English

Non-isolated Hypersurface Singularities and L\^e Cycles

Algebraic Geometry 2015-11-16 v2

Abstract

In this series of lectures, I will discuss results for complex hypersurfaces with non-isolated singularities. In Lecture 1, I will review basic definitions and results on complex hypersurfaces, and then present classical material on the Milnor fiber and fibration. In Lecture 2, I will present basic results from Morse theory, and use them to prove some results about complex hypersurfaces, including a proof of L\^e's attaching result for Milnor fibers of non-isolated hypersurface singularities. This will include defining the relative polar curve. Lecture 3 will begin with a discussion of intersection cycles for proper intersections inside a complex manifold, and then move on to definitions and basic results on L\^e cycles and L\^e numbers of non-isolated hypersurface singularities. Lecture 4 will explain the topological importance of L\^e cycles and numbers, and then I will explain, informally, the relationship between the L\^e cycles and the complex of sheaves of vanishing cycles.

Keywords

Cite

@article{arxiv.1410.3312,
  title  = {Non-isolated Hypersurface Singularities and L\^e Cycles},
  author = {David B. Massey},
  journal= {arXiv preprint arXiv:1410.3312},
  year   = {2015}
}

Comments

Notes from a series of lectures from the S\~ao Carlos singularities meeting of 2014. Revision made to Exercise 3.1 (a)

R2 v1 2026-06-22T06:21:34.556Z