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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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53105158210 · May 202619922001200920172026
48 results for expressivity gap

The study examines how averaging data improves model performance.

problem Understanding the generalization gap in machine learning models.
method Data averaging, covariance analysis, and stochastic gradient descent (SGD) noise modeling.
result A modified generalization gap is always non-negative for a large class of model parameter distributions.

Gated attention improves model curvature, enhancing performance on nonlinear tasks.

problem Understanding the geometric implications of gating in attention mechanisms.
method Modeling attention outputs as Gaussian distributions and analyzing Fisher--Rao geometry.
result Gated attention enables non-flat geometries, including positively curved manifolds.

New volume functions for random hyperbolic surfaces link to spectral gaps.

problem Analyzing spectral gaps in random hyperbolic surfaces.
method Introduced new volume functions VgT(l)V_g^T(l), derived their asymptotic expansions, and linked them to spectral gaps.
result Coefficients in the asymptotic expansion of VgT(l)V_g^T(l) are Friedman-Ramanujan functions.

New framework explains normalizing flows' power and limitations.

problem Understanding the expressive power and limitations of normalizing flows.
method Theoretical framework for well-conditioned coupling-based normalizing flows and volume-preserving flows.
result RealNVP is distributionally universal, but volume-preserving flows are not.

The motivations for using variational inference (VI) in neural networks differ significantly from those in latent variable models. This has a counter-intuitive consequence; more expressive variational approximations can provide significantly worse predictions as compared to those with less expressive families. In this …

2018-01-18abs ↗pdf ↗

Sine activation functions enable two-layer neural networks to learn modular addition more efficiently.

problem Learning modular addition with two-layer neural networks.
method Introduced and analyzed sine activation functions, providing theoretical and empirical evidence.
result Sine activation functions allow for constant-width network realizations of modular addition, whereas ReLU networks require linear width scaling.

Chaos in cerebellar cells enhances complexity of neural patterns.

problem Understanding how cerebellar granular layer represents complex information.
method Constructed a model of cerebellar granular layer with gap junctions, evaluated using reservoir computing.
result Chaotic dynamics in the cerebellar granular layer produce complex and diverse output patterns.

Implicit models can match or exceed explicit models with more test-time compute.

problem Understanding the expressive power and scaling of implicit models.
method Nonparametric analysis of expressive power, mathematical characterization of implicit operators, and test-time scaling experiments.
result Implicit models can progressively express more complex mappings through iteration, matching a richer function class with test-time compute.

We present a novel tractable generative model that extends Sum-Product Networks (SPNs) and significantly boosts their power. We call it Sum-Product-Quotient Networks (SPQNs), whose core concept is to incorporate conditional distributions into the model by direct computation using quotient nodes, e.g. $P(A|B) = \frac{P(…

2017-10-12abs ↗pdf ↗

We study spectral gaps of cellular differentials for finite cyclic coverings of knot complements. Their asymptotics can be expressed in terms of irrationality exponents associated with ratios of logarithms of algebraic numbers determined by the first two Alexander polynomials. From this point of view it is natural to s…

2016-07-13abs ↗pdf ↗

The paper explores how simplicity leads to better out-of-distribution generalization in models.

problem Understanding the theoretical principles behind out-of-distribution (OOD) generalization in modern models.
method Examining diffusion models in image generation to analyze compositional generalization abilities and develop a theoretical framework for simplicity-based OOD generalization.
result The true, generalizable model corresponds to the simplest among consistent models, and this simplicity can be quantified and used to establish sample complexity guarantees.

Study shows gap between uniform convergence and test error in random feature models.

problem Understanding the gap between uniform convergence and test error in random feature models.
method Analytical expressions for uniform convergence over norm balls, interpolators, and minimum norm interpolator risk derived and proved.
result Uniform convergence over interpolators still gives a non-trivial bound of test error even when classical uniform convergence is vacuous.

This paper identifies drift Lipschitz budget K as key to diffusion policy expressivity and statistical trade-offs.

problem Understanding and maximizing the expressivity of diffusion policies while managing statistical limitations.
method Identifying drift Lipschitz budget K as central, quantifying expressivity and statistical behavior, proving lower bounds, and providing practical implementation guidelines.
result Balancing expressivity and statistical complexity yields a finite-sample performance gap, with rates depending on sample size and drift type.

We investigate statistical uncertainty quantification for reinforcement learning (RL) and its implications in exploration policy. Despite ever-growing literature on RL applications, fundamental questions about inference and error quantification, such as large-sample behaviors, appear to remain quite open. In this paper…

2019-10-12abs ↗pdf ↗

Persistent homology enhances graph classification by capturing long-range graph properties.

problem Lack of formal assessment of persistent homology in graph learning.
method Brief introduction and theoretical discussion of persistent homology in graph context, followed by empirical analysis.
result Persistent homology improves graph classification, especially for data with prominent topological structures.

It is well-known that the expressivity of a neural network depends on its architecture, with deeper networks expressing more complex functions. In the case of networks that compute piecewise linear functions, such as those with ReLU activation, the number of distinct linear regions is a natural measure of expressivity.…

2019-01-25abs ↗pdf ↗

RNNs struggle with in-context retrieval, while Transformers excel.

problem In-context retrieval capability of RNNs.
method Theoretical analysis and experimental techniques (CoT, RAG, Transformer layer).
result Enhancing RNNs with techniques improves their in-context retrieval capability, closing the representation gap with Transformers.

This paper derives radial fields on manifolds of symmetric positive definite matrices.

problem Lack of an expression for radial fields on manifolds of symmetric positive definite matrices.
method Derives an expression for radial fields on manifolds of symmetric positive definite matrices.
result Derives an expression for radial fields on manifolds of symmetric positive definite matrices.

New approach connects quantum phases to VQA trainability, enabling better scaling.

problem Scalability issues in VQAs, especially barren plateaus.
method Analog VQA ansätze composed of quenches of a disordered Ising chain, tuning disorder strength.
result Thermalized and MBL phases reach maximal expressivity at large MM, but barren plateaus emerge at smaller MM in the thermalized phase.

SVB method provides scalable Bayesian proportional hazards model for high-dimensional gene expression data.

problem Bayesian methods for high-dimensional sparse survival data often sacrifice uncertainty quantification or computational scalability.
method Mean-field variational approximation for scalable Bayesian proportional hazards model.
result SVB method offers posterior distribution for parameters and variable selection via posterior inclusion probabilities.

This work explores test-time scaling strategies for LLMs, improving sample efficiency and expressiveness.

problem Understanding the sample efficiency and expressiveness of test-time scaling strategies for LLMs.
method Established separation and expressiveness results for self-consistency, best-of-nn, and self-correction strategies.
result Self-correction enables Transformers to simulate online learning over multiple tasks without prior knowledge.

The paper calculates mass and volume of Einstein metrics in four dimensions.

problem Calculating mass and volume of Einstein metrics in four dimensions.
method Using Green's function and conformal laplacian, the paper expresses ADM mass as an integral and proves a mass-volume inequality.
result Proves a lower bound for the mass of a metric in terms of its volume, and various mass gap theorems.

This work improves adversarial robustness in sparse coding models.

problem The gap between theoretical models and practical deployment in adversarial robustness.
method Combining a sparsity-promoting encoder with a linear classifier, and providing a robustness certificate.
result Bounding the robust risk and providing a robustness certificate for end-to-end classification.

Derives bounds for deterministic predictors using smooth loss functions.

problem Generalizing probabilistic predictors to deterministic ones.
method Exploits smoothness properties of loss and predictor classes, controlling the Jensen gap class through Rademacher complexity.
result Derives bounds for deterministic predictors involving flatness quantities from Jacobians and Hessians.

Paper explains why robust generalization is hard in deep learning models.

problem Difficulty in achieving robust generalization despite good training accuracy.
method Theoretical analysis of expressive power for deep neural networks.
result Expressive power of neural networks affects robust generalization.

Advanced GNNs improve molecular generation models.

problem Generating complete graphs with multiple nodes and edges based on labels.
method Replaced standard GNNs with more expressive GNNs in autoregressive and one-shot generation models.
result Advanced GNNs can improve performance of graph generative models, but expressiveness is not a necessity.

This work closes the gap between theory and practice for nICA identifiability.

problem Identifying latent components in nonlinearly mixed data.
method Finite-sample analysis of GCL-based nICA, combining GCL properties, statistical generalization, and numerical differentiation.
result Establishes a trade-off between function learner complexity and expressiveness.

Develops a three-currency HJM framework for Brazilian credit markets, finding significant credit spread differences between indexed segments.

problem Identifies and quantifies differences in corporate credit spreads between two parallel segments of the Brazilian bond market.
method Uses a Heath-Jarrow-Morton framework to model corporate credit as a separate economy, linking it to nominal and real economies through synthetic rates.
result Empirically finds a 640 basis point average difference in credit spreads between CDI-indexed and IPCA-indexed segments, stable through market cycles.