On the problem of spurious eigenvalues in the approximation of linear elliptic problems in mixed form

In the approximation of linear elliptic operators in mixed form, it is well known that the so-called inf-sup and ellipticity in the kernel properties are sufficient (and, in a sense to be made precise, necessary) in order to have good approximation properties and optimal error bounds. One might think, in the spirit of Mercier-Osborn-Rappaz-Raviart and in consideration of the good behavior of commonly used mixed elements (like Raviart

• Type: Journal
• Year: 2000
• Where: MOC
• Authors: Daniele Boffi, Franco Brezzi, Lucia Gastaldi
• Keywords: Approximations, Linear Elliptic Operators, MOC 2000, Optimal Error