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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.

168,742 papers · 148 categories

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61122183244 · Jun 202019922001200920172026
48 results for Amplitude Shift Keying

Optimizing over-the-air convex optimization, analog schemes are nearly optimal at low SNR.

problem Optimizing over-the-air convex optimization with coded gradients.
method Analyzes coded gradients over an additive Gaussian noise channel, considers analog coding schemes.
result Analog coding schemes nearly match the optimal convergence rate at low SNR, but a slowdown is inevitable.

Improved formulation of spinfoam quantum gravity with cosmological constant, ensuring all amplitudes are finite and providing semiclassical asymptotics.

problem Ensuring the finiteness of spinfoam amplitudes and providing semiclassical asymptotics for quantum gravity.
method Using state-integral model of PSL(2, C\mathbb{C}) Chern-Simons theory and implementing simplicity constraint.
result All spinfoam amplitudes are finite and provide semiclassical asymptotics with oscillatory terms related to the Regge action.

Bayesian ARMA model with directional shifts captures structural breaks in compositional time series.

problem Structural breaks in compositional time series due to external shocks or policy changes.
method Developed a Bayesian Dirichlet ARMA model augmented with a directional-shift intervention mechanism.
result The model captures structural breaks through interpretable parameters and produces coherent probabilistic forecasts.

This study analyzes cryptocurrency market dynamics using a novel qq-dependent detrended cross-correlation method.

problem Capturing correlations at varying fluctuation amplitudes and time scales in complex systems.
method Extends traditional metrics with qq-dependent detrended cross-correlation coefficient ρ(q,s) and qqMSTs.
result Significant shifts in network structures during major disruptions, leading to decentralized correlations.

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.

This research examines how model explanations change under distribution shifts in tabular data.

problem Detecting distribution shifts in tabular data affecting model performance and explanations.
method Investigates the relationship between model performance and explanation characteristics under distribution shifts.
result Explanation shifts are a better indicator for detecting predictive performance changes than traditional distribution shift techniques.

This paper shows how learning the phase-amplitude coupling improves bio-signal classification.

problem Discarding phase component in bio-signal feature extraction leads to poor generalization.
method Introducing a novel self-supervised learning task called Phase-Swap to detect phase-amplitude coupling.
result Neural networks trained on Phase-Swap task generalize better across subjects and recording sessions.

Paper proposes an efficient method for calibrating spatio-temporal forecasts.

problem Real-world spatio-temporal forecasting challenges like signal anomalies and distributional shifts.
method Learning with Calibration (ST-TTC) for real-time bias correction.
result ST-TTC improves spatio-temporal forecasting accuracy with reduced computational cost.

A fast method for estimating radar amplitude density parameters.

problem Accurate estimation of amplitude density function parameters in radar applications.
method Projecting amplitude data onto horizontal and vertical axes, then using MLE for α\alpha-stale distribution parameters.
result The average of computed MLEs based on two projections is a fast and accurate estimator for amplitude distribution parameters.

Atiyah classes of DG manifolds of positive amplitude are invariant under weak equivalences.

problem Defining and studying Hochschild cohomology of DG manifolds of positive amplitude.
method Using poly-differential operators and derived intersection, proving invariance under weak equivalences.
result Hochschild cohomology of DG manifolds of positive amplitude is invariant under weak equivalences.

The paper provides exact multivariate amplitude distributions for non-stationary Gaussian or algebraic fluctuations.

problem Capturing the statistical properties of fluctuating correlations in non-stationary systems.
method Developed a random matrix model to average multivariate amplitude distributions from short time scales to large time scales.
result Explicit multivariate distributions for non-stationary correlation systems are provided, capturing the degree of non-stationarity.

We define a topological quantum membrane theory on a seven dimensional manifold of G2G_2 holonomy. We describe in detail the path integral evaluation for membrane geometries given by circle bundles over Riemann surfaces. We show that when the target space is CY3×S1CY_3\times S^1 quantum amplitudes of non-local observables …

2006-11-29abs ↗pdf ↗

Ultra-short laser pulses with femtosecond to attosecond pulse duration are the shortest systematic events humans can create. Characterization (amplitude and phase) of these pulses is a key ingredient in ultrafast science, e.g., exploring chemical reactions and electronic phase transitions. Here, we propose and demonstr…

2018-03-15abs ↗pdf ↗

We demonstrate the equivalence of all loop closed topological string amplitudes on toric local Calabi-Yau threefolds with computations of certain knot invariants for Chern-Simons theory. We use this equivalence to compute the topological string amplitudes in certain cases to very high degree and to all genera. In parti…

2002-06-18abs ↗pdf ↗

PolarBM models complex-valued audio signals in polar coordinates, improving over conventional methods.

problem Discarding structural information in complex-valued problems simplifies models but loses important amplitude-phase relationships.
method Proposes PolarBM, a novel Boltzmann machine for complex-valued variables in polar coordinates, and LogPolarBM for logarithmic amplitude.
result PolarBM and LogPolarBM achieve superior modeling accuracy compared to conventional models, including deep neural networks.

We introduce a fully coherent spin network amplitude whose expansion generates all SU(2) spin networks associated with a given graph. We then give an explicit evaluation of this amplitude for an arbitrary graph. We show how this coherent amplitude can be obtained from the specialization of a generating functional obtai…

2012-01-17abs ↗pdf ↗

We study topological open string amplitudes on orientifolds without fixed planes. We determine the contributions of the untwisted and twisted sectors as well as the BPS structure of the amplitudes. We illustrate our general results in various examples involving D-branes in toric orientifolds. We perform the computation…

2004-11-24abs ↗pdf ↗

The paper proves a category of dg manifolds with finite positive amplitude.

problem Understanding the structure of dg manifolds with finite positive amplitude.
method Using path spaces and homotopy transfer theorem for curved L[1]L_\infty[1]-algebras.
result Proves that dg manifolds of finite positive amplitude form a category of fibrant objects.

Algorithm finds frequencies, amplitudes, and phases of sinusoids in noisy data.

problem Finding frequencies, amplitudes, and phases of sinusoids in noisy data.
method Maximum likelihood approach to estimate tone parameters from contaminated observations. Successively estimates frequencies and jointly optimizes amplitudes and phases.
result Near-linear computational complexity (O(N)) for estimating MM number of sinusoidal sources.

This paper establishes non-asymptotic learning bounds for the DR covariate shift adaptation.

problem Distribution shift between training and test domains in machine learning.
method Doubly-robust (DR) estimator combining density ratio estimation and pilot regression model.
result First non-asymptotic learning bounds for DR covariate shift adaptation.

We decompose the exchange rates returns of 41 currencies (incl. gold) into their sign and amplitude components. Then we group together all exchange rates with a common base currency, construct Minimal Spanning Trees for each group independently, and analyze properties of these trees. We show that both the sign and the …

2009-11-16abs ↗pdf ↗

The paper analyzes the amplitude of functions on the sphere, improving FDA methods.

problem Analyzing trajectories on non-linear manifolds with time variability.
method Developed tools for temporal alignment, geodesic computation, and mean calculation on S2\mathbb{S}^2.
result Efficient and accurate tools for analyzing manifold-valued functions on S2\mathbb{S}^2.

Transformers predict scattering amplitudes in theoretical physics.

problem Computing exact coefficients of scattering amplitudes in N = 4 SYM theory.
method Applied Transformers to predict integer coefficients of scattering amplitudes.
result Transformers achieve high (> 98%) accuracy on predicting scattering amplitudes.

The study diagnoses fairness issues in healthcare models under distribution shifts.

problem Understanding and diagnosing fairness changes in machine learning models under distribution shifts in healthcare.
method Causal framing and conditional independence tests to characterize distribution shifts.
result Knowledge of distribution shifts helps diagnose fairness transfer failures, including complex cases.

The transition amplitudes between coherent states on a coherent state manifold are expressed in terms of the embedding of the coherent state manifold into a projective Hilbert space. Consequences for the dimension of projective Hilbert space and a simple geometric interpretation of Calabi's diastasis follows.

1997-07-31abs ↗pdf ↗

Proposes a new complex Gaussian distribution for better modeling of complex-valued signals.

problem Limited ability of Gaussian distribution to represent diverse amplitude characteristics.
method Introduces a power-weighted noncentral complex Gaussian distribution on the complex plane.
result Consistently outperforms conventional distributions in log-likelihood for speech power spectra.

We explore the performance of several automatic bandwidth selectors, originally designed for density gradient estimation, as data-based procedures for nonparametric, modal clustering. The key tool to obtain a clustering from density gradient estimators is the mean shift algorithm, which allows to obtain a partition not…

2013-10-29abs ↗pdf ↗

Quantum tech speeds up financial risk assessment.

problem Improving credit valuation adjustments using quantum mechanics.
method Developed a quantum algorithm using Bayesian quantum amplitude estimation and engineered likelihood functions.
result Significant speedup in quantum computations for CVA over classical methods.

Bayesian framework improves uncertainty estimates under covariate shifts.

problem Neural networks' unreliable uncertainty estimates under covariate shifts.
method Adaptive prior conditioned on training and new covariates, amortized variational inference.
result Significantly improved uncertainty estimates under distribution shifts.

Neural networks learn simpler features first, then more complex ones; Fourier analysis reveals this pattern.

problem Understanding the learning dynamics of neural networks, especially with natural image data.
method Fourier analysis of translation-invariant and power-law spectra to study feature learning.
result Simple neural networks first rely on amplitude information, then phase information, and power-law spectra can accelerate learning phase information.

New framework identifies worst-case shifts for predictive resource allocation models.

problem Identifying harmful shifts in predictive models for resource allocation.
method Hierarchical model structure and submodular optimization for worst-case loss.
result Empirical evidence shows divergent worst-case shifts identified by different metrics.

Enhances quantum sensing by eliminating multiple oscillations in field amplitude estimation.

problem Multiple oscillations in field amplitude estimation due to inter-qubit interactions at high qubit densities.
method Adopting a quantum circuit learning framework to approximate a target function by optimizing gate parameters.
result Elimination of multiple oscillations, leading to enhanced dynamic range of quantum sensing.

Unified framework for distribution shift estimation, explanation, and improvement.

problem Estimating, explaining, and improving model performance on target domains with distribution shift.
method Entropic Projection Alignment (EPA) aligns source and target distributions by matching moments and minimizing KL divergence.
result EPA consistently outperforms state-of-the-art baselines while offering computational efficiency.

Paper quantifies label shift with robustness guarantees using distribution feature matching.

problem Estimating target label distribution under label shift.
method Distribution feature matching (DFM) framework and robustness analysis.
result General performance bound and robustness analysis in misspecified settings.