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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.

168,657 papers · 148 categories

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48 results for linear spaces

In this paper, we give complete classifications of linear \infty-harmonic maps between Euclidean and Heisenberg spaces, between Nil and Sol spaces. We also classify all \infty-harmonic linear endomorphisms of Sol space and show that there is a subgroup of \infty-harmonic linear automorphisms in the group of linea…

2007-11-05abs ↗pdf ↗

We describe the ringed-space structure of moduli spaces of jets of linear connections (at a point) as orbit spaces of certain linear representations of the general linear group. Then, we use this fact to prove that the only (scalar) differential invariants associated to linear connections are constant functions, as wel…

2015-03-14abs ↗pdf ↗

Linear classifiers in product space forms improve scRNA-seq data classification.

problem Linear classification in products of Euclidean, spherical, and hyperbolic spaces.
method Novel formulations of linear classifiers on Riemannian manifolds, proving expressive power, and formalizing perceptron and SVM classifiers.
result Linear classifiers in product space forms have the same expressive power as in Euclidean space of the same dimension.

Since non-compact RCD(0, N) spaces have at least linear volume growth, we study noncompact RCD(0, N) spaces with linear volume growth in this paper. One of the main results is that the diameter of level sets of a Busemann function grow at most linearly on a noncompact RCD(0, N) space satisfying the linear volume growth…

2016-03-16abs ↗pdf ↗

The article analyzes LCE in Hilbert space, deriving new formulas and regularisation methods.

problem Analyzing conditional expectation in infinite-dimensional Hilbert space.
method Establishing analytical properties and regularisation for LCE in Hilbert space, deriving new formulas.
result Simple derivation and intuitive justification of conditional mean embedding formula.

State spaces of multifactor approximations of nonnegative Volterra processes are linear transformations of the nonnegative orthant.

problem Characterizing state spaces of multifactor approximations of nonnegative Volterra processes.
method Explicit linear transformation of the nonnegative orthant.
result State spaces of multifactor approximations of nonnegative Volterra processes are given by explicit linear transformation of the nonnegative orthant.

The paper generalizes equivariant neural networks on homogeneous spaces to the non-linear setting.

problem Equivariant neural networks on homogeneous spaces.
method Deriving generalized steerability constraints for non-linear equivariant layers.
result The universality of the derived construction for non-linear equivariant layers.

This article provides an attempt to extend concepts from the theory of Riemannian manifolds to piecewise linear spaces. In particular we propose an analogue of the Ricci tensor, which we give the name of an Einstein vector field. On a given set of piecewise linear spaces we define and discuss (normalized) Ricci flows. …

2015-08-22abs ↗pdf ↗

Calculates affine transformations for specific homogeneous spaces.

problem Computing groups of affine transformations on homogeneous spaces.
method Analyzes conditions for affine connections and uses them to establish group isomorphisms.
result Groups of affine transformations are locally isomorphic under specified conditions.

Finite translation surfaces can be classified by the order of their singularities. When generalizing to infinite translation surfaces, however, the notion of order of a singularity is no longer well-defined and has to be replaced by new concepts. This article discusses the nature of two such concepts, recently introduc…

2014-12-01abs ↗pdf ↗

The paper explores linear representations in language models using counterfactuals.

problem Understanding linear representations and geometric concepts in large language models.
method Formalized linear representation in output and input spaces, identified causal inner product.
result Unified understanding of linear representations and their connection to interpretation and control.

Extending Lévi-Civita's concept to non-quadratic spaces, this study finds extremal compatible linear connections.

problem Extending the Lévi-Civita connection to non-quadratic spaces.
method Hybrid conditional extremum problem, Lagrange multipliers, geometric approach.
result Existence and characterization of extremal compatible linear connections.

Gradient flow in parameters equals linear interpolation in outputs.

problem Understanding and optimizing training algorithms in deep learning.
method Proving equivalence between gradient flow in parameter space and linear interpolation in output space, and deriving formulas for global minima.
result Gradient flow in parameters can be transformed into linear interpolation in outputs, leading to global minima.

Online learning of linear operators between infinite-dimensional spaces is possible but with limitations.

problem Learning linear operators between infinite-dimensional Hilbert spaces in an online setting.
method Online learning approach for linear operators with bounded pp-Schatten norm, proving impossibility for operator norm.
result Separation between online learnability and uniform convergence for bounded linear operators.

Computes expected number of real intersection points of essential variety with random linear spaces.

problem Computing the expected number of real intersection points of the essential variety with random linear spaces.
method Two probability distributions for linear spaces: invariant under orthogonal group action and one motivated from computer vision. Used Monte Carlo simulation for the latter.
result Expected number of real intersection points lies in the interval (3.95 - 0.05, 3.95 + 0.05) with high probability.

A linear connection on a Finsler manifold is called compatible to the metric if its parallel transports preserve the Finslerian length of tangent vectors. Generalized Berwald manifolds are Finsler manifolds equipped with a compatible linear connection. Since the compatibility to the Finslerian metric does not imply the…

2020-01-13abs ↗pdf ↗

Bayesian optimisation algorithm for unknown search spaces with sub-linear regret.

problem Efficient optimisation of expensive black-box functions in unknown search spaces.
method Expands search space over iterations based on a hyperharmonic series, scales to high dimensions.
result Sub-linear regret growth for both algorithms.

We prove that if an analytic subset AA of a linear metric space XX is not contained in a σZωσZ_ω-subset of XX then for every Polish convex set KK with dense affine hull in XX the sum A+KA+K is non-meager in XX and the sets A+A+KA+A+K and AA+KA-A+K have non-empty interior in the completion Xˉ\bar X of XX. This implies t…

2015-08-28abs ↗pdf ↗

Study concordance of alternating torus knots to L-space knots.

problem When are linear combinations of alternating torus knots concordant to L-space knots?
method Proved Allen's conjecture for alternating torus knots and established a necessary condition.
result Linear combinations of alternating torus knots are concordant to L-space knots if and only if they are a single torus knot.

Develops a correspondence between symplectic orbits and Grassmannians.

problem Understanding the homotopy types of Grassmannians of linear subspaces in symplectic vector spaces.
method Uses orbit fibrations and linear symplectic reduction to compute homotopy types.
result Recover observations from Arnold, Oh-Park, and Lee-Leung in different cases.

Develops a new approach to study nonlinear PDEs and their singularities.

problem Understanding the propagation domains of solutions to nonlinear PDEs.
method Derived geometric machinery and sheaf theory to study nonlinear PDEs and their singular supports.
result Estimates the domains of propagation for solutions of non-linear systems.

Classifies non-linear Fredholm maps linking to stable homotopy groups of spheres.

problem Classifying non-linear proper Fredholm maps between Hilbert spaces.
method Using stable homotopy groups of spheres to classify maps up to proper homotopy.
result Determines the non-trivial kernel of the map from stable homotopy groups to non-linear proper Fredholm maps.

Researchers classify quotients of lens spaces using linear actions and topological tools.

problem Classifying quotients of lens spaces under linear actions of (Z/p)2(\mathbb{Z}/p)^2.
method Postnikov towers and surgery theory.
result Quotients are classified up to homotopy by kk-invariants and up to homeomorphism by Pontrjagin classes.

Equations of motion for linear Hamiltonians in the real Jacobi group

problem Equations of motion for linear Hamiltonians in the real Jacobi group
method Using the energy function on the extended Siegel-Jacobi upper half space
result Equations of motion attached to linear Hamiltonians in the generators of the real Jacobi group

In this paper we consider a problem of searching a space of predictive models for a given training data set. We propose an iterative procedure for deriving a sequence of improving models and a corresponding sequence of sets of non-linear features on the original input space. After a finite number of iterations N, the n…

2013-12-19abs ↗pdf ↗

This paper presents a generalization of symplectic geometry to a principal bundle over the configuration space of a classical field. This bundle, the vertically adapted linear frame bundle, is obtained by breaking the symmetry of the full linear frame bundle of the field configuration space, and it inherits a generaliz…

1997-06-10abs ↗pdf ↗