On étudie la cohomologie du groupe des -difféomorphismes de la droite, qui sout -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.
We study the cohomology of the group consisting of all -diffeomorphisms of the line, which are -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.
@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}, volume = {62}, year = {2012}, pages = {77-85}, doi = {10.5802/aif.2699}, zbl = {1253.58007}, mrnumber = {2986265}, language = {en}, url = {http://dml.mathdoc.fr/item/AIF_2012__62_1_77_0} }
Ishida, Tomohiko. Second cohomology classes of the group of $C^1$-flat diffeomorphisms. Annales de l'Institut Fourier, Tome 62 (2012) pp. 77-85. doi : 10.5802/aif.2699. http://gdmltest.u-ga.fr/item/AIF_2012__62_1_77_0/
[1] Homologies of the group and its subgroups, J. Math. Kyoto Univ., Tome 20 (1980) no. 3, pp. 475-487 | MR 591806 | Zbl 0476.57016
[2] Cohomologies of the Lie algebra of formal vector fields, Izv. Akad. Nauk SSSR Ser. Mat., Tome 34 (1970), pp. 322-337 | MR 266195 | Zbl 0216.20302
[3] The cohomologies of Lie algebras of formal vector fields on the line, Funct. Anal. and Appl., Tome 7 (1973), p. 91-97, 194–203 | Article | Zbl 0284.17006
[4] Massey higher products, Trans. Amer. Math. Soc., Tome 124 (1966), pp. 431-449 | Article | MR 202136 | Zbl 0146.19201
[5] Algebra of formal vector fields on the line and Buchstaber’s conjecture, Funct. Anal. Appl., Tome 43 (2009), pp. 264-278 | Article | MR 2596653
[6] Normal forms for certain singularities of vectorfields, Ann. Inst. Fourier (Grenoble), Tome 23 (1973) no. 2, pp. 163-195 (Colloque International sur l’Analyse et la Topologie Différentielle (Colloques Internationaux du Centre National de la Recherche Scientifique, Strasbourg, 1972)) | Article | Numdam | MR 365620 | Zbl 0266.34046
[7] Filtering bases: a tool to compute cohomologies of abstract subalgebras of the Witt algebra, Unconventional Lie algebras, Amer. Math. Soc., Providence, RI (Adv. Soviet Math.) Tome 17 (1993), pp. 155-216 | MR 1254731 | Zbl 0801.17022