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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,742 papers · 148 categories

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19385675 · May 202619922001200920172026
48 results for nef anti-log canonical divisor

Study projective klt pairs with nef anti-canonical divisor and their properties.

problem Characterize properties of projective klt pairs with nef anti-log canonical divisors.
method Analyze maximally rationally connected fibration and use numerical dimension analogy.
result Numerical dimension of anti-log canonical divisor on XX matches that on a general fiber.

The paper classifies certain singular projective varieties with specific properties.

problem Classifying projective klt pairs with nef anti-log canonical divisors.
method Establishes a structure theorem using locally trivial rationally connected fibrations.
result Projective klt pairs can be decomposed into rationally connected and Calabi-Yau varieties.

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

problem Analyzing properties of algebraic fibre spaces with strictly nef relative anti-log canonical divisors.
method Using projective klt pairs and fibration techniques, the paper proves locally constant fibration properties and rational connectedness.
result The fibration is locally constant with rationally connected fibers, and the base is a canonically polarized hyperbolic projective manifold.

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

problem Understanding the fundamental groups of compact Kahler varieties with specific properties.
method Application of geometric analytic theory of Kahler spaces and study of Albanese maps.
result The fundamental group of compact Kahler varieties with nef anti-canonical bundle is almost Abelian.

The paper proves inequalities for orbifold second Chern classes in Fujiki's class.

problem Inequalities for orbifold second Chern classes of compact normal analytic varieties.
method Generic nefness theorems for tangent and cotangent sheaves, and an orbifold Bogomolov--Gieseker inequality for mixed polarizations.
result Semipositivity of the orbifold second Chern class for varieties with nef anti-canonical divisor.

The study of projective varieties with nef anticanonical divisors and log terminal singularities.

problem Understanding the structure and properties of projective varieties with specific divisor conditions.
method Analyzing the Albanese map and MRC fibration for klt projective varieties, showing locally constant fibrations and product decompositions.
result Generalization of results for smooth projective varieties to the klt case, including decomposition into rationally connected and projective varieties with trivial canonical divisor.

In this paper, we show that the canonical divisor of a smooth toroidal compactification of a complex hyperbolic manifold must be nef if the dimension is greater or equal to three. Moreover, if n3n\geq 3 we show that the numerical dimension of the canonical divisor of a smooth nn-dimensional compactification is always …

2015-02-22abs ↗pdf ↗

The Miyaoka-Yau inequality is proven for certain singular varieties with big canonical or anticanonical divisors.

problem Establishing the Miyaoka-Yau inequality for singular varieties with specific divisors.
method Defining the non-pluripolar product and establishing the Bogomolov-Gieseker type inequality for Higgs sheaves; investigating second Chern class inequalities.
result Proven the Miyaoka-Yau inequality for projective klt varieties with big canonical or anticanonical divisors.

The paper classifies minimal projective varieties satisfying a specific equality.

problem Classifying minimal projective varieties with a specific equality.
method Established a structure theorem for minimal projective klt varieties satisfying Miyaoka's equality.
result Minimal projective klt varieties with Miyaoka's equality have semi-ample canonical divisors and specific Kodaira dimensions.

We generalize the maximal time existence of Kähler-Ricci flow in Tian-Zhang and Song-Tian to conical case. Furthermore, if the twisted canonical bundle KM+(1β)[D]K_{M}+(1-β)[D] is big or big and nef, we can expect more on the limit behaviors of such conical Kähler-Ricci flow. Moreover, the results still hold for simple normal …

2014-11-26abs ↗pdf ↗

The paper extends intersection theory for b-divisors, proving monotonicity and volume inequalities.

problem Intersection theory for b-divisors and monotonicity of intersection products.
method Developed general intersection theory of nef b-divisors, defined restricted volume, proved monotonicity.
result Proved quantitative monotonicity of intersection product and new volume inequalities.

The goal of this paper is to study the geometry of cusped complex hyperbolic manifolds through their compactifications. We characterize toroidal compactifications with non-nef canonical divisor. We derive effective very ampleness results for toroidal compactifications of finite volume complex hyperbolic manifolds. We e…

2012-12-03abs ↗pdf ↗

Study Miyaoka-Yau inequality for certain projective manifolds.

problem Proving Miyaoka-Yau inequality for specific types of manifolds.
method Using recent work by K.~Zhang and delta-invariant introduced by Fujita and Odaka.
result Established Miyaoka-Yau type inequality for projective manifolds with nef anti-canonical line bundle.

Paper proves structure of compact Kähler 3-folds with specific bundles.

problem Characterizing compact Kähler 3-folds with nef anti-canonical bundles.
method Minimal Model Program, positivity of direct image sheaves, Q-conic bundles, orbifold vector bundles.
result Compact Kähler 3-folds with nef anti-canonical bundles are essentially one of three types.

The paper proves conditions for minimal compact Kähler manifolds with vanishing second Chern class.

problem Conditions for minimal compact Kähler manifolds with vanishing second Chern class.
method Study of the abundance conjecture and associated Iitaka fibrations.
result For a minimal compact Kähler manifold, the second Chern class vanishes if and only if the cotangent bundle is nef and the canonical bundle has numerical dimension 0 or 1.

The paper shows how compact Kähler manifolds with a special bundle can be broken down into simpler parts.

problem Understanding compact Kähler manifolds with a specific type of anti-canonical bundle.
method Introduced a new approach to extend a strategy from smooth projective varieties to singular Kähler spaces, using a flatness criterion for pseudo-effective sheaves.
result Compact Kähler manifolds with a nef anti-canonical bundle admit a locally trivial fibration with rational connected fibers and a Calabi-Yau base.

The paper provides a combinatorial criterion for realizing tropical pluri-canonical divisors.

problem Determining when a tropical pair corresponds to a smooth algebraic curve with a pluri-canonical divisor.
method Introducing tropical normalized covers and reducing the problem to their realizability.
result Generalizes previous work on tropical canonical divisors and incorporates recent progress on kk-differentials.

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

problem Characterizing finite quotients of projective spaces and Abelian varieties.
method Criterion based on reflexive sheaves and stability conditions.
result Characterization of finite quotients using Q\mathbb{Q}-Chern class inequalities and stability condition.

We use recent results by Bainbridge-Chen-Gendron-Grushevsky-Moeller on compactifications of strata of abelian differentials to give a comprehensive solution to the realizability problem for effective tropical canonical divisors in equicharacteristic zero. Given a pair (Γ,D)(Γ, D) consisting of a stable tropical curve ΓΓ

2017-10-17abs ↗pdf ↗

Fix a K3 lattice ΛΛ of rank two and LΛL\inΛ a big and nef divisor that is positive enough. We prove that the generic ΛΛ-polarised K3 surface has an integral nodal rational curve in the linear system L|L|, in particular strengthening previous work of the first named author. The technique is by degeneration, and also …

2019-07-02abs ↗pdf ↗

Holomorphic vector fields and anti-canonical divisors on complex manifolds are studied.

problem Existence of non-trivial holomorphic vector fields on compact complex manifolds.
method Vanishing result for measure preserving holomorphic vector fields, Gibbs stability, and log terminal singularities.
result No non-trivial holomorphic vector fields on compact complex manifolds with big anti-canonical line bundle.

We compute the class of the closure of the locus of canonical divisors in the projectivization of the Hodge bundle PHg\mathbb{P}\overline{\mathcal{H}}_g over Mg\overline{\mathcal{M}}_g which have a zero at a Weierstrass point. We also show that the strata of canonical and bicanonical divisors with a double zero span ext…

2018-12-12abs ↗pdf ↗

Study on algebraic fiber spaces and their anti-canonical divisors.

problem Understanding positivity conditions and base loci of algebraic fiber spaces.
method Algebraic and analytic methods for positivity of direct image sheaves.
result Algebraic fiber spaces with semi-ample relative anti-canonical divisor have a product structure.

The paper studies foliations on smooth projective varieties and their properties.

problem Characterizing and understanding foliations on smooth projective varieties.
method Develops a structure theorem for smooth projective varieties with almost nef regular foliations, using a smooth morphism and MRC fibration.
result An almost nef regular foliation on a smooth projective variety can be decomposed into a numerically flat regular foliation and a smooth morphism.

We show that a compact Kahler manifold with nonpositive holomorphic sectional curvature has nef canonical bundle. If the holomorphic sectional curvature is negative then it follows that the canonical bundle is ample, confirming a conjecture of Yau. The key ingredient is the recent solution of this conjecture in the pro…

2015-06-03abs ↗pdf ↗

Consider degenerations of Abelian differentials with prescribed number and multiplicity of zeros and poles. Motivated by the theory of limit linear series, we define twisted canonical divisors on pointed nodal curves to study degenerate differentials, give dimension bounds for their moduli spaces, and establish smootha…

2015-04-08abs ↗pdf ↗

The paper constructs a canonical connection on bundles over Riemann surfaces and relates it to the theta divisor.

problem Investigating connections on Riemann surface bundles and their geometric properties.
method Holomorphic connections and symplectic geometry on moduli spaces.
result A symplectic structure-preserving isomorphism between moduli spaces of connections and holomorphic connections on theta divisors.

Counterexample disproves log canonical Beauville--Bogomolov decomposition.

problem Disproving the log canonical Beauville--Bogomolov decomposition.
method Constructing a specific log canonical, K-trivial variety with non-birational fibers.
result Provides a counterexample to the Beauville--Bogomolov decomposition in the log canonical setting.

Study on volumes and scalar curvature in complex geometry, proving new bounds and conditions.

problem Understanding volumes and scalar curvature in complex geometry.
method Asymptotic behavior of Bergman kernel, Kähler-Ricci flow, singular Kähler-Einstein metrics, and gluing techniques.
result New bounds and conditions for volumes and scalar curvature in complex manifolds.

We give a criterion under which a solution g(t) of the Kahler-Ricci flow contracts exceptional divisors on a compact manifold and can be uniquely continued on a new manifold. As t tends to the singular time T from each direction, we prove convergence of g(t) in the sense of Gromov-Hausdorff and smooth convergence away …

2010-03-03abs ↗pdf ↗

Let X be a complex projective variety and D a reduced divisor on X. Under a natural minimal condition on the singularities of the pair (X, D), which includes the case of smooth X with simple normal crossing D, we ask for geometric criteria guaranteeing various positivity conditions for the log-canonical divisor K_X+D. …

2012-07-31abs ↗pdf ↗

It is conjectured that the moduli b-divisor of the Kawamata-Kodaira canonical bundle formula associated to a klt-trivial fibration (X,B)Z(X,B)\to Z is semi-ample. In this paper, we show the semi-ampleness of an arbitrarily small perturbation of the moduli b-divisor by a fixed appropriate divisor which roughly speaking come…

2012-07-17abs ↗pdf ↗

Let O(D)\mathcal{O}(D) be an equivariant line bundle which is big and nef on a complex projective nonsingular toric variety XX. Given a continuous toric metric \|\cdot\| on O(D)\mathcal{O}(D), we define the energy at equilibrium of (X,φDˉ)(X,φ_{\bar{D}}) where φDˉφ_{\bar{D}} is the weight of the metrized toric divisor $\bar{D…

2016-03-07abs ↗pdf ↗