|
|
|
On Davis–Januszkiewicz homotopy types II: Completion
and globalisation
Dietrich Notbohm and Nigel Ray
|
|
Algebraic & Geometric Topology 10
(2010) 1747–1780
|
Abstract
|
|
For any finite simplicial complex K, Davis and Januszkiewicz defined a family of
homotopy equivalent CW–complexes whose integral cohomology rings are isomorphic
to the Stanley–Reisner algebra of K. Subsequently, Buchstaber and Panov gave an
alternative construction, which they showed to be homotopy equivalent to the
original examples. It is therefore natural to investigate the extent to which the
homotopy type of a space X is determined by such a cohomology ring. Having
analysed this problem rationally in Part I, we here consider it prime by
prime, and utilise Lannes’ T–functor and Bousfield–Kan type obstruction
theory to study the p–completion of X. We find the situation to be more
subtle than for rationalisation, and confirm the uniqueness of the completion
whenever K is a join of skeleta of simplices. We apply our results to the
global problem by appealing to Sullivan’s arithmetic square, and deduce
integral uniqueness whenever the Stanley–Reisner algebra is a complete
intersection.
|
Keywords
arithmetic square, completion,
Davis–Januszkiewicz space, homotopy colimit, homotopy
type, Stanley–Reisner algebra, T–functor,
p–completion
|
Mathematical Subject Classification
Primary: 55P15, 55P60
Secondary: 05E99
|
Publication
Received: 16 December 2008
Revised: 8 April 2009
Accepted: 11 April 2009
Published: 29 August 2010
|
|