arXiv research

Extends K-stability theory to projective klt pairs with a big anticanonical class.

Uniformizes klt pairs using bounded symmetric domains.

Equality in Miyaoka-Yau inequality implies uniformization of Klt pairs.

The paper classifies certain singular projective varieties with specific properties.

The paper proves conditions for the Abundance conjecture in minimal projective klt pairs.

Let (X,D) be a klt pair. Assuming either K_X+D big or -(K_X+D) ample, and that the coefficients of D are greater than 1/2, we show that the Kähler-Einstein metric attached to (X,D) -whenever it exists- has cone singularities along D on the log-smooth locus of the pair intersected with the ample locus of K_X+D (in the n…

Reductive quotients preserve klt singularities in algebraic geometry.

We prove a version of Jonsson-Mustaţǎ's Conjecture, which says for any graded sequence of ideals, there exists a quasi-monomial valuation computing its log canonical threshold. As a corollary, we confirm Chi Li's conjecture that a minimizer of the normalized volume function is always quasi-monomial. Applying our techni…

In this paper, we study a projective klt pair $(X, Δ)$ with the nef anti-log canonical divisor $-(K_X+Δ)$ and its maximally rationally connected fibration $ψ: X \dashrightarrow Y$. We prove that the numerical dimension of the anti-log canonical divisor $-(K_X+Δ)$ on $X$ coincides with that of the anti-log canonical div…

We show that in any $\mathbb{Q}$-Gorenstein flat family of klt singularities, normalized volumes are lower semicontinuous with respect to the Zariski topology. A quick consequence is that smooth points have the largest normalized volume among all klt singularities. Using an alternative characterization of K-semistabili…

The paper studies fundamental groups of compact Kahler varieties with nef anti-canonical bundles.

We show that in any $\mathbb{Q}$-Gorenstein flat family of klt singularities, normalized volumes can only jump down at countably many subvarieties. A quick consequence is that smooth points have the largest normalized volume among all klt singularities. Using an alternative characterization of K-semistability developed…

The Chow-Mumford (CM) line bundle is a functorial line bundle on the base of any family of klt Fano varieties. It is conjectured that it yields a polarization on the moduli space of K-poly-stable klt Fano varieties. Proving ampleness of the CM line bundle boils down to showing semi-positivity/positivity statements abou…

The paper studies algebraic fibre spaces with specific properties and proves key results about their structure.

Surveying stability of klt singularities with new solutions.

Study projective KLT varieties with projectively flat cotangent sheaves.

We study several questions involving relative Ricci-flat Kähler metrics for families of log Calabi-Yau manifolds. Our main result states that if $p:(X,B)\to Y$ is a Kähler fiber space such that $\displaystyle (X_y, B|_{X_y})$ is generically klt, $K_{X/Y}+B$ is relatively trivial and $p_*(m(K_{X/Y}+B))$ is Hermitian fla…

The minimizer of a volume function is unique for klt singularities.

In this article we construct a canonical Kähler-Einstein current on a LC (log canonical) pairs of log general type as the limit of a sequence of canonical Kähler-Einstein currents on KLT(Kawamata log terminal) pairs of log general type. We call the volume form associated with the canonical Kähler-Einstein current the c…

In this paper, we prove that the zero-locus of any global holomorphic log-one-form on a projective log-smooth pair $\left(X,D\right)$ of log-general type must be non-empty. Applying this result, we give an answer to the algebraic hyperbolicity part of Shafarevich's conjecture, with the generic fiber being Kawamata-log-…

Generalizes Toledo invariant to singular klt varieties, proving Milnor-Wood inequality.

Proves finitely generated graded rings for klt singularities.

Criterion for projectivisation on klt spaces, characterizing quotients and stability.

The paper proves a key inequality for a specific type of complex spaces.

Paper extends Hodge correspondence to singular Kähler spaces.

We generalise Simpson's nonabelian Hodge correspondence to the context of projective varieties with klt singularities. The proof relies on a descent theorem for numerically flat vector bundles along birational morphisms. In its simplest form, this theorem asserts that given any klt variety X and any resolution of singu…

The paper proves the existence of singular cscK metrics on smoothable varieties.

Complex projective varieties are quotients of polydiscs under specific group actions.

Particle picking is currently a critical step in the cryo-EM single particle reconstruction pipeline. Despite extensive work on this problem, for many data sets it is still challenging, especially for low SNR micrographs. We present the KLT (Karhunen Loeve Transform) picker, which is fully automatic and requires as an …

The paper classifies minimal projective varieties satisfying a specific equality.

Characterizes stable sheaves for equality in orbifold BG inequality.

Study shows boundedness of klt singularities in 3D or with bounded Kollár components.

Study on positivity of CM line bundles on moduli space of klt good minimal models with κ=1.

Establishes Hermite-Einstein metrics on complex spaces with singularities.

The paper proves ACC for local volumes under boundedness conditions.

The study shows how certain singular Kähler metrics can define Kähler currents and RCD spaces.

Proves boundedness of log Fano cone singularities with bounded local volumes.

We prove a criterion for the existence of harmonic metrics on Higgs bundles that are defined on smooth loci of klt varieties. As one application, we resolve the quasi-etale uniformisation problem for minimal varieties of general type to obtain a complete numerical characterisation of singular quotients of the unit ball…

Optimizes bounds for threefold singularity volumes.

This is a survey on the recent theory on minimizing the normalized volume function attached to any klt singularities.

We prove that among all Kollár components obtained by plt blow ups of a klt singularity $o \in (X, D)$, there is at most one that is (log-)K-semistable. We achieve this by showing that if such a Kollár component exists, it uniquely minimizes the normalized volume function introduced in [Li15a] among all divisorial valu…

We investigate the holonomy group of singular Kähler-Einstein metrics on klt varieties with numerically trivial canonical divisor. Finiteness of the number of connected components, a Bochner principle for holomorphic tensors, and a connection between irreducibility of holonomy representations and stability of the tange…

The paper extends structure theorem to projective klt varieties with specific tangent sheaf properties.

Given a klt singularity $x\in (X, D)$, we show that a quasi-monomial valuation $v$ with a finitely generated associated graded ring is the minimizer of the normalized volume function $\widehat{\rm vol}_{(X,D),x}$, if and only if $v$ induces a degeneration to a K-semistable log Fano cone singularity. Moreover, such a mi…

For any flat projective family $(\mX,\mL)\rightarrow C$ such that the generic fibre $\mX_η$ is a klt Q-Fano variety and $\mL|_{\mX_η}\sim_{Q}-K_{X_η}$, we use the techniques from the minimal model program (MMP) to modify the total family. The end product is a family such that every fiber is a klt Q-Fano variety. Moreov…

New findings on Kähler-Einstein currents dominating Kähler forms on compact spaces.

The paper generalizes K-stability results to singular and weighted settings.

We study degenerate complex Monge-Ampère equations of the form $(ω+dd^c \varphi)^n = e^{t \varphi} μ$ where $ω$ is a big semi-positive form on a compact Kähler manifold $X$ of dimension $n$, $t \in \R^+$, and $μ=fω^n$ is a positive measure with density $f\in L^p(X,ω^n)$, $p>1$. We prove the existence and unicity of bou…