English
Related papers

Related papers: Equivariant fundamental classes in $RO(C_2)$-grade…

200 papers

In this paper, we compute the $RO(\mathbb{Z}/2)$-graded equivariant cohomology of rotation groups and Stiefel manifolds with particular involutions.

Algebraic Topology · Mathematics 2011-08-01 William Kronholm

B\'ezout's theorem, nonequivariantly, can be interpreted as a calculation of the Euler class of a sum of line bundles over complex projective space, expressing it in terms of the rank of the bundle and its degree. We give here a…

Algebraic Topology · Mathematics 2024-07-24 Steven R. Costenoble , Thomas Hudson , Sean Tilson

In this paper, we calculate $RO(C_2)$-graded cohomology of $C_2$-equivariant Eilenberg-Mac Lane spaces $K(\underline{Z/2}, n+\sigma)$ for $n\geq 0$. These can be used to give the relation between equivariant lambda algebra and equivariant…

Algebraic Topology · Mathematics 2023-01-13 UĞur Yiğit

This paper determines the RO(G)-graded Eilenberg-MacLane cohomology of the real, infinite, equivariant Grassmannians in the case G=Z/2. Possible connections with motivic characteristic classes for quadratic bundles are briefly discussed.

Algebraic Topology · Mathematics 2015-05-27 Daniel Dugger

We study the topology of the moduli space of flat SU(2)-bundles over a nonorientable surface X. This moduli space may be identified with the space of homomorphisms Hom(\pi_1(X),SU(2)) modulo conjugation by SU(2). In particular, we compute…

Symplectic Geometry · Mathematics 2009-02-06 Thomas Baird

The purpose of this paper is to present a ``Cech-De Rham'' model for the cohomology of leaf spaces. This model lends itself to the construction of characteristic classes (in the cohomology of classifying spaces) by explicit geometrical…

Differential Geometry · Mathematics 2007-05-23 Marius Crainic , Ieke Moerdijk

On negatively curved compact manifolds, it is possible to associate to every closed form a bounded cocycle - hence a bounded cohomology class - via integration over straight simplices. The kernel of this map is contained in the space of…

Geometric Topology · Mathematics 2025-09-16 Ludovico Battista , Stefano Francaviglia , Marco Moraschini , Filippo Sarti , Alessio Savini

Let $C_n$ denote a cyclic group of order $n$. In this paper we investigate modules and chain complexes over the constant integral Mackey functor $\underline{\mathbb{Z}}$ and perform some related homological calculations. Along the way we…

Algebraic Topology · Mathematics 2026-02-24 Daniel Dugger , Christy Hazel

For a $C^{*}$-category with a strict $G$-action we construct examples of equivariant coarse homology theories. To this end we first introduce versions of Roe categories of objects in $C^{*}$-categories which are controlled over bornological…

K-Theory and Homology · Mathematics 2023-06-21 Ulrich Bunke , Alexander Engel

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

We describe torsion classes in the first cohomology group of $\text{SL}_2(\mathbb{Z})$. In particular, we obtain generalized Dickson's invariants for p-power polynomial rings. Secondly, we describe torsion classes in the zero-th homology…

Number Theory · Mathematics 2019-05-15 Taiwang Deng

In this paper, we compute the $RO(C_n)$-graded coefficient ring of equivariant cohomology for cyclic groups $C_n$, in the case of Burnside ring coefficients, and in the case of constant coefficients. We use the invertible Mackey functors…

Algebraic Topology · Mathematics 2024-03-04 Samik Basu , Pinka Dey

A Bott manifold is the total space of some iterated $\mathbb C P^1$-bundle over a point. We prove that any graded ring isomorphism between the cohomology rings of two Bott manifolds preserves their Pontrjagin classes. Moreover, we prove…

Algebraic Topology · Mathematics 2015-05-27 Suyoung Choi , Mikiya Masuda , Satoshi Murai

We study the $RO(G)$-graded Bredon cohomology of a point in the case where $G$ is a cyclic group of odd order, expanding on the information provided by previous studies. Our methods center on the purely algebraic aspects of this matter,…

Algebraic Topology · Mathematics 2026-02-24 Daniel Dugger , Christy Hazel

We give a complete description of the bigraded Bredon cohomology ring of smooth projective real quadrics, with coefficients in the constant Mackey functor $ \mathbf{Z} $. These invariants are closely related to the integral motivic…

Algebraic Topology · Mathematics 2007-05-23 Pedro F. dos Santos , Paulo Lima-Filho

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

We give explicit examples of degree 3 cohomology classes not Poincare dual to submanifolds, and discuss the realisability of homology classes by submanifolds with Spin-C normal bundles.

Geometric Topology · Mathematics 2007-05-23 C. Bohr , B. Hanke , D. Kotschick

A torus manifold is an even-dimensional manifold acted on by a half-dimensional torus with non-empty fixed point set and some additional orientation data. It may be considered as a far-reaching generalisation of toric manifolds from…

Algebraic Topology · Mathematics 2007-05-23 Mikiya Masuda , Taras Panov

For the cyclic group $C_2$ we give a complete description of the derived category of perfect complexes of modules over the constant Mackey ring $\underline{\mathbb{Z}/\ell}$, for $\ell$ a prime. This is fairly simple for $\ell$ odd, but for…

Algebraic Topology · Mathematics 2023-07-03 Daniel Dugger , Christy Hazel , Clover May

The moduli space of stable bundles of rank 2 and degree 1 on a Riemann surface has rational cohomology generated by the so-called universal classes. The work of Baranovsky, King-Newstead, Siebert-Tian and Zagier provided a complete set of…

Algebraic Geometry · Mathematics 2007-05-23 Tamas Hausel , Michael Thaddeus