paper

Geometric obstructions for -fillings of 3-manifolds

arXiv:2601.09650

Abstract

We consider the realisation problem for normal 1-types of 4-manifolds with a given boundary. More precisely, given a normal 1-type and closed 3-dimensional -manifold , does there exist a compact 4-dimensional -manifold with boundary ? We describe a three stage obstruction theory for the existence of such a 4-manifold, with our main contribution being a `tertiary' obstruction that we describe geometrically via Wall's quadratic self-intersection form.

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