Maximal index automorphisms of free groups with no attracting fixed points on the boundary are Dehn twists.
Martino, Armando (2002)
Algebraic & Geometric Topology
Similarity:
Martino, Armando (2002)
Algebraic & Geometric Topology
Similarity:
Benson Farb, Michael Handel (2007)
Publications Mathématiques de l'IHÉS
Similarity:
Let Out(F) denote the outer automorphism group of the free group F with >3. We prove that for any finite index subgroup Γ<Out(F), the group Aut(Γ) is isomorphic to the normalizer of Γ in Out(F). We prove that Γ is : every injective homomorphism Γ→Γ is surjective. Finally, we prove that the abstract commensurator Comm(Out(F)) is isomorphic to Out(F).
Feighn, Mark, Handel, Michael (1999)
Annals of Mathematics. Second Series
Similarity:
Bestvina, Mladen, Feighn, Mark, Handel, Michael (2000)
Annals of Mathematics. Second Series
Similarity:
Jensen, Craig A., Wahl, Nathalie (2004)
Algebraic & Geometric Topology
Similarity:
Crisp, John (2005)
Geometry & Topology
Similarity:
Cohn, P. (2002)
Serdica Mathematical Journal
Similarity:
The theorem of Czerniakiewicz and Makar-Limanov, that all the automorphisms of a free algebra of rank two are tame is proved here by showing that the group of these automorphisms is the free product of two groups (amalgamating their intersection), the group of all affine automorphisms and the group of all triangular automorphisms. The method consists in finding a bipolar structure. As a consequence every finite subgroup of automorphisms (in characteristic zero) is shown to be conjugate...
Pettet, Alexandra (2005)
Algebraic & Geometric Topology
Similarity:
Paoluzzi, Luisa, Paris, Luis (2002)
Algebraic & Geometric Topology
Similarity:
Willis, George A. (2004)
The New York Journal of Mathematics [electronic only]
Similarity:
Pedro V. Silva, Pascal Weil (2008)
RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
Similarity:
We revisit the problem of deciding whether a finitely generated subgroup is a free factor of a given free group . Known algorithms solve this problem in time polynomial in the sum of the lengths of the generators of and exponential in the rank of . We show that the latter dependency can be made exponential in the rank difference rank - rank, which often makes a significant change.