D’après une extension d’une conjecture fondamentale de R. Bott, toute variété compacte (sans bord) simplement connexe à courbure positive est rationellement elliptique, i.e., seul un nombre fini de groupes d’homotopie de sont infinis. On montre cette conjecture dans le cas où admet une action par isométries dont l’orbite principale a codimension au plus est de deux. Notre preuve utilise la géométrie de l’espace quotient pour contrôler la topologie de la fibre homotopique de l’inclusion d’une orbite dans , et s’applique à des contextes plus généraux.
An extension of a fundamental conjecture by R. Bott suggests that all simply connected closed almost non-negatively curved manifolds are rationally elliptic, i.e., all but finitely many homotopy groups of such are finite. We confirm this conjecture when in addition supports an isometric action with orbits of codimension at most two. Our proof uses the geometry of the orbit space to control the topology of the homotopy fiber of the inclusion map of an orbit in , and is applicable to more general contexts.
Keywords: Almost Non-negative Curvature, Rational ellipticity, Morse Theory, Cohomogeneity
Mot clés : Courbure presque positive, Ellipticité rationelle, Théorie de Morse, Cohomogénéité
Grove, Karsten 1 ; Wilking, Burkhard 2 ; Yeager, Joseph 3
@article{AIF_2019__69_7_2921_0, author = {Grove, Karsten and Wilking, Burkhard and Yeager, Joseph}, title = {Almost non-negative curvature and rational ellipticity in cohomogeneity two}, journal = {Annales de l'Institut Fourier}, pages = {2921--2939}, publisher = {Association des Annales de l{\textquoteright}institut Fourier}, volume = {69}, number = {7}, year = {2019}, doi = {10.5802/aif.3340}, language = {en}, url = {https://aif.centre-mersenne.org/articles/10.5802/aif.3340/} }
TY - JOUR AU - Grove, Karsten AU - Wilking, Burkhard AU - Yeager, Joseph TI - Almost non-negative curvature and rational ellipticity in cohomogeneity two JO - Annales de l'Institut Fourier PY - 2019 SP - 2921 EP - 2939 VL - 69 IS - 7 PB - Association des Annales de l’institut Fourier UR - https://aif.centre-mersenne.org/articles/10.5802/aif.3340/ DO - 10.5802/aif.3340 LA - en ID - AIF_2019__69_7_2921_0 ER -
%0 Journal Article %A Grove, Karsten %A Wilking, Burkhard %A Yeager, Joseph %T Almost non-negative curvature and rational ellipticity in cohomogeneity two %J Annales de l'Institut Fourier %D 2019 %P 2921-2939 %V 69 %N 7 %I Association des Annales de l’institut Fourier %U https://aif.centre-mersenne.org/articles/10.5802/aif.3340/ %R 10.5802/aif.3340 %G en %F AIF_2019__69_7_2921_0
Grove, Karsten; Wilking, Burkhard; Yeager, Joseph. Almost non-negative curvature and rational ellipticity in cohomogeneity two. Annales de l'Institut Fourier, Tome 69 (2019) no. 7, pp. 2921-2939. doi : 10.5802/aif.3340. https://aif.centre-mersenne.org/articles/10.5802/aif.3340/
[1] Lectures on the Blaschke conjecture (2014) (http://people.mpim-bonn.mpg.de/hwbllmnn/archiv/blaschke1603.pdf)
[2] Sur les variétés à courbure strictement positive, Topology, Volume 1 (1962), pp. 301-311 | DOI | Zbl
[3] Nilpotent structures and invariant metrics on collapsed manifolds, J. Am. Math. Soc., Volume 5 (1992) no. 2, pp. 327-372 | DOI | MR | Zbl
[4] Rational LS category and its applications, Trans. Am. Math. Soc., Volume 273 (1982) no. 1, pp. 1-38 | MR | Zbl
[5] Rational homotopy theory, Graduate Texts in Mathematics, 205, Springer, 2001, xxxiv+535 pages | MR | Zbl
[6] The depth and LS category of a topological space, Math. Scand., Volume 123 (2018) no. 2, pp. 220-238 | DOI | MR | Zbl
[7] Rational homotopy theory. II, World Scientific, 2015, xxxvi+412 pages | Zbl
[8] Almost flat manifolds, J. Differ. Geom., Volume 13 (1978) no. 2, pp. 231-241 | DOI | MR
[9] Contributions of rational homotopy theory to global problems in geometry, Publ. Math., Inst. Hautes Étud. Sci., Volume 56 (1982), pp. 171-178 | DOI | Numdam | Zbl
[10] Dupin hypersurfaces, group actions and the double mapping cylinder, J. Differ. Geom., Volume 26 (1987) no. 3, pp. 429-459 | DOI | MR | Zbl
[11] Non-negative curvature obstructions in cohomogeneity one and the Kervaire spheres, Ann. Sc. Norm. Super. Pisa, Cl. Sci., Volume 5 (2006) no. 2, pp. 159-170 | Numdam | MR | Zbl
[12] Polar manifolds and actions, J. Fixed Point Theory Appl., Volume 11 (2012) no. 2, pp. 279-313 | DOI | MR | Zbl
[13] Groupoïdes d’holonomie et classifiants, Structure transverse des feuilletages (Toulouse, 1982) (Astérisque), Volume 116, Société Mathématique de France, 1984, pp. 70-97 | Zbl
[14] Algebraic topology, Cambridge University Press, 2002, xii+544 pages | Zbl
[15] Nilpotency, almost nonnegative curvature, and the gradient flow on Alexandrov spaces, Ann. Math., Volume 171 (2010) no. 1, pp. 343-373 | DOI | MR | Zbl
[16] Orbifolds from a metric viewpoint (2018) (https://arxiv.org/abs/1801.03472)
[17] Geometric resolution of singular Riemannian foliations, Geom. Dedicata, Volume 149 (2010), pp. 379-395 | DOI | MR | Zbl
[18] On contractible orbifolds, Proc. Am. Math. Soc., Volume 141 (2013) no. 9, pp. 3303-3304 | DOI | MR | Zbl
[19] Curvature explosion in quotients and applications, J. Differ. Geom., Volume 85 (2010) no. 1, pp. 117-139 | DOI | MR | Zbl
[20] Extending tensors on polar manifolds, Math. Ann., Volume 365 (2016) no. 3-4, pp. 1409-1424 | DOI | MR | Zbl
[21] A slice theorem for singular Riemannian foliations, with applications, Trans. Am. Math. Soc., Volume 371 (2019) no. 7, pp. 4931-4949 | DOI | MR | Zbl
[22] Riemannian foliations, Progress in Mathematics, 73, Birkhäuser, 1988, xii+339 pages | MR
[23] Isoparametrische Hyperflächen in Sphären, Math. Ann., Volume 251 (1980) no. 1, pp. 57-71 | DOI | Zbl
[24] Lecture notes on singular Riemannian foliations (https://www.marcoradeschi.com)
[25] Metrics of positive Ricci curvature on quotient spaces, Math. Ann., Volume 330 (2004) no. 1, pp. 59-91 | MR | Zbl
[26] How to lift positive Ricci curvature, Geom. Topol., Volume 19 (2015) no. 3, pp. 1409-1475 | DOI | MR | Zbl
[27] Three-dimensional geometry and topology. Vol. 1, Princeton Mathematical Series, 35, Princeton University Press, 1997, x+311 pages | MR | Zbl
[28] Geometric and Topological ellipticity in cohomogeneity two, Ph. D. Thesis, University of Maryland (USA) (2012) (http://hdl.handle.net/1903/12662) | MR
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