Table of contents : Table of Contents Preface 1. Diffeomorphism Groups: A First Glance 1.1. The group Diff^r(M) 1.2. The smooth structure of Diff^r(M) 1.3. Basic examples and classical diffeomorphism groups 1.3.5. Actions of Lie groups 1.3.6. Flows 1.3.7. Classical diffeomorphism groups and corresponding Lie algebras 1.4. Some properties of Lie algebras of vector fields 1.5. Splitting of the de Rham complex 2. The Simplicity of Diffeomorphism Groups 2.1. From perfectness to simplicity Some definitions from group theory [174], [79] Thurston's tricks The simplicial set Bar{G} A Kan complex 2.2. Epstein's theorem End of proof of Epsteins' theorem 2.3. Herman's theorem (74] Sketch of the proof of Herman-Sergeraert theorem 2.4. Foliations and diffeomorphism groups Haefliger structures and their classifying spaces 2.5. Equivariant diffeomorphisms Automorphisms Group of G-principal Bundles Automorphisms of a trivial bundle 3. The Geometry of the Flux 3.1. The flux homomorphism The subgroup Γ_w Fathi-Visetti and Ismagilov constructions Prequantization construction of the flux Question Interpretation of the Subgroup 3.2. The transgression of the flux An extension of the group Diff_c^∞(M)_0 The generalized Liouville form Cohomology and homology of diffeomorphism groups The transgression homomorphism 3.3 The flux and gauge groups The class of a gauge transformation Examples 3.4. More cohomology classes related to the flux Ismagilov construction The Action Functional Construction A More General Setting for the Action Proof of proposition 3.4.5. 4. Symplectic Diffeomorphism 4.1. The Weinstein chart Remark 4.1.3 4.2. A first glance at the kernel of the flux and new invariants Remark 4.2.3 The geometry of the Hofer metric The homomorphisms R and μ Remark 4.2.8 Computation of R on commutators An different construction of R in case Ω is exact The homomorphism μ 4.3. Statement of the main results 4.4. Symplectic of the torus T^{2n} Proof of theorem 4.3.1 for M = T^{2n} 4.5. The symplectic deformation lemma Isotopies of symplectic embedding End of proofs of the main results of this chapter 5. Volume-Preserving Diffeomorphism Groups 5.1. Statement of the main results Volume-preserving deformation lemma 5.1.4. 5.2. Proof of Thurston's fragmentation lemma Complements to the proof of the fragmentation lemma 5.3. Proof of the volume-preserving deformation lemma Remark 5.3.2 Continuation of the proof of the volume preserving deformation lemma PROOF OF LEMMA 5.3.3. 6. Contact Diffeomorphisms 6.1 Contact Geometry Preliminaries [105] DARBOUX' THEOREM. A contact invariant built-in the definition of contact diffeomorphisms 6.2. The Lychagin chart Legendre distributions. 6.3. Epstein's Axioms hold for contact diffcomorphisms Remark 6.3.3 Proof of lemma 6.3.1 CONTACT FRAGMENTATION LEMMA. 6.4. The transverse flux The structure of the kernels of S and s 6.5. The group of strictly contact diffeomorphisms 7. Isomorphisms between Diffeomorphism Groups 7.1. Statement of the main results 7.2. Pursell-Shanks and Omori's theorems 7.3. Takeus' theorem aud its generalizations 7.4. The General Theory Existence of proper F-invariant closed subset 7.5. The Contact Case 7.6. The symplectic and volume preserving cases 7.7. The Measure preserving homeomorphisms 7.8. Miscellaneous problems Bibliography 1-11 12-28 29-44 45-61 62-78 79-96 97-113 114-130 131-147 148-165 166-184 185-191 Index