Tensor-product approximation to operators and functions in high dimensions
Journal of Complexity
On the robustness of elliptic resolvents computed by means of the technique of hierarchical matrices
Applied Numerical Mathematics
Tensor decomposition in electronic structure calculations on 3D Cartesian grids
Journal of Computational Physics
Kronecker product approximation of demagnetizing tensors for micromagnetics
Journal of Computational Physics
Journal of Computational and Applied Mathematics
Tensor ranks for the inversion of tensor-product binomials
Journal of Computational and Applied Mathematics
Approximation of $2^d\times2^d$ Matrices Using Tensor Decomposition
SIAM Journal on Matrix Analysis and Applications
Tensor-Structured Galerkin Approximation of Parametric and Stochastic Elliptic PDEs
SIAM Journal on Scientific Computing
SIAM Journal on Scientific Computing
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The Kronecker tensor-product approximation combined with the **-matrix techniques provides an efficient tool to represent integral operators as well as certain functions F(A) of a discrete elliptic operator A in ℝd with a high spatial dimension d. In particular, we approximate the functions A−1 and sign(A) of a finite difference discretisation A∈ℝN×N with a rather general location of the spectrum. The asymptotic complexity of our data-sparse representations can be estimated by ** (np log qn), p = 1, 2, with q independent of d, where n=N1/d is the dimension of the discrete problem in one space direction. In this paper (Part I), we discuss several methods of a separable approximation of multi-variate functions. Such approximations provide the base for a tensor-product representation of operators. We discuss the asymptotically optimal sinc quadratures and sinc interpolation methods as well as the best approximations by exponential sums. These tools will be applied in Part II continuing this paper to the problems mentioned above.