The operator involved in quasiconvex functions is and this also arises as the governing operator in a worst case tug-of-war (Kohn and Serfaty (2006) [7]) and principal curvature of a surface. In Barron et al. (2012) [4] a comparison principle for was proved. A new and much simpler proof is presented in this paper based on Barles and Busca (2001) [3] and Lu and Wang (2008) [8]. Since is the minimal principal curvature of a surface, we show by example that does not have a unique solution, even if . Finally, we complete the identification of first order evolution problems giving the convex envelope of a given function.
@article{AIHPC_2014__31_2_203_0, author = {Barron, E.N. and Jensen, R.R.}, title = {A uniqueness result for the quasiconvex operator and first order PDEs for convex envelopes}, journal = {Annales de l'I.H.P. Analyse non lin\'eaire}, volume = {31}, year = {2014}, pages = {203-215}, doi = {10.1016/j.anihpc.2013.02.006}, mrnumber = {3181665}, zbl = {1302.35104}, language = {en}, url = {http://dml.mathdoc.fr/item/AIHPC_2014__31_2_203_0} }
Barron, E.N.; Jensen, R.R. A uniqueness result for the quasiconvex operator and first order PDEs for convex envelopes. Annales de l'I.H.P. Analyse non linéaire, Tome 31 (2014) pp. 203-215. doi : 10.1016/j.anihpc.2013.02.006. http://gdmltest.u-ga.fr/item/AIHPC_2014__31_2_203_0/
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