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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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326597129 · May 202619922001200920172026
48 results for Invariant Hulls

Study convex hulls of orbits for compact groups, defining new invariants related to polynomial degrees.

problem Understanding properties of convex hulls of coadjoint orbits of compact groups.
method Introduce partial convex hulls and use them to define numerical invariants.
result Orbits with new invariants form rational convex polyhedral cones related to Littlewood-Richardson cones.

Study Hull-Strominger system and Anomaly flow on specific solvmanifolds.

problem Characterize invariant solutions to Hull-Strominger system and investigate flow of invariant metrics.
method Characterization of invariant solutions using Gauduchon connections, investigation of Anomaly flow, and proof of flow immortality under certain conditions.
result Anomaly flow reduces to a special form and always converges to a Kähler metric when slope parameter is zero.

Investigates invariant hulls of functionals on manifolds.

problem Understanding meaningful functionals on manifolds through reparameterizations.
method Uses inner-variations to transform arbitrary functionals into invariant realizations.
result Explicit computations for volume functional in NN-dimensional manifolds, especially in N=2N=2.

A new, computationally friendly formula for a class of risk-averse preferences.

problem Characterizing a class of risk-averse preferences called uniformly weighted divergence preferences.
method Introducing a new formula that characterizes UWDP as the translation-invariant hull of state-independent expected utility.
result UWDP are the translation-invariant hull of state-independent expected utility over L0L^0.

We present a nonstandard hull construction for locally uniform groups in a spirit similar to Luxembourg's construction of the nonstandard hull of a uniform space. Our nonstandard hull is a local group rather than a global group. We investigate how this construction varies as one changes the family of pseudometrics used…

2012-03-29abs ↗pdf ↗

This paper defines maximal measurable cocycles for surface groups into Hermitian Lie groups and studies their algebraic hulls.

problem Understanding maximal measurable cocycles for surface groups into Hermitian Lie groups.
method Introducing the notion of maximal measurable cocycles, defining Toledo invariant, and studying the algebraic hulls.
result The algebraic hull of a maximal cocycle is reductive and its centralizer is compact.

The n-th hull of a union of curves in R^3 is the set of points with the property: Any plane passing through the point intersects the curves at least 2n times. The hull number u(L) of a link L is defined as the minimum number of non-empty hulls a representative of L can have. We show that the hull numbers of torus links…

2004-12-07abs ↗pdf ↗

The main result of this paper is a characterization of the minimal surface hull of a compact set KK in R3\mathbb R^3 by sequences of conformal minimal discs whose boundaries converge to KK in the measure theoretic sense, and also by 22-dimensional minimal currents which are limits of Green currents supported by conf…

2014-09-24abs ↗pdf ↗

The Delaunay tessellation of a locally finite subset of hyperbolic space is constructed using convex hulls in Euclidean space of one higher dimension. For finite and lattice-invariant sets it is proven to be a polyhedral decomposition, and versions (necessarily modified from the Euclidean setting) of the empty circumsp…

2013-08-22abs ↗pdf ↗

Develops harmonic metrics for Hull-Strominger system stability.

problem Existence of solutions to the Hull-Strominger system with balanced class.
method Uses non-Hermitian Yang-Mills connections and holomorphic Courant algebroids, introduces harmonic metrics.
result Expected existence of a numerical stability condition for generic families of solutions.

Study analyzes correlation structure in two-factor Hull-White model for XVA calculations.

problem Capturing the correlation structure in two-factor Hull-White model for accurate XVA calculations.
method Combination of approximation formula and Monte-Carlo simulation to investigate correlation structure.
result Hull-White model effectively captures de-correlation of the yield curve under specific parameter conditions.

Deep learning models generalize by extending decision boundaries outside the convex hull of training data.

problem Understanding how deep learning models generalize beyond their training data.
method Investigation of decision boundaries inside and outside the convex hull of training sets, using various neural network architectures and training regimes.
result Over-parameterization is necessary for deep learning models to extend decision boundaries outside the convex hull of their training data.

The integer hull of a polyhedron is the convex hull of the integer points contained in it. We show that the vertices of the integer hulls of a rational family of polyhedra of size O(n) have quasipolynomial coordinates. As a corollary, we show that the stable commutator length of elements in a surgery family is a ratio …

2010-11-05abs ↗pdf ↗

Study characterizes hulls and capacities on Riemannian manifolds, proving isoperimetric inequalities.

problem Characterizing hulls and capacities on Riemannian manifolds.
method Investigates strictly outward minimising hulls and uses p-capacities to recover their areas.
result Sharp isoperimetric inequality on complete noncompact manifolds with nonnegative Ricci curvature.

The convex hull of a set K in space consists of points which are, in a certain sense, "surrounded" by K. When K is a closed curve, we define its higher hulls, consisting of points which are "multiply surrounded" by the curve. Our main theorem shows that if a curve is knotted then it has a nonempty second hull. This pro…

2002-04-10abs ↗pdf ↗

New proofs given for space curves with totally positive torsion.

problem Description of convex hulls of space curves with totally positive torsion.
method New proofs of parametric representation, surface area, and volume formulas.
result Recovery of formulas for convex hull's surface area and volume.

We introduce the notion of a ``projective hull'' for subsets of complex projective varieties, parallel to the idea of the polynomial hull in affine varieties. With this concept, a generalization of J. Wermer's classical theorem on the hull of a curve in CnC^n is established in the projective setting. The projective hul…

2005-10-13abs ↗pdf ↗

Researchers link vertex algebras to non-Kähler solutions of the Hull-Strominger system.

problem Constructing representations of vertex algebras from non-Kähler solutions of the Hull-Strominger system.
method Embedding the N=2 superconformal vertex algebra in the chiral de Rham complex of a string Courant algebroid, with a condition on the Hermitian-Yang-Mills connection.
result Any solution of the Hull-Strominger system satisfying the Hermitian-Yang-Mills condition has an associated N=2 embedding.

Estimates convex hulls of smooth function images with error bounds.

problem Estimating the convex hull of the image of a smooth boundary set.
method Using submersion properties and sampling inputs, derive bounds on Hausdorff distance.
result New tighter and more general error bounds for geometric inference.

For a convex curve in an even-dimensional affine space we introduce a series of convex domains (called Young hulls), describe their structure and give a formulas fo the volume of the biggest of these domains. This paper is an attempt to generalize the classical isoperimetric inequality for the volume of the convex hull…

1996-11-18abs ↗pdf ↗

We obtain an upper bound for the volume of the convex hull of a simple closed Frenet curve with exactly four vertices, i.e., four points of vanishing torsion, and lying on the boundary of its convex hull. Moreover, we show that the upper bound is attained when the curve intersects every plane in at most four points, a …

2018-05-29abs ↗pdf ↗

New flow defined to solve Hull-Strominger system, with estimates and convergence results.

problem Constructing solutions to the Hull-Strominger system of equations.
method Introducing a natural extension of pluriclosed flow and using string algebroids and higher gauge theory.
result Proves global existence and convergence of the flow on special backgrounds.

Optimum in Convex Hulls (OCH) generalizes clinical trial results to broader populations.

problem Clinical trials exclude confounding but limit recruitment; observational data are more inclusive but suffer from confounding.
method OCH uses convex hulls of conditional expectations or densities to approximate the true treatment effect from both observational and trial data.
result OCH estimates the treatment effect with state-of-the-art accuracy in terms of both expectations and densities.

We show how to construct the nonstandard hull of certain infinite-dimensional Lie algebras in order to generalize a theorem of Pestov on the enlargeability of Banach-Lie algebras. In the process, we consider a nonstandard smoothness condition on functions between locally convex spaces to ensure that the induced functio…

2008-04-03abs ↗pdf ↗

A wide range of fundamental machine learning tasks that are addressed by the maximum a posteriori estimation can be reduced to a general minimum conical hull problem. The best-known solution to tackle general minimum conical hull problems is the divide-and-conquer anchoring learning scheme (DCA), whose runtime complexi…

2019-07-16abs ↗pdf ↗

Automorphisms and subdivisions of Helly graphs are studied, leading to explicit models and rational translation lengths.

problem Understanding automorphisms and subdivisions of Helly graphs.
method Simple fine simplicial subdivisions and explicit simplicial models of the injective hull.
result Any automorphism of a Helly graph is either elliptic or hyperbolic, with rational translation lengths.

An iterated function system ΦΦ consisting of contractive similarity mappings has a unique attractor FRdF \subseteq \mathbb{R}^d which is invariant under the action of the system, as was shown by Hutchinson [Hut]. This paper shows how the action of the function system naturally produces a tiling T\mathcal{T} of the con…

2006-06-05abs ↗pdf ↗

We use twistor theory to identify the harmonic hull of an arbitrary connected open subset U of R^{2m} for m at least 2. It is the natural domain of analytic continuation in C^{2m} for harmonic functions on U.

2010-12-13abs ↗pdf ↗

GraphHull models networks with clear multi-scale explanations of community structure.

problem Lack of self-explainable models in graph machine learning.
method Two-level convex hulls with global archetypes and local prototypes.
result GraphHull models networks with clear multi-scale explanations.

The main result is a direct proof of the implication (LVKFk,3)(LT3k1,3)(LVKF_{k,3})\Rightarrow( LT_{3k-1,3}) below. Consider the following statements: (LVKF1,3LVKF_{1,3}) From any 11 points in R3 \mathbb{R}^{3} one can choose 3 pairwise disjoint triples whose convex hulls have a common point. (LVKFk,3LVKF_{k,3}) From any 6k+56k + 5 points in $ \m…

2019-03-21abs ↗pdf ↗

We construct new smooth solutions to the Hull-Strominger system, showing that the Fu-Yau solution on torus bundles over K3 surfaces can be generalized to torus bundles over K3 orbifolds. In particular, we prove that, for 13k2213 \leq k \leq 22 and 14r2214\leq r\leq 22, the smooth manifolds S1×k(S2×S3)S^1\times \sharp_k(S^2\times S^3)

2019-01-29abs ↗pdf ↗

The paper develops mixed-integer formulations for neural networks using partitioning.

problem Optimizing trained ReLU neural networks with balanced model size and tightness.
method Partitioning node inputs into groups, forming the convex hull via disjunctive programming.
result The proposed formulations outperform existing ones, especially with fewer partitions.