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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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89177266354 · Jun 202019922001200920172026
48 results for contractive approximation

Two methods for pricing swing contracts using neural networks or explicit functions.

problem Evaluating optimal energy purchases in swing contracts with firm constraints.
method Two approaches: explicit parametric function and neural network approximation.
result Neural network approach provides better prices in shorter computation time.

In principal-agent models, a principal offers a contract to an agent to perform a certain task. The agent exerts a level of effort that maximizes her utility. The principal is oblivious to the agent's chosen level of effort, and conditions her wage only on possible outcomes. In this work, we consider a model in which t…

2018-11-16abs ↗pdf ↗

The paper analyzes contraction rates for GP regression approximations.

problem Computational infeasibility of exact GP posterior in large-scale applications.
method Lanczos and conjugate gradient approximations of the posterior mean.
result Minimax contraction rates for these approximations in large-scale applications.

Bayesian KANs achieve near-minimax posterior contraction rates in anisotropic Besov spaces.

problem Statistical foundation for Bayesian Kolmogorov-Arnold networks in anisotropic Besov spaces.
method Sparse Bayesian KANs with spike-and-slab priors, hyperprior on model size, and approximation complexity bounds.
result Posterior contraction rates depend on intrinsic anisotropic smoothness and effective dimension of the compositional structure.

Bayesian nonparametric models get better posterior estimates via SPDE methods.

problem Estimating posterior distributions in nonparametric Bayesian models.
method Extending diffusion methods to SPDEs on Hilbert spaces for posterior contraction and Laplace approximation.
result Derivation of posterior contraction rates and finite-sample Bernstein von Mises results.

Study variance-reduced method for estimating fixed points in Banach spaces.

problem Estimating fixed points of contractive operators in Banach spaces with noisy evaluations.
method Variance-reduced stochastic approximation scheme in Banach spaces.
result Establish non-asymptotic bounds for operator defect and estimation error.

In this paper we use Bernstein and Chebyshev polynomials to approximate the price of some basket options under a bivariate Black-Scholes model. The method consists in expanding the price of a univariate related contract after conditioning on the remaining underlying assets and calculating the mixed exponential-power mo…

2014-04-11abs ↗pdf ↗

New bounds for SA with arbitrary norm contractions and Markovian noise.

problem Finite-time analysis of two-time-scale stochastic approximation with arbitrary norm contractions and Markovian noise.
method Use of generalized Moreau envelope for arbitrary norm contractions and solutions of Poisson equation for Markovian noise.
result Mean square error decays at rates of O(1/n2/3)O(1/n^{2/3}) and O(1/n)O(1/n) under different conditions.

The paper explores local-correlation models for pricing complex financial contracts.

problem Calibrating synthetic quanto forward contracts and composite options.
method Design on-line calibration procedures for local and stochastic volatility models.
result Calibration performance of local-correlation models compared to simpler approximations.

Uniform TD(0) bound derived for function approximation with Markov noise.

problem Uniform concentration bound for TD(0) with function approximation.
method Contractive stochastic approximation, martingale and Markov noises, Poisson equation, relaxed concentration inequalities.
result Uniform all-time concentration bound for TD(0) with linear function approximation.

Recently, \citet{SuttonMW15} introduced the emphatic temporal differences (ETD) algorithm for off-policy evaluation in Markov decision processes. In this short note, we show that the projected fixed-point equation that underlies ETD involves a contraction operator, with a γ\sqrtγ-contraction modulus (where γγ is the …

2015-08-14abs ↗pdf ↗

New MKABSDEs help calculate initial margins in financial contracts.

problem Calculating initial margins in financial contracts with dependencies.
method Introduced MKABSDEs, provided existence and uniqueness, applied to CVaR, used deterministic and Monte-Carlo methods for numerical approximations.
result MKABSDEs provide a new way to solve for initial margins in financial contracts.

We study the modelling and valuation of surrender and other behavioural options in life insurance and pension. We place ourselves in between the two extremes of completely arbitrary intervention and optimal intervention by the policyholder. We present a method that is based on differential equations and that can be use…

2014-12-05abs ↗pdf ↗

Based on a new coupling approach, we prove that the transition step of the Hamiltonian Monte Carlo algorithm is contractive w.r.t. a carefully designed Kantorovich (L1 Wasserstein) distance. The lower bound for the contraction rate is explicit. Global convexity of the potential is not required, and thus multimodal targ…

2018-05-01abs ↗pdf ↗

Study on nonsmooth contractive SA with constant stepsize and Q-learning.

problem Understanding convergence and bias in nonsmooth contractive SA with different noise types.
method Proposed prelimit coupling technique for steady-state convergence and derived asymptotic bias.
result Asymptotic bias of nonsmooth SA is proportional to the square root of the stepsize.

Bayesian model averaging fails under covariate shift, affecting neural networks' performance.

problem Bayesian model averaging's failure in neural networks under covariate shift.
method Explained the issue and proposed novel priors to improve robustness.
result Bayesian model averaging is problematic under covariate shift, especially with linear feature dependencies.

New pivoting strategy improves trace norm contraction in low-rank approximation.

problem Finding good low-rank approximations of symmetric, positive-definite matrices.
method Choosing rows with likelihood proportional to Aii2A_{ii}^2 for randomly pivoted partial Cholesky algorithm.
result Same trace norm contraction result in Frobenius norm for improved pivoting strategy.

New Q-learning method achieves optimal sample complexity for average-reward problems.

problem Challenges in achieving optimal sample complexity for average-reward Q-learning.
method Synchronous and asynchronous Q-learning with a new contraction principle.
result Optimal O~(ε2)\widetilde{O}(\varepsilon^{-2}) sample complexity guarantees.

The paper defines fair profit sharing ratios in Islamic PL contracts.

problem Determining fair profit sharing ratios in Islamic PL contracts.
method Introduces cc-fair profit sharing ratios and uses econometrics models to compute or approximate them.
result Elucidates the relation between profit sharing ratios and economic factors.

We propose a new non-parametric framework for learning incrementally stable dynamical systems x' = f(x) from a set of sampled trajectories. We construct a rich family of smooth vector fields induced by certain classes of matrix-valued kernels, whose equilibria are placed exactly at a desired set of locations and whose …

2018-04-13abs ↗pdf ↗

Model clarifies network effects on CVA, revealing significant differences in derivative contract values.

problem Network effects on CVA in financial contracts.
method Developed a model to analyze default probabilities in a network of contracts.
result Network effects can significantly alter CVA values, leading to multi-modal distributions.

Study on stochastic hypergradient computation for machine learning problems.

problem Efficient computation of hypergradients in machine learning models.
method Stochastic approximation schemes for hypergradient computation, focusing on empirical risk minimization.
result Bounds for the mean square error of hypergradient approximation under contraction assumptions.

In this paper, the author considers the numerical computation of CVA for large systems by Mote Carlo methods. He introduces two types of stochastic mesh methods for the computations of CVA. In the first method, stochastic mesh method is used to obtain the future value of the derivative contracts. In the second method, …

2015-10-15abs ↗pdf ↗

Unified framework for solving fixed-point equations in deterministic and stochastic settings.

problem Solving fixed-point equations for seminorm-contractive operators in both deterministic and stochastic contexts.
method Fixed-point theorem and stochastic approximation analysis.
result Unified finite-sample bounds for various reinforcement learning algorithms.

The paper analyzes convergence rates for stochastic approximation and reinforcement learning.

problem Establishing almost sure convergence rates for stochastic approximation and reinforcement learning under Markovian noise.
method A novel Lyapunov drift construction that applies a Poisson-equation based correction for Markovian noise to the Moreau-envelope smoothing for contractive mappings.
result Almost sure convergence rates for specific learning rates are derived, with rates arbitrarily close to o(n12η)o(n^{1 - 2η}) and o(n1)o(n^{-1}).

In this paper we propose a closed-form approximation for the price of basket options under a multivariate Black-Scholes model, based on Taylor expansions and the calculation of mixed exponential-power moments of a Gaussian distribution. Our numerical results show that a second order expansion provides accurate prices o…

2014-04-11abs ↗pdf ↗

Improved stochastic Halpern iteration for fixed-point approximation in normed spaces.

problem Approximating fixed-points of nonexpansive and contractive operators in normed finite-dimensional spaces.
method Stochastic Halpern iteration with minibatch, analyzing oracle complexity.
result Improved oracle complexity for nonexpansive operators, with a lower bound of Ω(ε3)Ω(\varepsilon^{-3}).

The paper uses neural networks to price complex life insurance contracts with multiple risk factors.

problem Pricing equity-linked life insurance contracts with various stochastic risk factors.
method Assuming hedging to reduce local variance, the price is expressed as a system of non-linear PDEs. Reformulated as a backward SDE with jumps, solved numerically using neural networks.
result Neural networks provide an efficient numerical solution for pricing these complex contracts.

The paper proves a conjecture about manifold limits and characterizes their structure.

problem Characterizing limits of manifolds with a uniform contractibility function.
method Short proof using Gromov-Hausdorff distance and ANR properties.
result Obstruction vanishes if and only if the manifold can be approximated by PL-manifolds.

We develop a polynomial method to optimize trading in markets with transaction costs.

problem Optimizing trading strategies in markets with proportional transaction costs.
method Polynomial approximation of the residual value function to determine optimal trading strategies.
result Identify the trade-off between trading frequency and trade sizes for satisfactory agreement with theoretically optimal strategies.

The study optimizes Gaussian process approximations for finite-rank models.

problem Posterior behavior of finite-rank approximations differs from parent GP priors.
method Locally supported basis expansions with dependent Gaussian coefficients.
result Finite-rank expansions inherit the same posterior contraction rate as parent GP priors.

Paper introduces a new pricing method for electricity swaps and options.

problem Pricing electricity swaps and options in markets with varying delivery periods.
method Introduces a weighted geometric averaging of futures prices over delivery periods.
result Arbitrage-free pricing framework for derivatives in electricity markets.

The paper explores coalescent contractions in contractible spaces, providing criteria and examples.

problem Existence and absence of coalescent contractions in contractible spaces.
method Analysis of contractible finite simplicial complexes and criteria for coalescent contractions.
result Criteria for contractible finite simplicial complexes that ensure no coalescent contractions.

Improved online Q-learning for MDPs with concentration bounds.

problem Online Q-learning in infinite-horizon discounted MDPs with sublinear regret for large gaps.
method Smoothed εnε_n-Greedy exploration scheme combining εnε_n-greedy and Boltzmann exploration, analyzed using concentration bounds for contractive Markovian stochastic approximation.
result Near-ildeO(N9/10) ilde{O}(N^{9/10}) regret bound for Smoothed εnε_n-Greedy exploration scheme.

This work analyzes nonexpansive stochastic approximations with Markovian noise, proving convergence in reinforcement learning.

problem Applying stochastic approximation to reinforcement learning settings with nonexpansive operators.
method Investigates nonexpansive stochastic approximations with Markovian noise, providing asymptotic and finite sample analysis.
result First-time proof of convergence for classical tabular average reward temporal difference learning.

New method stabilizes FQE by reweighting Bellman targets.

problem Stability guarantees for FQE often rely on Bellman completeness, which can fail with function approximation.
method Proposes stationary-weighted FQE, reweighting Bellman targets by stationary target-to-behavior density ratio.
result Proves finite-sample linear convergence to stationary projected Bellman fixed point without Bellman completeness.

Improved bounds for non-linear SA with fast convergence.

problem Stochastic approximation with non-linear mappings and multiple time scales.
method Mean squared error bounds with O(1/k)O(1/k) rate for contractive mappings.
result First O(1/k)O(1/k) rate for non-linear two-time-scale SA without additional smoothness assumptions.