English

Blowups of smooth hypersurfaces, their birational geometry and divisorial stability

Algebraic Geometry 2026-05-06 v3

Abstract

Let XX be a smooth nn-dimensional Fano hypersurface in Pn+1\mathbb P^{n+1} where n3n \geq 3. Let Γ\Gamma be a smooth positive-dimensional complete intersection of XX, a hypersurface and one of more hyperplanes in Pn+1\mathbb P^{n+1}. Let YXY \to X be the blowup of XX along Γ\Gamma. Let φ ⁣:YX\varphi \colon Y \rightarrow X be the blowup of XX along Γ\Gamma. We describe the Mori chamber decomposition of YY and its associated birational models. In particular, we show that YY is a Mori dream space. We classify for which XX and Γ\Gamma the variety YY is a Fano manifold and, if XX is a hyperplane, we classify the elementary Sarkisov links initiated by φ\varphi. Finally, we use this Mori chamber decomposition above to prove that certain Fano manifolds as above do not admit a K\"ahler-Einstein metric.

Keywords

Cite

@article{arxiv.2311.11386,
  title  = {Blowups of smooth hypersurfaces, their birational geometry and divisorial stability},
  author = {Livia Campo and Tiago Duarte Guerreiro and Erik Paemurru},
  journal= {arXiv preprint arXiv:2311.11386},
  year   = {2026}
}

Comments

21 pages. Updated the title and abstract to match the published version