An obstruction to smooth isotopy in dimension 4
Geometric Topology
2007-05-23 v2 Differential Geometry
Abstract
Techniques of gauge theory are used to define and compute an invariant of certain diffeomorphisms of 4-manifolds. The invariant vanishes for any diffeomorphism which is smoothly isotopic to the identity. As an application, we give the first example of a diffeomorphism of a simply-connected 4-manifold which is homotopic to the identity map, but not smoothly isotopic to the identity.
Cite
@article{arxiv.math/9807041,
title = {An obstruction to smooth isotopy in dimension 4},
author = {Daniel Ruberman},
journal= {arXiv preprint arXiv:math/9807041},
year = {2007}
}
Comments
Minor revisions (typos and one formula). AMS-LaTeX. 17 pages, 2 postscript figures. To appear in Mathematical Research Letters