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, Table des matières 1 Introduction 3

A. and .. ,

. One and .. Schwarz-preconditioner, , p.11

, Algebraic local SPSD splitting of an SPD matrix 13

, 4 Algebraic stable decomposition with

S. Geneo-coarse,

.. Extremum-efficient-coarse-space,

A. Approximate,

, 5 Numerical experiments 21

, Inria