Second cohomology classes of the group of C 1 -flat diffeomorphisms
Annales de l'Institut Fourier, Volume 62 (2012) no. 1, p. 77-85
We study the cohomology of the group consisting of all C ∞ -diffeomorphisms of the line, which are C 1 -flat to the identity at the origin. We construct non-trivial two second real cohomology classes and uncountably many second integral homology classes of this group.
On étudie la cohomologie du groupe des C ∞ -difféomorphismes de la droite, qui sout C 1 -tangents à l’identité à l’origine. On construit deux classes non-triviales de cohomologie réelle de degré deux et un nombre non-dénombrable de classes d’homologie de dimension deux de ce groupe.
DOI : https://doi.org/10.5802/aif.2699
Classification:  58D05,  57S05
Keywords: cohomology of diffeomorphism groups, flat diffeomorphism, Massey product 
@article{AIF_2012__62_1_77_0,
     author = {Ishida, Tomohiko},
     title = {Second cohomology classes of the group of $C^1$-flat diffeomorphisms},
     journal = {Annales de l'Institut Fourier},
     publisher = {Association des Annales de l'institut Fourier},
     volume = {62},
     number = {1},
     year = {2012},
     pages = {77-85},
     doi = {10.5802/aif.2699},
     zbl = {1253.58007},
     mrnumber = {2986265},
     language = {en},
     url = {https://aif.centre-mersenne.org/item/AIF_2012__62_1_77_0}
}

Second cohomology classes of the group of $C^1$-flat diffeomorphisms. Annales de l'Institut Fourier, Volume 62 (2012) no. 1, pp. 77-85. doi : 10.5802/aif.2699. https://aif.centre-mersenne.org/item/AIF_2012__62_1_77_0/

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