English
Related papers

Related papers: Generalized geometry, equivariant $\bar{\partial}\…

200 papers

The smooth action of a compact Lie group on a compact manifold can be resolved to an iterated space, as made explicit by Pierre Albin and the second author. On the resolution the lifted action has fixed isotropy type, in an iterated sense,…

Algebraic Topology · Mathematics 2022-12-15 Panagiotis Dimakis , Richard Melrose

We study Cohen-Macaulay actions, a class of torus actions on manifolds, possibly without fixed points, which generalizes and has analogous properties as equivariantly formal actions. Their equivariant cohomology algebras are computable in…

Algebraic Topology · Mathematics 2011-01-05 Oliver Goertsches , Dirk Toeben

We show that the equivariant cohomology of any hyperpolar action of a compact and connected Lie group on a symmetric space of compact type is a Cohen-Macaulay ring. This generalizes some results previously obtained by the authors.

Differential Geometry · Mathematics 2019-09-23 Oliver Goertsches , Sam Hagh Shenas Noshari , Augustin-Liviu Mare

Let the compact torus $T^{n-1}$ act on a smooth compact manifold $X^{2n}$ effectively with nonempty finite set of fixed points. We pose the question: what can be said about the orbit space $X^{2n}/T^{n-1}$ if the action is cohomologically…

Algebraic Topology · Mathematics 2023-02-20 Anton Ayzenberg , Vladislav Cherepanov

In this paper we give a geometric construction of the Borel equivariant (co)homology for spaces with a $G$-action, where $G$ is a compact Lie group with the property that the adjoint representation is orientable. A nice feature of these…

Algebraic Topology · Mathematics 2014-01-10 Haggai Tene

Let $\Gamma$ be a finite d-valent graph and G an n-dimensional torus. An ``action'' of G on $\Gamma$ is defined by a map, $\alpha$, which assigns to each oriented edge e of $\Gamma$ a one-dimensional representation of G (or, alternatively,…

Combinatorics · Mathematics 2007-05-23 Victor Guillemin , Catalin Zara

Considering the potential equivariant formality of the left action of a connected Lie group $K$ on the homogeneous space $G/K$, we arrive through a sequence of reductions at the case $G$ is compact and simply-connected and $K$ is a torus.…

Algebraic Topology · Mathematics 2023-11-28 Jeffrey D. Carlson

We study generalized moment maps for a Hamiltonian action on a connected compact $H$-twisted generalized complex manifold introduced by Lin and Tolman and prove the convexity and connectedness properties of the generalized moment maps for a…

Differential Geometry · Mathematics 2007-10-23 Yasufumi Nitta

We show that the cohomology algebra of the complement of a coordinate subspace arrangement in m-dimensional complex space is isomorphic to the cohomology algebra of Stanley-Reisner face ring of a certain simplicial complex on m vertices.…

Algebraic Topology · Mathematics 2016-09-07 Victor M. Buchstaber , Taras E. Panov

We derive a local ansatz for generalized K\"ahler surfaces with nondegenerate Poisson structure and a biholomorphic $S^1$ action which generalizes the classic Gibbons-Hawking ansatz for invariant hyperK\"ahler manifolds, and allows for the…

Differential Geometry · Mathematics 2022-02-09 Jeffrey Streets , Yury Ustinovskiy

The smooth action of a compact Lie group on a compact manifold can be resolved to an iterated space, as made explicit by Pierre Albin and the second author. On the resolution the lifted action has fixed isotropy type corresponding to the…

K-Theory and Homology · Mathematics 2021-01-05 Panagiotis Dimakis , Richard Melrose

We define the notion of a partial action on a generalized Boolean algebra and associate to every such system and commutative unital ring $R$ an $R$-algebra. We prove that every strongly $E^{\ast}$-unitary inverse semigroup has an associated…

Rings and Algebras · Mathematics 2025-03-04 Allen Zhang

Let $M$ be complex projective manifold and $A$ a positive line bundle on it. Assume that a compact and connected Lie group $G$ acts on $M$ in a Hamiltonian and holomorphic manner and that this action linearizes to $A$. Then, there is an…

Symplectic Geometry · Mathematics 2021-11-19 Andrea Galasso

Let $G$ be a compact Lie group. We study a class of Hamiltonian $(G \times S^{1})$-manifolds decorated with a function $s$ with certain equivariance properties, under conditions on the $G$-action which we call of (semi-)linear type. In this…

Symplectic Geometry · Mathematics 2024-06-04 Jonathan Fisher , Lisa Jeffrey , Alessandro Malusà , Steven Rayan

For a closed K\"{a}hler manifold with a Hamiltonian action of a connected compact Lie group by holomorphic isometries, we construct a formal Frobenius manifold structure on the equivariant cohomology by exploiting a natural DGBV algebra…

Differential Geometry · Mathematics 2007-05-23 Huai-Dong Cao , Jian Zhou

A generalized moment map is proposed for arbitrary symplectic actions of compact connected Lie groups on closed symplectic manifolds, in the spirit of the circle -valued maps introduced by D. McDuff in the case of non-Hamiltonian circle…

Symplectic Geometry · Mathematics 2016-09-07 Pierre Sleewaegen

We introduce the notion of measurable bounded cohomology for measured groupoids, extending continuous bounded cohomology of locally compact groups. We show that the measurable bounded cohomology of the semidirect groupoid associated to a…

Dynamical Systems · Mathematics 2025-09-19 Filippo Sarti , Alessio Savini

Let $(X,J) $ be an almost complex manifold with a (smooth) involution $\sigma:X\to X$ such that $Fix(\sigma)\neq \emptyset$. Assume that $\sigma$ is a complex conjugation, i.e, the differential of $\sigma$ anti-commutes with $J$. The space…

Algebraic Topology · Mathematics 2020-02-21 Avijit Nath , Parameswaran Sankaran

We study meromorphic actions of unipotent complex Lie groups on compact K\"ahler manifolds using moment map techniques. We introduce natural stability conditions and show that sets of semistable points are Zariski-open and admit geometric…

Complex Variables · Mathematics 2023-06-22 Daniel Greb , Christian Miebach

Let $X$ be a topological space upon which a compact connected Lie group $G$ acts. It is well-known that the equivariant cohomology $H_G^*(X;\Q)$ is isomorphic to the subalgebra of Weyl group invariants of the equivariant cohomology…

Algebraic Topology · Mathematics 2009-06-09 Tara Holm , Reyer Sjamaar