scholarly journals Asymptotic Density of Test Elements in Free Groups and Surface Groups

Author(s):  
Ilir Snopce ◽  
Slobodan Tanushevski
2000 ◽  
Vol 10 (06) ◽  
pp. 751-756 ◽  
Author(s):  
JOHN C. O'NEILL ◽  
EDWARD C. TURNER

We characterize test elements in the commutator subgroup of a direct product of certain groups in terms of test elements of the factors. This provides explicit examples of test elements in direct products whose factors are free groups or surface groups and a tool for doing the same for torsion free hyperbolic factors.


2016 ◽  
Vol 23 (02) ◽  
pp. 263-280
Author(s):  
Ann-Kristin Engel ◽  
Benjamin Fine ◽  
Gerhard Rosenberger

In [5, 6] the relationships between test words, generic elements, almost primitivity and tame almost primitivity were examined in free groups. In this paper we extend the concepts and connections to general free products and in particular to free products of cyclic groups.


2007 ◽  
Vol 14 (2) ◽  
pp. 263-284 ◽  
Author(s):  
Ilya Kapovich ◽  
Igor Rivin ◽  
Paul Schupp ◽  
Vladimir Shpilrain

2017 ◽  
Vol 5 ◽  
Author(s):  
MAHAN MJ

We show that Cannon–Thurston maps exist for degenerate free groups without parabolics, that is, for handlebody groups. Combining these techniques with earlier work proving the existence of Cannon–Thurston maps for surface groups, we show that Cannon–Thurston maps exist for arbitrary finitely generated Kleinian groups without parabolics, proving conjectures of Thurston and McMullen. We also show that point pre-images under Cannon–Thurston maps for degenerate free groups without parabolics correspond to endpoints of leaves of an ending lamination in the Masur domain, whenever a point has more than one pre-image. This proves a conjecture of Otal. We also prove a similar result for point pre-images under Cannon–Thurston maps for arbitrary finitely generated Kleinian groups without parabolics.


2008 ◽  
Vol 15 (01) ◽  
pp. 1-22 ◽  
Author(s):  
Gilbert Baumslag ◽  
Oleg Bogopolski ◽  
Benjamin Fine ◽  
Anthony Gaglione ◽  
Gerhard Rosenberger ◽  
...  

We consider some questions concerning finiteness properties in infinite groups which are related to Marshall Hall's theorem. We call these properties Property S and Property R, and they are trivially true in finite groups. We give several elementary proofs using these properties for results on finitely generated subgroups of free groups as well as a new elementary proof of Hall's basic result. Finally, we consider these properties within surface groups and prove an analog of Hall's theorem in that context.


2003 ◽  
Vol 13 (06) ◽  
pp. 705-731 ◽  
Author(s):  
ALEXANDRE V. BOROVIK ◽  
ALEXEI G. MYASNIKOV ◽  
VLADIMIR N. REMESLENNIKOV

We introduce a family of multiplicative distributions {μs|s∈(0,1)} on a free group F and study it as a whole. In this approach, the measure of a given set R⊆F is a function μ(R) : s → μs(R), rather then just a number. This allows one to evaluate sizes of sets using analytical properties of their measure functions μ(R). We suggest a new hierarchy of subsets R in F with respect to their size, which is based on linear approximations of the function μ(R). This hierarchy is quite sensitive, for example, it allows one to differentiate between sets with the same asymptotic density. Estimates of sizes of various subsets of F are given.


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