@Misc{ BaBaGaLĂ©22, author = { Bahouri, Hajer and Barilari, Davide and Gallagher, Isabelle and LĂ©autaud, Matthieu }, title = { Spectral summability for the quartic oscillator with applications to the Engel group }, journal = { Journal of Spectral Theory }, year = { 2022 }, pages = { 49 }, URL = { http://cvgmt.sns.it/paper/5596/ }, note = { cvgmt preprint} }