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Related papers: $C_2$-equivariant topological modular forms

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We compute the mod 2 homology of spin mapping class groups in the stable range. In earlier work we computed the stable mod p homology of the oriented mapping class group, and the methods and results here are very similar. The forgetful map…

Algebraic Topology · Mathematics 2007-05-23 Soren Galatius

We develop a new method to compute the homology groups of finite topological spaces (or equivalently of finite partially ordered sets) by means of spectral sequences giving a complete and simple description of the corresponding…

Algebraic Topology · Mathematics 2016-12-14 Nicolás Cianci , Miguel Ottina

We compute the homology of the space of equivariant loops on the classifying space of a simplicial monoid $M$ with anti-involution, provided $\pi_0 (M)$ is central in the homology ring of $M$. The proof is similar to McDuff and Segal's…

K-Theory and Homology · Mathematics 2020-11-11 Kristian Jonsson Moi

The homotopy type and homotopy groups of some spectra TAF of topological automorphic forms associated to a unitary similitude group GU of type (1,1) are explicitly described in quasi-split cases. The spectrum TAF is shown to be closely…

Algebraic Topology · Mathematics 2009-10-04 Mark Behrens , Tyler Lawson

We investigate one-point reduction methods of finite topological spaces. These methods allow one to study homotopy theory of cell complexes by means of elementary moves of their finite models. We also introduce the notion of h-regular…

Algebraic Topology · Mathematics 2014-10-01 Jonathan Ariel Barmak , Elias Gabriel Minian

We study the homotopy groups of the geometric fixed points of the real topological cyclic homology of $\mathbb{Z}/4$. We relate these groups to the values of the non-abelian derived functors of the functor $M \mapsto (M…

Algebraic Topology · Mathematics 2026-02-17 Thomas Read

Lurie and Gepner--Meier each define equivariant cohomology theories, namely \emph{tempered cohomology} and \emph{equivariant elliptic cohomology}, respectively, using derived algebraic geometry. We construct a natural equivalence between…

Algebraic Topology · Mathematics 2025-02-19 Jack Morgan Davies

We propose a new method to compute the $C_{2^n}$-equivariant homotopy groups of the Eilenberg-Mac Lane spectrum $H\underline{\mathbb{Z}}$ as a $RO(C_{2^n})$-graded Green functor using the generalized Tate squares. As an example, we…

Algebraic Topology · Mathematics 2023-02-06 Guoqi Yan

We analyze the $\mathbb{C}$-motivic (and classical) Adams-Novikov spectral sequence for the $\mathbb{C}$-motivic modular forms spectrum $\mathit{mmf}$ (and for the classical topological modular forms spectrum $\mathit{tmf}$). We primarily…

Algebraic Topology · Mathematics 2025-07-15 Daniel C. Isaksen , Hana Jia Kong , Guchuan Li , Yangyang Ruan , Heyi Zhu

We compute the homotopy type of the moduli space of flat, unitary connections over aspherical surfaces, after stabilizing with respect to the rank of the underlying bundle. Over the orientable surface M^g, we show that this space has the…

Algebraic Topology · Mathematics 2018-05-09 Daniel A. Ramras

As a generalization of the ring spectrum of topological modular forms, we construct a graded ring spectrum of topological Jacobi forms, $\operatorname{TJF}_*$. This is constructed as the global sections of a sheaf of $E_\infty$-ring spectra…

Algebraic Topology · Mathematics 2025-08-12 Tilman Bauer , Lennart Meier

We compute the homotopy groups at each unital abelian C*-algebra $C(T)$ in the Morita $3$-category of abelian C*-algebras, C*-algebras with central maps, C*-correspondences, and adjointable bimodule maps. We describe these groups in terms…

Operator Algebras · Mathematics 2026-04-01 Gregory Faurot , Giovanni Ferrer

Let $C_2$ denote the cyclic group of order two. Given a manifold with a $C_2$-action, we can consider its equivariant Bredon $RO(C_2)$-graded cohomology. In this paper, we develop a theory of fundamental classes for equivariant submanifolds…

Algebraic Topology · Mathematics 2021-12-01 Christy Hazel

We develop a theory of equivariant group presentations and relate them to the second homology group of a group. Our main application says that the second homology group of the Torelli subgroup of the mapping class group is finitely…

Geometric Topology · Mathematics 2020-06-09 Martin Kassabov , Andrew Putman

In this paper, we present a construction toward a new type of TQFTs at the crossroads of low-dimensional topology, algebraic geometry, physics, and homotopy theory. It assigns TMF-modules to closed 3-manifolds and maps of TMF-modules to…

Algebraic Topology · Mathematics 2025-09-17 Sergei Gukov , Vyacheslav Krushkal , Lennart Meier , Du Pei

We prove a topological reconstruction result for the category of cellular $A$-equivariant motivic spectra over the complex numbers where $A$ is a finite abelian group: after completion at an arbitrary prime, this is equivalent to the…

Algebraic Topology · Mathematics 2025-10-24 Keita Allen , Lucas Piessevaux

We describe in terms of generators and relations the ring structure of the $RO(C_2)$-graded $C_2$-equivariant stable stems $\pi_\star^{C_2}$ modulo the ideal of all nilpotent elements. As a consequence, we also record the ring structure of…

Algebraic Topology · Mathematics 2022-11-10 Eva Belmont , Zhouli Xu , Shangjie Zhang

For almost finite groupoids, we study how their homology groups reflect dynamical properties of their topological full groups. It is shown that two clopen subsets of the unit space has the same class in H_0 if and only if there exists an…

Operator Algebras · Mathematics 2014-02-26 Hiroki Matui

We prove that homotopy invariants of finite degree distinguish homotopy classes of maps of a connected compact CW-complex to a nilpotent connected CW-complex with finitely generated homotopy groups.

Algebraic Topology · Mathematics 2012-09-11 Semen Podkorytov

Let $\mathbb{G}$ be a compact Hausdorff group acting on a compact Hausdorff space $X$, $\alpha$ an irreducible $\mathbb{G}$-representation, and $C(X)$ the $C^*$-algebra of complex-valued continuous functions on $X$. We prove that the…

Operator Algebras · Mathematics 2026-03-17 Alexandru Chirvasitu