English

Orthogonality to matrix subspaces, and a distance formula

Functional Analysis 2017-05-23 v1

Abstract

We obtain a necessary and sufficient condition for a matrix AA to be Birkhoff-James orthogonal to any subspace W\mathscr W of Mn(C)\mathbb M_n(\mathbb C). Using this we obtain an expression for the distance of AA from any unital CC^* subalgebra of Mn(C)\mathbb M_n(\mathbb C).

Keywords

Cite

@article{arxiv.1705.07288,
  title  = {Orthogonality to matrix subspaces, and a distance formula},
  author = {Priyanka Grover},
  journal= {arXiv preprint arXiv:1705.07288},
  year   = {2017}
}

Comments

12 pages

R2 v1 2026-06-22T19:53:24.744Z