TY - JOUR AU - Brasco, Lorenzo TI - On torsional rigidity and principal frequencies: an invitation to the Kohler-Jobin rearrangement technique JO - ESAIM: Control, Optimisation and Calculus of Variations PY - 2014 SP - 315 EP - 338 VL - 20 IS - 2 PB - EDP-Sciences UR - http://www.numdam.org/articles/10.1051/cocv/2013065/ DO - 10.1051/cocv/2013065 LA - en ID - COCV_2014__20_2_315_0 ER -