@article{SLSEDP_2011-2012____A24_0, author = {Fran\c{c}ois Hamel and Nikolai Nadirashvili and Emmanuel Russ}, title = {Symmetrization of functions and principal eigenvalues of elliptic operators}, journal = {S\'eminaire Laurent Schwartz {\textemdash} EDP et applications}, note = {talk:24}, pages = {1--15}, publisher = {Institut des hautes \'etudes scientifiques & Centre de math\'ematiques Laurent Schwartz, \'Ecole polytechnique}, year = {2011-2012}, doi = {10.5802/slsedp.19}, language = {en}, url = {https://proceedings.centre-mersenne.org/articles/10.5802/slsedp.19/} }