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Sparse Approximation Algorithms for High Dimensional Parametric Initial Value Problems
(2013)SAM Research ReportWe consider the efficient numerical approximation on nonlinear systems of initial value Ordinary Differential Equations (ODEs) on Banach state spaces $\mathcal{S}$ over $\mathbb{R}$ or $\mathbb{C}$. We assume the right hand side depends $in$ $affine$ $fashion$ on a vector $y =(y_j)_{j \geq 1}$ of possibly countably many parameters, normalized such that $|y_j| \leq 1$. Such affine parameter dependence of the ODE arises, among others, in ...Report -
Scaling Limits in Computational Bayesian Inversion
(2014)Research ReportComputational Bayesian inversion of operator equations with distributed uncertain input parameters is based on an infinite-dimensional version of Bayes’ formula established in [31] and its numerical realization in [27, 28]. Based on the sparsity of the posterior density shown in [29], dimensionadaptive Smolyak quadratures afford higher convergence rates than MCMC in terms of the number M of solutions of the forward (parametric operator) ...Report -
A Note on Sparse, Adaptive Smolyak Quadratures for Bayesian Inverse Problems
(2013)SAM Research ReportWe present a novel, deterministic approach to inverse problems for identification of parameters in differential equations from noisy measurements. Based on the parametric deterministic formulation of Bayesian inverse problems with unknown input parameter from infinite dimensional, separable Banach spaces, we develop a practical computational algorithm for the efficient approximation of the infinite-dimensional integrals with respect to ...Report -
Sparse, adaptive Smolyak algorithms for Bayesian inverse problems
(2012)SAM Research ReportBased on the parametric deterministic formulation of Bayesian inverse problems with unknown input parameter from infinite dimensional, separable Banach spaces proposed in [28], we develop a practical computational algorithm whose convergence rates are provably higher than those of Monte-Carlo (MC) and Markov-Chain Monte-Carlo methods, in terms of the number of solutions of the forward problem. In the formulation of [28], the forward ...Report -
Sparsity in Bayesian Inversion of Parametric Operator Equations
(2013)SAM Research ReportWe establish posterior sparsity in Bayesian inversion for systems with distributed parameter uncertainty subject to noisy data. We generalize the particular case of scalar diffusion problems with random coefficients in [29] to broad classes of operator equations. For countably parametric, deterministic representations of uncertainty in the forward problem which belongs to a certain sparsity class, we quantify analytic regularity of the ...Report -