%0 Journal Article %A Cahen, Benjamin %T Formal deformations and principal series representations of ${\rm SL}(2,{\mathbb R})$ and ${\rm SL}(2,{\mathbb C})$ %J Czechoslovak Mathematical Journal %D 2020 %P 935-951 %V 70 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.21136/CMJ.2020.0053-19/ %R 10.21136/CMJ.2020.0053-19 %G en %F 10_21136_CMJ_2020_0053_19