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Sparse wavelet methods for option pricing under stochastic volatility
(2004)Research ReportReport -
hp-dGFEM for Second-Order Elliptic Problems in Polyhedra II
(2009)Research reportThe goal of this paper is to establish exponential convergence of hp-version interior penalty (IP) discontinuous Galerkin (dG) finite element methods for the numerical approximation of linear second-order elliptic boundary-value problems with piecewise analytic data in threedimensional polyhedral domains. More precisely, we shall analyze the convergence of the hp-IP dG methods considered in [30] which are based on !-geometric anisotropic ...Report -
Anistropic stable Lévy copula processes
(2006)We consider the valuation of derivative contracts on baskets of risky assets whose prices are Lévy like Feller processes of tempered stable type. The dependence among the marginals’ jump structure is parametrized by a Lévy copula. For marginals of regular, exponential Lévy type in the sense of [6] we show that the infinitesimal generator A of the resulting Lévy copula process is a pseudo-differential operator whose principal ...Report -
Adaptive wavelet algorithms for elliptic PDE's on product domains
(2006)Research ReportWith standard isotropic approximation by (piecewise) polynomials of xed order in a domain D c Rd, the convergence rate in terms of the number N of degrees of freedom is inversely proportional to the space dimension d. This so-called curse of dimensionality can be circumvented by applying sparse tensor product approximation, when certain high order mixed derivatives of the approximated function happen to be bounded in L2. It was shown in ...Report -
Sparse finite elements for stochastic elliptic problems - higher order moments
(2003)SAM Research ReportWe define the higher order moments associated to the stochastic solution of an elliptic BVP in D \subset Rd with stochastic source terms and boundary data. We prove that the k-th moment (or k-point correlation function) of the random solution solves a deterministic problem in Dk \subset Rdk. We discuss well-posedness and regularity in scales of Sobolev spaces with bounded mixed derivatives. We discretize this deterministic k-th moment ...Report -
Mixed hp-DGFEM for incompressible flows
(2002)SAM Research ReportWe consider several mixed discontinuous Galerkin approximations of the Stokes problem and propose an abstract framework for their analysis. Using this framework we derive a priori error estimates for hp-approximations on tensor product meshes. We also prove a new stability estimate for the discrete divergence bilinear form.Report -
Multiresolution weighted norm equivalences and applications
(2002)SAM Research ReportWe establish multiresolution norm equivalences in weighted spaces $L^2_w$ ((0,1)) with possibly singular weight functions $w(x) \geq 0$ in (0,1). Our analysis exploits the locality of the biorthogonal wavelet basis and its dual basis functions. The discrete norms are sums of wavelet coefficients which are weighted with respect to the collocated weight function $w(x)$ within each scale. Since norm equivalences for Sobolev norms are by now ...Report -
Rapid solution of first kind boundary integral equations in R³
(2002)SAM Research ReportWeakly singular boundary integral equations $(BIEs)$ of the first kind on polyhedral surfaces $\Gamma$ in $R^3$ are discretized by Galerkin BEM on shape-regular, but otherwise unstructured meshes of meshwidth $h$. Strong ellipticity of the integral operator is shown to give nonsingular stiffness matrices and, for piecewise constant approximations, up to $O(h^3)$ convergence of the farfield. The condition number of the stiffness matrix ...Report -
hp Discontinuous Galerkin Time Stepping for Parabolic Problems
(2000)SAM Research ReportThe algorithmic pattern of the hp Discontinuous Galerkin Finite Element Method (DGFEM) for the time semidiscretization of abstract parabolic evolution equations is presented. In combination with a continuous $hp$ discretization in space we present a fully discrete hp-scheme for the numerical solution of parabolic problems. Numerical examples for the heat equation in a two dimensional domain confirm the exponential convergence rates which ...Report -
Wavelet-discretizations of parabolic integro-differential equations
(2001)SAM Research ReportWe consider parabolic problems u + Au = f in (0,T)x Ω, T < ∞, where Ω ⊂ Rd is a bounded domain and A is a strongly elliptic, classical pseudo-differential operator of order ρ ∈ [0,2] in H ρ/2 (Ω). We use a θ-scheme for time discretization and a Galerkin method with N degrees of freedom for space discretization. The full Galerkin matrix for A can be replaced with a sparse matrix using a wavelet basis, and the linear systems for each time ...Report