Search arXivSearch

arXiv · math/0603455

A Functor Converting Equivariant Homology to Homotopy

Abstract

In this paper, we prove an equivariant version of the classical Dold-Thom theorem. Associated to a finite group, a CW-complex on which this group acts and a covariant coefficient system in the sense of Bredon, we functorially construct a topological abelian group by the coend construction. Then we prove that the homotopy groups of this topological abelian group are naturally isomorphic to the Bredon equivariant homology of the CW-complex. At the end we present several examples of this result.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Zhaohu Nie. 2007-08-01. A Functor Converting Equivariant Homology to Homotopy. https://doi.org/10.1112/blms%2Fbdm029

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Uniqueness of differential Poincaré duality models

We prove the remaining even-dimensional case of the Lambrechts--Stanley "uniqueness" conjecture for 1-connected differential Poincaré duality models. Together with our previous odd-dimensional result, this shows that any two such algebras weakly homotopy equivalent as PDGAs admit direct PDGA quasi-isomorphisms into a common connected differential Poincaré duality algebra. We use our previous method of obtaining differential Poincaré duality models as nondegenerate quotients of Hodge extensions, the new ingredient being a Hodge extension in the middle degree.

math.AT

Coulomb branches for quaternionic representations

I describe the \emph{Chiral rings} $\caR_{3,4}$ for $3$D, $N=4$ supersymmetric $G$-gauge theory and matter fields in quaternionic representations~$E$: first, by incorporating \emph{twisted} real structures in the construction of~\cite{bfn}, and second, more explicitly, by Weyl group descent from the maximal torus. A topological obstruction $w_4(E)$ (modulo squares) appears for $\caR_3$; a secondary obstruction $η\cdot E$, appears for $\caR_4$. The two combine to a gauging obstruction of~$E$ by~$G$ in $4$D, $N=2$ supersymmetry, enhancing Witten's original obstruction. I classify the obstructions for connected~$G$. Freedom of the chiral rings over the Toda bases reduces calculations to the case of semi-simple rank~$1$. For representations whose weights include the roots of~$G$, an Abelianization formula describes the $\caR$ in terms of the maximal torus and the Weyl group. My approach an alternative and generalization to a recent paper arXiv:2201.09475.}

math.AT

Homotopy Theory for Ordered Simplicial Complexes

We construct a model structure on the category of ordered simplicial complexes, Quillen equivalent to the standard model structure on simplicial sets. This shows that simplicial complexes, which are fully combinatorial in nature, provide a new model for the homotopy theory of spaces.

math.AT