Abstract The conic bundle implementation of the spectral method for large scale semidefinite programming solves in each iteration a quadratic subproblem by an interior point approach. For larger cutting model sizes limiting operation is collecting and factorizing Schur complement primal-dual KKT system. We explore possibilities to improve on this iterative approach that exploits structural low ...

In 1969 Lindenstrauss and Rosenthal showed that if a Banach space is isomorphic to a complemented subspace of an Lp-space, then it is either a Lp-space or isomorphic to a Hilbert space. This is the motivation of this paper where we study non–Hilbertian complemented operator subspaces of non commutative Lp-spaces and show that this class is much richer than in the commutative case. We investigat...

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.