme, which in turn generalizes that of a simple normal crossing scheme. On such a space YY, we define a sheaf LSY\mathcal{LS}_Y, intrinsic to YY, by means of an explicit construction. Our main theorem establishes a bijection between the set LS(Y)\operatorname{LS}(Y) of isomorphism classes of log structures on YY over the log point Speck\operatorname{Spec} k^\dagger that are compatible with the ggtc structure and the set Γ(Y,LSY×)\Gamma(Y,\mathcal{LS}_Y^\times) of nowhere vanishing global sections of LSY\mathcal{LS}_Y. The definition of LSY\mathcal{LS}_Y by explicit construction permits the effective construction of log structures on YY; it also enables logarithmic birational geometry, in particular the construction - in some cases - of resolutions of singular log structures. Our work generalizes [GS06], Theorem 3.22, adapting the original proof with techniques from the theory of 22-groups and local line bundle systems.

Keywords

Cite

@article{arxiv.2312.13867,
  title  = {How to make log structures},
  author = {Alessio Corti and Helge Ruddat},
  journal= {arXiv preprint arXiv:2312.13867},
  year   = {2026}
}

Comments

Substantial revision and extension after referee report

R2 v1 2026-06-28T13:58:43.239Z