We show that for entire maps of the form z ↦ λexp(z) such that the orbit of zero is bounded and Lebesgue almost every point is transitive, no absolutely continuous invariant probability measure can exist. This answers a long-standing open problem.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-fm198-3-6,
author = {Neil Dobbs and Bart\l omiej Skorulski},
title = {Non-existence of absolutely continuous invariant probabilities for exponential maps},
journal = {Fundamenta Mathematicae},
volume = {201},
year = {2008},
pages = {283-287},
zbl = {1167.37024},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm198-3-6}
}
Neil Dobbs; Bartłomiej Skorulski. Non-existence of absolutely continuous invariant probabilities for exponential maps. Fundamenta Mathematicae, Tome 201 (2008) pp. 283-287. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm198-3-6/