@article{openproblemtightnessofmaximumlikelihood,
  title = {Open problem: Tightness of maximum likelihood semidefinite relaxations},
  author = {Afonso S. Bandeira and Yuehaw Khoo and Amit Singer},
  year = {2014},
  eprint = {1404.2655},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1404.2655v1},
}