activity
19972022
most citedNew invariants of G_2-structures

41 citations · 300 across the 34 of their papers we have counts for

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27 papers · 1 filter

math.GT2022★ 2 cited

Infinite homotopy stable class for 4-manifolds with boundary

Anthony Conway, Diarmuid Crowley, Mark Powell

We show that for every odd prime , there exists an infinite family of topological 4-manifolds that are all stably homeomorphic to one another, all the m…

math.GT2022★ 1 cited

Turning vector bundles

Diarmuid Crowley, Csaba Nagy, Blake Sims +1

We define a turning of a rank- vector bundle to be a homotopy of bundle automorphisms from , the identity of , to , minus the…

math.GT2021

Simply-connected manifolds with large homotopy stable classes

Anthony Conway, Diarmuid Crowley, Mark Powell +1

For every and we construct pairwise homotopically inequivalent simply-connected, closed -dimensional manifolds, all of which are stably diffeomorphic…

math.GT2021★ 2 cited

Stably diffeomorphic manifolds and the realisation of modified surgery obstructions

Anthony Conway, Diarmuid Crowley, Mark Powell +1

For every we construct infinitely many -dimensional manifolds that are all stably diffeomorphic but pairwise not homotopy equivalent. Each of these manifolds has hyp…

math.GT2021★ 2 cited

Contact open books with flexible pages

Jonathan Bowden, Diarmuid Crowley

We give an elementary topological obstruction for a manifold of dimension to admit a contact open book with flexible Weinstein pages and : if t…

math.GT2020★ 3 cited

The derivative map for diffeomorphism of disks: An example

Diarmuid Crowley, Thomas Schick, Wolfgang Steimle

We prove that the derivative map , defined by taking the derivative of a diffeomorphism, can induce a nontrivial map on homotopy g…

math.GT2020★ 2 cited

The smooth classification of 4-dimensional complete intersections

Diarmuid Crowley, Csaba Nagy

We prove the "Sullivan Conjecture" on the classification of 4-dimensional complete intersections up to diffeomorphism. Here an -dimensional complete intersection is a smooth com…

math.GT2019★ 12 cited

Connected sum decompositions of high-dimensional manifolds

Imre Bokor, Diarmuid Crowley, Stefan Friedl +4

The classical Kneser-Milnor theorem says that every closed oriented connected 3-dimensional manifold admits a unique connected sum decomposition into manifolds that cannot be decom…

math.GT2017

On the cardinality of the manifold set

Diarmuid Crowley, Tibor Macko

We study the cardinality of the set of manifolds homotopy equivalent to a given manifold M and compare it to the cardinality of the structure set of M.

math.GT2016★ 16 cited

Harmonic spinors and metrics of positive curvature via the Gromoll filtration and Toda brackets

Diarmuid Crowley, Thomas Schick, Wolfgang Steimle

We construct non-trivial elements of order 2 in the homotopy groups , for * congruent 1 or 2 modulo 8, which are detected by the "assembling homomorp…

math.GT2016★ 6 cited

Embeddings of non-simply-connected 4-manifolds in 7-space. I. Classification modulo knots

D. Crowley, A. Skopenkov

We work in the smooth category. Let be a closed connected orientable 4-manifold with torsion free , where . Our main result is a complete readily calculable…

math.GT2015★ 13 cited

An analytic invariant of G_2 manifolds

Diarmuid Crowley, Sebastian Goette, Johannes Nordström

We prove that the moduli space of holonomy G_2-metrics on a closed 7-manifold is in general disconnected by presenting a number of explicit examples. We detect different connected…

math.GT2014★ 14 cited

The topology of Stein fillable manifolds in high dimensions II

Jonathan Bowden, Diarmuid Crowley, András I. Stipsicz +1

We continue our study of contact structures on manifolds of dimension at least five using complex surgery theory. We show that in each dimension 2q+1 > 3 there are 'maximal' almost…

math.GT2014★ 27 cited

The classification of 2-connected 7-manifolds

Diarmuid Crowley, Johannes Nordström

We present a classification theorem for closed smooth spin 2-connected 7-manifolds M. This builds on the almost-smooth classification from the first author's thesis. The main addit…

math.GT2013★ 33 cited

The topology of Stein fillable manifolds in high dimensions I

Jonathan Bowden, Diarmuid Crowley, András I. Stipsicz

We give a bordism-theoretic characterisation of those closed almost contact (2q+1)-manifolds (with q > 2) which admit a Stein fillable contact structure. Our method is to apply Eli…

math.GT2013

Finite group actions on Kervaire manifolds

Diarmuid Crowley, Ian Hambleton

The (4k+2)-dimensional Kervaire manifold is a closed, piecewise linear (PL) manifold with Kervaire invariant 1 and the same homology as the product of two (2k+1)-dimensional sphere…

math.GT2012★ 41 cited

New invariants of G_2-structures

Diarmuid Crowley, Johannes Nordström

We define a Z/48-valued homotopy invariant nu of a G_2-structure on the tangent bundle of a closed 7-manifold in terms of the signature and Euler characteristic of a coboundary wit…

math.GT2012★ 24 cited

The Gromoll filtration, KO-characteristic classes and metrics of positive scalar curvature

Diarmuid Crowley, Thomas Schick

Let X be a closed m-dimensional spin manifold which admits a metric of positive scalar curvature and let Pos(X) be the space of all such metrics. For any g in Pos(X), Hitchin used…

math.GT2011

Functorial semi-norms on singular homology and (in)flexible manifolds

Diarmuid Crowley, Clara Loeh

A functorial semi-norm on singular homology is a collection of semi-norms on the singular homology groups of spaces such that continuous maps between spaces induce norm-decreasing…

math.GT2010

Kreck-Stolz invariants for quaternionic line bundles

Diarmuid Crowley, Sebastian Goette

We generalise the Kreck-Stolz invariants s_2 and s_3 by defining a new invariant, the t-invariant, for quaternionic line bundles E over closed spin-manifolds M of dimension 4k-1 wi…

math.GT2010★ 4 cited

The additivity of the -invariant and periodicity in topological surgery

Diarmuid Crowley, Tibor Macko

For a closed topological manifold M with dim (M) >= 5 the topological structure set S(M) admits an abelian group structure which may be identified with the algebraic structure grou…

math.GT2009★ 2 cited

On the mapping class groups of $#_r(S^p \times S^p)$ for

Diarmuid Crowley

For M_r = #_r(S^p \times S^p), p=3, 7, we calculate the group of isotopy classes of orientation preserving diffeomorphisms of modulo isotopy classes with representatives whic…

math.GT2009

The smooth structure set of

Diarmuid Crowley

We calculate the smooth structure set of , , for and . As a consequence we show that in general cannot admit a grou…

math.GT2008

Stably diffeomorphic manifolds and l_{2q+1}(Z[π])

Diarmuid Crowley, Jörg Sixt

The monoids l_{2q+1}(Z[π]) detect s-cobordisms amongst certain bordisms between stably diffeomorphic 2q-dimensional manifolds and generalise the Wall simple surgery obstruction gro…