English

$PD_3$-pairs with compressible boundary

Geometric Topology 2026-05-15 v7 Algebraic Topology

Abstract

We extend work of Turaev and Bleile to relax the π1\pi_1-injectivity hypothesis in the characterization of the fundamental triples of PD3PD_3-pairs with aspherical boundary components. This is further extended to pairs (P,P)(P,\partial{P}) which also have spherical boundary components and with c.d.π1(P)2c.d.\pi_1(P)\leq2.

Cite

@article{arxiv.2006.08057,
  title  = {$PD_3$-pairs with compressible boundary},
  author = {Jonathan A. Hillman},
  journal= {arXiv preprint arXiv:2006.08057},
  year   = {2026}
}

Comments

v2:"geometric" homomorphisms identified, Theorem 7 rewritten. v3: estimates for free group factor. v4: rewritten. v5: \S5 rewritten, to bring forward the difference between the Algebraic and Topological Loop Theorems v6:new \s4 split off \S3 and new Corollary 11 split off Theorem 9. v7. \S4-\S6 rewritten, and examples illustrating independence of key hypotheses added

R2 v1 2026-06-23T16:19:10.792Z