English

A characterisation of the Z^n + Z(\delta) lattice and definite nonunimodular intersection forms

Geometric Topology 2008-02-12 v1 Number Theory

Abstract

We prove a generalisation of Elkies' theorem to nonunimodular definite forms (and lattices). Combined with inequalities of Froyshov and of Ozsvath and Szabo, this gives a simple test of whether a rational homology 3-sphere may bound a definite four-manifold. As an example we show that small positive surgeries on torus knots do not bound negative-definite four-manifolds.

Keywords

Cite

@article{arxiv.0802.1495,
  title  = {A characterisation of the Z^n + Z(\delta) lattice and definite nonunimodular intersection forms},
  author = {Brendan Owens and Saso Strle},
  journal= {arXiv preprint arXiv:0802.1495},
  year   = {2008}
}

Comments

21 pages, 1 figure