On the complemented subspaces of the Schreier spaces

On quasi-complemented subspaces of banach spaces.

Complemented Subspaces in the Normed Spaces

The purpose of this paper is to introduce and discuss the concept of orthogonality in normed spaces. A concept of orthogonality on normed linear space was introduced. We obtain some subspaces of Banach spaces which are topologically complemented.

Complemented Subspaces of Spaces Obtained by Interpolation

If Z is a quotient of a subspace of a separable Banach space X, and V is any separable Banach space, then there is a Banach couple (A0, A1) such that A0 and A1 are isometric to X ⊕ V , and any intermediate space obtained using the real or complex interpolation method contains a complemented subspace isomorphic to Z. Thus many properties of Banach spaces, including having non-trivial cotype, hav...

Contractively Complemented Subspaces of Pre-symmetric Spaces

In 1965, Ron Douglas proved that if X is a closed subspace of an L-space and X is isometric to another L-space, then X is the range of a contractive projection on the containing L-space. In 1977 Arazy-Friedman showed that if a subspace X of C1 is isometric to another C1-space (possibly finite dimensional), then there is a contractive projection of C1 onto X. In 1993 Kirchberg proved that if a s...

The Mackey Topology and Complemented Subspaces of Lorentz Sequence Spaces

In this paper we continue the study of Lorentz sequence spaces d(w,p), 0 < p < 1, initiated by N. Popa [8]. First we show that the Mackey completion of d(w,p) is equal to d(v, 1) for some sequence v. Next, we prove that if d(w, p) (2 h, then it contains a complemented subspace isomorphic to lp. Finally we show that if limn_1(X)"=1 wi)1 = °°, tnen every complemented subspace of d(w,p) with symme...