When is a matrix unitary or Hermitian plus low rank?

Gianna M. Del Corso, Federico Poloni, Leonardo Robol, Raf Vandebril. When is a matrix unitary or Hermitian plus low rank?. Numerical Lin. Alg. with Applic., 26(6), 2019. [doi]

@article{CorsoPRV19,
  title = {When is a matrix unitary or Hermitian plus low rank?},
  author = {Gianna M. Del Corso and Federico Poloni and Leonardo Robol and Raf Vandebril},
  year = {2019},
  doi = {10.1002/nla.2266},
  url = {https://doi.org/10.1002/nla.2266},
  researchr = {https://researchr.org/publication/CorsoPRV19},
  cites = {0},
  citedby = {0},
  journal = {Numerical Lin. Alg. with Applic.},
  volume = {26},
  number = {6},
}