Projections onto some function spaces

Supercloseness of Orthogonal Projections onto Nearby Finite Element Spaces

We derive upper bounds on the difference between the orthogonal projections of a smooth function u onto two finite element spaces that are nearby, in the sense that the support of every shape function belonging to one but not both of the spaces is contained in a common region whose measure tends to zero under mesh refinement. The bounds apply, in particular, to the setting in which the two fini...

compactifications and function spaces on weighted semigruops

chapter one is devoted to a moderate discussion on preliminaries, according to our requirements. chapter two which is based on our work in (24) is devoted introducting weighted semigroups (s, w), and studying some famous function spaces on them, especially the relations between go (s, w) and other function speces are invesigated. in fact this chapter is a complement to (32). one of the main fea...

Function Spaces of Posets with Projections

Projections onto linear subspaces

Viewing vector/matrix multiplications as " projections onto linear subspaces " is one of the most useful ways to think about these operations. In this note, I'll put together necessary pieces to achieve this understanding.

Ideal Projections onto Planes

In this paper we classify all ideal projections from C[x, y] onto the linear span of 1, x, y. In particular we show that every such projection is a limit of interpolating projections. That verifies one particular case of a conjecture of C. deBoor. §