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We show that for topological groups and loop contractible coefficients the cohomology groups of continuous group cochains and of group cochains that are continuous on some identity neighbourhood are isomorphic. Moreover, we show a similar…

Algebraic Topology · Mathematics 2013-02-14 Martin Fuchssteiner , Christoph Wockel

Characteristic class relations in Dolbeault cohomology follow from the existence of a holomorphic Cartan geometry (for example, a holomorphic conformal structure or a holomorphic projective connection). These relations can be calculated…

Differential Geometry · Mathematics 2025-12-22 Benjamin McKay

Let G be a compact Lie-group, X a compact G-CW-complex. We define equivariant geometric K-homology groups K^G_*(X), using an obvious equivariant version of the (M,E,f)-picture of Baum-Douglas for K-homology. We define explicit natural…

K-Theory and Homology · Mathematics 2012-10-12 Paul Baum , Herve Oyono-Oyono , Thomas Schick , Michael Walter

Using factorizable Hopf algebras, we construct modular invariant partition functions of charge conjugation, or Cardy, type as characters of coends in categories that share essential features with the ones appearing in logarithmic CFT. The…

High Energy Physics - Theory · Physics 2017-08-23 Jurgen Fuchs , Christoph Schweigert , Carl Stigner

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 $\varphi$ and $\varphi'$ be two homotopic actions of the topological group $G$ on the topological space $X$. To an object $A$ in the $G$-equivariant derived category $D_{\varphi}(X)$ of $X$ relative to the action $\varphi$ we associate…

Algebraic Topology · Mathematics 2016-05-23 Andrés Viña

Consider a Hamiltonian action of a compact connected Lie group on a conformal symplectic manifold. We prove a convexity theorem for the moment map under the assumption that the action is of Lee type, which establishes an analog of Kirwan's…

Symplectic Geometry · Mathematics 2023-11-27 Youming Chen , Reyer Sjamaar , Xiangdong Yang

The equivariant cohomology of a space with a group action is not only a ring but also an algebra over the cohomology ring of the classifying space of the acting group. We prove that toric manifolds (i.e. compact smooth toric varieties) are…

Algebraic Topology · Mathematics 2008-11-28 Mikiya Masuda

We calculate relations on characteristic classes which are obstructions preventing closed K\"ahler manifolds from carrying holomorphic Cartan geometries. We apply these relations to give global constraints on the phase spaces of complex…

Differential Geometry · Mathematics 2019-11-12 Benjamin McKay

We consider a class of homogeneous manifolds including all semisimple coadjoint orbits. We describe manifolds of that class admitting deformation q uantizations equivariant under the action of $G$ and the corresponding quantum group. We…

Quantum Algebra · Mathematics 2009-11-07 Joseph Donin , Vadim Ostapenko

We present a construction of Chern-Weil characteristic classes for pairs Cartan geometries sharing the same underlying data. Given any model Cartan geometry $(Q,\omega)$ with underlying data $(G,V)$ and a second Cartan geometry $(P,\theta)$…

Differential Geometry · Mathematics 2026-05-07 Luca Accornero , Mateus M. de Melo , Ivan Struchiner

This thesis is devoted to algorithmic aspects of the implementation of Cartan's moving frame method to the problem of the equivalence of submanifolds under a Lie group action. We adopt a general definition of a moving frame as an…

Differential Geometry · Mathematics 2019-09-06 Irina Kogan

By combining the ideas of Cartan's equivalence method and the method of the equivariant moving frame for pseudo-groups, we develop an efficient method for solving equivalence problems arising from horizontal Lie pseudo-group actions. The…

Differential Geometry · Mathematics 2018-11-02 Orn Arnaldsson

We characterize cohomogeneity one manifolds and homogeneous spaces with a compact Lie group action admitting an invariant metric with positive scalar curvature.

Differential Geometry · Mathematics 2022-03-14 Georg Frenck , Fernando Galaz-Garcia , Philipp Reiser

Let $G$ be a linear Lie group acting properly and isometrically on a $G$-spin$^c$ manifold $M$ with compact quotient. We show that Poincar\'e duality holds between $G$-equivariant $K$-theory of $M$, defined using finite-dimensional…

K-Theory and Homology · Mathematics 2024-09-02 Hao Guo , Varghese Mathai

In this paper, we study continuous Rokhlin property of $\mathrm{C}^*$-dynamical systems using techniques of equivariant $\mathrm{KK}$-theory and quantum group theory. In particular, we determine the $\mathrm{KK}$-equivalence class and give…

Operator Algebras · Mathematics 2015-12-22 Yuki Arano , Yosuke Kubota

We study equivariant birationality from the perspective of derived categories. We produce examples of nonlinearizable but stably linearizable actions of finite groups on smooth cubic fourfolds.

Algebraic Geometry · Mathematics 2023-04-19 Christian Böhning , Hans-Christian Graf von Bothmer , Yuri Tschinkel

We give a classification of open equivariant topological conformal field theories in terms of Calabi-Yau $A_\infty$-categories endowed with a group action.

Algebraic Topology · Mathematics 2015-12-14 Ramses Fernandez-Valencia

The mapping class group of a compact oriented surface of genus greater than one with boundary acts ergodically on connected components of the representation variety corresponding to a connected compact Lie group, for every choice of…

Dynamical Systems · Mathematics 2007-05-23 Doug Pickrell , Eugene Z. Xia

We compute the equivariant complex K-theory ring of a cohomogeneity-one action of a compact Lie group at the level of generators and relations and derive a characterization of K-theoretic equivariant formality for these actions. Less…

Algebraic Topology · Mathematics 2022-03-15 Jeffrey D. Carlson