О гомотопическом разложении фактора момент–угол-комплекса и его приложениях

Труды Математического института им. В.А. Стеклова РАН. 2022. Т. 317. С. 132–156.

Limonchenko I., Solomadin G.

In this paper we prove that the quotient of any real or complex moment-angle complex by any closed subgroup in the naturally acting compact torus on it is equivariantly homotopy equivalent to the homotopy colimit of a certain toric diagram. For any quotient we prove an equivariant homeomorphism generalizing the well-known Davis-Januszkiewicz construction for quasitoric manifolds and small covers. We deduce formality of the corresponding Borel construction space under the natural assumption on the group action in the complex case leading to the new description of the equivariant cohomology for the quotients by any coordinate subgroups. We prove the weak Toral Rank Conjecture for the partial quotient of any moment-angle complex by the diagonal circle action. We give an explicit construction of partial quotients by circle actions having arbitrary torsion in integral cohomology.

Keywords: quasitoric manifold, moment-angle complex, квазиторическое многообразие, homotopy colimit, toric diagram, partial quotient, Buchstaber number, гомотопический копредел, торическая диаграмма, момент-угол комплекс, частичный фактор, число Бухштабера

Publication based on the results of: Geometrical and homological methods in Mathematics and data analysis (2022)