Publications (24)
On lattice polarizable cubic fourfolds
Song Yang, Xun Yu
We extend non-emtpyness and irreducibility of Hassett divisors to the moduli spaces of -polarizable cubic fourfolds for higher rank lattices , which in turn provides a system…
Nonrational varieties with unirational parametrizations of coprime degrees
Song Yang, Xun Yu, Zigang Zhu
We show that there exists a -dimensional family of smooth cubic threefolds admitting unirational parametrizations of coprime degrees. This together with Clemens--Griffiths' work…
Automorphism groups of smooth cubic threefolds
Li Wei, Xun Yu
In this paper, we classify groups which faithfully act on smooth cubic threefolds. It turns out that there are exactly maximal ones and we describe them with explicit examples…
Smooth projective surfaces with infinitely many real forms
Tien-Cuong Dinh, Cécile Gachet, Hsueh-Yung Lin +3
The aim of this paper is twofold. First of all, we confirm a few basic criteria of the finiteness of real forms of a given smooth complex projective variety, in terms of the Galois…
Automorphisms of elliptic surfaces and Salem numbers of maximal degree
Hélène Esnault, Keiji Oguiso, Xun Yu
Using elliptic structures, we show that any supersingular K3 surface of Artin invariant in characteristic , , has an automorphism the entropy of which is the…
On smooth and isolated curves in general complete intersection Calabi-Yau threefolds
Xun Yu
Recently Knutsen found criteria for the curves in a complete linear system on a smooth surface in a nodal K-trivial threefold to deform to a scheme of fin…
Minimum positive entropy of complex Enriques surface automorphisms
Keiji Oguiso, Xun Yu
We determine the minimum positive entropy of complex Enriques surface automorphisms. This together with McMullen's work completes the determination of the minimum positive entropy…
K3 surface entropy and automorphism groups
Xun Yu
We derive a characterization of the complex projective K3 surfaces which have automorphisms of positive entropy in term of their Néron-Severi lattices. Along the way, we classify…
Classification of full exceptional collections of line bundles on three blow-ups of
Wanmin Liu, Song Yang, Xun Yu
A fullness conjecture of Kuznetsov says that if a smooth projective variety admits a full exceptional collection of line bundles of length , then any exceptional collection…
On automorphism groups of smooth hypersurfaces
Song Yang, Xun Yu, Zigang Zhu
We show that smooth hypersurfaces in complex projective spaces with automorphism groups of maximum size are isomorphic to Fermat hypersurfaces, with a few exceptions. For the excep…
Smooth rational projective varieties with non-finitely generated discrete automorphism group and infinitely many real forms
Tien-Cuong Dinh, Keiji Oguiso, Xun Yu
We show, among other things, that for each integer , there is a smooth complex projective rational variety of dimension , with discrete non-finitely generated automorph…
Coble's question and complex dynamics of inertia groups on surfaces
Keiji Oguiso, Xun Yu
We study the inertia groups of some smooth rational curves on 2-elementary K3 surfaces and singular K3 surfaces from the view of topological entropy, with an application to a long…
On K3 surfaces with hyperbolic automorphism groups
Koji Fujiwara, Keiji Oguiso, Xun Yu
We show the finiteness of the Néron-Severi lattices of complex projective K3 surfaces whose automorphism groups are non-elementary hyperbolic with explicit descriptions, under the…
On the number of real forms of a complex variety
Gerard van der Geer, Xun Yu
We give a bound on the number of weighted real forms of a complex variety with finite automorphism group, where the weight is the inverse of the number of automorphisms of the real…
Bloch's conjecture for (anti-)autoequivalences on K3 surfaces
Zhiyuan Li, Xun Yu, Ruxuan Zhang
In this paper, we investigate Bloch's conjecture for autoequivalence on K3 surfaces. We introduce the notion of reflective autoequivalence of twisted K3 surfaces and prove Bloch's…
Rational cubic fourfolds in Hassett divisors
Song Yang, Xun Yu
We prove that every Hassett's Noether-Lefschetz divisor of special cubic fourfolds contains a union of three codimension-two subvarieties, parametrizing rational cubic fourfolds, i…
Elliptic fibrations on K3 surfaces and Salem numbers of maximal degree
Xun Yu
We study the maximal Salem degree of automorphisms of K3 surfaces via elliptic fibrations. By generalizing \cite{EOY14}, we establish a characterization of such maximum in terms of…
Automorphism groups of smooth quintic threefolds
Keiji Oguiso, Xun Yu
We study automorphism groups of smooth quintic threefolds. Especially, we describe all the maximal ones with explicit examples of target quintic threefolds. There are exactly …
PLOT-CT: Pre-log Voronoi Decomposition Assisted Generation for Low-dose CT Reconstruction
Bin Huang, Xun Yu, Yikun Zhang +3
Low-dose computed tomography (LDCT) reconstruction is fundamentally challenged by severe noise and compromised data fidelity under reduced radiation exposure. Most existing methods…
Automorphism groups of cubic fivefolds and fourfolds
Song Yang, Xun Yu, Zigang Zhu
In this paper, we introduce notions of partitionability and characteristic sets of homogeneous polynomials and give a complete classification of groups faithfully acting on smooth…
Smooth complex projective rational surfaces with infinitely many real forms
Tien-Cuong Dinh, Keiji Oguiso, Xun Yu
We construct a smooth complex projective rational surface with infinitely many mutually non-isomorphic real forms. This gives the first definite answer to a long standing open ques…
McKay correspondence and new Calabi-Yau threefolds
Xun Yu
In this note, we consider crepant resolutions of the quotient varieties of smooth quintic threefolds by Gorenstein group actions. We compute their Hodge numbers via McKay correspon…
On Castelnuovo theory and non-existence of smooth isolated curves in quintic threefolds
Xun Yu
We give some necessary conditions for a smooth irreducible curve to be isolated in a smooth quintic threefold, and also find a lower bound for $h^1(\mathcal…
Hodge cohomology on blow-ups along subvarieties
Sheng Rao, Song Yang, Xiangdong Yang +1
We establish a blow-up formula for Hodge cohomology of locally free sheaves on smooth proper varieties over an algebraically closed field of positive characteristic. For this, we i…