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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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295988117 · May 202619922001200920172026
48 results for divisorial stability

Equivalence proven between divisorial stability and quotient log divisorial stability.

problem Equivalence of divisorial stability and log divisorial stability under finite group actions.
method Interpolation technique and equivariant divisorial stability construction.
result Equivariant divisorial stability of a polarized variety is equivalent to log divisorial stability of its quotient.

We introduce a new effective stability named "divisorial stability" for Fano manifolds which is weaker than K-stability and is stronger than slope stability along divisors. We show that we can test divisorial stability via the volume function. As a corollary, we prove that the first coordinate of the barycenter of the …

2015-08-17abs ↗pdf ↗

We prove that among all Kollár components obtained by plt blow ups of a klt singularity o(X,D)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…

2016-04-19abs ↗pdf ↗

Proves existence of Kähler-Einstein metrics in big cohomology classes.

problem Existence of Kähler-Einstein metrics in big cohomology classes.
method Using a divisorial stability condition and Fujita-Odaka type delta invariants, building up from scratch the theory of pluripotential theory.
result Uniform Yau-Tian-Donaldson existence theorem for Kähler-Einstein metrics in the big cohomology class setting.

For any Q\mathbb{Q}-Gorenstein klt singularity (X,o)(X,o), we introduce a normalized volume function vol^\widehat{\rm vol} that is defined on the space of real valuations centered at oo and consider the problem of minimizing vol^\widehat{\rm vol}. We prove that the normalized volume has a uniform positive lower bound by pro…

2015-11-25abs ↗pdf ↗

We discuss a technique to construct Ricci-flat hermitian metrics on complements of (some) anticanonical divisors of almost homogeneous manifolds and discuss when this metric is complete and Kähler. This construction has a strong interplay with invariance groups of the same dimension as the manifold acting with an open …

2003-07-11abs ↗pdf ↗

Paper rigorously defines Feynman graph integrals on Kähler manifolds.

problem Establishing convergence of Feynman graph integrals on Kähler manifolds.
method Using Getzler's rescaling technique, graph integrands are extended to forms with divisorial-type singularities in the compactification of configuration spaces.
result Feynman graph integrals are rigorously defined as Cauchy principal value integrals.

We compute a closed formula for the class of the closure of the locus of curves in Mg\overline{\mathcal{M}}_g that admit an abelian differential of signature κ=(k1,...,kg2)κ=(k_1,...,k_{g-2}).

2015-09-11abs ↗pdf ↗

We investigate the notion of symplectic divisorial compactification for symplectic 4-manifolds with either convex or concave type boundary. This is motivated by the notion of compactifying divisors for open algebraic surfaces. We give a sufficient and necessary criterion, which is simple and also works in higher dimens…

2014-07-02abs ↗pdf ↗

We prove the existence and uniqueness of the weak Kahler-Ricci flow on projective varieties with log terminal singularities. It is also shown that the weak Kahler-Ricci flow can be uniquely continued through divisorial contractions and flips if they exist. We then propose an analytic version of the Minimal Model Progra…

2009-09-26abs ↗pdf ↗

Study of K-moduli of prime Fano threefolds of genus twelve, proving boundary purely divisorial.

problem Understanding the boundary of K-moduli of prime Fano threefolds of genus twelve.
method Developed a modular relation between Fano threefolds and their anticanonical K3 surfaces, proving forgetful morphism is an open immersion.
result Proved the boundary of K-moduli of V22V_{22} is purely divisorial and consists of four irreducible components.

We compute the hybrid limit (in the sense of Boucksom-Jonsson) of the family of Kähler-Einstein volume forms on a degeneration of canonically polarized manifolds. The limit measure is a weighted sum of Dirac masses at divisorial valuations, determined by the natural algebro-geometric limit of the family. We also make s…

2019-11-08abs ↗pdf ↗

Study shows hypercomplex twistor spaces lack divisors and special metrics.

problem Characterizing properties of hypercomplex twistor spaces.
method Analyzing the general fiber's lack of divisors and curves, proving trascendental degree and absence of special metrics.
result Proves hypercomplex twistor spaces have no divisors, curves, Kähler, or pluriclosed metrics.

We establish the existence of the K"ahler-Ricci flow on projective varieties with log canonical singularities. This generalizes some of the existence results of Song-Tian \cite{ST3} in case of projective varieties with klt singularities. We also prove that the normalized K"ahler-Ricci flow will converge to the \ka-Eins…

2019-06-11abs ↗pdf ↗

Study collapsing Calabi-Yau metrics and flows on fiber spaces.

problem Understanding the behavior of Calabi-Yau metrics and flows during collapsing.
method Analyzing the collapsing of Calabi-Yau metrics and Kähler-Ricci flows on fiber spaces.
result Identify the collapsed Gromov-Hausdorff limit and bounds for Hausdorff measure.

The paper defines two types of hyperbolicity for complex manifolds and proves related results.

problem Defining and studying hyperbolicity for a broader class of complex manifolds.
method Introducing SKT hyperbolicity and Gauduchon hyperbolicity, proving results using SKT and Gauduchon metrics.
result Every SKT hyperbolic manifold is also Kobayashi/Brody hyperbolic and every Gauduchon hyperbolic manifold is divisorially hyperbolic.

The paper solves a 5-manifold foliation problem using a Sasaki-Ricci flow.

problem Solving foliation singularities on Sasakian 5-manifolds.
method Applying the Sasaki-Ricci flow to resolve cyclic quotient foliation singularities.
result Proves a Sasaki analogue of the analytic minimal model program.

This is a continuation to the paper [arXiv:1511.08164] in which a problem of minimizing normalized volumes over Q\mathbb{Q}-Gorenstein klt singularities was proposed. Here we consider its relation with K-semistability, which is an important concept in the study of Kähler-Einstein metrics on Fano varieties. In particul…

2015-12-22abs ↗pdf ↗

We study the analytic and topological invariants associated with complex normal surface singularities. Our goal is to provide topological formulae for several discrete analytic invariants whenever the analytic structure is generic (with respect to a fixed topological type), under the condition that the link is a ration…

2018-09-11abs ↗pdf ↗

Let VV be a regular neighborhood of a negative chain of 22-spheres (i.e. exceptional divisor of a cyclic quotient singularity), and let Bp,qB_{p,q} be a rational homology ball which is smoothly embedded in VV. Assume that the embedding is simple, i.e. the corresponding rational blow-up can be obtained by just a sequen…

2019-04-09abs ↗pdf ↗

Introduces valuative stability for polarised varieties, equivalent to K-stability.

problem Characterizing K-stability for polarised varieties.
method Introduces valuative stability, equivalent to K-stability for test configurations with integral central fibre.
result Equivalence of valuative stability and K-stability for polarised varieties.

The homology groups of many natural sequences of groups {Gn}n=1\{G_n\}_{n=1}^{\infty} (e.g. general linear groups, mapping class groups, etc.) stabilize as nn \rightarrow \infty. Indeed, there is a well-known machine for proving such results that goes back to early work of Quillen. Church and Farb discovered that many sequ…

2012-01-23abs ↗pdf ↗

We can talk about two kinds of stability of the Ricci flow at Ricci flat metrics. One of them is a linear stability, defined with respect to Perelman's functional F\mathcal{F}. The other one is a dynamical stability and it refers to a convergence of a Ricci flow starting at any metric in a neighbourhood of a considere…

2004-10-04abs ↗pdf ↗

Study max- and min-stability under first-order stochastic dominance, finding new functional characterizations.

problem Understanding max- and min-stability in stochastic dominance.
method Representation theorem for functionals satisfying max-stability, combining max- and min-stability to define Lambda-quantiles.
result New characterizations of functionals, including Lambda-quantiles, in finance and political science.

For a polarized algebraic manifold (X,L)(X,L), let TT be an algebraic torus in the group of all holomorphic automorphisms of XX. Then strong relative K-stability will be shown to imply asymptotic relative Chow-stability. In particular, by taking TT to be trivial, we see that asymptotic Chow-stability follows from stron…

2013-07-08abs ↗pdf ↗

This paper enhances stability selection by evaluating overall results robustness and identifying optimal regularization values.

problem Improving the robustness and reliability of high-dimensional variable selection.
method Developed a stability estimator to evaluate stability of stability selection results, calibrating key parameters.
result Identified optimal regularization value and improved stability of variable selection.

This work explores the trade-offs between stability and accuracy in statistical estimation.

problem Understanding the statistical cost of algorithmic stability.
method Statistical decision-theoretic perspective, focusing on worst-case and average-case stability.
result Optimal stable estimators for mean estimation and regression settings are developed, revealing trade-offs between stability and accuracy.

The paper examines stability of harmonic and symphonic maps with forms and potentials.

problem Stability of harmonic and symphonic maps with forms and potentials.
method Analyzes stability of F F -harmonic and F F -symphonic maps with forms and potentials.
result Stability conditions for harmonic and symphonic maps are established.

New stability measures for similar features improve feature selection accuracy.

problem Existing stability measures fail to distinguish similar features in highly correlated datasets.
method Introduce new adjusted stability measures that consider feature similarities.
result One new stability measure considers highly similar features as interchangeable.