English

Embeddings of weighted projective spaces

Algebraic Geometry 2026-02-25 v1 Combinatorics

Abstract

Let XX be a projective toric variety of dimension nn and let LL be a ample line bundle on XX. For k0k \geq 0, it is in general difficult to determine whether LkL^{\otimes k} is very ample and whether it additionally gives a projectively normal embedding. These two properties are equivalent to the very ampleness, respectively normality, of the corresponding polytope. By a result of Ewald-Wessels, both statements are classically known to hold for kn1k \geq n - 1. We study embeddings of weighted projective spaces P(a0,...,an)\mathbb{P}(a_0, ..., a_n) via their corresponding rectangular simplices Δ(λ1,...,λn)\Delta(\lambda_1, ..., \lambda_n). We give multiple criteria (depending on arithmetic properties of the weights aia_i) to obtain bounds for the power kk which are sharp in many cases. We also introduce combinatorial tools that allow us to systematically construct families exhibiting extremal behaviour. These results extend earlier work of Payne, Hering and Bruns-Gubeladze.

Keywords

Cite

@article{arxiv.2510.05076,
  title  = {Embeddings of weighted projective spaces},
  author = {Praise Adeyemo and Dominic Bunnett and Fabián Levicán-Santibáñez},
  journal= {arXiv preprint arXiv:2510.05076},
  year   = {2026}
}

Comments

28 pages, comments are welcome!

R2 v1 2026-07-01T06:19:38.610Z