English

Projections and idempotents with fixed diagonal and the homotopy problem for unit tight frames

Functional Analysis 2011-03-04 v2

Abstract

We investigate the topological and metric structure of the set of idempotent operators and projections which have prescribed diagonal entries with respect to a fixed orthonormal basis of a Hilbert space. As an application, we settle some cases of conjectures of Larson, Dykema, and Strawn on the connectedness of the set of unit-norm tight frames.

Keywords

Cite

@article{arxiv.0906.0139,
  title  = {Projections and idempotents with fixed diagonal and the homotopy problem for unit tight frames},
  author = {Julien Giol and Leonid V. Kovalev and David Larson and Nga Nguyen and James E. Tener},
  journal= {arXiv preprint arXiv:0906.0139},
  year   = {2011}
}

Comments

New title and introduction

R2 v1 2026-06-21T13:08:03.158Z