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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.

168,982 papers · 148 categories

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2555107641,019 · Jun 202019922001200920172026
48 results for stochastic realizable setting

Clarifies when certain stochastic PDEs have affine state processes.

problem Characterizing stochastic PDEs with affine state processes.
method Characterization of initial points for affine realizations.
result Characterizes the set of initial points for affine realizations.

Clarifies when certain stochastic PDEs have affine solutions.

problem Existence of affine realizations for semilinear SPDEs driven by Lévy processes.
method Analyzes conditions for affine solutions to SPDEs driven by Lévy processes.
result Conditions for the existence of affine realizations are established.

Efficient RL algorithm for MDPs with linear QπQ^π realizability, achieving optimal regret bound.

problem Efficient reinforcement learning under linear QπQ^π realizability assumption for MDPs with stochastic dynamics.
method Frozen Policy Iteration algorithm that uses high-confidence data and freezes policy for well-explored states.
result Achieves optimal regret bound of O~(d2H6T)\widetilde{O}(\sqrt{d^2H^6T}) for linear (contextual) bandits.

Deep learning approximates SPDE solutions from noise trajectories.

problem Approximating solutions to stochastic partial differential equations (SPDEs).
method Uses neural networks to approximate SPDE solutions based on noise realizations.
result Accurately estimates SPDE solutions and functionals like mean and variance.

This study tightens bounds on how GD and SGD generalize in smooth convex optimization problems.

problem Understanding how GD and SGD generalize in smooth stochastic convex optimization problems.
method Provided tight excess risk lower bounds for GD and SGD under different conditions.
result Lower bounds suggest overfitting occurs and gaps remain in some cases.

Asymptotic analysis of short-maturity options on realized variance in local-stochastic volatility models.

problem Analyzing the behavior of short-maturity options on realized variance in local-stochastic volatility models.
method Large deviations theory and variational problems to solve rate functions for different cases.
result Explicit solutions for the rate function in the uncorrelated case and upper/lower bounds and expansions for the correlated case.

BOSH optimizes functions with stochastic evaluations more efficiently and precisely.

problem Optimizing functions with noisy evaluations can lead to suboptimal solutions.
method BOSH uses a hierarchical Gaussian process to generate a growing pool of realizations.
result BOSH provides more efficient and higher-precision optimization than standard BO.

This paper compares HMC and RNN expressivity using SRT.

problem Comparing expressivity of HMC and RNN models.
method Embed HMC and RNN in a GUM, use SRT to compare structured covariance series.
result Conditions for realizing covariance series by GUM, HMC, or RNN.

Enhanced volatility forecasting using options data and rough volatility model.

problem Improving realized volatility forecasting accuracy.
method Infer spot volatility from options data using rough stochastic volatility model, accelerate estimation with deep learning, benchmark against traditional models.
result Augmented HAR-RV-RHeston model outperforms traditional models in daily and long-term forecasting.

Study on the optimization of neural networks with ReLU activation and the degeneracy of their parametrizations.

problem Understanding the optimization landscape of neural networks with ReLU activation.
method Analyzing the optimization problem over the space of neural network realizations and establishing inverse stability of the realization map.
result Inverse stability of the realization map is not guaranteed in general but can be established for shallow networks, allowing optimization over restricted sets.

In this work, we highlight a connection between the incremental proximal method and stochastic filters. We begin by showing that the proximal operators coincide, and hence can be realized with, Bayes updates. We give the explicit form of the updates for the linear regression problem and show that there is a one-to-one …

2018-07-12abs ↗pdf ↗

Study finds roughness in volatility despite diffusive instantaneous volatility.

problem Determining the roughness of volatility in financial assets.
method Non-parametric method based on normalized pp-th variation for estimating roughness of sample paths.
result Realized volatility exhibits rough behavior with a significantly smaller Hurst exponent than instantaneous volatility.

Develops a GMM method to estimate roughness in stochastic volatility models.

problem Estimating roughness in stochastic volatility models with fractional Brownian motion.
method GMM approach for log-normal models with integrated variance and noisy realized variance.
result Consistent and asymptotically normal parameter estimator with bias correction.

New framework tackles stochastic latent subgroup heterogeneity in online decision-making.

problem Stochastic latent heterogeneity in online decision-making where individual responses vary with unobserved subgroups.
method Latent heterogeneous bandit framework using EM-greedy algorithm to learn subgroup probabilities and reward parameters.
result Achieves optimal estimation and classification guarantees, revealing a fundamental stochastic barrier in online decision-making.

Study Brownian motion on Grassmann manifold using matrix stochastic calculus.

problem Understanding Brownian motion on non-compact Grassmann manifold.
method Realize Brownian motion as matrix diffusion process, use matrix stochastic calculus, and hyperbolic Stiefel fibration.
result Connection to generalized Maass Laplacian of complex hyperbolic space.

MTNPs jointly model multiple correlated tasks from various sources.

problem Naive NPs can only model a single stochastic process and infer tasks independently.
method MTNPs are a hierarchical extension of NPs that jointly infer tasks from multiple stochastic processes, considering inter-task correlation and handling incomplete data.
result MTNPs successfully model multiple tasks jointly, discovering and exploiting their correlations in various real-world data.

We study learning in a noisy bisection model: specifically, Bayesian algorithms to learn a target value V given access only to noisy realizations of whether V is less than or greater than a threshold theta. At step t = 0, 1, 2, ..., the learner sets threshold theta t and observes a noisy realization of sign(V - theta t…

2012-02-14abs ↗pdf ↗

Unified framework models multiple financial and insurance term structures.

problem Modeling multiple term structures in various markets.
method Extended Heath-Jarrow-Morton (HJM) approach under real-world probability.
result Characterization of local martingale deflators and existence of affine realizations.

PLoM learns stochastic solutions to PDEs with limited data.

problem Synthesizing solutions to nonlinear PDEs with scarce data.
method Probabilistic Learning on Manifolds constrained by PDEs.
result Learned stochastic solutions minimize PDE residuals.

Study detects P-type bifurcations in single system realizations using unreliable kernel density estimates.

problem Detecting P-type bifurcations in signals with unreliable kernel density estimates.
method Create persistence diagrams from single system realization, statistically analyze resulting set, compare point process modeling methods.
result Subsampling outperforms other point process modeling methods in predicting P-type bifurcations.

New method estimates volatility for processes with jumps of unbounded variation.

problem Estimating volatility of processes with jumps of unbounded variation.
method Developed a new volatility estimator using debiasing of truncated realized quadratic variation.
result Method outperforms existing alternatives in simulations.

No-regret learning fails to converge to Nash equilibria in mixed strategies.

problem Limiting behavior of mixed strategies in repeated games.
method Study of optimal no-regret learning algorithms for 2x2 competitive games.
result Limiting mixed strategies cannot converge to Nash equilibria under mean-based and monotonic updates.

New algorithm for model selection in contextual bandits reduces regret.

problem Adapting to the complexity of the optimal policy in contextual bandits.
method Designing an algorithm that balances exploration and exploitation, achieving optimal regret bounds.
result Achieves ildeO(T2/3dm1/3) ilde{O}(T^{2/3}d^{1/3}_{m^\star}) regret with no prior knowledge of the optimal dimension dmd_{m^\star}.

New bounds show linear predictors rarely overfit with certain optimization methods.

problem Bounding test error for linear predictors with stochastic optimization methods.
method Coupling argument for fixed point methods like stochastic and batch mirror descent.
result Locally-adapted rates that depend on predictor properties, not global problem structure.

Optimal algorithm for maximizing rewards in contextual bandits with resource constraints.

problem Maximizing rewards in contextual bandits with resource constraints.
method Proposed a universal and optimal algorithmic framework for CBwK by reducing it to online regression.
result Established the optimality of the proposed algorithm for various function classes.

Polynomial chaos surrogates handle intrinsic noise in stochastic models.

problem Handling intrinsic noise in stochastic models with parametric uncertainty.
method Developed a PCE surrogate on a joint space of intrinsic and parametric uncertainty using Rosenblatt transformations and Karhunen-Loeve expansion.
result Quantified intrinsic noise contribution to model output variance using PCE Sobol indices.

Proposes a method to estimate time-dependent probability density functions using binary classifiers.

problem Estimating time-dependent probability density functions of stochastic processes.
method Trains a time-dependent binary classifier to discriminate between realizations of a stochastic process at two nearby time instants.
result Explicitly models and accurately reconstructs complex time-dependent, multi-modal, and near-degenerate densities.

Study improves resilience against adversarial clean-label attacks in real and noisy settings.

problem Ensuring accurate predictions in the presence of adversarial clean-label samples.
method Sequential learning from a stream of i.i.d. data, allowing abstention for uncertain predictions.
result Theoretical analysis and adaptations for the agnostic setting with a clean-label adversary and noise.

We study the stochastic Riemannian gradient algorithm for matrix eigen-decomposition. The state-of-the-art stochastic Riemannian algorithm requires the learning rate to decay to zero and thus suffers from slow convergence and sub-optimal solutions. In this paper, we address this issue by deploying the variance reductio…

2016-05-26abs ↗pdf ↗

A new stochastic primal--dual algorithm for solving a composite optimization problem is proposed. It is assumed that all the functions/operators that enter the optimization problem are given as statistical expectations. These expectations are unknown but revealed across time through i.i.d. realizations. The proposed al…

2019-01-23abs ↗pdf ↗

Develops robust methods for infinite-dimensional stochastic processes.

problem Measuring covariations in stochastic evolution equations in infinite dimensions.
method Asymptotic theory for jump robust measurement of covariations.
result Identifies scaling limits for realized covariations.