Let denote the isometry group of . We prove that if G is a paradoxical subgroup of then there exist G-equidecomposable Jordan domains with piecewise smooth boundaries and having different volumes. On the other hand, we construct a system of Jordan domains with differentiable boundaries and of the same volume such that has the cardinality of the continuum, and for every amenable subgroup G of , the elements of are not G-equidecomposable; moreover, their interiors are not G-equidecomposable as geometric bodies. As a corollary, we obtain Jordan domains A,B ⊂ ℝ² with differentiable boundaries and of the same area such that A and B are not equidecomposable, and int A and int B are not equidecomposable as geometric bodies. This gives a partial solution to a problem of Jan Mycielski.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-fm177-2-4, author = {M. Laczkovich}, title = {Equidecomposability of Jordan domains under groups of isometries}, journal = {Fundamenta Mathematicae}, volume = {177}, year = {2003}, pages = {151-173}, zbl = {1019.05006}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm177-2-4} }
M. Laczkovich. Equidecomposability of Jordan domains under groups of isometries. Fundamenta Mathematicae, Tome 177 (2003) pp. 151-173. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm177-2-4/