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Related papers: Formality in an Equivariant Setting

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Functions which are covariant or invariant under the transformations of a compact linear group $G$ acting in a euclidean space $\real^n$, can be profitably studied as functions defined in the orbit space of the group. The orbit space is the…

Mathematical Physics · Physics 2007-05-23 G. Sartori , G. Valente

An ergodic action of a compact quantum group G on an operator algebra A can be interpreted as a quantum homogeneous space for G. Such an action gives rise to the category of finite equivariant Hilbert modules over A, which has a module…

Operator Algebras · Mathematics 2019-01-29 Kenny De Commer , Makoto Yamashita

In this expository article we give a categorical definition of the integral cohomology ring of a stack. We show that for quotient stacks the categorical cohomology may be identified with equivariant cohomology. Via this identification we…

Algebraic Geometry · Mathematics 2011-08-08 Dan Edidin

Let p, ell be distinct primes and let q be a power of p. Let G be a connected compact Lie group. We show that there exists an integer b such that the mod ell cohomology of the classifying space of a finite Chevalley group G(F_q) is…

Algebraic Topology · Mathematics 2008-10-10 Masaki Kameko

We introduce the notion of the \emph{equivariant covering type} of a space $X$ on which a finite group $G$ acts, and study its properties. The equivariant covering type measures the size of $G$-equivariant good covers of $X$ and is thus an…

Algebraic Topology · Mathematics 2024-11-27 Dejan Govc , Waclaw Marzantowicz , Petar Pavesic

For a finite group $G$, we define an equivariant cobordism category $\mathcal{C}_d^G$. Objects of the category are $(d-1)$-dimensional closed smooth $G$-manifolds and morphisms are smooth $d$-dimensional equivariant cobordisms. We identify…

Algebraic Topology · Mathematics 2022-03-25 Gergely Szűcs , Søren Galatius

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 three previous papers, we introduce the notion of formal manifolds and study…

Differential Geometry · Mathematics 2025-01-22 Fulin Chen , Binyong Sun , Chuyun Wang

Equivariant compactifications of reductive groups can be described by combinatorial data. On the other hand, equivariant compactifications of the additive group G^n_a are more complicated in at least two respects. First, they often admit…

Algebraic Geometry · Mathematics 2007-05-23 Brendan Hassett , Yuri Tschinkel

We prove a localization formula for group-valued equivariant de Rham cohomology of a compact G-manifold. This formula is a non-trivial generalization of the localization formula of Berline-Vergne and Atiyah-Bott for the usual equivariant de…

Differential Geometry · Mathematics 2007-05-23 Anton Alekseev , Eckhard Meinrenken , Chris Woodward

Recent work of Chen He has determined through GKM methods the Borel equivariant cohomology with rational coefficients of the isotropy action on a real Grassmannian and an real oriented Grassmannian through GKM methods. In this expository…

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

In [1] we introduced the concept of structured space, which is a topological space that locally resembles some algebraic structures. In [2] we proceeded the study of these spaces, developing two cohomology theories. The aim of this paper is…

Algebraic Topology · Mathematics 2020-04-28 Manuel Norman

This is the second in a series of papers on a new equivariant cohomology that takes values in a vertex algebra. In an earlier paper, the first two authors gave a construction of the cohomology functor on the category of O(sg) algebras. The…

Differential Geometry · Mathematics 2020-08-10 Bong H. Lian , Andrew R. Linshaw , Bailin Song

Given a grading by an abelian group G on a semisimple Lie algebra L over an algebraically closed field of characteristic 0, we classify up to isomorphism the simple objects in the category of finite-dimensional G-graded L-modules. The…

Representation Theory · Mathematics 2015-07-22 Alberto Elduque , Mikhail Kochetov

We partially describe equivariant Dirac and generalized complex structures on a homogeneous space $G/K$ by giving equivalent data involving only the Lie algebra. We consider real semisimple adjoint orbits in any semisimple Lie algebra over…

Differential Geometry · Mathematics 2010-08-12 Brett Milburn

This is a survey on formality results relying on weight structures. A weight structure is a naturally occurring grading on certain differential graded algebras. If this weight satisfies a purity property, one can deduce formality. Algebraic…

Algebraic Topology · Mathematics 2024-06-28 Coline Emprin , Geoffroy Horel

One of the interesting and important rational homotopy properties of a topological space $X$ is that of {\em formality}. In this paper we prove the non-formality property of some family homogeneous spaces.

Representation Theory · Mathematics 2018-09-12 Zofia Stȩpień

We give simple upper bounds for rational sectional category and use them to compute invariants of the type of Farber's topological complexity of rational spaces. In particular we show that the sectional category of formal morphisms reaches…

Algebraic Topology · Mathematics 2015-03-10 J. G. Carrasquel-Vera

We show that for a Hamiltonian action of a compact torus $G$ on a compact, connected symplectic manifold $M$, the $G$-equivariant cohomology is determined by the residual $S^1$ action on the submanifolds of $M$ fixed by codimension-1 tori.…

Symplectic Geometry · Mathematics 2007-05-23 Rebecca Goldin , Tara S. Holm

Let $X$ be a connected complex manifold equipped with a holomorphic action of a complex Lie group $G$. We investigate conditions under which a principal bundle on $X$ admits a $G$--equivariance structure.

Complex Variables · Mathematics 2016-11-29 Indranil Biswas , Arjun Paul

We give a combinatorial model structure to the category of, not necessarily conilpotent, differential graded (dg) cocommutative coalgebras and an $\infty$-category structure to the category of curved Lie algebras over an algebraically…

Quantum Algebra · Mathematics 2026-03-25 Alexander Mallon , You Wang