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Related papers: K-moduli of Fano threefolds and genus four curves

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We study K-stability of smooth Fano threefolds of Picard rank $2$ and degree $22$ which can be obtained by blowing up a smooth complete intersection of two quadrics in $\mathbb{P}^5$ along a conic. We also describe the automorphism groups…

We prove that every smooth Fano threefold from the family No 2.8 is K-stable. Such a Fano threefold is a double cover of the blow-up of $\mathbb{P}^3$ at one point branched along an anti-canonical divisor.

Algebraic Geometry · Mathematics 2022-11-16 Yuchen Liu

The K-moduli space of Fano varieties has been popular in recent research of algebraic geometry. There has been a lot of progress in dimension 3 and we will try to construct explicitly a compactified K-moduli space for the Fano family 2.24.

Algebraic Geometry · Mathematics 2023-09-29 Dongchen Jiao

In this note, we prove two results regarding the variation of K-moduli. The first one reveals the relationship between the chamber decomposition for K-semistable domains and the variation of GIT. The second one presents the relationship…

Algebraic Geometry · Mathematics 2026-03-16 Fei Si , Zheng Zhang , Chuyu Zhou

By work of Looijenga and others, one has a good understanding of the relationship between GIT and Baily-Borel compactifications for the moduli spaces of degree 2 K3 surfaces, cubic fourfolds, and a few other related examples. The…

Algebraic Geometry · Mathematics 2019-08-15 Radu Laza , Kieran G. O'Grady

Explicit birational geometry of 3-folds represents a second phase of Mori theory, going beyond the foundational work of the 1980s. This paper is a tutorial and colloquial introduction to the explicit classification of Fano 3-folds (Q-Fano…

Algebraic Geometry · Mathematics 2007-05-23 Selma Altınok , Gavin Brown , Miles Reid

We produce a list of 64 families of Fano fourfolds of K3 type, extracted from our database of at least 634 Fano fourfolds constructed as zero loci of general global sections of completely reducible homogeneous vector bundles on products of…

Algebraic Geometry · Mathematics 2025-05-23 Marcello Bernardara , Enrico Fatighenti , Laurent Manivel , Fabio Tanturri

We analyse the local structure of the K-moduli space of Fano varieties at a toric singular K-polystable Fano 3-fold, which deforms to smooth Fano 3-folds with anticanonical volume 28 and Picard rank 4. In particular, by constructing an…

Algebraic Geometry · Mathematics 2024-10-04 Liana Heuberger , Andrea Petracci

We show that the moduli space of elliptic curves of minimal degree in a general Fano variety of lines of a cubic fourfold is a non-singular curve of genus $631$. The curve admits a natural involution with connected quotient. We find that…

Algebraic Geometry · Mathematics 2020-01-20 Denis Nesterov , Georg Oberdieck

We explicitly determine the optimal degenerations of Fano threefolds $X$ in family No 2.23 of Mori-Mukai's list as predicted by the Hamilton-Tian conjecture. More precisely, we find a special degeneration $(\mathcal{X}, \xi_0)$ of $X$ such…

Algebraic Geometry · Mathematics 2026-04-14 Minghao Miao , Linsheng Wang

Building on the work of Mukai, we explore the birational geometry of the moduli spaces M_{S,L} of semistable rank two torsion-free sheaves, with c_1=-K_S and c_2=2, on a polarized degree one del Pezzo surface (S,L); this is related to the…

Algebraic Geometry · Mathematics 2018-09-18 C. Casagrande , G. Codogni , A. Fanelli

General hyperplane sections of a Fano threefold $Y$ of index 2 and Picard rank 1 are del Pezzo surfaces, and their Picard group is related to a root system. To the corresponding roots, we associate objects in the Kuznetsov component of $Y$…

Algebraic Geometry · Mathematics 2025-08-06 Matteo Altavilla , Marin Petkovic , Franco Rota

We establish an algebraic approach to prove the properness of moduli spaces of K-polystable Fano varieties and reduce the problem to a conjecture on destabilizations of K-unstable Fano varieties. Specifically, we prove that if the stability…

Algebraic Geometry · Mathematics 2021-07-20 Harold Blum , Daniel Halpern-Leistner , Yuchen Liu , Chenyang Xu

We study the moduli space $\mathcal{F}_{T_1}$ of quasi-trielliptic K3 surfaces of type I, whose general member is a smooth bidegree $(2,3)$-hypersurface of $\mathbb{P}^1\times \mathbb{P}^2$. Such moduli space plays an important role in the…

Algebraic Geometry · Mathematics 2023-01-02 Yitao Chen , Haoyu Wu , Hanyu Yao

This survey article is an accompaniment to the 2025 Summer Research Institute in Algebraic Geometry Bootcamp on K-stability and K-moduli. It is aimed at graduate students and intended to provide the necessary background to begin research on…

Algebraic Geometry · Mathematics 2026-02-26 Kristin DeVleming

We introduce a new subclass of Fano varieties (Casagrande-Druel varieties), that are $n$-dimensional varieties constructed from Fano double covers of dimension $n-1$. We conjecture that a Casagrande-Druel variety is K-polystable if the…

Algebraic Geometry · Mathematics 2023-09-25 Ivan Cheltsov , Tiago Duarte Guerreiro , Kento Fujita , Igor Krylov , Jesus Martinez-Garcia

We study moduli spaces of stable objects in the Kuznetsov components of Fano threefolds. We prove a general non-emptiness criterion for moduli spaces, which applies to the cases of prime Fano threefolds of index $1$, degree $10 \leq d \leq…

Algebraic Geometry · Mathematics 2024-06-14 Chunyi Li , Yinbang Lin , Laura Pertusi , Xiaolei Zhao

We study the behaviour on some nodal hyperplanes of the isomorphism, described in a paper of 2019 by Boissi\`ere, Camere and Sarti, between the moduli space of smooth cubic threefolds and the moduli space of hyperk\"ahler fourfolds of…

Algebraic Geometry · Mathematics 2025-03-27 Lucas Li Bassi

A general curve $C$ of genus six is canonically embedded into the smooth del Pezzo surface $\Sigma \subseteq \mathbb{P}^1 \times \mathbb{P}^2$ of degree $5$ as a divisor in the class $\mathcal{O}_{\Sigma}(2,2)$. In this article, we study…

Algebraic Geometry · Mathematics 2023-04-27 Junyan Zhao

We give new proofs of the K-polystability of two smooth Fano threefolds. One of them is a~smooth divisor in $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^2$ of degree $(1,1,1)$, which is unique up to isomorphism. Another one is the~blow…

Algebraic Geometry · Mathematics 2021-07-13 Ivan Cheltsov , Hendrik Süß