In this paper we present a new way for proving the existence of non-measurable sets using a convenient operation of a discrete group on the Euclidian sphere. The only choice assumption used in this construction is the Hahn-Banach theorem, a weaker hypothesis than the Boolean Prime Ideal Theorem. Our construction proves that the Hahn-Banach theorem implies the existence of a non-Lebesgue-measurable set of reals. In fact we prove (under Hahn-Banach theorem) that there is no finitely additive, rotation invariant extension of Lebesgue measure to all subsets of the three-dimensional Euclidean space.
@article{hal-00004713,
author = {Foreman, Matthew and Wehrung, Friedrich},
title = {The Hahn-Banach Theorem implies the existence of a non-Lebesgue measurable set},
journal = {HAL},
volume = {1991},
number = {0},
year = {1991},
language = {en},
url = {http://dml.mathdoc.fr/item/hal-00004713}
}
Foreman, Matthew; Wehrung, Friedrich. The Hahn-Banach Theorem implies the existence of a non-Lebesgue measurable set. HAL, Tome 1991 (1991) no. 0, . http://gdmltest.u-ga.fr/item/hal-00004713/