A hybrid interpolation ACA accelerated method for parabolic boundary integral operators
<|reference_start|>A hybrid interpolation ACA accelerated method for parabolic boundary integral operators: We consider piecewise polynomial discontinuous Galerkin discretizations of boundary integral reformulations of the heat equation. The resulting linear systems are dense and block-lower triangular and hence can be solved by block forward elimination. For the fast evaluation of the history part, the matrix is subdivided into a family of sub-matrices according to the temporal separation. Separated blocks are approximated by Chebyshev interpolation of the heat kernel in time. For the spatial variable, we propose an adaptive cross approximation (ACA) framework to obtain a data-sparse approximation of the entire matrix. We analyse how the ACA tolerance must be adjusted to the temporal separation and present numerical results for a benchmark problem to confirm the theoretical estimates.<|reference_end|>
@article{ambikasaran2024a,
    title={A hybrid interpolation ACA accelerated method for parabolic boundary
  integral operators},
    author={Sivaram Ambikasaran and Ritesh Khan and Johannes Tausch and Sihao Wang},
    journal={arXiv preprint arXiv:2408.04080},
    year={2024},
    archivePrefix={arXiv},
    eprint={2408.04080},
    primaryClass={math.NA cs.NA}
}