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arXiv research

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.

169,051 papers · 148 categories

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51101152202 · Jun 202019922001200920182026
48 results for convex hierarchies

Unified analysis of mean-field and convex hierarchies for estimating Ising model free energy.

problem Estimating the free energy of Ising models in various regimes.
method Unified analysis using mean-field approximation and convex hierarchies, proving tight bounds and optimality.
result Unified tight bounds for both mean-field and convex hierarchies, showing they are within O((nJF)2/3)O((n\|J\|_{F})^{2/3}) of the free energy.

We add a set of convex constraints to the lasso to produce sparse interaction models that honor the hierarchy restriction that an interaction only be included in a model if one or both variables are marginally important. We give a precise characterization of the effect of this hierarchy constraint, prove that hierarchy…

2012-05-22abs ↗pdf ↗

When related learning tasks are naturally arranged in a hierarchy, an appealing approach for coping with scarcity of instances is that of transfer learning using a hierarchical Bayes framework. As fully Bayesian computations can be difficult and computationally demanding, it is often desirable to use posterior point es…

2012-06-13abs ↗pdf ↗

Maximum A posteriori Probability (MAP) inference in graphical models amounts to solving a graph-structured combinatorial optimization problem. Popular inference algorithms such as belief propagation (BP) and generalized belief propagation (GBP) are intimately related to linear programming (LP) relaxation within the She…

2017-09-19abs ↗pdf ↗

New algorithm handles large-scale interaction models efficiently.

problem Large-scale interaction modeling with strong hierarchy constraints.
method Convex optimization, proximal gradient descent, screening rules, active-set strategy.
result Framework can handle p=50,000p = 50,000 with over 4900x speed-up.

Study curvature operators with sectional curvature bounds using convex algebraic geometry.

problem Characterize algebraic curvature operators with sectional curvature bounds.
method Apply convex algebraic geometry techniques, including spectrahedra and hierarchies of inner and outer approximations.
result For n5n \geq 5, the set of curvature operators is a spectrahedron or a spectrahedral shadow, providing counter-examples to the Helton--Nie Conjecture.

Many high dimensional sparse learning problems are formulated as nonconvex optimization. A popular approach to solve these nonconvex optimization problems is through convex relaxations such as linear and semidefinite programming. In this paper, we study the statistical limits of convex relaxations. Particularly, we con…

2015-03-04abs ↗pdf ↗

New tools in nonlinear random matrices improve understanding of the Sum of Squares hierarchy.

problem Improving the Sum of Squares (SoS) hierarchy's performance on average-case problems.
method Developed new tools in nonlinear random matrices and applied them to analyze the SoS hierarchy.
result Subexponential-time SoS lower bounds for various problems, offering evidence for the low-degree likelihood ratio hypothesis.

This paper develops a cohomological hierarchy for bistable visual paradoxes.

problem Understanding the hierarchy of visual paradoxes built from bistable elements.
method Develops a cohomological hierarchy using Z2\mathbb{Z}_2 coefficients and a discrete Stokes theorem.
result Reveals a hierarchy of paradox classes from H0H^0 through H2H^2, refined at each degree by the relative/absolute distinction.

Constructs integrable hierarchies for generalized Frobenius manifolds with non-flat unity.

problem Integrable hierarchies for generalized Frobenius manifolds with non-flat unity.
method Constructs a bihamiltonian integrable hierarchy of hydrodynamic type.
result Integrable hierarchy possesses Virasoro symmetries and a tau structure.

Study identifies pitfalls in assessing hierarchies for multi-class classification.

problem Lack of understanding in selecting hierarchies for multi-class classification.
method Analyzed and compared popular approaches to extracting hierarchies.
result Hierarchy quality becomes irrelevant when using powerful classifiers.

Legendre transformations link related integrable hierarchies.

problem Understanding relationships between integrable hierarchies.
method Legendre-type transformations of generalized Frobenius manifolds.
result Linear reciprocal transformations link related hierarchies.

Twisted UU- and twisted U/KU/K-hierarchies are soliton hierarchies introduced by Terng to find higher flows of the generalized sine-Gordon equation. Twisted O(J,J)O(J)×O(J)\frac {O(J,J)}{O(J)\times O(J)}-hierarchies are among the most important classes of twisted hierarchies. In this paper, interesting first and higher flows of twi…

2011-03-31abs ↗pdf ↗

We propose a formally completely integrable extension of heat hierarchy based on the space of symmetries isomorphic to the Weyl algebra A1\mathcal{A}_1. The extended heat hierarchy will be the basic model for the analysis of the extension of KP hierarchy, and other integrable equations.

2014-01-19abs ↗pdf ↗

How should statistical procedures be designed so as to be scalable computationally to the massive datasets that are increasingly the norm? When coupled with the requirement that an answer to an inferential question be delivered within a certain time budget, this question has significant repercussions for the field of s…

2013-09-30abs ↗pdf ↗

New hierarchies derived from KP hierarchy using non-formal operators and Yang-Mills action.

problem Formal solutions of KP hierarchy and their non-formal counterparts.
method Developed new hierarchies of non-linear equations on non-formal pseudo-differential operators.
result Expressed one hierarchy as Yang-Mills action minimization.

Symmetry reduction of Painlevé IV to Flaschka-Newell Painlevé II

problem Isomonodromic deformation problem associated with rank-two meromorphic connections
method Symmetry Ψ(λ)=σ1Ψ(λ)σ1Ψ(-λ)= σ_1 Ψ(λ) σ_1
result Induced isomonodromic dynamics coincides with Flaschka-Newell Painlevé II hierarchy

Scroll structures on solutions of 4D integrable equations are involutive and governed by a dispersionless hierarchy.

problem Characterizing the geometry of solutions to 4D integrable equations.
method Defining rational normal scrolls and showing their involutivity.
result Involutive scroll structures are governed by a dispersionless integrable hierarchy.

Constructs tri-Hamiltonian structure and Frobenius manifold for asymmetric gAL hierarchy

problem Tri-Hamiltonian structure and Frobenius manifold for asymmetric gAL hierarchy
method Local tri-Hamiltonian structure construction and Frobenius manifold construction
result Dispersionless limits of flows belong to Principal Hierarchy

A relation between the Goldstein-Petrich hierarchy for plane curves and the Toda lattice hierarchy is investigated. A representation formula for plane curves is given in terms of a special class of ττ-functions of the Toda lattice hierarchy. A representation formula for discretized plane curves is also discussed.

2013-10-26abs ↗pdf ↗

HAKE embeds entities in polar coordinates to model semantic hierarchies in knowledge graphs.

problem Lack of modeling semantic hierarchies in knowledge graph embeddings.
method HAKE embeds entities in a polar coordinate system, where the radial coordinate represents hierarchy levels and the angular coordinate distinguishes entities at the same level.
result HAKE significantly outperforms existing methods on link prediction tasks in knowledge graphs.

New integrable deformations for topological hierarchies from Frobenius manifolds.

problem Integrable deformations of topological hierarchies from Frobenius manifolds.
method Construction of integrable deformations with polynomial tau-structures.
result Conjecture of universal object for Riemann--Hopf hierarchy.

We introduce two families of soliton hierarchies: the twisted hierarchies associated to symmetric spaces. The Lax pairs of these two hierarchies are Laurent polynomials in the spectral variable. Our constructions gives a hierarchy of commuting flows for the generalized sine-Gordon equation (GSGE), which is the Gauss-Co…

2010-10-27abs ↗pdf ↗

Paper investigates methods to improve classification by inducing a hierarchy from flat labels.

problem Improving classification performance on datasets lacking a natural hierarchy.
method The approach involves clustering conditional distributions and using a hierarchical classifier with the induced hierarchy.
result The methods can discover latent hierarchies and improve accuracy in various applications.

We prove that the extended Toda hierarchy of \cite{CDZ} admits nonabelian Lie algebra of infinitesimal symmetries isomorphic to the half of the Virasoro algebra. The generators LmL_m, m1m\geq -1 of the Lie algebra act by linear differential operators onto the tau function of the hierarchy. We also prove that the tau fu…

2003-08-15abs ↗pdf ↗

Paper addresses limitations of traditional hierarchical clustering methods.

problem Traditional hierarchical clustering methods face limitations in binary trees and ultrametrics.
method Introduces the notion of a valid hierarchy and a two-step algorithm to construct a binary tree and prune it to enforce validity.
result Proposes a method to recover the finest valid hierarchy, which is not constrained to binary structures.

We present the Lax pair formalism for certain extension of the continuous limit of the classical Toda lattice hierarchy, provide a well defined notion of tau function for its solutions, and give an explicit formulation of the relationship between the CP1CP^1 topological sigma model and the extended Toda hierarchy. We al…

2003-06-29abs ↗pdf ↗

We propose an extension of the differential system for constant mean curvature (CMC) surfaces in a three dimensional space form to an associated hierarchy of evolution equations by the higher-order commuting symmetries. The infinite sequence of higher-order conservation laws of CMC surfaces admit the corresponding exte…

2013-12-27abs ↗pdf ↗

This is the third in a series of papers attempting to describe a uniform geometric framework in which many integrable systems can be placed. A soliton hierarchy can be constructed from a splitting of an infinite dimensional group LL as positive and negative subgroups L_+, L_- and a commuting sequence in the Lie algebr…

2014-06-19abs ↗pdf ↗

Study bihamiltonian structures and Frobenius manifolds for specific Toda hierarchies.

problem Local bihamiltonian structures and Frobenius manifolds for asymmetric rational reductions of 2D-Toda hierarchy.
method Construct three-dimensional generalized Frobenius manifold, relate to other hierarchies via transformations.
result Explicit relation between RR2T and bi-graded Toda and constrained KP hierarchies.

Solves Cauchy problem for a KP hierarchy on non-formal operators and relates to diffeomorphisms.

problem Solving the Cauchy problem for a Kadomtsev-Petviashvili hierarchy on non-formal operators.
method Introduces a version of the KP hierarchy on a regular Frölicher Lie group of non-formal pseudodifferential operators and solves its Cauchy problem.
result Establishes a link between the dressing operator and the action of diffeomorphisms and non-formal Sato-like operators on jet spaces.

We observe that the modular class of a Poisson-Nijhenhuis manifold has a canonical representative and that, under a cohomological assumption, this vector field is bi-hamiltonian. In many examples the associated hierarchy of flows reproduces classical integrable hierarchies.

2006-07-30abs ↗pdf ↗

The shape of homogeneous, generic, smooth convex bodies as described by the Euclidean distance with nondegenerate critical points, measured from the center of mass represents a rather restricted class M_C of Morse-Smale functions on S^2. Here we show that even M_C exhibits the complexity known for general Morse-Smale f…

2012-04-24abs ↗pdf ↗

Novel method extracts hierarchical brain connectivity patterns from fMRI.

problem Functional hierarchical organization of the human brain.
method Sparse Connectivity Patterns (SCPs) with hierarchy of sparse overlapping patterns, deep factorization of correlation matrices.
result Reproducible multi-scale hierarchical SCPs more stable than single-scale patterns.

ProHOC detects OOD samples in class hierarchies, predicting them to correct internal nodes.

problem Binary OOD detection ignores semantic relationships between OOD and ID classes.
method Probabilistic hierarchical model using multi-depth networks trained for ID classification.
result ProHOC effectively classifies OOD samples to their correct internal nodes in class hierarchies.

We construct integrable hierarchies of flows for curves in centroaffine R3{\mathbb R}^3 through a natural pre-symplectic structure on the space of closed unparametrized starlike curves. We show that the induced evolution equations for the differential invariants are closely connected with the Boussinesq hierarchy, and …

2013-03-06abs ↗pdf ↗