English

Algebraic subdivision in simplicially controlled categories

Algebraic Topology 2014-05-14 v1

Abstract

We generalise the notion of subdivision of a finite-dimensional locally finite simplicial complex XX to geometric algebra, namely to the simplicially controlled categories A(X)\mathbb{A}^*(X), A(X)\mathbb{A}_*(X) of Ranicki and Weiss. We prove a squeezing result: a bounded chain equivalence of sufficiently algebraically subdivided chain complexes can be squeezed to a simplicially controlled chain equivalence of the unsubdivided chain complexes. Giving X×RX\times\mathbb{R} a bounded triangulation measured in the open cone O(X+)O(X_+) we use algebraic subdivision to define a functor "Z":B(A(X))B(A(X×R))\mathrm{"}-\otimes\mathbb{Z}\mathrm{"}:\mathbb{B}(\mathbb{A}(X))\to \mathbb{B}(\mathbb{A}(X\times\mathbb{R})) that corresponds to tensoring with the simplicial chain complex of Z\mathbb{Z} and algebraically subdividing to be bounded over O(X+)O(X_+). We show that C0B(A(X))C\simeq 0 \in \mathbb{B}(\mathbb{A}(X)) if and only if "CZ"\mathrm{"}C\otimes\mathbb{Z}\mathrm{"} is boundedly chain contractible over O(X+)O(X_+). These results have applications to Poincar\'e duality and homology manifold detection as a finite-dimensional locally finite simplicial complex XX is a homology manifold if and only if it has XX-controlled Poincar\'e duality. We prove a Poincar\'e duality squeezing theorem that such a space XX with sufficiently controlled Poincar\'e duality must have XX-controlled Poincar\'e duality and we prove a Poincar\'e duality splitting theorem with the consequence that XX is a homology manifold if and only if X×RX\times\mathbb{R} has bounded Poincar\'e duality over O(X+)O(X_+).

Keywords

Cite

@article{arxiv.1405.2973,
  title  = {Algebraic subdivision in simplicially controlled categories},
  author = {Spiros Adams-Florou},
  journal= {arXiv preprint arXiv:1405.2973},
  year   = {2014}
}

Comments

35 pages, 5 figures

R2 v1 2026-06-22T04:12:28.766Z