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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.

168,657 papers · 148 categories

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481115 · Mar 202519922001200920172026
48 results for Iitaka fibrations

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 study shows boundedness and constructs a moduli space for Calabi-Yau fibrations.

problem Boundedness and moduli spaces of K-stable Calabi-Yau fibrations over curves.
method Fixed volumes and Iitaka volumes of general fibers, adiabatic sense construction.
result Constructs a separated coarse moduli space of K-stable Calabi-Yau fibrations.

Study Kodaira dimensions on almost complex manifolds, proving integrability and structural descriptions.

problem Understanding Kodaira dimensions on almost complex manifolds.
method Using pseudoholomorphic pluricanonical maps, defining new dimensions, and applying probabilistic combinatorics.
result Almost complex structures with top Kodaira dimension are integrable, and for compact 4-manifolds, they have elliptic fibration structures.

Analyzes Kodaira-Iitaka dimension and multiplicity using intersection theory.

problem Understanding Kodaira-Iitaka dimension and multiplicity in analytic terms.
method Expresses dimensions and multiplicity in terms of intersection theory of plurisubharmonic envelopes.
result Introduces non-pluripolar numerical Kodaira-Iitaka dimension and shows it dominates the classical dimension.

Given a (meromorphic) fibration f:XYf:X\to Y where XX and YY are compact complex manifolds of dimensions nn and mm, we define LfL_f to be the invertible subsheaf of the sheaf of holomorphic mm-forms of XX given by the saturation of fKYf^*K_Y, where KYK_Y is the canonical sheaf of YY. We define the Kodaira dimension…

2002-11-04abs ↗pdf ↗

In this article, we study the higher-order regularity of the Kähler-Ricci flow on compact Kähler manifolds with semi-ample canonical line bundle. We proved, using a parabolic analogue of Hein-Tosatti's work on collapsing Calabi-Yau metrics, that when the generic fibers of the Iitaka fibration are biholomorphic to each …

2020-01-30abs ↗pdf ↗

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.

By applying the positivity theorem of direct images and a pluricanonical version of the structure theorem on the cohomology jumping loci à la Green-Lazarsfeld-Simpson, we show that the klt Kähler version of the Iitaka conjecture Cn,mC_{n,m} (Ueno, 1975) for f:XYf:X\to Y (surjective morphism between compact Kähler manifolds…

2019-07-15abs ↗pdf ↗

This is the first of a series of papers, in which we study the plurigenera, the Kodaira dimension and more generally the Iitaka dimension on compact almost complex manifolds. Based on the Hodge theory on almost complex manifolds, we introduce the plurigenera, Kodaira dimension and Iitaka dimension on compact almost com…

2018-08-02abs ↗pdf ↗

Study nondegenerate fibrations of Euclidean spaces and their relation to sphere fibrations.

problem Classify and understand nondegenerate fibrations of Euclidean spaces.
method Topological and geometric analysis of nondegenerate fibrations, including continuity at infinity.
result Prove that every germ of a nondegenerate fibration extends to a global fibration.

The paper explores Kodaira dimension on almost complex manifolds.

problem Understanding Kodaira dimension on non-integrable almost complex manifolds.
method Generalization of Kodaira dimension to almost complex manifolds and study of its behavior under deformations.
result Kodaira dimension is invariant under holomorphic deformations for smooth projective manifolds but not for non-projective manifolds.

Singular fibrations over surfaces generalize Lefschetz fibrations and have new construction methods.

problem Understanding and constructing singular fibrations over surfaces.
method Explains how to construct examples of singular fibrations with a single singularity and outlines previous results.
result Closed orientable 4-manifolds with large first Betti number and vanishing second Betti number do not admit singular fibrations.

Third in a series, this paper constructs non-trivial Cayley fibrations with conical singularities.

problem Constructing non-trivial Cayley fibrations with conical singularities.
method Using gluing methods and stability results for weak and usual fibrations.
result Construction of examples of Cayley fibrations on twisted connected sum G2G_2 manifolds.

Auroux, Donaldson and Katzarkov introduced broken Lefschetz fibrations as a generalization of Lefshcetz fibrations in order to describe near-symplectic 4-manifolds. We first study monodromy representations of higher sides of genus-1 simplified broken Lefschetz fibrations. We then completely classify diffeomorphism type…

2010-12-18abs ↗pdf ↗

A fibration of R3\mathbb{R}^3 by oriented lines is given by a unit vector field V:R3S2V : \mathbb{R}^3 \to S^2, for which all of the integral curves are oriented lines. A line fibration is called skew if no two fibers are parallel. Skew fibrations have been the focus of recent study, in part due to their close relationship…

2019-11-15abs ↗pdf ↗

A smooth fibration of R3\mathbb{R}^3 by oriented lines is given by a smooth unit vector field VV on R3\mathbb{R}^3, for which all of the integral curves are oriented lines. Such a fibration is called skew if no two fibers are parallel, and it is called nondegenerate if V\nabla V vanishes only in the direction of VV.…

2019-03-31abs ↗pdf ↗

Study fibrations over S2S^2 with same singularities, showing monodromies are equivalent up to direct sums.

problem Classifying torus fibrations over S2S^2 up to fibre sum stabilisation.
method Analyzing monodromies and using direct sums with certain torus Lefschetz fibrations.
result Global monodromies of fibrations with same singularities are Hurwitz equivalent after direct sums.

The paper proves finiteness for stable Lagrangian fibrations with a given divisor.

problem Finiteness of deformation classes of hyperkähler Lagrangian fibrations.
method Survey and proof of finiteness for stable Lagrangian fibrations with a given discriminant divisor.
result Finiteness for stable Lagrangian fibrations with a given discriminant divisor.

We classify the Seifert fibrations of any given lens space L(p,q). We give an algorithmic construction of a Seifert fibration of L(p,q) over the base orbifold S^2(m,n) with the coprime parts of m and n arbitrarily prescribed. This algorithm produces all possible Seifert fibrations, and the equivalences between the resu…

2016-08-24abs ↗pdf ↗

Bryant-Salamon constructed three 1-parameter families of complete manifolds with holonomy G2\mathrm{G}_2 which are asymptotically conical to a holonomy G2\mathrm{G}_2 cone. For each of these families, including their asymptotic cone, we construct a fibration by asymptotically conical and conically singular coassociativ…

2020-02-15abs ↗pdf ↗

We show that there exists a non-trivial simplified broken Lefschetz fibration which has infinitely many homotopy classes of sections. We also construct a non-trivial simplified broken Lefschetz fibration which has a section with non-negative square. It is known that no Lefschetz fibration satisfies either of the above …

2011-04-06abs ↗pdf ↗

It is known that an arbitrary smooth, oriented 4-manifold admits the structure of what is called a broken Lefschetz fibration. Given a broken fibration, there are certain modifications, realized as homotopies of the fibration map, that enable one to construct infinitely many distinct fibrations of the same manifold. Th…

2009-05-04abs ↗pdf ↗

The paper extends trisection construction for Lefschetz fibrations with (n)(-n)-sections.

problem Constructing trisections for 4-manifolds with specific Lefschetz fibrations.
method Explicit construction of trisections using monodromies of Lefschetz fibrations.
result Trisections for various 4-manifolds constructed from Lefschetz fibrations.

New methods for computing volumes and constructing Fano fibrations.

problem Understanding Fano fibrations and their weighted volumes.
method New methods for computing weighted volumes, including Laplace transforms and incomplete Gamma-functions. Conjectural construction of Fano fibrations.
result Conjectural construction of Fano fibrations with asymptotically conical bases from degenerating Fano fibrations.

A fibration of Rn{\mathbb R}^n by oriented copies of Rp{\mathbb R}^p is called skew if no two fibers intersect nor contain parallel directions. Conditions on pp and nn for the existence of such a fibration were given by Ovsienko and Tabachnikov. A classification of smooth fibrations of R3{\mathbb R}^3 by skew oriente…

2014-12-29abs ↗pdf ↗

In this article, we generalize the classification of genus one Lefschetz fibrations to genus one simplified broken Lefschetz fibrations, which have fibers of genera one and zero. We classify genus one Lefschetz fibrations over the 2-disk with certain non-trivial global monodromies using chart descriptions, and identify…

2010-10-27abs ↗pdf ↗

Using the recent results of Siebert and Tian about the holomorphicity of genus 2 Lefschetz fibrations with irreducible singular fibers, we show that any genus 2 Lefschetz fibration becomes holomorphic after fiber sum with a holomorphic fibration.

2002-04-23abs ↗pdf ↗

We construct universal Lefschetz fibrations, defined in analogy with classical universal bundles. We also introduce the cobordism groups of Lefschetz fibrations, and we see how these groups are quotients of the singular bordism groups via the universal Lefschetz fibrations.

2014-03-10abs ↗pdf ↗

A hyperelliptic broken Lefschetz fibration is a generalization of a hyperelliptic Lefschetz fibration. We construct and compute a local signature of hyperelliptic directed broken Lefschetz fibrations by generalizing Endo's local signature of hyperelliptic Lefschetz fibrations. It is described by his local signature and…

2011-10-24abs ↗pdf ↗

The paper connects fibrations to generalized complex structures in semi-toric geometry.

problem Understanding the relationship between fibrations and generalized complex structures.
method Using moment maps in semi-toric geometry and Gompf--Thurston methods for Lie algebroids.
result Constructs self-crossing stable generalized complex four-manifolds and proves compatibility with connected sums.