@article{SLSEDP_2011-2012____A24_0,
     author = {Hamel, Fran\c{c}ois and Nadirashvili, Nikolai and Russ, Emmanuel},
     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 = {http://archive.numdam.org/articles/10.5802/slsedp.19/}
}