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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.

168,695 papers · 148 categories

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178356534712 · Jun 202019922001200920172026
48 results for separable functions

Spectral analysis shows neural networks separate from linear methods in approximating functions.

problem Separating two-layer neural networks from linear methods in function approximation.
method Spectral-based approach using Kolmogorov width and kernel spectrum.
result Upper and lower bounds on separation, explicit hard functions identified.

Single-microphone, speaker-independent speech separation is normally performed through two steps: (i) separating the specific speech sources, and (ii) determining the best output-label assignment to find the separation error. The second step is the main obstacle in training neural networks for speech separation. Recent…

2019-08-04abs ↗pdf ↗

Mirror flow optimizes separable data problems, converging to a maximum margin classifier.

problem Optimizing classification problems with separable data using mirror flow.
method Examine mirror flow on linearly separable classification problems, focusing on the horizon function of the mirror potential.
result Mirror flow converges to a maximum margin classifier for separable data under certain conditions.

Study on size and depth of neural networks for approximating benign functions, showing barriers and explicit results.

problem Understanding how size and depth of neural networks affect their ability to approximate benign functions.
method Analyzing ReLU networks for benign functions, proving barriers and explicit results.
result Explicit benign functions that cannot be approximated by networks of certain sizes or depths, showing barriers to size and depth separation.

PPG separates policy and value function training phases for better reinforcement learning efficiency.

problem Challenges in traditional reinforcement learning methods for policy and value function optimization.
method Integrates Phasic Policy Gradient framework that splits policy and value function training into distinct phases.
result Significantly improves sample efficiency on Procgen Benchmark compared to PPO.

Develops a new framework for causal models on cyclic graphs, solving unique solvability issues.

problem Challenges in specifying unique probability distributions for cyclic functional causal models.
method Introduces a new probability rule and graph-separation property (p-separation) for cyclic fCMs.
result Proves p-separation is sound and complete for all consistent cyclic fCMs, recovering d-separation for DAGs.

We give effective proofs of residual finiteness and conjugacy separability for finitely generated nilpotent groups. In particular, we give precise asymptotic bounds for a function introduced by Bou-Rabee that measures how large the quotients that are need to separate non-identity elements of bounded length from the ide…

2015-02-18abs ↗pdf ↗

TSL learns separable models to avoid signal cancellation and off-support extrapolation.

problem Signal cancellation and off-support extrapolation in additive models.
method Tensor Separation Learning (TSL) via stagewise greedy procedure with orthogonal refitting.
result TSL avoids information loss caused by marginalizing higher-order interactions.

We characterize the class of separable Banach spaces XX such that for every continuous function f:XRf:X\to\mathbb{R} and for every continuous function ε:X(0,+)ε:X\to\mathbb(0,+\infty) there exists a C1C^1 smooth function g:XRg:X\to\mathbb{R} for which f(x)g(x)ε(x)|f(x)-g(x)|\leqε(x) and g(x)0g'(x)\neq 0 for all xXx\in X (that is, gg has no…

2005-10-27abs ↗pdf ↗

This paper extends depth separation results to piece-wise oscillatory functions.

problem Approximating functions with piece-wise oscillatory structure using neural networks.
method Extends existing results to piece-wise oscillatory functions using proof strategy from (Eldan and Shamir, 2016).
result Approximation by one-hidden-layer networks holds at a poly(d) rate for functions with constant domain radius and oscillation rate.

We show that for every Lipschitz function ff defined on a separable Riemannian manifold MM (possibly of infinite dimension), for every continuous ε:M(0,+)ε:M\to (0,+\infty), and for every positive number r>0r>0, there exists a CC^\infty smooth Lipschitz function g:MRg:M\to\mathbb{R} such that f(p)g(p)ε(p)|f(p)-g(p)|\leqε(p) for every …

2006-02-02abs ↗pdf ↗

Existing depth separation results for constant-depth networks essentially show that certain radial functions in Rd\mathbb{R}^d, which can be easily approximated with depth 33 networks, cannot be approximated by depth 22 networks, even up to constant accuracy, unless their size is exponential in dd. However, the func…

2019-04-15abs ↗pdf ↗

Study on self-similar sets on Riemannian manifolds with new separation conditions.

problem Analyzing self-similar sets on Riemannian manifolds with new separation conditions.
method Formulated weak separation and finite type conditions for conformal iterated function systems on Riemannian manifolds.
result Obtained formulas for Hausdorff dimensions of self-similar and graph self-similar sets.

In this work we show that randomized (block) coordinate descent methods can be accelerated by parallelization when applied to the problem of minimizing the sum of a partially separable smooth convex function and a simple separable convex function. The theoretical speedup, as compared to the serial method, and referring…

2012-12-04abs ↗pdf ↗

Proves depth 2 neural networks can't approximate certain functions as well as depth 3 networks.

problem Approximating functions with depth 2 networks in high dimensions.
method Lower bound proof using worst-to-average-case random self-reducibility.
result Proves depth 2 networks can't approximate certain functions as well as depth 3 networks, resolving an open problem.

In this paper, we propose a two-step training procedure for source separation via a deep neural network. In the first step we learn a transform (and it's inverse) to a latent space where masking-based separation performance using oracles is optimal. For the second step, we train a separation module that operates on the…

2019-10-22abs ↗pdf ↗

Speech separation refers to extracting each individual speech source in a given mixed signal. Recent advancements in speech separation and ongoing research in this area, have made these approaches as promising techniques for pre-processing of naturalistic audio streams. After incorporating deep learning techniques into…

2019-12-17abs ↗pdf ↗

Develops large-sample theory for non-stationary source separation.

problem Lack of large-sample results for non-stationary source separation methods.
method Large-sample theory for NSS-JD method under specific assumptions.
result Consistency of unmixing estimator and its convergence to Gaussian distribution.

Diffusion models can memorize training data, limiting their creativity and privacy.

problem Memorization in diffusion models that reproduces training data instead of generating novel outputs.
method Dual-separation approach via statistical estimation and network approximation.
result Pruning-based method reduces memorization while maintaining generation quality.

New findings on depth vs. width in neural networks, showing depth can improve learnability.

problem Understanding the role of depth in neural networks, especially when width is unbounded.
method Analyzing sample complexity for learnability in norm-controlled depth-2 and depth-3 ReLU networks.
result Depth can improve learnability of functions that are otherwise unlearnable with depth-2 networks.

The paper uses deep neural networks to estimate economic models without separability restrictions.

problem Estimating economic models with complex interaction effects and non-separable restrictions.
method Uses deep neural networks as a nonparametric sieve to approximate regression functions from nonlinear latent variable models.
result Economic shape, sparsity, or separability restrictions are imposed more straightforwardly when a flexible latent variable model is used.

The Stone-Weierstrass theorem aids in solving inverse problems on specific manifolds.

problem Inverse problems on holomorphically separable Kähler manifolds and conformally transversally anisotropic manifolds.
method Application of the Stone-Weierstrass theorem to show uniqueness in inverse problems.
result Generalization and simplification of earlier results in inverse problems.

New non-separable covariance kernels for spatiotemporal data derived from harmonic oscillator physics.

problem Capturing complex spatiotemporal dependencies in Gaussian processes.
method Hybrid spectral method based on the harmonic oscillator, deriving explicit covariance kernels.
result Explicit non-separable covariance kernels with space-time interactions.

Classifies polynomial growth solutions to drift-harmonic equations on asymptotically paraboloidal manifolds.

problem Classifying polynomial growth solutions to drift-harmonic equations on specific types of manifolds.
method Inductive argument that alternates between constructing and asymptotically controlling drift-harmonic functions.
result All drift-harmonic functions with polynomial growth asymptotically separate variables and dimensions of spaces are computed.

Paper calculates distances between strata in Teichmüller space, proving a constant separation.

problem Measuring distances in the Weil-Petersson metric on Teichmüller space.
method Analyzes distances between strata, proving a constant separation and providing bounds.
result Proves the optimal value for minimal separation between strata is a constant δ1,1δ_{1,1}.

Gradient descent converges with arbitrary stepsize for separable data under Fenchel-Young losses.

problem Understanding the conditions under which gradient descent converges with arbitrary stepsize.
method Using Fenchel-Young losses and leveraging the classical perceptron argument to derive convergence rates.
result GD converges with arbitrary stepsize for a majority of Fenchel-Young losses, with better rates for specific loss functions.

We propose a new blind source separation algorithm based on mixtures of alpha-stable distributions. Complex symmetric alpha-stable distributions have been recently showed to better model audio signals in the time-frequency domain than classical Gaussian distributions thanks to their larger dynamic range. However, infer…

2017-11-13abs ↗pdf ↗