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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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61123184245 · Jun 202019922001200920172026
48 results for relaxed assumptions

Study improves denoising score matching under relaxed manifold assumptions.

problem Improving denoising score matching under relaxed manifold assumptions.
method Model density with nonparametric Gaussian mixtures, relax manifold assumption, derive non-asymptotic bounds.
result Non-asymptotic bounds on approximation and generalization errors, rates of convergence determined by intrinsic dimension.

We propose convex relaxations for convolutional neural nets with one hidden layer where the output weights are fixed. For convex activation functions such as rectified linear units, the relaxations are convex second order cone programs which can be solved very efficiently. We prove that the relaxation recovers the glob…

2018-12-31abs ↗pdf ↗

Study relaxes identification assumptions for natural direct effects in non-randomized settings.

problem Identifying causal direct effects under unmeasured confounding.
method Developed relaxed conditions for identifying natural direct effects in non-randomized settings.
result Identified natural direct effect under unmeasured confounding conditions.

Paper relaxes independence assumption for non-centered data.

problem Failing to account for dependencies in data leads to model failures.
method Proposes 'Kronecker-sum-structured mean' assumption to relax zero-mean requirement.
result Models with nonconvex but unimodal log-likelihoods can be solved efficiently.

The study revisits portfolio diversification by relaxing assumptions for skewed, multi-regime, and leptokurtic asset returns.

problem Underestimation of risk in portfolio diversification due to assumptions that are inconsistent with real-world asset returns.
method Calibrated a Markov-modulated Levy process model to equity market data to demonstrate the merits of the approach.
result The calibrated models effectively match empirical moments and show the importance of relaxing assumptions in portfolio diversification.

We propose a new topic modeling procedure that takes advantage of the fact that the Latent Dirichlet Allocation (LDA) log likelihood function is asymptotically equivalent to the logarithm of the volume of the topic simplex. This allows topic modeling to be reformulated as finding the probability simplex that minimizes …

2019-04-03abs ↗pdf ↗

Paper relaxes stability and generalization assumptions for SGD.

problem Stability and generalization for SGD under restrictive assumptions.
method Introduces on-average model stability and develops novel bounds.
result First-ever-known fast bounds in low-noise setting using stability approach.

The paper shows that relaxing assumptions about causal graphs can lead to exponentially large equivalence classes.

problem The size of Markov equivalence classes under relaxed assumptions.
method Analytical proofs for three settings: sparse random directed acyclic graphs, uniformly random acyclic directed mixed graphs, and uniformly random directed cyclic graphs.
result Exponentially large lower bounds for the expected size of Markov equivalence classes.

Paper tackles offline RL with weak assumptions on both function classes and data coverage.

problem Achieve sample-efficient offline RL with weak assumptions on both factors.
method Simple algorithm based on primal-dual formulation of MDPs, with density-ratio function modeling dual variables.
result Polynomial sample complexity achieved under realizability and single-policy concentrability.

New method relaxes TV distance for two-sample testing without distributional assumptions.

problem Challenges in certifying equality or providing tight bounds on TV distance for two distributions.
method Examined blurred total variation distance, a relaxation of TV distance.
result Provided theoretical guarantees for upper and lower bounds on blurred TV distance.

This paper analyzes the convergence of Federated Average under relaxed assumptions.

problem Lack of theoretical analysis for Federated Average under assumptions beyond smoothness.
method Relaxing assumptions of strong smoothness to semi-smoothness and semi-Lipschitz properties, and introducing a bound on the gradient.
result Provides a theoretical convergence study on Federated Learning under new assumptions.

A generalization of the Flow-box Theorem is given. The assumption of continuous differentiability of the vector field is relaxed to a local Lipschitz condition. The theorem holds in any Banach space.

2003-05-14abs ↗pdf ↗

Paper presents a randomized algorithm for SPCA with high probability approximation.

problem Sparse Principal Component Analysis (SPCA) is NP-hard.
method Based on basic SDP relaxation, the algorithm constructs deterministic and randomized solutions.
result The algorithm achieves an approximation ratio of at most the sparsity constant with high probability.

Paper revisits set membership estimation for linear systems with relaxed disturbance bounds.

problem Set membership estimation for linear systems with disturbances bounded by convex sets.
method Adopted block-martingale small-ball condition and random perturbed control policies to establish convergence rates.
result Established convergence rates for disturbances bounded by general convex sets.

AR algorithm simplifies backpropagation with improved scalability and biological plausibility.

problem Improving backpropagation algorithms for complex neural networks and biological plausibility.
method Introducing learnable backwards weights and avoiding nonlinear derivative computations; relaxing frozen feedforward pass assumption.
result Simplified AR algorithm maintains performance on complex CNN architectures and challenging datasets.

We show that the spectral norm of a random n1×n2××nKn_1\times n_2\times \cdots \times n_K tensor (or higher-order array) scales as O((k=1Knk)log(K))O\left(\sqrt{(\sum_{k=1}^{K}n_k)\log(K)}\right) under some sub-Gaussian assumption on the entries. The proof is based on a covering number argument. Since the spectral norm is dual to the tensor…

2014-07-07abs ↗pdf ↗

Paper studies Adam's convergence under relaxed assumptions, proving a rate of O(poly(log T)/sqrt(T)).

problem Understanding Adam's convergence in non-convex, stochastic optimization with unbounded gradients and noise.
method Introduced a comprehensive noise model and used it to prove Adam's convergence rate.
result Adam finds a stationary point with a rate of O(poly(log T)/sqrt(T)) in high probability.

Domain adaptation addresses the common problem when the target distribution generating our test data drifts from the source (training) distribution. While absent assumptions, domain adaptation is impossible, strict conditions, e.g. covariate or label shift, enable principled algorithms. Recently-proposed domain-adversa…

2019-03-05abs ↗pdf ↗

We study the problem of controlling linear time-invariant systems with known noisy dynamics and adversarially chosen quadratic losses. We present the first efficient online learning algorithms in this setting that guarantee O(T)O(\sqrt{T}) regret under mild assumptions, where TT is the time horizon. Our algorithms rely …

2018-06-19abs ↗pdf ↗

The leverage effect-- the correlation between an asset's return and its volatility-- has played a key role in forecasting and understanding volatility and risk. While it is a long standing consensus that leverage effects exist and improve forecasts, empirical evidence paradoxically do not show that most individual stoc…

2016-05-20abs ↗pdf ↗

This note relaxes conditions for Kähler metrics with bounded entropy and scalar curvature.

problem Boundedness conditions for Kähler metrics with bounded entropy and scalar curvature.
method Slightly relaxes the boundedness condition on the scalar curvature.
result Apriori estimates and C3,αC^{3,α} estimate for the potential of the Kähler metrics under relaxed conditions.

This thesis relaxes assumptions for causal discovery, making methods applicable to more complex systems.

problem Learning causal structures from observational data with latent variables.
method Alternative definition of k-Triangle Faithfulness for non-Gaussian distributions and uniform consistency proof.
result Uniform consistency of causal discovery algorithm under modified faithfulness assumption.

A new method for efficient causal structure learning at scale.

problem Causal structure learning is computationally challenging at scale.
method Relaxed sparsest-permutation formulation with support-level relaxation and masked zero-fill incomplete Cholesky factorization.
result The method enables scalable comparison of candidate orderings and matches the accuracy of slower baselines.

GPIRT uses Gaussian processes to estimate latent traits and IRFs from binary responses.

problem Nonparametric IRT models struggle to estimate flexible IRFs and latent traits simultaneously.
method GPIRT employs Gaussian process priors to relax IRF assumptions while estimating latent traits.
result GPIRT provides a flexible solution to IRT challenges, including active learning.

New framework relaxes independence assumption for graph-mixing dependencies.

problem Tackles limitations of existing generalization results for graph-mixing dependencies.
method Proposes a framework where dependencies decay with graph distance, derives generalization bounds leveraging online-to-PAC framework.
result Derives high-probability generalization guarantees that depend on mixing rate and graph's chromatic number.

Paper relaxes faithfulness assumption for causal discovery using interventions.

problem Violation of faithfulness assumption in natural systems leads to incorrect causal structure identification.
method Use intervention-immediacy faithfulness assumption to identify causal structures with hard interventions.
result Interventions contain information about causal structure that can identify causal structures when faithfulness is violated.

We generalize stochastic smoothing for gradient estimation of non-differentiable functions.

problem Gradient estimation for non-differentiable functions.
method Developed a general framework for relaxation and gradient estimation of non-differentiable black-box functions using stochastic smoothing with reduced assumptions.
result Empirically validated the effectiveness of variance reduction strategies for various non-differentiable tasks.

The stochastic block model (SBM) is a popular tool for community detection in networks, but fitting it by maximum likelihood (MLE) involves a computationally infeasible optimization problem. We propose a new semidefinite programming (SDP) solution to the problem of fitting the SBM, derived as a relaxation of the MLE. W…

2014-06-21abs ↗pdf ↗

Study proves optimal controls for stochastic Volterra equations with singular kernels.

problem Existence of optimal controls for stochastic Volterra equations with singular kernels.
method Sufficient conditions based on integrability and growth hypotheses.
result Existence of optimal relaxed and strict controls under classical convexity assumptions.

A new GP interpolation method for better predictive distributions in ranges of interest.

problem Improving predictive distributions in specific ranges of interest.
method Relaxed Gaussian process interpolation, relaxing interpolation constraints outside ranges of interest.
result Better predictive distributions in ranges of interest, especially in non-stationary cases.

We consider the question whether a static potential on an asymptotically flat 3-manifold can have nonempty zero set which extends to the infinity. We prove that this does not occur if the metric is asymptotically Schwarzschild with nonzero mass. If the asymptotic assumption is relaxed to the usual assumption under whic…

2014-03-17abs ↗pdf ↗

Adaptive Monte Carlo methods are recent variance reduction techniques. In this work, we propose a mathematical setting which greatly relaxes the assumptions needed by for the adaptive importance sampling techniques presented by Vazquez-Abad and Dufresne, Fu and Su, and Arouna. We establish the convergence and asymptoti…

2010-01-20abs ↗pdf ↗