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The quantization of vector bundles is defined. Examples are constructed for the well controlled case of equivariant vector bundles over compact coadjoint orbits. (Coadjoint orbits are symplectic spaces with a transitive, semisimple symmetry…

q-alg · Mathematics 2009-10-30 Eli Hawkins

The index, which is given in terms of the number of zero modes of the Dirac operator with definite chirality, plays a central role in various topological aspects of gauge theories. We investigate its properties in non-commutative geometry.…

High Energy Physics - Theory · Physics 2010-10-27 Hajime Aoki , Jun Nishimura , Yoshiaki Susaki

Let $M$ be a compact Riemannian manifold endowed with an isometric action of a compact Lie group. The method of the Witten deformation is used to compute the virtual representation-valued equivariant index of a transversally elliptic, first…

Differential Geometry · Mathematics 2021-01-28 Igor Prokhorenkov , Ken Richardson

Using a homological invariant together with an obstruction class in a certain Ext^2-group, we may classify objects in triangulated categories that have projective resolutions of length two. This invariant gives strong classification results…

Operator Algebras · Mathematics 2017-04-20 Rasmus Bentmann , Ralf Meyer

In this paper we introduce the systematic study of invariant functions and equivariant mappings defined on Minkowski space under the action of the Lorentz group. We adapt some known results from the orthogonal group acting on the Euclidean…

Representation Theory · Mathematics 2025-03-27 Miram Manoel , Leandro Nery de Oliveira

We give a brief introduction to the Berline-Vergne localization formula for the finite-dimensional setting and indicate how the Duistermaat-Heckman formula is derived from it. We consider applications of the localization formula when it is…

Symplectic Geometry · Mathematics 2007-05-23 A. A. Bytsenko , M. Libine , F. L. Williams

We initiate a systematic investigation of group actions on compact medain algebras via the corresponding dynamics on their spaces of measures. We show that a probability measure which is invariant under a natural push forward operation must…

General Topology · Mathematics 2025-03-11 Uri Bader , Aviv Taller

Equationally compact subgroups of countable groups were introduced by Banaschewski. For all known cases the orbit closure of such a subgroup is a countable subset in the space of subgroups and has finite Cantor-Bendixson rank. We show that…

Group Theory · Mathematics 2016-08-19 Gabor Elek , Konrad Krolicki

We develop a fundamental theory of compact quantum group equivariant finite extensions of C*-algebras. In particular we focus on the case of quantum homogeneous spaces and give a Tannaka-Krein type result for equivariant correspondences. As…

Operator Algebras · Mathematics 2023-01-13 Mao Hoshino

Let X be a compact manifold with boundary, and suppose that the boundary is the total space of a fibration with base Y and fibre Z. Let D be a generalized Dirac operator associated to a Phi-metric g on X. Under the assumption that D is…

Differential Geometry · Mathematics 2007-05-23 Eric Leichtnam , Rafe Mazzeo , Paolo Piazza

For a compact metric space $X$ with a group $G$ acting on it continuously, an invariant random compact is a Borel probability measure on the space of nonempty compact subsets of $X$ that is invariant under the action of $G$. The action is…

Dynamical Systems · Mathematics 2026-05-29 Bryna Kra , Scott Schmieding

We classify compact homogeneous geometries of irreducible spherical type and rank at least 2 which admit a transitive action of a compact connected group, up to equivariant 2-coverings. We apply our classification to polar actions on…

Group Theory · Mathematics 2014-04-17 Linus Kramer , Alexander Lytchak

We consider divergent orbits of the group of diagonal matrices in the space of lattices in Euclidean space. We define two natural numerical invariants of such orbits: The discriminant - an integer - and the type - an integer vector. We then…

Dynamical Systems · Mathematics 2017-10-17 Ofir David , Uri Shapira

Operads were originally defined by May to have right actions of the symmetric groups, but later formulations have also used no groups actions at all or group actions by such families as the braid groups. We call such families action…

Category Theory · Mathematics 2026-03-23 Alexander Corner , Nick Gurski

In this paper we develop a systematic theory of compact operator semigroups on locally convex vector spaces. In particular we prove new and generalized versions of the mean ergodic theorem and apply them to different notions of mean…

Dynamical Systems · Mathematics 2022-04-26 Henrik Kreidler

This paper presents algebraic methods for the study of polynomial relative invariants, when the group G formed by the symmetries and relative symmetries is a compact Lie group. We deal with the case when the subgroup H of symmetries is…

Dynamical Systems · Mathematics 2012-07-09 Patricia H. Baptistelli , Miriam Manoel

For a compact Lie group G, we use G-equivariant Poincar\'e duality for ordinary RO(G)-graded homology to define an equivariant intersection product, the dual of the equivariant cup product. Using this, we give a homological construction of…

Algebraic Topology · Mathematics 2013-07-23 Philipp Wruck

We present a comparative study of certain invariants defined for group actions and their analogues defined for orbifolds. In particular, we prove that Fadell's equivariant category for $G$-spaces coincides with the Lusternik-Schnirelmann…

Algebraic Topology · Mathematics 2022-08-30 Andres Angel , Hellen Colman

We define the notions of a compact perception pair, compactification of a perception pair, and compactification of a space of group equivariant non-expansive operators. We prove that every perception pair with totally bounded space of…

General Topology · Mathematics 2022-10-11 Faraz Ahmad

In this article, we start to recall the inversion formula for the convolution with the Box spline. The equivariant cohomology and the equivariant K-theory with respect to a compact torus G of various spaces associated to a linear action of…

Differential Geometry · Mathematics 2015-03-17 C. De Concini , C. Procesi , M. Vergne