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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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63127190253 · May 202619922001200920182026
48 results for frequency shift invariance

Paper improves music transcription models with invariance and data augmentation.

problem Improving accuracy of frame-based music transcription models.
method Translation-invariant network combining filterbank and CNN, trained with pitch-shift augmented data.
result Top-performing model in MIREX evaluation, reducing model complexity and avoiding overfitting.

The paper addresses instability in CNNs' first layer by proving max pooling's shift invariance.

problem Instability in CNNs' first layer, leading to sensitivity to small input shifts.
method Establishing conditions for max pooling's shift invariance and deriving a measure of stability.
result Max pooling approximates a nearly shift-invariant complex modulus under certain conditions.

FreSh shifts model's initial frequency spectrum to match target signal, improving neural representation performance.

problem MLPs' low-frequency bias limits capturing high-frequency details accurately.
method FreSh selects embedding hyperparameters to align model's initial output spectrum with target signal's spectrum.
result FreSh improves performance across various neural representation methods and tasks with minimal computational overhead.

Bird sounds possess distinctive spectral structure which may exhibit small shifts in spectrum depending on the bird species and environmental conditions. In this paper, we propose using convolutional recurrent neural networks on the task of automated bird audio detection in real-life environments. In the proposed metho…

2017-03-07abs ↗pdf ↗

We analyze the structure of the \emph{frequency space} Q(F)Q(F) of a nonabelian free group F=F(a1,...,ak)F=F(a_1,...,a_k) consisting of all shift-invariant Borel probability measures on F\partial F and construct a natural action of Out(F)Out(F) on Q(F)Q(F). In particular we prove that for any outer automorphism φφ of FF the \emph{conju…

2003-11-05abs ↗pdf ↗

Many spectral unmixing methods rely on the non-negative decomposition of spectral data onto a dictionary of spectral templates. In particular, state-of-the-art music transcription systems decompose the spectrogram of the input signal onto a dictionary of representative note spectra. The typical measures of fit used to …

2016-09-30abs ↗pdf ↗

Estimating signals with linear recurrence relations under Gaussian noise is nearly as hard as sparse signals.

problem Estimating discrete-time signals with unknown linear recurrence relations in Gaussian noise.
method Analyzing shift-invariant subspaces and their Fourier coefficients as reproducing filters.
result The statistical complexity is nearly the same as for ss-sparse signals, and the estimator is tractable.

New framework explains leading digit patterns without probabilistic assumptions.

problem Explaining leading digit distributions without relying on probabilistic models.
method Shift-invariant functional equation and affine-plus-periodic formulas.
result Unified mathematical foundation for understanding digit distributions.

Paper extends SI method for detecting CPs in complex systems' frequency domain.

problem Identifying change points in complex systems' frequency domain.
method Extends SI framework to frequency domain using DFT properties and develops valid p-values.
result Reliable detection of genuine CPs with strong statistical guarantees.

Study links harmonic maps to shift-invariant subspaces in complex function spaces.

problem Understanding the relationship between harmonic maps and shift-invariant subspaces.
method Operator-theoretic methods to derive a criterion for the finiteness of the uniton number.
result Derives a criterion for the finiteness of the uniton number in harmonic maps.

We describe a pair of invariants for actions of finite groups on shifts of finite type, the left-reduced and right-reduced shifts. The left-reduced shift was first constructed by U. Fiebig, who showed that its zeta function is an invariant, and in fact equal to the zeta function of the quotient dynamical system. We als…

2005-06-14abs ↗pdf ↗

MCLNN improves music genre classification by learning frequency bands.

problem Classifying music genres using neural networks adapted from image recognition.
method MCLNN learns frequency bands, reducing susceptibility to frequency shifts and enabling concurrent exploration of feature combinations.
result MCLNN outperforms state-of-the-art Convolutional Neural Networks on the Ballroom music dataset.

New framework learns sufficient invariant features robustly across distribution shifts.

problem Learning robust models under distribution shifts between training and test datasets.
method Sufficient Invariant Learning (SIL) framework and Adaptive Sharpness-aware Group Distributionally Robust Optimization (ASGDRO) algorithm.
result Empirical evaluations confirm ASGDRO's robustness against distribution shifts.

Efficiently estimates densities of multidimensional shift-invariant distributions.

problem Density estimation for shift-invariant multidimensional distributions.
method Efficient algorithms for learning any distribution in the class from samples, using total variation distance.
result Shift-invariant distributions can be learned efficiently with a number of samples and time proportional to 1/εd+21/ε^{d+2} and 1/ε2d+21/ε^{2d+2} respectively.

Estimates model performance under distribution shift using domain-invariant predictors.

problem Poor performance of models on test distributions different from training distributions.
method Uses domain-invariant predictors as a proxy for unknown target labels.
result Shows that the complexity of latent representations influences target risk.

Proposes FSM-IRL to learn invariant network representations considering feature and structural shifts.

problem Spatial heterogeneity and temporal dynamics lead to OOD generalization issues in geographic networks.
method Introduces FSM-IRL model that accounts for feature and structural distribution shifts using causal attention and reweighting.
result Demonstrates strong learning capabilities on geographic and social network datasets in OOD scenarios.

Quantum theory reinterprets financial pricing by focusing on observable price transitions.

problem Traditional financial models rely on latent variables; this paper proposes a new observable approach.
method Shift operators, spectral calculus, and Lindblad semigroups are used to define observable frequency operators and convolution generators.
result The framework leads to a nonlocal pricing equation that converges to classical Black-Scholes-Merton under small mesh limits.

The paper explores how to make machine learning models robust to domain shifts.

problem Machine learning models are unreliable in domains different from training.
method Introducing a broad formal notion of invariance and causal structures.
result The true underlying causal structure of the data plays a critical role in robustness.

FredNormer improves time series forecasting by adapting to frequency domain patterns.

problem Current normalization methods struggle with non-stationary time series due to their time-domain approach.
method FredNormer analyzes frequency components, adapts weights, and improves robustness.
result FredNormer boosts forecasting accuracy by 33.3% on ETTm2 dataset.

Paper tackles distribution shifts in prediction models with unobserved confounding.

problem Distribution shifts in prediction models with unobserved confounding.
method Linear structural causal model, invariant covariate representations, data-driven representation learning method.
result Optimizes for a lower-dimensional linear subspace and a prediction model confined to that subspace, achieving nearly ideal gap between target and source risk.

Minimal token perturbations reveal how Transformer models process information.

problem Understanding information propagation in Transformer models for interpretability.
method Study of minimal token perturbations on embedding space.
result Rare tokens cause larger shifts, and input information mixes deeper.

This paper develops methods for obtaining distribution-free prediction regions for invariant representations.

problem Distributional shifts in machine learning models.
method Invariant risk minimization and weighted conformity scores.
result Proves the effectiveness of adaptive conformal intervals for uncertainty estimation.

Framework detects shape shifts in functional profiles using Fréchet mean and shape invariant model.

problem Detecting shape shifts in functional profiles.
method Combining Fréchet mean and shape invariant model for interpretable parameterization of profile deviations.
result Potential shifts in shape deformation process distinguished by significant shifts in amplitude and/or phase.

The paper develops methods to estimate frequencies in large discrete data sets with improved coverage and robustness.

problem Estimating frequencies in large, discrete data sets with valid coverage and robustness.
method Conformal inference methods using discrete sketches, marginal coverage for queries, and novel conformal calibration.
result Improved empirical performance compared to existing methods in simulations and real data.

DSLOB creates synthetic LOB data for benchmarking forecasting algorithms under distributional shifts.

problem Challenges in dealing with out-of-distribution limit order book data.
method Multi-agent market simulator to create labeled synthetic LOB dataset with and without market stress.
result Demonstrates the need for robust forecasting algorithms to handle distributional shifts.

New adaptive signal denoising method mimics oracle with better statistical properties.

problem Adaptive discrete-time signal denoising with linear oracle structure.
method Minimizes the 2\ell_2-norm of the estimation residual, proving oracle inequalities for 2\ell_2-loss.
result Improved statistical properties over \ell_\infty-fit estimators, especially in 2\ell_2- and pointwise losses.

High frequency limit for most of wave phenomena is known as quasiclassical limit or ray optics limit. Propagation of waves in this limit is described in terms of wave fronts and rays. Wave front is a surface of constant phase whose points are moving along rays. As it appears, their motion can be described by Hamilton e…

2001-08-23abs ↗pdf ↗

Deep neural networks approximate functions in shift-invariant spaces with controlled error.

problem Approximating functions in shift-invariant spaces with neural networks.
method Using deep ReLU neural networks, estimating approximation error bounds based on network width and depth.
result Deep neural networks achieve optimal approximation rates for Sobolev spaces up to a logarithmic factor.

This research focuses on invariant probabilistic predictions, showing they are not robust under distribution shifts.

problem The challenge of creating robust probabilistic predictions that remain consistent under distribution shifts.
method A causality-inspired framework to investigate invariance and robustness of probabilistic predictions with respect to proper scoring rules.
result Arbitrary distribution shifts do not admit invariant and robust probabilistic predictions, unlike point predictions.