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arXiv · 2206.03425

Inexact and primal multilevel FETI-DP methods: a multilevel extension and interplay with BDDC

Bedřich Sousedík
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Abstract

We study a framework that allows to solve the coarse problem in the FETI-DP method approximately. It is based on the saddle-point formulation of the FETI-DP system with a block-triangular preconditioner. One of the blocks approximates the coarse problem, for which we use the multilevel BDDC method as the main tool. This strategy then naturally leads to a version of multilevel FETI-DP method, and we show that the spectra of the multilevel FETI-DP and BDDC preconditioned operators are essentially the same. The theory is illustrated by a set of numerical experiments, and we also present a few experiments when the coarse solve is approximated by algebraic multigrid.

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Bedřich Sousedík. 2022-06-07. Inexact and primal multilevel FETI-DP methods: a multilevel extension and interplay with BDDC. https://doi.org/10.1002/nme.7057

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