English

Normal complex surface singularities with rational homology disk smoothings

Algebraic Geometry 2014-05-08 v2 Geometric Topology

Abstract

In this paper we show that if the minimal good resolution graph of a normal surface singularity contains at least two nodes (i.e. vertex with valency at least 3) then the singularity does not admit a smoothing with Milnor fiber having rational homology equal to the rational homology of the 4-disk D4D^4 (called a rational homology disk smoothing). Combining with earlier results, this theorem then provides a complete classification of resolution graphs of normal surface singularities with a rational homology disk smoothing, verifying a conjecture of J. Wahl regarding such singularities. Indeed, together with a recent result of J. Fowler we get the complete list of normal surface singularities which admit rational homology disk smoothings.

Keywords

Cite

@article{arxiv.1311.1929,
  title  = {Normal complex surface singularities with rational homology disk smoothings},
  author = {Heesang Park and Dongsoo Shin and András I. Stipsicz},
  journal= {arXiv preprint arXiv:1311.1929},
  year   = {2014}
}

Comments

21 pages, 2 figures; corrected an error in the proof of Proposition 3.4, simplified proofs of key lemmas

R2 v1 2026-06-22T02:03:37.272Z