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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.

169,181 papers · 148 categories

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169337506674 · Jun 202019922001200920182026
48 results for equivariant matrix-valued functions

Classifies contravariant matrix-valued valuations on polytopes without continuity assumptions.

problem Classifying contravariant matrix-valued valuations on polytopes without continuity assumptions.
method Complete classification of contravariant matrix-valued valuations on polytopes in Rn\mathbb{R}^n without continuity assumptions.
result The only such valuation is the general Lutwak-Yang-Zhang matrix in dimension n4n \geq 4, and a new function in dimension 3.

Study G2G_2-metrics from non-integrable special Lagrangian fibrations.

problem Understanding G2G_2-metrics from non-integrable special Lagrangian fibrations.
method Decompose SU(3)\mathrm{SU}(3)-structures into solder 1-forms, connection 1-forms, and equivariant matrix-valued functions.
result Describe regular parts of G2G_2-manifolds with Lagrangian-type actions.

New MVG mechanism improves differential privacy for matrix-valued queries.

problem Lack of optimal methods for matrix-valued queries in differential privacy.
method Proposes MVG mechanism using matrix-variate Gaussian noise.
result Proves MVG mechanism preserves (ε,δ)(ε,δ)-differential privacy.

Classifies SL(n) covariant matrix-valued valuations on Lp-spaces.

problem Classifying SL(n) covariant matrix-valued valuations on Lp-spaces.
method Established a complete classification for continuous and SL(n) covariant matrix-valued valuations on Lp(Rn,|x|2dx), eliminating matrix symmetry assumption.
result Unique characterization of such valuations by the moment matrix in n>2, rotation matrix in 2D.

Long term optimal investment problems are studied in a factor model with matrix valued state variables. Explicit parameter restrictions are obtained under which, for an isoelastic investor, the finite horizon value function and optimal strategy converge to their long-run counterparts as the investment horizon approache…

2014-08-29abs ↗pdf ↗

Paper improves matrix-valued data classification using nonparametric LDA.

problem Classification of matrix-valued data in neuroimaging and signal processing.
method Nonparametric LDA based on NPMLE for vectorized and scaled matrices.
result Improves classification performance across various data structures.

Researchers developed a new Riemannian manifold for SPD matrix-valued optimal transport problems.

problem Optimal transport between SPD matrix-valued measures.
method Formulated as a generalized optimal transport problem with block SPD matrices, endowed with a novel Riemannian manifold structure.
result The novel Riemannian manifold allows solving SPD matrix-valued optimal transport problems using Riemannian optimization.

Recovering matrix valued potentials from wave equation data on stationary spacetimes.

problem Recovering a time-dependent matrix valued potential from wave equation data.
method Reduction to non-Abelian light ray transform and study of the transform.
result Sufficient conditions for solving the inverse problem on stationary spacetimes.

We extend Kyle's model to include stochastic liquidity and multiple assets.

problem Modeling informed trading with stochastic liquidity and multiple assets.
method Developed a variational formulation and derived a matrix-valued martingale depth process.
result A linear-Gaussian equilibrium with stochastic matrix-valued price impact.

Improved hypothesis testing and change-point detection using diffusion-based methods.

problem Limited power of score-based hypothesis tests and change-point detection.
method Extending score-based Fisher divergence to diffusion-divergence by multiplying score functions with a matrix-valued function or weight matrix.
result Theoretical quantification and demonstration of optimal performance of diffusion-based algorithms.

We give a complete classification of conformally covariant differential operators between the spaces of ii-forms on the sphere SnS^n and jj-forms on the totally geodesic hypersphere Sn1S^{n-1}. Moreover, we find explicit formulæ for these new matrix-valued operators in the flat coordinates in terms of basic operators …

2016-05-30abs ↗pdf ↗

A new method estimates SDEs using occupation kernels.

problem Learning multivariate stochastic differential equations (SDEs).
method Two-step procedure: estimate drift, then diffusion. Occupation kernels used in RKHS.
result Validated on simulated and real-world data.

Algorithm predicts performance of learning in multi-layer networks with matrix-valued hidden variables.

problem Signal recovery and learning in multi-layer neural networks with matrix-valued hidden variables.
method Unified approximation algorithm for MAP and MMSE inference, extending ML-VAMP to handle matrix-valued unknowns.
result Performance of ML-Mat-VAMP algorithm can be predicted in a random large-system limit.

The paper develops methods for calculating equivariant homology from Morse functions.

problem Calculating equivariant homology from equivariant Morse functions.
method Alter equivariant Morse functions to stable ones, use generic equivariant metrics, and analyze the Morse spectral sequence.
result Equivariant Morse functions induce a filtration that computes equivariant homology.

The paper analyzes stability of random matrix products with Markovian noise.

problem Analyzing stability of random matrix products with Markovian noise.
method Using a super-Lyapunov drift condition and controlled growth of matrix-valued functions, the paper provides an exponential stability result for the p-th moment of random matrix product.
result Finite-time p-th moment bounds for linear stochastic approximation and TD learning algorithms.

Study proposes efficient estimators for matrix-valued linear regression under sparsity assumptions.

problem Estimation of parameters in matrix-valued linear regression models.
method Explicit optimization-free estimators for matrix-valued linear regression models with sparsity assumptions.
result Established non-asymptotic convergence rates for the proposed estimators.

Classification of SL(n) covariant valuations on Orlicz spaces.

problem Classifying continuous SL(n) covariant valuations on Orlicz spaces.
method Complete classification without symmetric assumptions, focusing on moment matrix and a new functional in dimension two.
result The moment matrix is the only SL(n) covariant valuation for n≥3, and a new functional appears in dimension two.

The paper proves a formula for complex Monge-Ampère equations on manifolds.

problem Proving a mean value formula for complex Monge-Ampère equations.
method Using subharmonic Hermitian matrix valued functions and Liouville type theorems.
result Obtained a Liouville theorem for complex Monge-Ampère equations.

Extends DCP framework to Hadamard manifolds for geodesically convex functions.

problem Verifying convexity in nonlinear programs on Hadamard manifolds.
method Introduces Disciplined Geodesically Convex Programming (DGCP) framework, defining compositions and transformations for geodesically convex functions.
result Allows verification of geodesic convexity for a broader range of functions, including statistical estimators and matrix-valued optimization.

Study solutions of elliptic sinh-Gordon equation, focusing on spectral genus two.

problem Investigate solutions of the elliptic sinh-Gordon equation of spectral genus g<3.
method Parametrize solutions by complex matrix-valued polynomials, analyze flows and isospectral sets.
result Construct three conformal maps to R^4 on every elliptic curve, constrained Willmore.

Online graph learning from matrix-valued time series data.

problem Identifying dependency structure among sensors in a network.
method Extends VAR models to matrix-variate models, proposes online procedures for graph learning, and introduces Lasso-type approaches.
result Demonstrates effectiveness of online graph learning methods in both synthetic and real data.

Deep neural networks can approximate invariant/equivariant functions with fewer parameters.

problem Approximating functions that respect group symmetries with neural networks.
method Constructing deep neural networks with GG-actions and GG-equivariant/invariant affine transformations.
result Deep neural networks can approximate GG-invariant/equivariant functions with exponentially fewer parameters.

Optimal portfolio choice with cross-impact propagators, solving complex equations.

problem Maximizing revenue-risk in a continuous-time portfolio choice problem with cross-impact.
method Formulated as a maximization problem, solved explicitly using operator resolvents and stochastic Fredholm equations.
result Sufficient conditions for the absence of price manipulation, providing financial insights.

An impossibility result shows limitations in learning symmetries and equivariant functions.

problem Learning symmetries and equivariant functions simultaneously is impossible under certain conditions.
method Careful study of approximation for groups and semigroups, analysis of neural networks.
result Linearly equivariant networks can be used to learn equivariant functions, but group-convolutional networks have limitations.

The paper computes metrics and Einstein tensors on even-dimensional manifolds.

problem Computing metrics and Einstein tensors on even-dimensional Riemannian manifolds.
method Development of spectral Einstein functionals and equivariant Bismut Laplacian.
result Explicit computation of the equivariant noncommutative residue density.

Universal MLPs with a single hidden layer can learn any function.

problem Learning on various data structures like sequences, images, sets, and graphs.
method Using group theory, the paper proves the universality of a broad class of equivariant MLPs with a single hidden layer.
result Having a hidden layer on which the group acts regularly is sufficient for universal equivariance (invariance).

Formula proves symmetry breaking operators for differential forms.

problem Symmetry breaking operators between differential forms on spheres and their hyperplanes.
method Explicit residue formula for meromorphic continuation of operators.
result Simple construction of symmetry breaking operators and determination of zeros.