English

Configurations of points on a line up to scaling or translation

Algebraic Geometry 2024-01-23 v3

Abstract

We prove that the Losev--Manin compactification of the space of configurations of nn points on P1\{0,}{\mathbb P}^1 \backslash \{0,\infty\} modulo scaling degenerates (isotrivially) to a compactification of the space of configurations of nn points on A1{\mathbb A}^1 modulo translation. The latter resembles the compactification constructed by Ziltener and Mau--Woodward, but allows the marked points to coincide, making it a Gan1{\mathbb G}_a^{n-1}-variety, which mirrors the fact that the Losev--Manin space is toric. The degeneration is compatible with the actions of Gmn1{\mathbb G}_m^{n-1} and Gan1{\mathbb G}_a^{n-1} in the sense that these actions fit together globally in the total space of the degeneration.

Keywords

Cite

@article{arxiv.2102.11357,
  title  = {Configurations of points on a line up to scaling or translation},
  author = {Adrian Zahariuc},
  journal= {arXiv preprint arXiv:2102.11357},
  year   = {2024}
}

Comments

The paper is superseded by arXiv:2111.13743 (which improves the methods, results, and style of the current paper) and no longer intended for publication