Improved convergence bounds for two-level methods with an improved convergence bounds for two-level methods with an aggressive coarsening and massive polynomial smoothing

dc.contributor.authorTezaur, Radek
dc.contributor.authorVaněk, Petr
dc.date.accessioned2022-02-28T11:00:28Z
dc.date.available2022-02-28T11:00:28Z
dc.date.issued2018
dc.description.abstract-translatedAn improved convergence bound for the polynomially accelerated two-level method of Brousek et al. [Electron. Trans. Numer. Anal., 44 (2015), pp. 401–442, Section 5] is proven. This method is a reinterpretation of the smoothed aggregation method with an aggressive coarsening and massive polynomial smoothing of Vanek, ˇ Brezina, and Tezaur [SIAM J. Sci. Comput., 21 (1999), pp. 900–923], and its convergence rate estimate is improved here quantitatively. Next, since the symmetrization of the method requires two solutions of the coarse problem, a modification of the method is proposed that does not have this disadvantage, and a qualitatively better convergence result for the modification is established. In particular, it is shown that a bound of the convergence rate of the method with a multiply (k-times) smoothed prolongator is asymptotically inversely proportional to d 2k, where d is the degree of the smoothing polynomial. In earlier works, this acceleration effect is only quadratic. Finally, for another modified multiply smoothed method, it is proved that this convergence improvement is not limited only to an asymptotic regime but holds true everywhere.en
dc.format22 s.cs
dc.format.mimetypeapplication/pdf
dc.identifier.citationTEZAUR, R. VANĚK, P. IMPROVED CONVERGENCE BOUNDS FOR TWO-LEVEL METHODS WITH AN IMPROVED CONVERGENCE BOUNDS FOR TWO-LEVEL METHODS WITH AN AGGRESSIVE COARSENING AND MASSIVE POLYNOMIAL SMOOTHING. Electronic Transactions on Numerical Analysis, 2018, roč. 48, č. July, s. 264-285. ISSN: 1068-9613cs
dc.identifier.document-number459295400014
dc.identifier.doi10.1553/etna_vol48s264
dc.identifier.issn1068-9613
dc.identifier.obd43935116
dc.identifier.uri2-s2.0-85053502293
dc.identifier.urihttp://hdl.handle.net/11025/47059
dc.language.isoenen
dc.project.IDLO1506/PUNTIS - Podpora udržitelnosti centra NTIS - Nové technologie pro informační společnostcs
dc.publisherKent State Universityen
dc.relation.ispartofseriesElectronic Transactions on Numerical Analysisen
dc.rights© Kent State Universityen
dc.rights.accessopenAccessen
dc.subject.translatedconvergence boundsen
dc.subject.translatedtwo-level methodsen
dc.subject.translatedaggressive coarseningen
dc.subject.translatedmasssive polynomial smoothingen
dc.titleImproved convergence bounds for two-level methods with an improved convergence bounds for two-level methods with an aggressive coarsening and massive polynomial smoothingen
dc.typečlánekcs
dc.typearticleen
dc.type.statusPeer-revieweden
dc.type.versionpublishedVersionen

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