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Let G be a connected compact Lie group acting on a manifold M and let D be a transversally elliptic operator on M. The multiplicity of the index of D is a function on the set of irreducible representations of G. Let T be a maximal torus of…

Differential Geometry · Mathematics 2016-02-10 Michèle Vergne

In this series of papers, we propose a theory of enumerative invariants counting self-dual objects in self-dual categories. Ordinary enumerative invariants in abelian categories can be seen as invariants for the structure group $\mathrm{GL}…

Algebraic Geometry · Mathematics 2025-04-01 Chenjing Bu

The main result of the paper is a determinantal formula for the restriction to a torus fixed point of the equivariant class of a Schubert subvariety in the torus equivariant integral cohomology ring of the Grassmannian. As a corollary, we…

Algebraic Geometry · Mathematics 2007-05-23 V. Lakshmibai , K. N. Raghavan , P. Sankaran

We introduce the notion of $\mathrm{R}$-Eulerian sequences for any $\mathcal{N}_\infty$-ring spectrum $\mathrm{R}$ of finite orientation order. We prove that each $\mathrm{R}$-Eulerian sequence determines a stable $\mathrm{R}$-cohomology…

Algebraic Topology · Mathematics 2026-02-03 Prasit Bhattacharya , Alex Waugh , Mingcong Zeng , Foling Zou

This paper is devoted to the explicit description of the Galois descent obstruction for hyperelliptic curves of arbitrary genus whose reduced automorphism group is cyclic of order coprime to the characteristic of their ground field. Along…

Algebraic Geometry · Mathematics 2017-01-06 Reynald Lercier , Christophe Ritzenthaler , Jeroen Sijsling

We investigate higher-order geometric $k$-splines for template matching on Lie groups. This is motivated by the need to apply diffeomorphic template matching to a series of images, e.g., in longitudinal studies of Computational Anatomy. Our…

Chaotic Dynamics · Physics 2015-05-20 F. Gay-Balmaz , D. D. Holm , D. M. Meier , T. S. Ratiu , F. -X. Vialard

A new invariant of Poisson manifolds, a Poisson K-ring, is introduced. Hypothetically, this invariant is more tractable than such invariants as Poisson (co)homology. A version of this invariant is also defined for arbitrary algebroids.…

Differential Geometry · Mathematics 2007-05-23 Viktor L. Ginzburg

We construct a birational invariant for certain algebraic group actions. We use this invariant to classify linear representations of finite abelian groups up to birational equivalence, thus answering, in a special case, a question of E. B.…

Algebraic Geometry · Mathematics 2007-05-23 Zinovy Reichstein , Boris Youssin

We show that if an open cover of a finite dimensional space is equivariant with respect to some finite group action on the space then there is an equivariant refinement of bounded dimension. This will generalize some constructions of…

Algebraic Topology · Mathematics 2013-10-25 Adam Mole , Henrik Rueping

We introduce equivariant versions of uniform rationality: given an algebraic group G, a G-variety is called G-uniformly rational (resp. G-linearly uniformly rational) if every point has a G-invariant open neighborhood equivariantly…

Algebraic Geometry · Mathematics 2017-03-28 Charlie Petitjean

We prove an equivariant deformation result for Hamiltonian stationary Lagrangian submanifolds of a Kahler manifold, with respect to deformations of its metric and almost complex structure that are compatible with an isometric Hamiltonian…

Differential Geometry · Mathematics 2015-11-23 Renato G. Bettiol , Paolo Piccione , Bianca Santoro

We introduce the notion of equivariant basic cohomology for singular Riemannian foliations with transverse infinitesimal actions, and prove some elementary properties such as its invariance under homotopies. For the particular case of…

Differential Geometry · Mathematics 2023-06-21 Francisco C. Caramello

We develop two approaches to obstruction theory for deformations of derived isomorphism classes of complexes $Z^\bullet$ of modules for a profinite group $G$ over a complete local Noetherian ring $A$ of positive residue characteristic…

Number Theory · Mathematics 2013-09-03 Frauke M. Bleher , Ted Chinburg

Let X be a smooth variety over a number field k embedded as a degree d subvariety of $\mathbb{P}^n$ and suppose that X is a counterexample to the Hasse principle explained by the Brauer-Manin obstruction. We consider the question of whether…

Number Theory · Mathematics 2019-02-13 Brendan Creutz , Bianca Viray

Continuing our previous work on graded twisting of Hopf algebras and monoidal categories, we introduce a graded twisting construction for equivariant comodule algebras and module categories. As an example we study actions of quantum…

Quantum Algebra · Mathematics 2021-06-09 Julien Bichon , Sergey Neshveyev , Makoto Yamashita

Given any finite quiver, we consider a complete flag of vector spaces over each vertex. Consider the unipotent invariant subalgebra of the coordinate ring of the filtered quiver representation subspace. We prove that the dimension of the…

Algebraic Geometry · Mathematics 2016-09-27 Mee Seong Im , Lisa M. Jones

We study equivariant projective compactifications of reductive groups obtained by closing the image of a group in the space of operators of a projective representation. We describe the structure and the mutual position of their orbits under…

Algebraic Geometry · Mathematics 2015-06-26 Dmitri A. Timashev

In this article we describe the $G_{comp}\times G_{comp}$-equivariant topological $K$-ring of a {\em cellular} toroidal embedding $\mathbb{X}$ of a complex connected reductive algebraic group $G$. In particular, our results extend the…

Algebraic Geometry · Mathematics 2025-06-11 Alexis Tchoudjem , V. Uma

This article is concerned with the question: For which pairs of hyperbolic Euler-Lagrange systems in the plane does there exist a rank-$1$ B\"acklund transformation relating them? We express some obstructions to such existence in terms of…

Analysis of PDEs · Mathematics 2019-12-03 Yuhao Hu

We introduce an equivariant version of Hochschild cohomology as the deformation cohomology to study equivariant deformations of associative algebras equipped with finite group actions.

Rings and Algebras · Mathematics 2018-04-17 Goutam Mukherjee , Raj Bhawan Yadav