REVERSIBLE MAPS AND PRODUCTS OF INVOLUTIONS ...
Type de document :
Pré-publication ou Document de travail
URL permanente :
Titre :
REVERSIBLE MAPS AND PRODUCTS OF INVOLUTIONS IN GROUPS OF IETS
Auteur(s) :
Discipline(s) HAL :
Mathématiques [math]/Systèmes dynamiques [math.DS]
Mathématiques [math]/Théorie des groupes [math.GR]
Mathématiques [math]/Théorie des groupes [math.GR]
Résumé en anglais : [en]
An element f of a group G is reversible if it is conjugated in G to its own inverse; when the conjugating map is an involution, f is called strongly reversible. We describe reversible maps in certain groups of interval ...
Lire la suite >An element f of a group G is reversible if it is conjugated in G to its own inverse; when the conjugating map is an involution, f is called strongly reversible. We describe reversible maps in certain groups of interval exchange transformations namely Gn ≃ (S 1) n ⋊ Sn, where S 1 is the circle and Sn is the group of permutations of {1, ..., n}. We first characterize strongly reversible maps, then we show that reversible elements are strongly reversible. As a corollary, we obtain that composites of involutions in Gn are product of at most four involutions. We prove that any reversible Interval Exchange Transformation (IET) is reversible by a finite order element and then it is the product of two periodic IETs. In the course of proving this statement, we classify the free actions of BS(1, −1) by IET and we extend this classification to free actions of finitely generated torsion free groups containing a copy of Z 2. We also give examples of faithful free actions of BS(1, −1) and other groups containing reversible IETs. We show that periodic IETs are product of at most 2 involutions. For IETs that are products of involutions, we show that such 3-IETs are periodic and then are product of at most 2 involutions and we exhibit a family of non periodic 4-IETs for which we prove that this number is at least 3 and at most 6.Lire moins >
Lire la suite >An element f of a group G is reversible if it is conjugated in G to its own inverse; when the conjugating map is an involution, f is called strongly reversible. We describe reversible maps in certain groups of interval exchange transformations namely Gn ≃ (S 1) n ⋊ Sn, where S 1 is the circle and Sn is the group of permutations of {1, ..., n}. We first characterize strongly reversible maps, then we show that reversible elements are strongly reversible. As a corollary, we obtain that composites of involutions in Gn are product of at most four involutions. We prove that any reversible Interval Exchange Transformation (IET) is reversible by a finite order element and then it is the product of two periodic IETs. In the course of proving this statement, we classify the free actions of BS(1, −1) by IET and we extend this classification to free actions of finitely generated torsion free groups containing a copy of Z 2. We also give examples of faithful free actions of BS(1, −1) and other groups containing reversible IETs. We show that periodic IETs are product of at most 2 involutions. For IETs that are products of involutions, we show that such 3-IETs are periodic and then are product of at most 2 involutions and we exhibit a family of non periodic 4-IETs for which we prove that this number is at least 3 and at most 6.Lire moins >
Langue :
Anglais
Collections :
Source :
Date de dépôt :
2025-01-24T17:10:37Z
Fichiers
- document
- Accès libre
- Accéder au document
- IETRevArX.pdf
- Accès libre
- Accéder au document
- 1907.01808
- Accès libre
- Accéder au document