Paper develops a finite dimensional approximation scheme for Riemannian manifolds.
problem Integration on Riemannian manifolds.
method New finite dimensional approximation scheme motivated by categorical colimit.
result Establishes a generalization for L 1 L^{1} L 1 -functionals on Riemannian manifolds. We develop high-order approximations for the Heston model.
problem Modeling the Heston model with high accuracy and efficiency.
method Combining approximation schemes on different random grids to achieve any order of convergence.
result Achieve any order of convergence for the Heston model.
We consider a general class of high order weak approximation schemes for stochastic differential equations driven by Lévy processes with infinite activity. These schemes combine a compound Poisson approximation for the jump part of the Lévy process with a high order scheme for the Brownian driven component, applied bet…
Efficient simulation scheme for rough Heston model reduces computational cost.
problem Accurate and efficient simulation of the rough Heston model for option pricing.
method Weak simulation scheme based on Markovian approximations of the rough Heston process.
result The new scheme exhibits second order weak convergence with linear computational cost.
Paper proposes a new numerical scheme for solving BSDEs.
problem Solving backward stochastic differential equations (BSDEs).
method Uses Lagrange interpolation to approximate derivatives and changes sample point distributions for different stability and convergence.
result Guarantees convergence of the scheme under certain conditions on sample point distributions.
A fast, accurate method for pricing American options with free boundaries.
problem Pricing American options with free boundaries efficiently and accurately.
method A sixth-order compact finite difference scheme with a dynamic staggered boundary scheme and 3(2) R-K Bogacki-Shampine time stepping.
result An efficient sixth-order compact scheme for pricing American options with free boundaries.
A new numerical scheme approximates nonlinear filtering densities for noisy and partial measurements.
problem Approximating nonlinear filtering densities for noisy and partial measurements.
method Deep splitting scheme applied to the Fokker--Planck equation followed by Bayes' formula.
result Convergence rate established for the numerical scheme under parabolic Hörmander condition.
The paper analyzes convergence of Riemannian SA schemes for stochastic optimization.
problem Stochastic optimization problems on Riemannian manifolds.
method Analyzes convergence of Riemannian stochastic approximation schemes using exponential map or retraction functions.
result Shows Riemannian SA schemes find an O ( b ∞ + log n / n ) {\mathcal{O}}(b_\infty + \log n / \sqrt{n}) O ( b ∞ + log n / n ) -stationary point within O ( n ) {\mathcal{O}}(n) O ( n ) iterations. Compact scheme solves option pricing for jump-diffusion models.
problem Solving option pricing equations under jump-diffusion models.
method Fourth-order compact scheme for PIDEs, employing smoothing operator.
result Fourth-order convergence rate achieved for option pricing.
Novel weak MLMC scheme for Lévy-driven SDEs, applied to financial derivatives pricing.
problem Approximating solutions to Lévy-driven SDEs for financial derivatives pricing.
method Weak multilevel Monte-Carlo scheme with state space discretization of Lévy processes.
result Efficient approximation of financial derivatives pricing models.
New method approximates CVaR with less data for heavy-tailed risks.
problem Lack of data for accurate CVaR approximation in heavy-tailed distributions.
method Importance sampling based extrapolation for heavy-tailed distributions.
result Statistically consistent approximations with reduced data requirements.
Develops a curvature-corrected tangent space method for manifold-valued data.
problem Generalizing real-valued data approximation to manifold-valued data.
method Systematic approach to developing global-geometry aware, computationally feasible approximation schemes.
result Proposes CC-tHOSVD for low-rank approximation of manifold-valued data.
Develops multifactor approximations for SVEs with completely monotone kernels.
problem Approximating SVEs with kernels of completely monotone type.
method Multifactor approximation, Euler discretization, L 2 L^2 L 2 -estimation, convergence analysis. result New multifactor Euler scheme reduces computational cost and outperforms SVEs for option pricing.
New high-order approximations for CIR process using random grids.
problem Approximating the Cox-Ingersoll-Ross process with high order.
method Combining discretization schemes on different random grids.
result Weak approximations of order 2 k 2k 2 k for all k ∈ N ∗ k\in\mathbb{N}^* k ∈ N ∗ . We approximate sticky diffusions using Markov chains for efficient simulation.
problem Approximating sticky diffusions for accurate simulation.
method CTMC approximation of sticky diffusions, efficient matrix exponentials, and Euler scheme comparison.
result Second order convergence of CTMC approximation for sticky diffusions.
Variational approximations for curve flows on Riemannian manifolds.
problem Approximating solutions to curvature and elastic flow problems on Riemannian manifolds.
method Variational formulations, finite element approximations, piecewise linear elements, stability analysis.
result Derived schemes can compute rotationally symmetric self-shrinkers and geodesics.
New learning scheme solves high-dimensional semi-linear PDEs using sparse grids and Picard approximations.
problem Solving high-dimensional semi-linear parabolic PDEs.
method Probabilistic learning scheme based on Picard iteration with SGD, employing sparse grid approximation.
result Convergence proof and polynomial complexity in ε − 1 ε^{-1} ε − 1 for high-dimensional PDEs. Study on improving the linear two-time-scale stochastic approximation method with a restarting scheme.
problem Characterizing and optimizing the finite-time complexity of linear two-time-scale stochastic approximation.
method Analysis of mean square errors, introduction of a restarting scheme to improve performance.
result The method achieves an exact convergence to the desired solution with improved complexity under time-varying step sizes.
New numerical method for quantile hedging in imperfect markets.
problem Quantile hedging in non-linear markets with imperfections.
method Piecewise Constant Policy Timestepping (PCPT) coupled with monotone finite difference approximation.
result Convergence of the proposed numerical scheme proved using BSDE arguments.
Study validates numerical method for singular FBSDEs convergence.
problem Solving singular FBSDEs and associated PDEs.
method Particles approximation for transport operator and tree approximation for diffusion operator.
result Convergence rate of numerical method proved under reasonable conditions.
This note gives a simple analysis of a randomized approximation scheme for matrix multiplication proposed by Sarlos (2006) based on a random rotation followed by uniform column sampling. The result follows from a matrix version of Bernstein's inequality and a tail inequality for quadratic forms in subgaussian random ve…
Develops LSH schemes for f-divergences and mutual information loss.
problem Approximating nearest neighbors in high-dimensional probability distributions.
method General framework and specific LSH schemes for f-divergences and mutual information loss.
result Generalized Jensen-Shannon divergence can be approximated by Hellinger distance.
Paper solves non-Markovian optimal stopping problems using discrete approximations.
problem Non-Markovian optimal stopping problems in continuous-time processes.
method Discrete-type approximation scheme based on variational inequalities.
result Constructs ε-optimal stopping times and optimal values in full generality.
Study different masking schemes for a universal marginaliser.
problem Understand how well a neural approximator learns conditional distributions.
method Compare networks trained with various masking schemes.
result Neural approximators perform differently based on the masking scheme.
This paper explores how random sampling and coding can speed up approximate matrix multiplication.
problem Efficiently computing large-scale matrix multiplications in distributed systems.
method Proposes two schemes: coding for recovery and random sampling for approximation.
result Investigates tradeoffs between recovery threshold and approximation error.
The paper analyzes fixed step-size SA schemes on Riemannian manifolds.
problem Developing efficient algorithms for optimization on curved spaces.
method Fixed step-size stochastic approximation schemes in a Riemannian framework.
result The schemes converge to the solution as the step-size approaches zero.
Asymptotic error distribution for approximation of a stochastic integral with respect to continuous semimartingale by Riemann sum with general stochastic partition is studied. Effective discretization schemes of which asymptotic conditional mean-squared error attains a lower bound are constructed. Two applications are …
We introduce a simulation scheme for Brownian semistationary processes, which is based on discretizing the stochastic integral representation of the process in the time domain. We assume that the kernel function of the process is regularly varying at zero. The novel feature of the scheme is to approximate the kernel fu…
New numerical methods for evolving curves on curved spaces.
problem Evolve curves on Riemannian manifolds efficiently and accurately.
method Variational approximations and numerical schemes for curvature flow, curve diffusion, and elastic flow.
result Effective numerical schemes for geometric evolution equations on Riemannian manifolds.
New sampling scheme improves ML accuracy in physics simulations.
problem Improving accuracy of ML models in physics simulations.
method Taylor-based data sampling scheme for DNNs.
result Reduces error in DNN solutions of ODE systems.
Positive results for agnostic regression with various losses.
problem Agnostic regression with bounded sample compression.
method Generic and efficient sample compression schemes for real-valued functions.
result Exact and approximate compression schemes for specific losses.
Improved multilevel scheme for value-at-risk computation.
problem Discontinuity in Heaviside function affects value-at-risk computation.
method Adaptive multilevel stochastic approximation to mitigate discontinuity.
result Best complexity improved to O( ε − 2 ∣ ln ε ∣ 5 2 \varepsilon^{-2}|\ln{\varepsilon}|^\frac52 ε − 2 ∣ ln ε ∣ 2 5 ). Novel IMEX scheme solves financial PDEs with mixed derivatives.
problem Numerical approximations for financial PDEs with mixed derivatives.
method Second order finite volume IMEX Runge-Kutta scheme.
result Achieves true second order convergence with non-regular initial conditions.
This thesis develops efficient computational schemes for Bayesian inference in digital receivers.
problem Efficient inference in digital receivers to minimize expected loss.
method Two schemes: exact (GDL) and approximate (VB and TVB).
result GDL guarantees reduction in operators and TVB improves performance for correlated models.
Efficiently simulates SABR model with novel sampling methods.
problem Sampling integrated variance and terminal forward price in SABR model.
method Moment-matched shifted lognormal approximation for integrated variance, CEV approximation for terminal forward price.
result Enhanced simulation scheme is highly efficient, accurate, and reliable.
Estimates expected information gain using density approximations and dimension reduction.
problem Estimating expected information gain in nonlinear and non-Gaussian settings.
method Flexible transport-based schemes for EIG estimation, optimal sample allocation, and gradient-based upper bounds on mutual information.
result Optimal sample allocation and dimension reduction schemes improve EIG estimation accuracy and convergence rate.
Bayesian learning in undirected graphical models|computing posterior distributions over parameters and predictive quantities is exceptionally difficult. We conjecture that for general undirected models, there are no tractable MCMC (Markov Chain Monte Carlo) schemes giving the correct equilibrium distribution over param…
Method sanitizes IFM in CNN layers to control privacy loss.
problem Controlling privacy loss in CNNs using input feature maps.
method Sample-and-hold approximation scheme to sanitize IFM, unfolding tensors for independence from CNN configuration.
result Control the privacy loss by adjusting the sanitization degree.
A discretization scheme for nonnegative diffusion processes is proposed and the convergence of the corresponding sequence of approximate processes is proved using the martingale problem framework. Motivations for this scheme come typically from finance, especially for path-dependent option pricing. The scheme is simple…
In this work, we revisit fast dimension reduction approaches, as with random projections and random sampling. Our goal is to summarize the data to decrease computational costs and memory footprint of subsequent analysis. Such dimension reduction can be very efficient when the signals of interest have a strong structure…
New gradient coding schemes reduce decoding error in both random and adversarial straggler settings.
problem Creating efficient approximate gradient coding schemes for distributed optimization.
method Introduced novel approximate gradient codes based on expander graphs, achieving optimal decoding coefficients.
result Achieved nearly optimal error in random setting and nearly half the error in adversarial setting compared to existing codes.
Paper explores properties of slice-matching operators for measure transfer.
problem Efficiently transferring measures in high dimensions.
method Examines an associated slice-matching operator with source, target measures and slicing directions.
result Establishes invariance, equivariance, Lipschitz continuity, and error bounds.
Paper analyzes AVI scheme for noisy Bellman approximations.
problem Analyzing stability and convergence of noisy value iteration.
method Uses neural networks to approximate Bellman operator, considers biased approximations and sampling errors.
result Verifiable conditions for stability and convergence of AVI.
In this paper we discuss the possibility of using multilevel Monte Carlo (MLMC) methods for weak approximation schemes. It turns out that by means of a simple coupling between consecutive time discretisation levels, one can achieve the same complexity gain as under the presence of a strong convergence. We exemplify thi…
New compact finite difference scheme outperforms standard methods in Bates model hedging.
problem Improving hedging performance in Bates model option pricing.
method High-order compact finite differences compared to standard finite differences.
result The new scheme outperforms standard methods in all experiments.
Analyzes a non-asymptotic SA scheme for non-convex, smooth objectives.
problem Analyzes SA schemes under relaxed assumptions for non-convex, smooth objectives.
method General SA scheme with state-dependent drift and mean field not necessarily gradient type.
result Analyzes the online EM algorithm and policy-gradient method for reinforcement learning.
A new EVI framework improves ParVI methods by maintaining variational structure and reducing KL-divergence.
problem Improving variational inference methods for better approximation of target distributions.
method EVI framework that minimizes the VI objective function based on an energy-dissipation law, including a new 'Approximation-then-Variation' scheme.
result The new scheme significantly decreases KL-divergence and outperforms existing ParVI methods in fidelity.
New method improves credit risk estimation and pricing.
problem Estimating risk measures and CDO tranche prices in credit portfolios.
method Mod-Poisson approximation schemes based on mod-φ convergence.
result The method provides more accurate estimates with less computational time.