For x ∈ (0,1), the univoque set for x, denoted (x), is defined to be the set of β ∈ (1,2) such that x has only one representation of the form x = x₁/β + x₂/β² + ⋯ with . We prove that for any x ∈ (0,1), (x) contains a sequence increasing to 2. Moreover, (x) is a Lebesgue null set of Hausdorff dimension 1; both (x) and its closure are nowhere dense.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-fm227-1-5, author = {Fan L\"u and Bo Tan and Jun Wu}, title = {Univoque sets for real numbers}, journal = {Fundamenta Mathematicae}, volume = {227}, year = {2014}, pages = {69-83}, zbl = {06330487}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm227-1-5} }
Fan Lü; Bo Tan; Jun Wu. Univoque sets for real numbers. Fundamenta Mathematicae, Tome 227 (2014) pp. 69-83. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm227-1-5/