Nous prouvons que les notions d'entropie de Krengel et d'entropie de Poisson pour les transformations préservant une mesure infinie ne coïncident pas toujours : nous construisons une transformation conservative préservant une mesure infinie qui a une entropie de Krengel nulle (la transformation induite sur un ensemble de mesure 1 est l'odomètre de Von Neumann-Kakutani), mais dont la suspension de Poisson a une entropie strictement positive.
We prove that the notions of Krengel entropy and Poisson entropy for infinite-measure-preserving transformations do not always coincide: We construct a conservative infinite-measure-preserving transformation with zero Krengel entropy (the induced transformation on a set of measure 1 is the Von Neumann-Kakutani odometer), but whose associated Poisson suspension has positive entropy.
@article{AIHPB_2012__48_2_368_0, author = {Janvresse, \'Elise and de la Rue, Thierry}, title = {Zero Krengel entropy does not kill Poisson entropy}, journal = {Annales de l'I.H.P. Probabilit\'es et statistiques}, volume = {48}, year = {2012}, pages = {368-376}, doi = {10.1214/10-AIHP393}, mrnumber = {2954259}, zbl = {1269.37003}, language = {en}, url = {http://dml.mathdoc.fr/item/AIHPB_2012__48_2_368_0} }
Janvresse, Élise; de la Rue, Thierry. Zero Krengel entropy does not kill Poisson entropy. Annales de l'I.H.P. Probabilités et statistiques, Tome 48 (2012) pp. 368-376. doi : 10.1214/10-AIHP393. http://gdmltest.u-ga.fr/item/AIHPB_2012__48_2_368_0/
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