The aim of this article is to answer a question posed by J. Oprea in his talk at the Workshop "Homotopy and Geometry".
@article{bwmeta1.element.bwnjournal-article-bcpv45i1p91bwm, author = {Hattori, Akio}, title = {4-dimensional c-symplectic $S^1$-manifolds with non-empty fixed point set need not be c-Hamiltonian}, journal = {Banach Center Publications}, volume = {43}, year = {1998}, pages = {91-93}, zbl = {0994.57032}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-bcpv45i1p91bwm} }
Hattori, Akio. 4-dimensional c-symplectic $S^1$-manifolds with non-empty fixed point set need not be c-Hamiltonian. Banach Center Publications, Tome 43 (1998) pp. 91-93. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-bcpv45i1p91bwm/
[000] [A-B] M. F. Atiyah and R. Bott, The moment map and equivariant cohomology, Topology 23 (1984), 1-28. | Zbl 0521.58025
[001] [G] D. Gottlieb, Lifting actions in fibrations, Lecture Notes in Math. Vol. 657 (1977), pp. 217-254.
[002] [H-Y] A. Hattori and T. Yoshida, Lifting compact group actions in fiber bundles, Japan. J. Math. 2 (1976), 13-25. | Zbl 0346.57014
[003] [L-O] G. Lupton and J. Oprea, Cohomologically symplectic spaces: toral actions and the Gottlieb group, Trans. Amer. Math. Soc. 347 (1995), 261-288. | Zbl 0836.57019
[004] [M] D. McDuff, The moment map for circle actions on symplectic manifolds, J. Geom. Phys. 5 (1988), 149-160. | Zbl 0696.53023