@Misc{ 
  GiKeKuOh17,
  author = { Gigli, Nicola and Ketterer, Christian and Kuwada, Kazumasa and Ohta, Shin-Ichi },
  title = { Rigidity for the spectral gap on $RCD(K,\infty)$-spaces },
  journal = {  },
  year = { 2017 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/7441/ },
  note = { cvgmt preprint}
}