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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.

169,341 papers · 148 categories

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481216 · Jul 202619922001200920182026
48 results for ample locus

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…

2012-12-06abs ↗pdf ↗

Study on Bergman kernels near analytic hypersurfaces with exponential decay.

problem Analyzing the behavior of Bergman kernels near analytic hypersurfaces.
method Uniform estimates and asymptotic analysis of partial Bergman kernels for sections vanishing along hypersurfaces.
result Uniform estimate and asymptotic behavior of Bergman kernels near vanishing locus.

In this paper we prove that the Kähler-Einstein metrics for a toroidal canonical degeneration family of Kähler manifolds with ample canonical bundles Gromov-Hausdorff converge to the complete Kähler-Einstein metric on the smooth part of the central fiber when the base locus of the degeneration family is empty. We also …

2003-03-10abs ↗pdf ↗

Continuity of complex Monge-Ampère potentials on Kähler manifolds.

problem Continuity of solutions to complex Monge-Ampère equations on compact Kähler manifolds.
method Extending DiNezza-Lu's approach to big cohomology classes, proving continuity on Zariski open sets.
result Singular Kähler-Einstein metrics have continuous potentials on the ample locus outside of the non-klt part.

Let (X,ω)(X,ω) be a compact Kähler manifold. We obtain uniform Hölder regularity for solutions to the complex Monge-Ampère equation on XX with LpL^p right hand side, p>1p>1. The same regularity is furthermore proved on the ample locus in any big cohomology class. We also study the range $\MAH(X,ω)$ of the complex Monge-Am…

2011-12-06abs ↗pdf ↗

In this paper, we study the boundary behavior of the negatively curved Kähler-Einstein metric attached to a log canonical pair (X,D)(X,D) such that KX+DK_X+D is ample. In the case where XX is smooth and DD has simple normal crossings support (but possibly negative coefficients), we provide a very precise estimate on the p…

2014-10-20abs ↗pdf ↗

New system solves curvature for ample vector bundles, proving Griffiths conjecture.

problem Proving Griffiths conjecture on vector bundle positivity.
method Proposes Hermitian-Yang-Mills elliptic system for curvature.
result Solutions provide metrics with positive curvature in Griffiths sense.

Let XX be a smooth variety and let LL be an ample line bundle on XX. If π1alg(X)π^{alg}_{1}(X) is large, we show that the Seshadri constant ε(pL)ε(p^{*}L) can be made arbitrarily large by passing to a finite étale cover p:XXp:X'\rightarrow X. This result answers affirmatively a conjecture of J.-M. Hwang. Moreover, we prove an …

2014-11-04abs ↗pdf ↗

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

2006-03-17abs ↗pdf ↗

Solves Demailly's system for direct sums of ample line bundles on Riemann surfaces.

problem Proving the existence of smooth solutions for Demailly's system.
method Used Demailly's system and Leray-Schauder degree theory to reduce the problem.
result Proved existence of smooth solutions for direct sums of ample line bundles.

Study local curvature of Kähler-Ricci flow on semi-ample manifolds.

problem Local curvature estimates of long-time solutions to Kähler-Ricci flow.
method Local curvature estimates using semi-ample canonical line bundles.
result Set of singular fibers where curvature blows up is independent of initial metric.

The paper studies volumes of direct images for high tensor powers of ample bundles.

problem Understanding asymptotics of Monge-Ampère volumes for high tensor powers of ample line bundles.
method Analyzes the leading term of asymptotics and classifies bundles saturating a topological bound.
result Provides a characterization of bundles admitting projectively flat Hermitian structures in the case of high symmetric powers of ample vector bundles.

Monodromy and vanishing cycles computed for ample linear systems on simply connected surfaces.

problem Characterizing curves that can be vanishing cycles in degenerations of linear systems.
method Computing mapping class group-valued monodromy and identifying it with r-spin mapping class groups.
result Identifies simple closed curves as vanishing cycles and provides characterizations of discriminants and Lefschetz fibrations.

The paper studies positivity properties of cotangent bundles in complex hyperbolic manifolds with cusps.

problem Positivity properties of cotangent bundles in complex hyperbolic manifolds with cusps.
method Analyzes intrinsic positivity properties of cotangent bundles using toroidal compactifications and ample line bundles.
result The cotangent bundle is ample modulo the boundary divisor for sufficiently small rational numbers.

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 ↗

Continuous metrics on ample bundles lie in infinite-dimensional cones.

problem Understanding the structure of positive metrics on ample line bundles.
method Analyzing bounded graded filtrations and embedding into Mabuchi-flat cones.
result Continuous metrics embed isometrically into the space of positive metrics.

Proves projectivity and ampleness of a Kähler manifold using complex Monge-Ampère equation.

problem Projectivity and ampleness of a compact Kähler manifold with negative Ricci curvature.
method An alternate proof using a C2C^2-estimate for a complex Monge-Ampère equation.
result Proves projectivity and ampleness of the Kähler manifold.

Study on curvature of direct image bundle for higher powers of relatively ample line bundles.

problem Analyzing the curvature of direct image bundles associated with higher powers of relatively ample line bundles.
method Obtained asymptotic of curvature for L2L^2-metric and Qullien metric on direct image bundles up to lower order terms.
result The analytic torsion τk(ˉ)τ_k(\bar{\partial}) satisfies o(kn1)o(k^{n-1}).

In this paper, we study the Nakano-positivity and dual-Nakano-positivity of certain adjoint vector bundles associated to ample vector bundles. As applications, we get new vanishing theorems about ample vector bundles. For example, we prove that if EE is an ample vector bundle over a compact Kähler manifold XX, $S^kE\…

2010-06-08abs ↗pdf ↗

This paper generalizes the cut locus concept for almost distance functions.

problem Generalizing the cut locus concept for almost distance functions.
method Introducing 1-Lipschitz functions called almost distance functions and studying their singular loci.
result Obtained a structure theorem for the singular locus of an almost distance function on a 2D Finsler manifold.

Proves complex Finsler bundles with positive curvature are ample and biholomorphic to projective space.

problem Solving a 1975 problem posed by S. Kobayashi about complex Finsler vector bundles with positive Kobayashi curvature.
method Analyzes properties of complex Finsler vector bundles with positive Kobayashi curvature.
result Complex Finsler vector bundles with positive Kobayashi curvature are ample and biholomorphic to projective space.

Study the geometry of lightlike loci on mixed type surfaces in Lorentz-Minkowski 3-space.

problem Characterize the differential geometric properties of lightlike loci on mixed type surfaces.
method Define a frame field and lightlike ruled surfaces along the lightlike locus, analyze their singularities and intersections.
result Establish a relationship between the singularities of lightlike ruled surfaces and the differential geometric properties of the lightlike locus.

In this study, we investigate the locus of the centers of the Meusnier spheres. Just as focal curve is the locus of the centers of the osculating spheres, we investigate the geometrical interpretation on the locus of the centers of the Meusnier spheres. We proved that if the curve is a principal line, the locus of the …

2013-07-16abs ↗pdf ↗

The paper solves a 25-year-old problem about maximal growth distributions on manifolds.

problem Existence and classification of maximal growth distributions on smooth manifolds.
method Higher order convex integration and new criteria for ampleness of differential relations.
result Positive answer to the open question about parallelizable manifolds admitting maximal growth distributions.

We study the singular locus of solutions to Hamilton-Jacobi equations with a Hamiltonian independent of uu. In a previous paper, we proved that the singular locus is what we call a balanced split locus. In this paper, we find and classify all balanced split sets, identifying the cases where the only balanced split loc…

2008-07-13abs ↗pdf ↗

The paper describes the CR umbilical locus of a real ellipsoid in complex space.

problem Characterizing the CR umbilical locus of a real ellipsoid in complex space.
method Analyzing the set of points where the ellipsoid can be osculated by a biholomorphic image of the sphere up to 6th order.
result The CR umbilical locus is the union of stable curves and a non-trivial real variety defined by sextic equations.

Laplacian of distance function shows negative infinity at cut locus points.

problem Understanding the Laplacian of distance functions on Riemannian manifolds.
method Analyzing the Laplacian of the distance function to a point on a smooth Riemannian manifold.
result The Laplacian of the distance function is -\infty at points of the cut locus.

Let XX be a canonically polarized variety, i.e. a complex projective variety such that its canonical class KXK_{X} defines an ample $\Q-$line bundle, and satisfying the conditions G1G_1 and S2S_2. Our main result says that XX admits a Kähler-Einstein metric iff XX has semi-log canonical singularities i.e. iff XX is…

2013-04-08abs ↗pdf ↗

The paper studies geometric loci and their invariants in complex dynamics.

problem Analyzing geometric loci and their invariants in complex dynamics.
method Intersection theory and dynamical invariants on the flex and gothic loci.
result Determined the divisor class of the flex locus and various tautological intersection numbers on the gothic locus.

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 ↗