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Related papers: Formality in an Equivariant Setting

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We show that the isotropy action of a homogeneous space $G/K$, where $G$ and $K$ are compact, connected Lie groups and $K$ is defined by an automorphism on $G$, is equivariantly formal and that $(G, K)$ is a Cartan pair.

Differential Geometry · Mathematics 2018-03-16 Oliver Goertsches , Sam H. Noshari

We compute the Borel equivariant cohomology ring of the left $K$-action on a homogeneous space $G/H$, where $G$ is a connected Lie group, $H$ and $K$ are closed, connected subgroups and $2$ and the torsion primes of the Lie groups are units…

Algebraic Topology · Mathematics 2025-12-24 Jeffrey D. Carlson

Let $G$ be a compact connected Lie group and $K$ a connected Lie subgroup. In this paper, we collect an assortment of results on equivariant formality of the isotropy action of $K$ on $G/K$. If the isotropy action of $K$ on $G/K$ is…

Algebraic Topology · Mathematics 2024-08-22 Jeffrey D. Carlson , Chi-Kwong Fok

We completely characterize the pairs of connected Lie groups $G > K$ such that $\mathrm{rank}(G) - \mathrm{rank}(K) = 1$ and the left action of $K$ on $G/K$ is equivariantly formal. The analysis requires us to correct and extend an existing…

Algebraic Topology · Mathematics 2023-11-28 Jeffrey Carlson , Chen He

In this note we classify all homogeneous spaces $G/H$ admitting a $G$-invariant $G_2$-structure, assuming that $G$ is a compact Lie group and $G$ acts effectively on $G/H$. They include a subclass of all homogeneous spaces $G/H$ with a…

Differential Geometry · Mathematics 2012-08-02 Hong Van Le , Mobeen Munir

For a finite abelian group $G$, we compute the $G$-equivariant formal group law corresponding to the $G$-equivariant complex cobordism spectrum with its canonical complex orientation.

Algebraic Topology · Mathematics 2015-03-31 William C. Abram

We find an interpretation of the complex of variational calculus in terms of the Lie conformal algebra cohomology theory. This leads to a better understanding of both theories. In particular, we give an explicit construction of the Lie…

Quantum Algebra · Mathematics 2015-12-18 Alberto De Sole , Victor Kac

We associate a bivariant theory to any suitable oriented Borel-Moore homology theory on the category of algebraic schemes or the category of algebraic G-schemes. Applying this to the theory of algebraic cobordism yields operational…

Algebraic Geometry · Mathematics 2016-01-20 José Luis González , Kalle Karu

This article investigates equivariant parametrized cellular cohomology, a cohomology theory introduced by Costenoble-Waner for spaces with an action by a compact Lie group $G$. The theory extends the $RO(G)$-graded cohomology of a $G$-space…

Algebraic Topology · Mathematics 2024-10-21 Agnès Beaudry , Chloe Lewis , Clover May , Sabrina Pauli , Elizabeth Tatum

This is a paper in a series that studies smooth relative Lie algebra homologies and cohomologies based on the theory of formal manifolds and formal Lie groups. In a previous paper, we introduce the notion of formal manifolds and develop the…

Functional Analysis · Mathematics 2024-07-15 Fulin Chen , Binyong Sun , Chuyun Wang

This is the first paper in a series that studies smooth relative Lie algebra homologies and cohomologies based on the theory of formal manifolds and formal Lie groups. In this paper, we lay the foundations for this study by introducing the…

Differential Geometry · Mathematics 2024-07-11 Fulin Chen , Binyong Sun , Chuyun Wang

Let $\Gamma$ be a finite group acting linearly on a vector space $V$. We compute the Lie algebra cohomology of the Lie algebra of $\Gamma$-invariant formal vector fields on $V$. We use this computation to define characteristic classes for…

Representation Theory · Mathematics 2007-05-23 Ilya Shapiro , Xiang Tang

We show that for every symmetric space G/K of compact type with K connected, the K-action on G/K by left translations is equivariantly formal.

Differential Geometry · Mathematics 2012-03-01 Oliver Goertsches

The complexity of an action of a reductive algebraic group G on an algebraic variety X is the codimension of a generic B-orbit in X, where B is a Borel subgroup of G. We classify affine homogeneous spaces G/H of complexity one. These…

Algebraic Geometry · Mathematics 2015-06-26 Ivan V. Arzhantsev , Olga V. Chuvashova

We compute the Hodge and de Rham cohomology of the classifying space BG (defined as etale cohomology on the algebraic stack BG) for reductive groups G over many fields, including fields of small characteristic. These calculations have a…

Algebraic Geometry · Mathematics 2018-07-18 Burt Totaro

The purpose of this article is to give an exposition of topological properties of spaces of homomorphisms from certain finitely generated discrete groups to Lie groups $G$, and to describe their connections to classical representation…

Algebraic Topology · Mathematics 2016-09-28 Frederick R. Cohen , Mentor Stafa

For a linear algebraic group $G$ over a field $k$, we define an equivariant version of the Voevodsky's motivic cobordism $MGL$. We show that this is an oriented cohomology theory with localization sequence on the category of smooth…

Algebraic Geometry · Mathematics 2012-06-27 Amalendu Krishna

The group of continuous binary operations on a topological space is studied; its relationship with the group of homeomorphisms is established. The category of binary $G$-spaces and bi-equivariant maps is constructed, which is a natural…

General Topology · Mathematics 2023-07-13 Pavel S. Gevorgyan

An equivariant topological field theory is defined on a cobordism category of manifolds with principal fiber bundles for a fixed (finite) structure group. We provide a geometric construction which for any given morphism $G \to H$ of finite…

Quantum Algebra · Mathematics 2018-10-22 Christoph Schweigert , Lukas Woike

This is a survey on the equivariant cohomology of Lie group actions on manifolds, from the point of view of de Rham theory. Emphasis is put on the notion of equivariant formality, as well as on applications to ordinary cohomology and to…

Differential Geometry · Mathematics 2019-03-29 Oliver Goertsches , Leopold Zoller