We show that the group of piecewise-linear homeomorphisms of R having bounded slopes surjects onto the group QI(R) of all quasi-isometries of R. We prove that the following groups can be imbedded in QI(R): the group of compactly supported piecewise-linear homeomorphisms of R, the Richard Thompson group F , and the free group of continuous rank.

We introduce and characterize extremal 2-cuts for good fractal necklaces. Using this characterization the related topological properties of 2-cuts, we prove that every necklace has a unique IFS in certain sense. Also, two necklaces admit only rigid homeomorphisms thus group self-homeomorphisms is countable. In addition, weaker co-Hopfian property also obtained.

1. For each i>0, let 7, denote the closed interval O^x^ 1 and let °I¡ denote the open interval 0<*< 1. Let 7°° =fli>o 7 and °7°° = rii>o °h7°° is the Hilbert cube or parallelotope sometimes denoted by Q. °7°° is homeomorphic to the space sometimes called s, the countable infinite product of lines. The principal theorems of this paper are found in §§5, 7, 8, and 9. In §5 it is shown as a special...

We show that the group G∞ of germs at infinity of orientation-preserving homeomorphisms of R admits no action on the line. This gives an example of a left-orderable group of the same cardinality as Homeo+(R) that does not embed in Homeo+(R). As an application of our techniques, we construct a finitely generated group Γ ⊂ G∞ that does not extend to Homeo+(R) and, separately, extend a theorem of ...