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JOURNALS // Sibirskii Zhurnal Vychislitel'noi Matematiki // Archive

Sib. Zh. Vychisl. Mat., 2022 Volume 25, Number 4, Pages 409–416 (Mi sjvm820)

This article is cited in 2 papers

New convergence mode for the generalized spectrum approximation

S. Kamouche, H. Guebbai

Laboratoire des Mathématiques Appliquées et de Modélisation, Université 8 Mai 1945, B.P. 401, Guelma, 24000, Algérie

Abstract: In this paper, we introduce a new convergence mode to deal with the generalized spectrum approximation of two bounded operators. This new technique is obtained by extending the well-known $\nu$-convergence used in the case of classical spectrum approximation. This new vision allows us to see the $\nu$-convergence assumption as a special case of our new method compared to the hypotheses needed in old methods, those required in this paper are weaker. In addition, we prove that the property $U$ holds, which solves the spectral pollution problem arising in spectrum approximation of unbounded operator.

Key words: generalized spectrum, $\nu$-convergence, property $U$, spectral approximation.

MSC: 47A58, 47A05, 45L05, 15A18

Received: 22.02.2022
Revised: 31.03.2022
Accepted: 18.07.2022

DOI: 10.15372/SJNM20220406


 English version:
Numerical Analysis and Applications, 2022, 15:4, 336–342


© Steklov Math. Inst. of RAS, 2026